2-5 NOVEMBER 2014 I ATLÂNTICO BÚZIOS RESORT Armação dos Búzios - Rio de Janeiro, Brazil

1 COMPARATIVE BITUMEN EXTRACTION FROM AN ID TITLE MAIN AUTHOR COUNTRY INSTITUTION AREA RODRIGO CABRAL Analytical AT12 IMMATURE PETROLEUM SOURCE ROCK USING SFE AND Brasil Petrobras S.A. DA SILVA Techniques ASE BEST PRACTICE FOR ROCK-EVAL PYROLYSIS WITH VIOLAINE Analytical AT01 França IFPEN CARLOS EMPHASIS ON UNCONVENTIONAL PROSPECTS LAMOUREUX-VAR Techniques OIL-BEARING FLUID INCLUSION BIOMARKERS FROM THE Analytical AT13 EDUARDO SILVA Brasil PETROBRAS NOROSKA PRE-SALT SUCCESSION, OFFSHORE BRAZIL Techniques COELHO GC×GC AS A TOOL TO DETERMINE MATURATION AND GABRIELA Analytical AT02 Brasil UNICAMP FLASH PYROLYSIS COUPLED TO GC×GC?TOF BIODEGRADATION CHEMICAL MARKERS IN CRUDE OILS SALAZAR Techniques CLÉCIO Estados MS AND GC?HIGH RESOLUTION TOF MS FOR Analytical MOGOLLON AT14 FERNANDO Unidos da LECO Corporation CHARARCTERIZATION OF CRUDE OIL AND PETROLEUM Techniques EFFECT OF ARTIFICIAL MATURATION AT DIFFERENT KLITZKE América ROSANA FRACTIONS TYPES OF POTENTIAL SOURCE ROCKS: FOCUSING PETROBRAS/ Analytical AT03 CARDOSO LOPES Brasil ON POLAR COMPOUNDS EVALUATION BY FT-ICR-MS CENPES Techniques ANALYSES OF BICYCLIC AND TRICYCLIC ACIDS PEREIRA SIDNEY GONÇALO Analytical TECHNIQUE AT15 BIOMARKERS IN POTIGUAR BASIN ? BRAZIL OILS BY ESI- Brasil UFPI DE LIMA Techniques Analytical AND APCI-TOF MS AT04 THE ISOTOPIC STRUCTURES OF ORGANIC COMPOUNDS JOHN M. EILER Brasil Caltech Techniques Universidad MATRIX SOLID-PHASE DISPERSION FOR HYDROCARBON ELENA Analytical A REVIEW OF ADVANCED GEOCHEMICAL Estados AT16 Colômbia Industrial de J. M. (MIKE) Biomarker Analytical ISOLATION FROM BITUMINOUS ROCK STASHENKO Techniques AT05 TECHNOLOGIES FOR SOURCE DETERMINATION AND Unidos da Santander MOLDOWAN Technologies, Inc. Techniques QUANTIFICATION OF OIL MIXTURES América RECENT DEVELOPMENTS IN HYDROPYROLYSIS (HYPY) University of AM01 WILL MEREDITH Inglaterra Artificial Maturation FOR PETROLEUM GEOCHEMISTRY Nottingham 2H/1H RATIOS OF FORMATION WATERS FROM THE ALEXANDRE POTIGUAR BASIN, BRAZIL: A COMPARISON BETWEEN Analytical COMPOSITIONAL DESCRIPTION OF BRAZILIAN TYPE-I JOELMA AT06 DE ANDRADE Brasil Petrobras AM02 Brasil PETROBRAS Artificial Maturation ISOTOPE RATIO INFRARED SPETROSCOPY (IRIS) AND Techniques KEROGEN USING HYDROUS PYROLYSIS PRODUCTS PIMENTEL LOPES FERREIRA ISOTOPE RATIO MASS SPECTROMETRY (IRMS) Division of Geochemistry, COMPOUND SPECIFIC CARBON ISOTOPE ANALYSIS OF NEW APPROACH FOR COMPARING KINETIC MODELS OF ALEXANDRE Research & LIGHT HYDROCARBONS (C1 - C10): APPLICATION ON Analytical AM03 PETROLEUM GENERATION BASED ON ROCK-EVAL AND REGINA BINOTTO Brasil Artificial Maturation AT07 DE ANDRADE Brasil Petrobras Development THE GEOCHEMICAL CHARACTERIZATION OF MARINE Techniques HYDROUS PYROLYSIS EXPERIMENTS FERREIRA Center of OILS FROM NORTHEASTERN BRAZIL PETROBRAS Estados NOVEL GEOCHEMICAL TECHNOLOGIES REVEAL J. M. (MIKE) Biomarker Analytical EFFECT OF HYDROUS PYROLYSIS IN BIOMARKER AT08 Unidos da NOELIA FRANCO EVERYTHING YOU WANTED TO KNOW ABOUT HEAVY OIL MOLDOWAN Technologies, Inc. Techniques AM04 DISTRIBUTION OF OCCLUDED COMPOUNDS IN THE Brasil UFRJ Artificial Maturation América R. CAMECA, ASPHALTENE STRUCTURES 29 Quai des THE NANOSIMS: ORGANIC GEOCHEMISTRY AT SUB-µM Analytical ARTIFICIAL MATURATION APPLYING HYDROUS AT09 PHILIPPE SALIOT Brasil Grésillons, 92622 TÂNIA VALÉRIA Umiversidade LATERAL RESOLUTION Techniques PYROLYSIS EXPERIMENTS ON ORGANIC- RICH SHALES Gennevilliers, AM05 DE OLIVEIRA Brasil Federal do Rio Artificial Maturation FROM THE IPUBI MBR., SANTANA FM., ARARIPE BASIN, France. DELGADO Grande do Sul BRAZIL INCREASING THE RESOLUTION OF BIODEGRADATION RENZO CORRÊA Analytical AT10 Brasil UFRJ SCALES WITH NON-GC EXPERIMENTS SILVA Techniques CHANGES IN OIL PROPERTIES WITH THE ADVANCE ANDRÉ LUIZ OF THERMAL MATURATION INDUCED BY HYDROUS ISOLATION AND ANALYSIS OF POLYCYCLIC AROMATIC AM06 DURANTE Brasil PETROBRAS Artificial Maturation PYROLYSIS FOR A BRAZILIAN SOURCE ROCK HYDROCARBONS (PAHS) IN CRUDE OIL USING SPIGOLON CLEVERSON JOSÉ Petrobras/ Analytical CONTAINING A TYPE-I KEROGEN AT11 MOLECULARLY IMPRINTED SOLID-PHASE EXTRACTION Brasil F. DE OLIVEIRA Cenpes/GEOQ Techniques (MISPE) COUPLED WITH GAS CHROMATOGRAPHY-MASS HYDROUS PYROLYSIS EXPERIMENTS ON A PERMIAN THAYSA LORENI Universidade SPECTROMETRY (GC/MS) AM07 COAL SAMPLE FROM THE LEÃO-BUTIÁ COALFIELD, COLMAN DE Brasil Federal do Rio Artificial Maturation PARANÁ BASIN MORAIS Grande do Sul

2 3 PETROBRAS/ Estados School of Geology FLUORESCENCE BEHAVIOR OF ALGINITES IN ARTIFICIAL CARLA VIVIANE ENERGY AND THE ENVIRONMENT-RELATING RELEASES Environmental AM08 Brasil CENPES/PDGEO/ Artificial Maturation EG07 R. PAUL PHILP Unidos da and Geophysics, MATURATION EXPERIMENTS ARAUJO TO SOURCES WITH ENVIRONMENTAL FORENSICS Geochemistry GEOQ América Uni. of Oklahoma

ORIGIN OF H2S IN FRANQUERA, MOPORO AND LA CEIBA GEOCHEMICAL CHARACTERIZATION OF THE HYDROUS Gas and Surface GS01 OILFIELDS: EVIDENCE FROM SULFUR ISOTOPES AND FRANK CABRERA Venezuela PDVSA-INTEVEP AM09 PYROLYSIS PRODUCTS FROM A RECENT MICROBIAL FURUKAWA, G.G. Brasil UFRJ Artificial Maturation Geochemistry MAT CHEMICAL ANALYSIS OF FLUIDS

Estados THE INNOVATIVE APPLICATIONS OF STABLE ISOTOPES IN GeoIsoChem Gas and Surface NEW STRATEGIES CHEMOMETRIC FOR EVALUATION OF PALOMA SANTANA GS02 ANDERI DEEV Unidos da BD01 Brasil UNICAMP Biodegradation PETROLEUM GEOCHEMISTRY Corporation Geochemistry BIODEGRADATION OF CRUDE OILS BY GCXGC PRATA América ALAIN Gas and Surface Darcy Ribeiro GS03 OIL VERSUS GAS CHARGE IN THE SOLIMÕES BASIN Brasil HRT TARBALL CHARACTERIZATION BY ESI(-) LTQ XL LAERCIO LOPES PRINZHOFER Geochemistry BD02 Brasil North Fluminense Biodegradation ORBITRAP MARTINS ERICA TAVARES Gas and Surface State University GS04 THE ORIGIN OF H2S IN BRAZILIAN PRESALT RESERVOIRS Brasil Petrobras DE MORAIS Geochemistry USING O-CONTAINING ACIDIC POLAR COMPOUNDS CHEMISTRY ANITA JOCELYNE PRELIMINARY RESULTS OF A SURFACE GEOCHEMISTRY PETROBRAS BD03 OF BIODEGRADED PETROLEUM AS BIOMARKER OF Brasil INSTITUTE - Biodegradation CARLOS S. MARSAIOLI STUDYUSING MULTIPLE METHODS IN THE CINZENTO Research and Gas and Surface BIODEGRADATION UNICAMP GS05 BANDEIRA DE Brasil DIAPIR SEEP, RECÔNCAVO BASIN, STATE OF BAHIA, Development Geochemistry MELLO BRAZIL Center (CENPES) MICROBIAL DEGRADATION OF PHENANTHRENE AND GEORGIANA BD04 Brasil LENEP/UENF Biodegradation METHYLPHENANTHRENES IN LABORATORY CONDITIONS FEITOSA DA CRUZ GEOCHEMICAL MONITORING: BASELINES FOR THE SURFACE (SOILS) AND FOR RESERVOIR FLUIDS OF THE MERCEDES Surface Exploration ORINOCO OIL BELT CRUDES PRODUCED BY VERONICA GS06 França PDVSA GAS BD05 Venezuela PDVSA Biodegradation ?ZAPATOS-MATA R? FIELD, ?AREA MAYOR ANACO?, CAVANI Technologies DIFFERENTIAL BIODEGRADATION CARMONA EASTERN BASIN, VENEZUELA

EVALUATION OF CRUDE (COL) AS A STANDARD IN Chemistry of Geo- RECOGNITION OF ONSHORE SURFACE SEEPS AND Estados CG01 COMPOUND-SPECIFIC ISOTOPE ANALYSIS OF C15+ IN DELFIN RIVAS Venezuela PDVSA-Intevep Surface Exploration Organic Molecule GS07 MICROSEEPS BY DETERMINATION OF SOIL DIAMONDOID JEREMY DAHL Unidos da Stanford University SATURATED FRACTION OF CRUDE OILS Technologies CONCENTRATIONS América

ACETATE IN FORMATION WATERS AT THE SOUTHEAST Chemistry of Geo- Facultad de CG02 BEATRIZ ANGULO Venezuela PDVSA Intevep OF THE MARACAIBO BASIN Organic Molecule Ciencias Instituto HYDROCARBON GENERATION POTENTIAL IN THE de Ciencias de la SYNTHESIS OF 3-N-PROPYLERGOSTANE BIOMARKERS. FRANCISCO DE OG01 LILIANA LÓPEZ Venezuela Oil Geochemistry Chemistry of Geo- TALARA BASIN, PERU Tierra, Universidad CG03 STRUCTURAL PROOF OF 3-N-PROPYLERGOSTANOIC ASSIS MACHADO Brasil UNICAMP Organic Molecule Central de ACIDS IDENTIFIED IN CAMPOS BASIN OILS. REIS Venezuela

CHARACTERIZATION OF PAHS INPUTS TO A TROPICAL Pontifícia NEW GAS-CONDENSATES RESERVOIR ON GOLFO DE MOISES DAVID URBAN ESTUARY (GUANABARA BAY) CONSIDERING END- CRISTIANE Universidade Environmental OG02 VENEZUELA BASIN, OFFSHORE, VENEZUELA. SOURCE Venezuela PDVSA Intevep Oil Geochemistry EG01 Brasil PIRELA ESCOBAR MEMBER COMPOSITION AND A STATISTICAL APPROACH RIBEIRO MAUAD Católica do Rio de Geochemistry ROCK AND FLUIDS GEOCHEMICAL CHARACTERIZATION (PCA/MLR) Janeiro ORIGIN OF OIL IN WESTERN SHAIM REGION, WEST CELESTE YARA OG03 MAKAROVA ANNA Rússia Repsol-Russia Oil Geochemistry AROMATIC HYDROCARBONS IN SEDIMENTS OF THE Environmental SIBERIAN BASIN, RUSSIA EG02 DOS SANTOS Brasil UFRJ AMAZON REGION Geochemistry SIQUEIRA IDENTIFICATION OF ARYL ISOPRENOIDS IN OILS FROM IGOR V. A. F. DE OCCURRENCE OF POLYCYCLIC AROMATIC CAMILA OG04 SERGIPE?ALAGOAS BASIN, NORTHEASTERN BRAZIL Brasil PETROBRAS Oil Geochemistry Environmental SOUZA EG03 HYDROCARBONS IN RECENT SEDIMENTS AND BENTHIC CARNEIRO DOS Brasil UFPA USING TRIPLE QUADRUPOLE GC-MS/MS Geochemistry ORGANISMS OF AN AMAZON ESTUARY SANTOS PETROLEUM ENGINEERING ISOTOPIC EVIDENCE FOR SULFURIZATION OF HUMIC Universidade RUT AMELIA DÍAZ Environmental GEOCHEMICAL EVALUATION OF OIL MIGRATION IN AND EG04 ACID IN SEDIMENTS OF THE TROPICAL UPWELLING Brasil Federal RAMOS Geochemistry ELIANE SOARES SYSTEM OF CABO FRIO (RJ). Fluminense OG05 STROMATOLITES SAMPLES: INFLUENCE OF WATER Brasil EXPLORATION Oil Geochemistry DE SOUZA FORMATION SALINITY LABORATORY OIL SPILL CHARACTERIZATION USING ORGANIC WAGNER LEONEL Environmental (LENEP/UENF), EG06 Brasil Petrobras GEOCHEMISTRY CASE STUDIES BASTOS Geochemistry MACAÉ, BRAZIL.

4 5 Universidade DISTRIBUTION OF HYDROCARBON FAMILIES IN THE HIGH-RESOLUTION MOLECULAR ORGANIC HENRRY RIVERA Federal do Rio de OG06 CENTRAL AREA OF THE NEIVA SUB-BASIN, COLOMBIA. Colômbia ECOPETROL Oil Geochemistry GEOCHEMISTRY FOR THE DEPOSITIONAL ALESSANDRO DUQUE PROCESSES FOR MIGRATION AND CHARGE OG17 Brasil Janeiro, Instituto Oil Geochemistry PALEOENVIRONMENTCLASSIFICATION OF BRAZILIAN CASILLI de Química, CRUDE OILS BIOMARKER AND N-ALKANES ISOTOPE PROFILE STUDY MICHEL RICARDO LAGOA-LADETEC OG07 IN OIL SAMPLES FROM RECÔNCAVO BASIN, MIRANGA DE BARROS Brasil UNICAMP Oil Geochemistry Facultad de

FIELD, BRAZIL. CHAVES Ciencias Instituto VERTICAL VARIABILITY IN CRUDE OIL COMPOSITION: ES- SALVADOR LO de Ciencias de la COMPARTMENTALIZATION ANALYSIS OF THREE CRUDES JHAISSON OG18 SOC WELL, SOCORORO FIELD, EASTERN VENEZUELAN Venezuela Oil Geochemistry OG08 Venezuela PDVSA-INTEVEP Oil Geochemistry MÓNACO Tierra, Universidad FROM LAKE MARACAIBO BASIN VASQUEZ BASIN Central de

SOURCE FACIES DIFERENCIATION AND PETROLEUM Venezuela VLADIMIR CHARGE HISTORY IN THE SOUTHWEST REGION OF THE CARBON ISOTOPE ANALYSIS OF SPECIFIC BIOMARKERS JARBAS VICENTE OG09 BLANCO- Colômbia Ecopetrol S.A. Oil Geochemistry OG19 Brasil Petrobras Oil Geochemistry LLANOS BASIN USING HIGH-RESOLUTION ORGANIC IN BRAZILIAN OILS: NOVEL PATTERNS AND LIMITATIONS POLEY GUZZO VELANDIA GEOCHEMICAL TECHNOLOGIES LEONARDO ORIGIN AND MATURITY OF CRUDE OILS AND OIL SEEPS OG20 SÁNCHEZ Venezuela PDVSA Oil Geochemistry GEOCHEMICAL STUDY OF COMPARTMENTALIZATION IN FROM FALCÓN BASIN, WESTERN VENEZUELA CARRASCO OG10 RESERVOIRS OF BLOCK V-VI LAMAR, MARACAIBO BASIN, NATASHA ACOSTA Venezuela PDVSA-Intevep Oil Geochemistry ADVANCED GEOCHEMICAL TECHNOLOGIES FOR Integrated VENEZUELA Estados DETERMINING MULTIPLE SOURCES, FACIES AND OIL- SILVANA M. Petroleum ICP-ECOPETROL, OG21 Unidos da Oil Geochemistry MIXTURES OF OIL PRODUCED IN THE SANTOS BASIN, BARBANTI Expertise Colombian América HYDROCARBON MIGRATION HISTORY IN THE BRAZIL Company JULIAN NARANJO Petroleum OG11 LLANOS FOOTHILLS BASIN, COLOMBIA, USING FLUID Colômbia Oil Geochemistry Maersk Oil, VESGA Institute, GEOCHEMICAL COMPOSITION OF CRUDE OILS INCLUSIONS Esplanaden ECOPETROL-ICP AND BIODEGRADED SEEPAGE OILS IN BELIZE AND OG22 H.I. PETERSEN Dinamarca 50, DK-1263 Oil Geochemistry S.A GUATEMALA: EVIDENCE FOR CHARGING FROM DIEGO ARMANDO Copenhagen K, GEOCHEMICAL STUDY OF RESERVOIR corporacion CRETACEOUS CARBONATE SOURCE ROCKS OG12 MARTINEZ Colômbia Oil Geochemistry Denmark CONTINUITY IN COTOPERÍ-ORITUPANO FIELD. Natfrac Schlumberger CARRILLO CHEMOMETRIC RECOGNITION OF GENETICALLY Estados Information CRUDE OIL AND GAS FROM THE CAMPOS Repsol OG23 DISTINCT OIL FAMILIES IN THE LOS ANGELES BASIN, K.E. PETERS Unidos da Oil Geochemistry OG13 RAFAEL TOCCO SPAIN Oil Geochemistry Solutions, Mill BASINOF BRASIL: A GEOCHEMICAL CHARACTERIZATION Exploration CALIFORNIA América Valley, CA 94941

GEOCHEMICAL CHARACTERIZATION FROM THE APPLICATION OF COMPREHENSIVE TWO-DIMENSIONAL NELSON OG14 NORTHERN AREA OF THE EASTERN LLANOS BASIN, Colombia Ecopetrol Oil Geochemistry GAS CHROMATOGRAPHY - TIME OF FLIGHT MASS DÉBORA A. SANCHEZ OG24 Brasil IQ/UFRJ Oil Geochemistry COLOMBIA. SPECTROMETRY TO EVALUATE MATURATION OF AZEVEDO

BRAZILIAN CRUDE OILS GEOCHEMICAL CHARACTERIZATION OF OIL SPILLS

AND OIL SAMPLES FROM WELLS OF ADJACENT AREAS, EVALUATING SOURCE-ROCK MATURATION CHANGES MARIO A. OG15 IN ORDER TO DETERMINE THE ORIGIN, BY OIL-OIL Colômbia Ecopetrol Oil Geochemistry DUE TO THERMAL CONTRAST BETWEEN SALT AND SAVIO FRANCIS Petrobras, E&P- GUZMÁN-VEJA PSBM01 Brasil Oil Geochemistry CORRELATION, TWO STUDY CASES, MONAGAS, OTHER OVERLYING SEDIMENTS USING AN INTEGRATED DE MELO GARCIA EXP/GEO/MSP

VENEZUELA STRUCTURAL RESTORATION APPROACH

THE ORIGIN OF HEAVY CRUDE OILS IN MEXICO AND MARIO A. AN EXAMPLE OF QUANTITATIVE ESTIMATION OF OG16 Colômbia Ecopetrol Oil Geochemistry CARLOS PINTO COLOMBIA GUZMÁN VEGA PSBM02 OVERPRESSURE CAUSED BY OIL GENERATION IN Brasil PETROBRAS Oil Geochemistry FRACALOSSI CAMPOS BASIN, BRAZIL.

6 7 Helmholtz Centre Potsdam, BIOLOGICAL MARKER ANALYSIS OF COAL SAMPLES JANAINA B. DA GFZ German SR01 Brasil UFRGS Oil Geochemistry FROM CHICO LOMÃ, BRAZIL COSTA Research Centre POSSIBLE CONTROLS OF ANDES-ASSOCIATED for Geosciences, Section 4.3., VOLCANIC ACTIVITY ON HYDROCARBON GENERATION BIOGEOCHEMISTRY FEATURES OF SEDIMENTS FROM GEO/CENPES/ Telegrafenberg, SR02 RAMSÉS CAPILLA Brasil Oil Geochemistry PSBM03 AND LEAKAGE IN THE ON/OFFSHORE NORTHERN VICTORIA SACHSE Alemanha 14473 Potsdam, Oil Geochemistry CABO FRIO UPWELLING SYSTEM PETROBRAS Germany ; Institute AUSTRAL BASIN, SOUTHERN ARGENTINA, SOUTH for Geology and AMERICA Geochemistry of ALKANE BIOMARKER STRATIGRAPHY OF IRATI Petroleum and DARLLY ERIKA Coal, EMR Group; SR03 FORMATION IN THE SOUTHERN PORTION OF PARANÁ Brasil UERJ Oil Geochemistry SILVA DOS REIS RWTH Aachen BASIN. University, Germany CRISTINA Universidade THE LINK BETWEEN STRATIGRAPHIC AND PETROLEUM LUIIZ FELIPE OVERVIEW ON KWANZA BASIN POTENTIAL SOURCE SR04 FERNANDA ALVES Portugal Fernando Pessoa; Oil Geochemistry PSBM04 SYSTEM MODELS: INSIGHTS FOR HYDROCARBON CARVALHO Brasil PETROBRAS Oil Geochemistry ROCKS RODRIGUES Halliburton EXPLORATION COUTINHO HELIO JORGE INVESTIGATING A CAMBRIAN-ORDOVICIAN SOURCE SR05 P. SEVERIANO Brasil UENF Oil Geochemistry POSSIBLE CAUSES AND CONSEQUENCES OF ROCK IN THE PARNAÍBA BASIN, BRAZIL RIBEIRO PSBM05 ANOMALOUS GEOTHERMAL REGIMES IN CARBONATE ROGER BAUDINO Espanha Repsol Exploration Oil Geochemistry

PLATFORMS THE IMMATURE FACIES OF PIMENTEIRAS FORMATION CONSUELO LIMA (DEVONIAN) OF THE PARNAÍBA BASIN, STATE OF Universidade SR06 NAVARRO DE Brasil Oil Geochemistry BASIN MODELING : A KEY TOOL FOR ASSESSING TOCANTINS, BRAZIL: PALYNOFACIES AND ORGANIC Federal da Bahia PSBM06 P. JERMANNAUD Brasil BEICIPFRANLAB Oil Geochemistry ANDRADE UNCONVENTIONAL PLAY GEOCHEMISTRY.

MODELING OIL COMPOSITION IN RESERVOIRS ORGANIC GEOCHEMICAL CHARACTERIZATION OF 30F-1X SR07 CARLOS RAMÍREZ Venezuela Oil Geochemistry PSBM07 SUBMITTED TO BIODEGRADATION IN OFFSHORE GUSTAVO GARCIA Brasil Petrobras Biodegradation CORE SAMPLES FROM MARACAIBO BASIN, VENEZUELA. OILFIELDS IN THE BRAZILIAN SOUTHEASTERN MARGIN Source Rock ORGANIC FACIES DISTRIBUTION IN THE PASSIVE UNDERSTANDING GEOCHEMICAL PROPERTIES BY LUÍS MAURÍCIO LANDANN Characterization SR08 MARGIN OF THE BARINAS APURE BASIN: COASTAL LIMIT Venezuela PDVSA PSBM08 COMPOSITIONAL SIMULATION OF PETROLEUM VERTICAL SALGADO ALVES Brasil PETROBRAS Oil Geochemistry ESCORCIA and Organic MOVEMENT APPLICATION MIGRATION AND EVAPORATIVE FRACTIONATION CORRÊA Petrography UNIVERSIDADE Source Rock Estados AROMATIC STEROIDS BIOMARKER APPLIED TO HIGH LINA LILIANA GEOCHEMICAL BASIN MODELS FOR UNCONVENTIONAL GeoIsoChem DO RIO Characterization PSBM09 JAMES CHEN Unidos da Oil Geochemistry SR09 RESOLUTION STRATIGRAPHY: IRATI FORMATION, OSORIO Brasil SHALE PLAYS Corporation DEJANEIRO - and Organic América SOUTHERN OF PARANÁ BASIN, BRAZIL SANABRIA UERJ Petrography

PREDICTION OF LOW-MATURITY GAS ACCUMULATIONS: Source Rock FREDERIC PSBM10 APPLICATION TO THE EASTERN MEDITERRANEAN Brasil Beicip-Franlab Oil Geochemistry ORGANIC-RICH SEDIMENTS : QUICK ASSESSMENT OF Characterization SCHNEIDER SR10 BEAUMONT França IFPEN ?BIOGENIC PLAY? DEPOSITIONAL ENVIRONMENT CHARACTERIZATION. and Organic Petrography Schlumberger Institute for Brazil Geology and QUANTITATIVE PREDICTION OF CO2 AND H2S IN THE Research and PSBM11 ADRIAN KLEINE Alemanha Oil Geochemistry Geochemistry Source Rock GULF OF GABES, OFFSHORE TUNISIA Geoengineering LATE CRETACEOUS ORGANIC MATTER RICH SEDIMENTS of Petroleum Characterization Center, Rio de SR11 OF ONSHORE MOROCCO (TARFAYA BASIN) AND THEIR VICTORIA SACHSE Alemanha and Coal, EMR and Organic Janeiro, Brazil RELATION TO OCEANIC ANOXIC EVENTS Group; RWTH Petrography Estados PETROLEUM GENERATION KINETICS: SINGLE- VS. KENNETH ERIC Aachen University, PSBM12 Unidos da Schlumberger Oil Geochemistry MULTIPLE-HEATING RAMP OPEN-SYSTEM PYROLYSIS PETERS Germany América

CONTROLLING FACTORS IN MIXED BIOGENIC/ PSBM13 THERMOGENIC PETROLEUM SYSTEMS ? A CASE STUDY BJORN WYGRALA Alemanha Schlumberger Petroleum Systems FROM THE LEVANTINE BASIN

OCCURRENCE, DISTRIBUTION AND CHARACTER OF YOLIMA BLANCO- PSBM14 HYDROCARBON SOURCE KITCHENS IN THE SOUTHERN Colômbia Ecopetrol S.A. Petroleum Systems VELANDIA FOREDEEP OF THE LLANOS BASIN, COLOMBIA

8 9 Division of POZO D-129 FORMATION, NEW SHALE PLAY? A CASE Geochemistry, MARTIN EUGENIO Unconventional UP02 STUDY IN AN OIL FIELD ON THE FOLD BELT OF GOLFO Argentina YPF S.A. Research and FASOLA Petroleum Systems IGOR VIEGAS Source Rock SAN JORGE BASIN, ARGENTINA GEOCHEMICAL CHARACTERIZATION OF SILURIAN AND Development ALVES Characterization SR12 DEVONIAN SECTION, SOUTHERN SECTOR OF THE Brasil Center (CENPES), UPMC Univ. Paris FERNANDES DE and Organic AMAZONAS BASIN, BRAZIL. PETROBRAS, 06 et CNRS, UMR SOUZA Petrography 21941-915, Rio PALEOENVIRONMENTAL CONTROL ON PRIMARY FLUIDS 7193 ISTeP ? SYLVAIN GAREL- Unconventional de janeiro, RJ, UP03 CHARACTERISTICS OF LACUSTRINE SOURCE ROCKS, França Total, Exploration LAURIN Petroleum Systems Brazil THE EXAMPLE OF THE AUTUN BASIN (FRANCE) & Production Source Rock - Exploration Estados Characterization division SR13 MAKING MOVIES OF OIL GENERATION JEREMY DAHL Unidos da Stanford University and Organic Petrobras América GEOCHEMICAL CHARACTERIZATION OF Petrography TAISSA RÊGO Research & Unconventional UP04 UNCONVENTIONAL SHALE OIL AND GAS IN MESOZOIC Brasil Source Rock MENEZES Development Petroleum Systems ANALYSIS OF MOLECULAR BIOMARKERS OF GUSTAVO SEDIMENTARY SECTION ? NEUQUÉN BASIN ARGENTINA Characterization Center SR14 CAP CARBONATE FROM AMAZONIAN CRATON, RODRIGUES DE Brasil Unicamp and Organic GEOCHEMICAL CHARACTERIZATION OF ASPHALTIC TATIANY DE NEOPROTEROZOIC, BRAZIL SOUSA JÚNIOR Unconventional Petrography UP05 SANDSTONES BASED ON BIOMARKER ANALYSIS FREE ALMEIDA FORTINI Brasil LENEP/UENF Source Rock Petroleum Systems AND OCCLUDED THE ASPHALTENICS STRUCTURES BRITTO OIL EXPLORATION IN THE MEDITERRANEAN BASIN: THE ALBERT UNIVERSITAT DE Characterization SR15 Espanha MARIA-FERNANDA PRE-MESSINIAN SOURCE ROCKS PERMANYER BARCELONA and Organic NEW ROCK-EVAL METHOD FOR CHARACTERIZATION OF Unconventional UP06 ROMERO- França IFPEN Petrography SHALE PLAYS Petroleum Systems Integrated SARMIENTO

Petroleum Source Rock IMPACT OF HIGH (900 BAR) WATER PRESSURE ON OIL GEOCHEMICAL EVALUATION OF OUTCROPS FROM MARCUS F. Expertise Characterization GENERATION AND MATURATION IN KIMMERIDGE CLAY SR16 TAPAJÓS RIVER VALLEY, SOUTHERN EDGE OF THE Brasil University of Unconventional TENÓRIO Company, 22280- and Organic UP07 AND MONTEREY SOURCE ROCKS: IMPLICATIONS FOR CLEMENT UGUNA Inglaterra AMAZONAS BASIN Nottingham Petroleum Systems 030, Rio de Petrography HYDROCARBON RETENTION AND GAS GENERATION IN Janeiro, RJ, Brazil SHALE GAS SYSTEMS Source Rock BIOMARKER CHARACTERIZATION OF BARREIRINHA AND Universidade do Institute of PEDRO H. V. Characterization SR17 CURIRI FORMATIONS, UPPER DEVONIAN OF AMAZONAS Brasil Estado do Rio de Geology and GARCIA and Organic BASIN Janeiro Geochemistry Petrography POROSITY, PERMEABILITY AND METHANE SORPTION of Petroleum Unconventional EVALUATION OF HYDROCARBON GENERATION Source Rock UP08 CAPACITY OF OIL AND GAS SHALES AT DIFFERENT RALF LITTKE Alemanha Ecopetrol S.A., and Coal, EMR Petroleum Systems POTENTIAL OF THE CRETACEOUS SEQUENCE IN THE ROBERT Characterization STAGES OF THERMAL MATURATION SR18 ICP, Piedecuesta – Group, RWTH NORTHERN SECTOR OF THE MIDDLE MAGDALENA MÁRQUEZ and Organic Colombia Aachen University, VALLEY BASIN, COLOMBIA Petrology Germany

Organic Estados DESIGNING TIGHT-SHALE PRODUCTION STRATEGIES BY Unconventional Geochemistry Source Rock UP09 JEREMY DAHL Unidos da Stanford University MAPPING OIL CRACKING Petroleum Systems ORBITAL CONTROLS ON LOWER JURASSIC SOURCE LORENZ Unit, IfG, Characterization América SR19 Alemanha ROCK DEPOSITION SCHWARK Christian- and Organic STUDY OF GAS ADSORPTION-DESORPTION PROPERTIES J. JOSUÉ ENCISO Université de Unconventional UP10 Albrechts- Petrology IN UNCONVENTIONAL RESERVOIRS OF MEXICO C Lorraine Petroleum Systems University CHARACTERIZATION OF SOLID BITUMEN AND ITS IMPACT REVIEW ON THE CBM POTENTIAL OF PERMIAN COALS Ecopetrol S.A., PRISCILA Instituto de IN POSSIBLE UNCONVENTIONAL RESERVOIRSFROM ROBERT Unconventional FROM THE PARANÁ BASIN, BRAZIL BASED ON RESULTS Unconventional UP11 ICP, Piedecuesta – UP01 DOS SANTOS Brasil Geociências, TABLAZO FORMATION, MAGDALENA MIDDLE BASIN, MÁRQUEZ Petroleum Systems FROM EXPLORATION WELLS IN RIO GRANDE DO SUL Petroleum Systems Colombia LOURENZI UFRGS COLOMBIA. AND SANTA CATARINA School of Geology UTILIZATION OF PETROLEUM GEOCHEMICAL CONCEPTS and Geophysics, Unconventional UP12 PAUL PHILP IN CHARACTERIZATION OF SHALE OIL PROSPECTS University of Petroleum Systems Oklahoma

10 11 ANALYTICAL TECHNIQUES The use of Rock-Eval can now be extended to assess unconventional fossil resource prospects, assuming an adequate AT01 choice of the heating program. Currently Rock-Eval pyrolysis can be applied to assess the potential of oil shale, to characterize heavy Best Practice for Rock-Eval pyrolysis with oil sections and oil sands and to pinpoint tar mats in a reservoir. emphasis on unconventional prospects This paper reviews the two main operational Rock-Eval methods “Basic/Bulk-Rock” and “Reservoir” and introduces a new method devoted to shale plays assessment, the “Shale Plays” method. Violaine Lamoureux-Vara¬*, Alain-Yves Hucb, Valérie Beaumonta, Maria-Fernanda Romero-Sarmientoa, « Basic / Bulk-Rock » Method Daniel Pillota, Géremie Letorta, Bernard Carpentiera, Khomsi The choice of a specific analytical method is mandatory and Trabelsia, Bruno Garciaa depends on the objectives and type of rock considered. In the case of source rocks, the “Basic/Bulk-Rock” method allows a a IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, 92852 rapid quantification of total organic carbon (TOC), mineral carbon Rueil-Malmaison, France content (MinC), estimation of thermal maturity (Tmax), residual b Associate Professor UPMC - Université Pierre et Marie Curie - petroleum potential (S2), hydrogen index (HI) and oxygen index (OI) Institut des Sciences de la Terre Paris (UMR 7193 UPMC-CNRS) / (Espitalié et al., 1977; Espitalié and Bordenave, 1993; Lafargue et Institute of Earth Sciences in Paris al., 1998; Behar et al., 2001). Recently, a specific methodology * [email protected] for the quantification of different types of carbonates, such as calcite, dolomite and siderite was developed (Pillot et al., 2013). Copyright 2014, ALAGO. The “Basic/Bulk-Rock” method is usually employed as a rapid This paper was selected for presentation by an ALAGO Scientific Committee screening tool for core samples or cuttings, which mainly focuses following review of information contained in an abstract submitted by the author(s). on characterization of source rocks in a conventional way. It is not dedicated to an accurate quantification of free hydrocarbons Introduction (S1), for two reasons: (i) it often relies on samples for which quality, The Rock-Eval is a versatile, high-tech instrument which imposed storage conditions and potential contamination by mud fluids do itself as a standard technics of geochemical characterization and not guarantee the reliability of S1 peak; (ii) during the analysis, the which has evolved over the last decades in terms of hardware, initial heating/recording temperature is set at 300°C for the sake of software and interpretation capabilities. Primarily built as a rapidity, and consequently a part of the light hydrocarbons is lost screening tool assessing basic organic attributes of source rocks and not recorded. The “Basic/Bulk-Rock” method is well adapted such as petroleum potential and thermal maturity, it progressively as a proxy of the Fisher assay providing the retorting potential of an enlarged its scope providing information on organic content and oil shale (Madec and Espitalié, 1984). kinetic parameters of source rocks. More recently it allowed scrutinizing content and nature of mineral carbon of rock samples. Reservoir Method Moreover by adjusting the heating program it proved its applicability For studying reservoir rocks, the “Reservoir” method allows the oil to get an insight into the occurrence and nature of accumulated content to be quantified specifically through a heating/recording hydrocarbons within reservoir sections. In this respect, four built- program starting at 180°C. It also allows checking at a glance if the in methods are readily available: “Basic/Bulk-Rock”, “Reservoir”, oil is conventional or heavy. Moreover the API gravity can be rapidly “Pure Organic Matter” and “Kinetics”. estimated (Trabelsi et al., 1994). In the presence of tar mats, a Rock- Eval screening allows identifying their occurrence and location As far as technology is concerned, the Rock-Eval instrument within a reservoir section penetrated by a well (Carpentier et al., displays unique features, which implications have to be emphasized. 1995) or helps in steering directional drilling to keep away from the Particularly, its twin oven design (pyrolysis and oxidation) is well fitted tar layers (Halpern et al., 1998). Regarding oil sands prospects, to allow the formation of a permanent carbonaceous coating of the bitumen contents and traces of carbonates can be quantified by inner pyrolysis furnace surface. This coating, which is oxidized in the means of the “Reservoir” method. Forecast of CO2 production single oven machines, prevents further adsorption and subsequent from carbonates during steam injection for enhanced oil recovery loss of hydrocarbons interfering with S1 and S2 values. This design is a valuable operational application of this approach (Uzcategui et also prevents unwanted oxidation of hydrocarbons condensed on al., 2011). the splitter outlet directed towards the CO/CO2 line.

12 13 AT02 on the sedimentary environment, maturity, migration and age of Shale Plays - Method Acknowledgments bedrock in some cases.1However, the separation and identification As far as tight, fractured or hybrid shale plays are concerned, We are grateful to the Norwegian Petroleum Directorate (NPD) and GC×GC as a tool to determine maturation and of biomarkers becomes a difficult task because of the variety of hydrocarbons present as fluids and the thermal maturity of rocks we specifically thank Dag Bering for his kindness and efficiency for biodegradation chemical markers in crude oils compounds, chemical classes, volatilities and polarities that can are the focuses of geochemical studies. In this respect assessing providing rock samples. also be found in low concentrations. In this sense, two-dimensional properly the amount and nature of the “free” hydrocarbons is a*Noroska G. S. Mogollón, aPaloma S. Prata, Fabio Augustoa. gas chromatography plays an important role in the identification, instrumental. Accordingly, and following our previous discussion, References characterization and separation of biomarkers through increased the use of the “Basic/Bulk-Rock” method which biases the S1 Behar, F., Beaumont, V. I., De B. Penteado, H. L., 2001. Rock-Eval 6 1UniversidadeEstadual de Campinas, Instituto de sensitivity and detectability.3An additional advantage isthat this peak should be banned. In the first instance, the “source rock” Technology: Performances and Developments. Oil & Gas Science and Química13083-970, São Paulo, SP, Brazil. technique may avoid the fractionating of petroleum because of the system being addressed as a “reservoir rock”, the “Reservoir” Technology, 56, 111-134. *[email protected] increment in the peak of capacity, which also reduces errors during method should be preferred. Using the “Reservoir” method Carpentier, B., Huc, A.Y., Hamou, P., Wilhems, A., 1995. Detection, the analysis. Thus, the main objective of this work is the optimization the vaporizable hydrocarbon content of the shale play can be distribution and origin of thin tar mats in the Miller field (North Sea, UK). Copyright 2014, ALAGO. of the parameters needed in two-dimensional gas chromatography quantified and easily discriminated from the kerogen response on Org. Geochem. 17th Int. Meet. on Org. Geochem., San Sebastian, 1995, This paper was selected for presentation by an ALAGO Scientific Committee GC×GC for separation and identification of biomarkers in crude oil the pyrogram (Fig.1A, 1B and 2). In order to refine the Rock-Eval 388-390. following review of information contained in an abstract submitted by the author(s). and its comparison with the conventional method by GC-MS. characterization of the shale plays, a specific modified reservoir Espitalié, J., Laporte, J.L., Madec, M ., Marquis, F., et al., 1977. Méthode method has been developed: the “Shale Plays” method (Romero- rapide de caractérisation des roches mères,de leur potentiel pétrolier et de Introduction Experimental Sarmiento et al., 2014, this conference). This method provides leur degré d’évolution. Revue de l’Institut Français du Pétrole (Oil Gas Sci. The separation of compounds in crude samples is one of the One Brazilian crude oil samples was selected. For sample improved parameters to quantify the content of hydrocarbons and Technol.) 32, 23-43. most challenging tasks withinchemical analysis. This difficulty processing and analysis chromatographic grade n-hexane and their nature (Fig.1C and 2). Through this temperature program Espitalié, J., Bordenave, M.L., 1993. Screening techniques for source rocks is based uponthe large number of compounds being present in n-pentane from TediaBrazil (São Paulo, Brazil) was used. For the devoted to the distillation and pyrolysis steps, the areas of interest evaluation; tools for source rocks routine analysis; Rock-Eval pyrolysis. each sample type. For example, in middle distillates it is estimated satured biomarker analysis approximately 0.1 g of each crude for the production of shale plays can be tentatively anticipated. App. Petrol. Geol., 273-261. that one million compounds of interest are considered.1 Due to oil were deposited in the top of glass column and eluted with HC content Halpern, H.I., Jones, P.J., Tobey, M.H., Al-Dubaisi, J.M., et al., 1998. the complexity of the sample a pre-treatment is required in order 60 mL of n-hexane. Moreover, for analysis by GC×GC-FID and GC×GC-qMSit the fractioning of the sample was not necessary, S2 Development and application of a technique to predict oil API gravity from to facilitate the study of its specific class of compounds that can T° reservoir core samples. Saudi Aramco Journal of Technology, 1998, 33-40. provide certain desired information. This pre-treatment meansthe approximately 0.1 g of each crude oil were also weighed and then A. Basic/Bulk-Rock Method S1 Lafargue, E., Marquis, F., Pillot, D., 1998. Rock-Eval 6 applications in separation of the petroleum in its various fractions which are called desasphatated with n-pentane. hydrocarbon exploration, production, and soil contamination studies. Revue Saturates, Aromatics, Resins and Asphaltenes (SARA).2This S2b de l’Institut Français du Pétrole (Oil Gas Sci. Technol.),53, 4, 421-437. separation is accomplished by a prior asphaltene precipitation with The lab-made GC×GC-FID prototype was based on HP-6890 T° Madec, M., Espitalié, J., 1984. Application of pyrolysis to the characterization n-pentane, the remaining fractions are separated through a column Series II GC-FID (Agilent, Santa Clara – CA, USA). The column B. Reservoir Method S1r S2a and the upgrading of the Toarcian oil shales from the Paris basin. Fuel, 63, of conventional glass, silica or alumina as the stationary phase, set used consisted on a 30 m × 0.25 mm × 0.25 µm HP-5 Sh2 1720-1725. and three solvent mixtures as mobile phase which will increase (5% phenylmethysiloxane) column (Agilent) connected through T° Pillot, D., Deville, E., Prinzhofer, A., 2013., Identification and Quantification progressively in polarity.The elution of saturated compoundsis a capillary of 1 m × 0.20 mm to a middle polar Rxi-17 (50% of Carbonate Species Using Rock-Eval Pyrolysis. Oil & Gas Science and phenylmethysiloxane) column (Restek)1.0 m × 0.15 mm × 0.15 Sh0 Sh1 performed with n-heptane, the aromatics with a 2:1 mixture of C. Shale Plays Method Technology, 1-9. n-heptane/toluene and finally the resin fraction is eluted with µm. The modulation period was set to 8.0 s and data acquisition Figure 1. Pyrograms for the reference shale Jet Rock-1 (courtesy Romero-Sarmiento, M., Letort, G., Pillot, D., Lamoureux-Var, V., Beaumont, 1:1:1 methylene chloride/toluene/methanol. Then each fraction was performed at 100 Hz. The oven temperature was programmed of the Norwegian Petroleum Directorate-NPD), Tmax=432°C, V., Huc, A.-Y., Garcia, B., 2014. New Rock-Eval method for characterization is analyzed by the conventional method,a one-dimensional gas from 100°C for 0.89 min to 330°C at 2.5°C min-1; the injector and TOC=11.9%, measured with the different Rock-Eval methods: A. of shale plays. This congress. chromatography. Such a pre-treatment resultsin an increase of detector temperatures were set at 280°C and 300°C, respectively. Basic/Bulk-Rock; B. Reservoir; C. Shale Plays. Trabelsi, K., Espitalié, J., Huc, A.-Y., 1994. Characterization of Extra Heavy the analytical errors during the characterization of the sample. Hydrogen at 0.6 mL min-1was used as carrier gas. Oils and Tar Deposits by modified Pyrolysis Methods. In Proceedings of However, the analysis of its fractions is necessary due to the the « Heavy Oil Technologies in a Wider Europe » Thermie EC Symposium, amount of compounds present in crude oil,which is so high that a The GC×GC-qMS system consisted in a modified QP2010+ Berlin 1994, 30-40. sample of crude quickly exceeds the peak of capacity available on (Shimadzu, Kyoto - Japan) GC-qMS. The column set and other Uzcategui, D., Lamoureux-Var, V. and Berger, E. 2011. H2S and CO2 conventional chromatography.Since 1990 the introduction of the chromatographic conditions were the same as above. The MS ion generation mechanisms on a steam injection project on Petrocedeño Field, two-dimensional gas chromatography has shown great potential source temperature was set to 280°C, and the photomultiplier was Orinoco Belt. Paper WHOC11-112, World Heavy Oil Congress, Edm for the analysis of complex samples, providing high resolution, operated at 0.7 kV. The mass scan range was set from m/z 100 sensitivity, detectability and higher peak of capacity, enabling the to 600, resulting an acquisition rate of 12.5 spectra per second. discovery of new compounds in complex matrices.GC×GC has Identification of peaks were performed by comparison with generally been applied to the analysis of hydrocarbons in order literature mass spectra, retention time and elution order. Figure 2. Oil content of the reference shale Jet Rock-1 (courtesy of to identify as many compounds being present in the sampleas The GC-qMS system was anAgilent GC 7890A/5975C VL MSD. the NPD) measured with the different Rock-Eval methods, at IFPEN possible, including biomarkers which are used in geochemistry The column used was on a 30 m × 0.25 mm × 0.25 µm HP-5 and NPD. since they exhibit fingerprintsthat provideimportant information (5% phenylmethysiloxane) column (J&W). The MS ion source

14 15 temperature was 280°C, the temperature of the transfer line was mentneitherfractionationofthesamples, in thesamewayduetothe AT03 and Type III from Mamu Formation, Benin Flank Basin (Nigeria) 300°C and the mass scan range was set from m/z 50 to 600. high resolvingpowerofthetechnique, waspossibletoidentifyfam- was object of this study. For type I kerogen the hydrous pyrolysis iliesofcompoundssuch as 8,14 secohopanos, diahopanosand Effect of artificial maturation at different types experiments were performed at different Temperatures (T = 300, Results and Discussion 3β-methylhopanes, whichwerecoelutedonconventionalchromato- of potential source rocks: Focusing on polar 310, 320, 340, 350, 355 e 360)°C and fixed time (t = 72 h) giving The chromatograms from GC-qMS for the first petroleum fraction graphic. Besides, theseresultswereusedto determine thegeochem- compounds evaluation by FT-ICR-MS technique up a total of seven samples of expelled oil (Binotto et all 2010). composed of saturated hydrocarbons for the biodegraded oil is icalparametersofthesamples, whichprovidedfurthergeologicalinfor- Eight samples of expelled oil from Type III kerogen was obtained shown below. mationbyconventionaltechniquessuch as GC-MS and GC-MS / MS. Rosana C. L. Pereiraa*, Rosane A. Fontesa,Regina fixing the T(340°C) and varying the hydrous pyrolysis time t (1, 2.5, Binottoa,Manoel J. R. Guimarães Netoa, BoniekG. Vazb 5, 10,20,50,100 e 200)h. The expelled oil samples (~ 1 mg) were Acknowledgements dissolved in 10 mL of toluene, and 0.5 mL of the resulting solution

The authors thank CNPq (Brazilian Research Council) for its fellow- a PETROBRAS/CENPES, Rio de Janeiro, RJ, Brazil were transferred to a 1 mL vial and diluted with 0.5 mL of methanol ship; ANP (Brazilian Petroleum Agency),Petrobras S/A andFUN- b Instituto de Química – Universidade Federal de Goiás, Goiânia, GO, Brazil containing 0.2% ammonium hydroxide. The general ESI conditions CAMP – UNICAMP for their financial support. *[email protected] were as follows: capillary voltage of 3.10 kV, tube lens -100 V and flow rate of 3 µL min-1. Ultrahigh resolution MS was performed

Figure 1. Chromatogram obtained in GC-qMS for the saturatedfractionfor the References Copyright 2014, ALAGO. using a Thermo Scientific 7.2 Tesla Fourier transform ion cyclotron 1 biodegraded oil Peters K.E, Moldowan J.M, 1993, The Biomarkers Guide. Interpreting This paper was selected for presentation by an ALAGO Scientific Committee resonance mass spectrometer (LTQ FT Ultra, ThermoScientific,

Molecular Fossils in Petroleum and Ancient Sediments, Prentice Hall, New following review of information contained in an abstract submitted by the author(s). Bremen, Germany). A scan range of m/z 200–1000 was used, and It can be observedhow the complexity of the chromatogram Jersey. one scan of 100 microscans was collected in each run. increases with biodegradation of oil, in comparison to the non- Introduction 2 biodegraded oil,whichalso contains a higher coelution, whereby Grice, K., Alexander, R., Kagi, R.I., 2000.Diamondoid hydrocarbon Generation and expulsion of oil from organic sedimentary rocks Results and Discussion an ion monitoring is necessary to obtain higher detectability of ratios as indicators of biodegradation in Australian crude oils. Organic have been achieved in the laboratory by a technique known as The ESI (-) FT-ICR mass spectraand the class profile (Figure 1) biomarkers. Geochemistry 31, 67–73 hydrous pyrolysis. This technique maintains a liquid water phase of original extracts of Type I and III kerogen show significant On the other hand, the chromatogram of crude oil by GC×GCis in contact with organic sedimentary rocks during their heating at compositional differences. The Type III kerogen presents a 3 shown in Figure 2 Reddy, C.M., Nelson, R.K., Sylva, S.P., Xu, L., Peacock, E.A., subcritical water temperatures. The expelled oil accumulates on distribution of low molecular weight compounds that not checked Raghuraman, B., Mullins, O.C., 2007. Identification and quantification the water surface and contains measurable hydrocarbons. The for Type I, which have high mass molecular profile Similar results of alkene-based drilling fluids in crude oils by comprehensive two- pyrolysate expelled by this technique is more closely analogous were reported by Salmon et al (2011) in the studies of molecular dimensional gas chromatography with flame ionization detection. Journal to crude oil expelled in the natural system than that techniques characterization by ESI FT-ICR (-) MS of sample of kerogen Type I of Chromatography A 1148, 100–107. that employer carrier gases, cryogenic traps, or solvent extraction from Green River formation.The extract of Type III is characterized methods. In hydrous pyrolysis systems, it was observed that by a greater diversity of classes of heteroatom-containing thepyrolysis products from kerogen or lignite degradation are compounds, while kerogen Type I show basically oxygen and dominatedby heteroatomic compounds, called ‘NSOs’, of very nitrogen-containing compounds. highmolecular weight (Lewan 2002). Figure 2. Chromatograms obtained in GC×GCfor biodegraded oil.

A clearadvantageisobserved in thechromatogramobtainedby GC×GC ofcrudeoil, To achieve a better understanding of the polar components whereanincrease in separation, detectionandsensitivityprovides a structuredan- composition at expelled oil,samples from kerogen Type I and Type dresolvedchromatogram, whichgivesan overview ofthesample. Thisisanaddi- III were selected and their hydrous pyrolysis products at different tional tool for theanalystatthe time ofidentification, sincehomologous series temperatures were analyzed by negative-ion electrospray Fourier are groupedintoclearlydefinedregionsof a GC×GC plot. Weidentifiedthe se- transform ion cyclotron resonance mass spectrometry (ESI(-) FT- ries of 8,14 secohopanesanddiahopanesrelatedwithbiodegradation, along- ICR MS). FT-ICR MS provides significant mass resolving power, m/ withthe 3β-methylhopanesindicatorsoflacustrineenvironmentswhich are m∆50%> 200,000 (m∆50% is the mass spectral full peak width hardlydetectedandresolvedby GC. The geochemicalparametersweredeter- at half-height), from 225

16 17 References AT04 established analytical techniques: Conventional methods of stable Lewan, M. D.; Ruble, T. E. 2002. Comparison of petroleum generation isotope analysis generally convert analytes to simple molecules kinetics by isothermal hydrous and nonisothermal open-system The Isotopic Structures of Organic Compounds (e.g., combustion of organics to CO2); this procedure provides only pyrolysisOrg. Geochem.33, 1457-1475. an overall ‘inventory’ of 13C or D, averaged across all possible sites

John M. Eiler1, Daniel A. Stolper1, Alexandre A. Ferreira2, Eugênio and numbers of substitutions but destroys any information that Binotto, R.; Rondón, N. D. F.; Lewan, M. D.; Santos Neto, E. V.; Mendonça V. Santos Neto2, Alex L. Sessions1 might have been recorded by differences in proportions of individual Filho, J. G.; Spigolon, A. L. D. 2010. Insights onbiomarker parameters isotopologues. Established methods of ‘clumped’ isotope analysis

of the Tremembé Formation (Type I kerogen), Brazil, based on hydrous 1 - Division of Geological and Planetary Sciences, California Institute of use low-resolution gas source mass spectrometers that can pyrolysis experiments, 27th Technology, MC 100-23, Pasadena, CA 91125, USA. only provide useful measurements of simple compounds having Annual Meeting of The Society for Organic Petrology (TSOP), Denver, 2 - Division of Geochemistry, PETROBRAS Research and Development straightforward mass spectra (e.g., CO2 or O2). SNIF-NMR and Colorado, USA. Center (CENPES), PETROBRAS, Rua Horácio Macedo, 950, Ilha do the various methods based on chemical or pyrolitic degradation Fundão, Rio de Janeiro, RJ 21941-915, Brazil. of organics generally only can observe single substitutions (usually Salmon, E.; Behar, F.; Hatcher, P. G. 2011. Molecular characterization only of 13C), and so miss most of the isotopic diversity that is

of Type I kerogen from the Green River Formation using advanced NMR [email protected] found in the deuterated and ‘clumped’ isotopic species. These techniques in combination with electrospray ionization/ultrahigh resolution methods also generally require large amounts of analyte and/or

mass spectrometryOrg. Geochem.42, 301-3015. Copyright 2014, ALAGO. labor intensive procedures and so have been slow to develop into

Figure 2.Acidic NSO class relative abundanceforoils expelled This paper was selected for presentation by an ALAGO Scientific Committee useful applied geochemical tools. during hydrous pyrolysis experiments at different temperatures and following review of information contained in an abstract submitted by the author(s). time of 72 h and O Class DBE distribution for oilsgenerated at 320 We will present the results of a recent effort to develop and and 360ºC. Most natural organic compounds are mixtures of a large number apply methods of high-resolution gas source mass spectrometry of isotopologues that differ in the molecular site(s) and/or number that enable the precise analysis of proportions of dozens of Theheteroatom class distribution for the oils obtained from Type I of their rare isotope substitutions. Most alkanes, fatty and amino isotopologues of common organic compounds, including site- kerogen at different temperatures and hydrous pyrolysis time (t) acids, sugars and similar-sized compounds posses dozens to specific substitutions and clumped isotope abundances. These of 72 h and the comparison of O Class DBE distribution from oils hundreds of singly and doubly substituted species (generally methods make use of a pair of gas source mass spectrometers: generated during Exp1 in two extreme temperatures (T = 320 and present in ppm or greater abundances), and a great many more the Thermo IRMS 253 Ultra — a prototype having a double 360° C) are presented. It is showed that the relative abundance rarer species containing three or more rare isotopes. focusing analyzer that reaches mass resolutions of ~25,000 and ofO2 classincreases while O3 and O4 decreasewith temperature a moveable array of multiple collectors — and the Thermo DFS- increasing. The changes observed for O-containing compoundsare Measurements of the proportions of individual isotopologues of a reverse geometry double focusing instrument that achieves related to a sequence of dehydration and/or decarboxylation organic compounds could potentially advance our understanding of mass resolutions up to 80-100,000, has a single collector, and is reactions.Thechanges observed in DBE distribution of O class show a variety of geochemical, biochemical, and environmental problems. adapted for our purposes by connection to a duel inlet sample an increase on the relative intensity of series with higher DBE values For example, it is recognized that a population of molecules that introduction system (i.e., to enable sample-standard comparison). for the oil generated at higher temperature. These series, DBE 7 to achieves equilibrium with respect to its isotopic distribution will Used together, these instruments are capable of mass resolution 17, correspond to compounds with a larger number of aromatic and form excesses of multiply substituted species (isotopic ‘clumps’), 13C from D-bearing isotopologues of molecular and fragment ion naphthenic cores. These results confirm the well-known occurrence in abundances that are inversely proportional to temperature. species up to ~100-150 amu, and routinely achieve precisions of of aromatization reactions, justifying theobserved shift to higher DBE This phenomenon is the basis of clumped isotope thermometry ~0.1-1.0 ‰ for most species of interest. values. of CO2, carbonate and O2, and could potentially be applied to other compounds including many organics. Similarly, SNIF-NMR The first well-established tool developed using these instruments Conclusions measurements of the carbon isotope structures of sugars and is a clumped isotope thermometer for methane, which examines The NSO composition of two kerogen (Type I and III) revealed by long-chain alkanes demonstrate the existence of distinctive site- the temperature dependent formation of 13CH3D (with trace ESI(-) FT-ICR MS shows significant differences. Also, compositional specific variations in 13C abundances of many compounds, some contributions from 12CH2D2). This analysis can be made using changes were easily observed on oils generated duringhydrous of which can be interpreted as a record of biosynthetic pathways. only the Ultra, and has been applied to diverse natural and synthetic pyrolysis experiments in different temperature and time conditions. Similar observations of site-specific isotope effects have been materials, including conventional and unconventional gas deposits, These results strongly encourage the application of FT-ICR MS made by mass spectrometry of N2O, and by selective chemical or various biogenic and hydrothermal methanes, and methane as an analytical tool for kinetic studies monitoring during artificial pyrolytic degradations of organic compounds. formed by laboratory cracking reactions and microbial cultures. maturation experiments. Results to-date indicate that natural methane normally forms in

However, until recently direct observations of proportions of internal isotopic equilibrium and that this formation temperature is Acknowledgements specific isotopologues have been made for only a few compounds, generally preserved through later gas migration or geological uplift The authors thank Petrobras S/A for financial support. and have generally considered only a handful of the many possible of host rocks. We will present case studies in which this tool is used isotopic substitutions. This largely reflects the limitations of to discriminate low temperature biogenic from high temperature

18 19 thermogenic gas in mixed deposits, and to recognize the products AT05 biomarkers such as steranes (CSIA-Bs), hopanes (CSIA-Bh) and conventional oil, condensate, seepage oil, heavy oil and source rock of secondary cracking in very mature parts of petroleum deposits, isoprenoids (CSIA-Bi). extracts. Diamondoids, especially the larger ones, are virtually inert even when they are mixed into lower maturity constituents. Finally, A Review of advanced Geochemical 4. Analysis of asphalteneand kerogenpyrolysates from biodegraded to both thermal and biological degradation. They can be applied to we will show data from laboratory cultures and natural samples Technologies for source determination and heavy oil and immature source rocks. any correlation effort. that reveal kinetic isotope effects producing non-equilibrium quantification of Oil Mixtures abundances of the clumped species in some biogenic gases. Quantitative diamondoid analysis (QDA) a b a This phenomenon appears to be common in biological systems J. M. (Mike) Moldowan *, Jeremy Dahl , Shaun Moldowana , Multiple applications of QDA have evolved since this method was c having rapid growth rates and high partial pressures of H2, but Geoffrey Bott introduced by Dahl et al. (1999). Initially it was found that diamondoid has not been observed to-date in natural sub-surface biogenic concentrations in oil respond to the level of conversion of liquid oil gas, perhaps due to slower growth rates and lower pH2. We will a Biomarker Technologies, Inc. (BTI), 638 Martin Avenue, Rohnert to gas and pyrobitumen (oil cracking).Diamondoid levels begin to present complementary data on proportions of 13C2H6, 13CH3— Park, CA 94928, USA; increase simultaneously with the depletion of certain biomarkers. 12CH2—12CH3 and 12CH3—13CH2—12CH3 in natural gases, b Stanford Institute for Materials and Energy Science (SIMES), It was found that the C29-ααα20R-sterane goes to a very low which appear to record the mechanisms and progress of ‘cracking’ Stanford University, Stanford, CA 94305, USA; concentration at the same point as oil begins to crack, and the level reactions. c GB Scientific, Inc., 1090 Industrial Avenue, Suite B, So. Lake of conversion of liquid to gas and pyrobitumen can be calculated. Tahoe, CA 96150 USA Isotopically labeled diamondoids of the same carbon structures Integration of data from the DFS with the Ultra enables analysis are added as internal standards to insure accuratemeasurements. of a great many additional measurements that are challenging or [email protected] Increased diamondoid concentrations often occur in black oil with impossible using either instrument alone. Examples we will present website: www.biomarker-inc.com significant C29-ααα20R-sterane concentrations. Such cases reveal include: (1) measurement of 12CH2D2 in methane, which can be oil that was co-sourced from both a deep and shallow sources. used to distinguish high-temperature equilibrated methane from Copyright 2014, ALAGO. biogenic methane having a kinetic isotope fractionation, and/or This paper was selected for presentation by an ALAGO Scientific Committee Additionally it was found that the ratios of certain diamondoids can to deconvolve mixtures of methane sources, and (2) 13C and D following review of information contained in an abstract submitted by the author(s). be used as source parameters (Schultz et al., 2001). However, isotopic structures of hexane, which includes several isotopologues fingerprints of the light diamondoids are prone to being augmented Figure 1. Diamondoid correlation parameters are tested in their role to that may constrain its biological sources, natural of its cracking by secondary effects.Higher-diamondoid distributions are an unravel oil mixtures. (a) Cretaceous and Oligocene end-member oil samples reactions, and temperatures of its formation and/or storage. Introduction extension of this method that is less prone to secondaryfractionation from Eastern Venezuela are mixed in the ratios specified by the key. Non- effects and offers more options for source-related fingerprinting mixed end-member oils show different QEDA fingerprints and the mixtures Classical biomarker analysis, gas chromatography and bulk (see QEDA, below). can be quantified by assessing their intermediate profiles. (b) the same end- isotope analysis have played a role in defining the world’s petroleum member oil-sample mixtures, including an additional sample of Oligocene systems. But those methods have reached their limitations in Because diamondoids are volatile and biodegradation resistant, condensate, are evaluated by CSIA-D to show how such mixtures can be many cases. After many repetitive studies the same conclusions yet less volatile than gas, QDA is used to determine the location of quantitatively unraveled. can be reached and the same components can always be missed marine oil and gas seeps through piston core surveys.More recently when only the same technology is being applied. Often a missed QDAapplicationshave been successfully extended to land-based Diamondoid isotopic analysis (CSIA-D) source component can even account for the major charge in a studies for hydrocarbon seepages onto soil (Dahl et al., 2014).QDA Correlation by CSIA-D issimilar to QEDA (Moldowan et al., 2011), basin. Computer-generated basin models cannot compensate is now beingapplied to determinethe level of oil-cracking in tight except it relies on source-related isotopic differences in the for missed hydrocarbon sources, which means that application shale as an aid to production and prospecting for unconventional diamondoids, rather than fingerprint histograms of their relative of new advanced geochemical technologies (AGTs) is a must for oil and gas (Dahl et al., 2011). concentrations.CSIA-D is complimentary to QEDA as isotope basin modelers who want to propose new drilling targets that lead ratios are to biomarker parameters, except there is a great stability to discoveries.In this presentation we review several key AGTs that Quantitative extended diamondoid analysis (QEDA) in the cages of diamondoid molecules. This is not the case for have opened new vistas in petroleum system models where ever Using the knowledge from QDA that ratios of diamondoids of different biomarkers and most other molecules in oil. Like QEDA, CSIA-D they have been applied. structures are source dependent we developed a method to measure measurements are applicable to all liquid-petroleum sample types. extended diamondoids including triamantane, three tetramantane We have also found that oil generated in the laboratory from Technologies Reviewed isomers, four pentamantane isomers and cyclohexamantane either kerogen or isolated asphaltenes contains source related (Zinniker et al, 2011). Because these molecures are present in diamondoid assemblages that can be used for correlation. 1. Quantitative diamondoid analysis (QDA) as an indicator of extremely low concentrations it was necessary to standardize the source, maturity and mixing. analysis with synthetically-produced isotopically labeled (deuterium- Biomarker isotope analysis (CSIA-B) 2. Quantitative extended diamondoid analysis (QEDA) fingerprinting labeled) diamondoids of the same carbon structures. The value of CSIA measurements (Figure 2) can also be taken on alkanes diamondoids exceeding three molecular cages. application of QEDA to source correlation, along with CSIA-D (Figure and sterane, hopane and isoprenoid biomarkers that can be 3. Compound specific isotope analysis (CSIA), which includes 1) cannot be overstated as the universal correlation method. This is sequestered for the analysis. The special requirement for accurate applications to alkanes (CSIA-Ac), diamondoids (CSIA-D), and because diamondoids are universally present in all petroleum liquids: and precise CSIA measurements of any compound is to prepare a

20 21 petroleum fraction that displays the GC-FID peak of interest without AT06 the two methods are compared, and suggest that IRIS-based a significant co-elution from other compounds. Fractionations to measurements of formation water are possible. obtain the unencumbered peaks are often dependent on specific 2H/1H Ratios of Formation Waters from the zeolites that are selected based on the molecular cross-sections of Potiguar Basin, Brazil: a Comparison Between Experimental the compoundsto be segregatedcompared to the molecular cross- Isotope Ratio Infrared Spetroscopy (IRIS) and Samples were drawn from the easternmost Brazilian equatorial section of the specific zeolite channels. Electronic interactions Isotope Ratio Mass Spectrometry (IRMS) basin, the Potiguar Basin, deposited during the rifting of Gondwana between the zeolite and the hydrocarbon might also play a role. in the Early Cretaceous (Santos Neto & Hayes, 1999). A total of 11 formation waters were collected from production wells Alexandre A. Ferreira1, 4, Eugênio V. Santos Neto1, Alex L. (onshore) not subject to water injection or any other Enhanced Oil a Mean 2H ( ) from replicate injections. SD are standard Sessions2, Arndt Schimmelmann3, Peter E. Sauer3, Cleverson J. δ 1σ Recovery method, meaning that the original isotopic signatures deviations, identified for each method. F. Oliveira1, Francisco R. Aquino Neto4 of the formation waters should be preserved. δ 2H values were determined according to the following methods: (a)IRMS1 – 1 – Division of Geochemistry, PETROBRAS Research and conversion to H2 gas at 500 oC in contact with Indiana Zinc, with Development Center (CENPES), PETROBRAS, Rua Horácio dual-inlet analysis on a Thermo-Finnigan DeltaPlusXP isotope- Macedo, 950, Ilha do Fundão, Rio de Janeiro, RJ 21941-915, ratio mass spectrometer. Samples were analyzed in duplicate or Brazil. triplicate, and results were normalized to the VSMOW and SLAP 2 – Division of Geological and Planetary Sciences, California standards; (b)IRMS2 – chromium reduction at 750 oC using Institute of Technology, MC 100-23, Pasadena, CA 91125, USA. Thermo H-device and the same spectrometer as in (a). Samples 3 – Department of Geological Sciences, Indiana University, 1001 Figure 2. Four oil-source types from West Africa (Angola and Gabon) are were analyzed in triplicate; (c)IRIS1 – off-axis integrated cavity East Tenth Street, Bloomington, IN 47405-1405, USA. distinguished by hopane and sterane isotope analysis. The four types in output spectroscopy (OA-ICOS) using the Liquid Water Isotope 4 – Universidade Federal do Rio de Janeiro, Instituto de Química, order of increasingly heavy hopanes include: rift-derived lacustrine (lightest), Analyzer (Los Gatos Research) coupled to a CTC-LC-PAL. Figure 1.Average 2H values (‰, VSMOW) of formation waters LAGOA-LADETEC, Ilha do Fundão, 21941-909, Rio de Janeiro, δ Tertiary predominantly terrestrial, unspecified marine and open marine Samples were analyzed in six replicates, with the first three results plotted for visual comparison of the applied methods. Error bars RJ, Brazil. (heaviest), respectively. being discarded. Standards were spaced between samples within correspond to the measured standard deviations. each run. A previous clean-up step included the use of activated [email protected] References charcoal and solid phase extraction; (d)IRIS2 – wavelength- In order to evaluate the differences among all methods, they were Schultz, L.K.; Wilhelms, A.; Rein, E.; Steen, A.S. (2001) Application of scanned cavity ring-down spectroscopy (WS-CRDS) using the compared, two at a time, using Student´s t-test and Snedecor´s Copyright 2014, ALAGO. diamondoids to distinguish source rock facies. Organic Geochemistry 32, isotopic water analyzer L1102-i (Picarro, Inc.). In this case, each F distribution from STATISTICA®. The comparisons were made This paper was selected for presentation by an ALAGO Scientific Committee 365-375. sample was analyzed eight times and the first four δ 2H values through the average 2H values (of all samples) calculated for each following review of information contained in an abstract submitted by the author(s). δ Dahl, J.E.; Moldowan, J.M.; Peters, K.E.; Claypool, G.E.; Rooney, M.A.; were discarded.A proprietary method from Picarro, including the method. It was assumed that these values were normally distributed

Michael, G.E.; Mello, M.R.; Kohnen, M.L. (1999) Diamondoid hydrocarbons Introduction clean-up procedure, was applied in this case. and that the samples were homogeneous and independent. All the as indicators of natural oil cracking. Nature 399, 54-57. calculated t and F values were lower than the listed ones, meaning Over the last few decades, studies of the origin and evolution of Moldowan, J.; Zinniker, D.; Liu, Z.; Rovenskaya-Nemchenko, A.; Dahl, J.; that, in all cases, no statistically significant difference was found for formation waters in sedimentary basins have indeed improved our Results and Discussion Nemchenko, T. (2011) Geochemical parameters for unravelling mixtures. The measured 2H values are listed in Table 1 and plotted in a level of confidence of 95%. understanding of the subsurface flow of fluids (Monjerezi et al., δ 25th IMOG, September 18-23, Interlaken, Abs P-291, p. 424. Figure 1 for each sample. Standard deviations (SD) were higher 2011). The isotopic characterization of these waters usually plays Zinniker, D.; Moldowan, J.M.; Dahl, J.; Denisevich, P. (2011) New techniques for IRMS1, which could be interpreted as a result of the multiple a key role in this context. 2H/1H and 18O/16O ratios of formation Conclusions for understanding and mapping high-maturity transfer steps (H2O and H2) during the procedure using Indiana 2H/1H ratios of 11 formation water samples were determined waters have been used as proxies for evaporation, isotope petroleum systems. Examples from the San Joaquin Basin, San Juan zinc. Besides, SD values were more variable due to random errors using two IRMS conventional methods and two IRIS laser-based exchange with rock minerals under high-temperature conditions, Basin, and US Gulf Coast. 25th IMOG, September 18-23, Interlaken, present in this process. The lowest SD values, on the other hand, methods. The dispersion of values was higher for IRMS1 and and mixing with seawater or sedimentary brines (Varsányi & AbsP-031, P. 179. were observed for IRMS2 and IRIS2. Deviations in 2H values the most precise methods were IRMS2 and IRIS2. Although Ó.Kóvacs, 2009). In this study, we present a comparison of the δ Dahl, J.; Moldowan, S.; Moldowan, J.M. (2011) Designing tight-shale for sample MA2 could be associated with the higher organic no statistically significant differences among all methods were δ2H values of formation waters measured by IRMS methods and production strategies using diamondoid nanotechnology. 25th IMOG, content of this sample. Sample NA1, on its turn, is the one with the observed and the spectroscopic analyses seem to be a natural IRIS (Isotope Ratio Infrared Spectroscopy) methods. The latter has September 18-23, Interlaken, Abs O-73, p. 134. higher salinity, and could have especifically impacted the optical alternative over the mass spectrometers, we suggest a careful been recognized as a rapid, cost-effective and field-deployable Dahl, J.; Moldowan, J.M.; Nali, M.; Galimberti, R. (2014) Diamondoids measurements, causing the higher observed discrepancies. There pre-treatment of formation water samples to remove dissolved technology, with similar results to the traditional methods for clean in Surface Sediments for Identification of Petroleum Seeps. Abstract were no known reasons for the depletion in 2H for sample PA7 organic compounds as well as salts. In both cases, measurements water samples (West et al., 2010), but is susceptible to interference accepted for oral presentation at the AAPG International Meeting, Istanbul, (IRMS2) or the enrichment in 2H for sample PA2 (IRMS1). based on IRIS methods can be directly affected either by spectral from organic molecules, particularly alcohols. Clean-up procedures Turkey. September 14-17, 2014. To be presented. interference or changes on the injected water volume, respectively were thus tested and applied before the IRIS methods in order Table 1. Average 2H values(‰, VSMOW)a of formation waters (at least with the hardware applied in this work). to eliminate the presence of organic contaminants that could δ obtained by IRMS (light gray) and IRIS methods (dark gray). All the influence the isotopic measurements due to interferences on values were represented with one decimal place for comparison. the water absorption spectrum (Schmidt et al., 2012). Data from

22 23 Acknowledgements AT07 Experimental The proposal for the existence of two petroleum systems - A and B - in the study area was based on the following observations: (a) The authors thank PETROBRAS for permission to publish the Two crude oil samples and four condensate samples were drawn similarities in the isotopic profile, absolute δ13C values and isotopic from a northeastern Brazilian basin. Compound specific carbon results of this investigation and Mark Davis and Gregor Hsiao for Compound Specific Carbon Isotope Analysis amplitudes regarding distinct classes of compounds within the isotope analysis of the correspondent light fractions (C3-C10) were the water analyses at Picarro. of Light Hydrocarbons (C1 - C10): Application same group, condensates (A) or oils (B) (Fig. 1); (b) different ranges performed on an Agilent 7890 gas chromatograph coupled to a of isotopic variation for C1-C4 (Fig. 2). In this case, the observed on the Geochemical Characterization of Marine Delta V Plus mass spectrometer via a Conflo III interface (Thermo parallelism could be attributed to differences in thermal maturation. References Oils from Northeastern Brazil Scientific). The chromatograph was equipped with a split-splitless However, the δ2H profile clearly distinguishes the same two Monjerezi, M.; Vogt, R.D.; Aagaard, P.; Gebru, A.G.; Saka, J.D.K., 2011. injector (280 ºC), and the samples were introduced (0.1 µL) in groups, reflecting the existence of two source rocks; (c) finally, the average C1 content for gases from system A was higher than 85%, Using 87Sr/86Sr and δ2H isotopes along with major chemical composition Alexandre A. Ferreira*1, Clarisse L. Torres2, Juliana A. Iemini1, split mode (20:1), without dilution. GC oven temperature was whereas, for system B, was about 60%. programmed from 35 ºC (hold 10 min) to 96 ºC with a heating to assess groundwater salinization in lower Shire valley, Malawi. Applied Jarbas V.P. Guzzo1, Ygor S. Rocha1 rate of 1.1 ºC/min. Then a heating rate of 30 ºC/min was applied Geochemistry, 26 (12), 2201-2214. until 320 ºC and held for 5 min. Helium was the carrier gas, with 1 – Division of Geochemistry, PETROBRAS Research and a constant flow rate of 1.3 mL/min. For the isotopic calibration, Santos Neto, E.V.; Hayes, J.M., 1999 Use of hydrogen and carbon stable Development Center (CENPES), PETROBRAS, Rua Horácio a secondary standard - a mixture of seven pure compounds isotopes characterizing oils from the Potiguar Basin (onshore), northeastern Macedo, 950, Ilha do Fundão, Rio de Janeiro, RJ 21941-915, Brazil. from different classes (n-heptane, toluene, 4-methyl-heptane, Brazil. American Association of Petroleum Geologists Bulletin, 83 (3), 496-518. 2 – Fundação Gorceix, Rua Carlos Walter Marinho Campos, 57, n-octane, ethyl-cyclohexane, m-xylene and n-decane), diluted in Vila Itacolomy, Ouro Preto, MG 35400-000, Brazil. n-hexane - was used (Torres & Ferreira, 2014). Compounds were

Schimdt, M.; Maseyk, K.; Lett, C.; Biron, P.; Richard, P.; Bariac, T.; Seibt, separated using an HP-PONA (50 m x 0,20 mm x 0,50 μm). U., 2012. Reducing and correcting for contamination of ecosystem water *[email protected] Carbon isotope analyses of the gases (C1-C4) were performed stable isotopes measured by isotope ratio infrared spectroscopy. Rapid Copyright 2014, ALAGO. on an Agilent 6890 gas chromatograph coupled to a Delta V Communications in Mass Spectrometry, 26 (2), 141-153. This paper was selected for presentation by an ALAGO Scientific Committee Advantage mass spectrometer via a GC Combustion III interface (Thermo Scientific). The samples were manually injected (10 following review of information contained in an abstract submitted by the author(s). Varsányi, I.; Ó.Kovács, L., 2009 Origin, chemical and isotopic evolution of µL) in a split/splitless inlet (split ratio 54:1; T=200 ºC). The oven formation water in geopressured zones in the Pannonian Basin, Hungary. temperature was programmed from 40ºC (hold 1.5 min) to 200 ºC Introduction Chemical Geology, 264 (1-4), 187-196. with a heating rate of 30 ºC/min (hold 3.2 min). Helium was used as The geochemical characterization of crude oils has been widely the carrier gas (constant flow, 1.7 mL/min). used in the petroleum industry to improve our understanding of West, A.G., Goldsmith, G.R., Brooks, P.D., Dawson, T.E., 2010 the distribution of hydrocarbons in the subsurface. Information For the isotopic calibration, a secondary standard (natural gas Discrepancies between isotope ratio infrared spectroscopy and isotope regarding reservoir continuity, filling history or biodegradation, for sample) was employed. GC separation was provided by a Poraplot ratio mass spectrometry for the stable isotope analysis of plant and soil example, has been provided for the optimization of exploration Q column (25 m x 32 mm i.d.). In both cases, the criteria for the waters. Rapid Communications in Mass Spectrometry, 24 (14), 1948-1954. strategies or the prediction of oil quality. acceptance of the isotopic values included complete baseline Figure 2. a - δ13CVPDB and b - δ DVSMOW values of C1-C4, present in separation and signal intensities (m/z 44) above ~ 500 mV, and the the associated gas phase of each correspondent well. Most of the geochemical interpretation for oils is based on the assumed error was ± 0.5 ‰. biomarkers characterization and carbon and hydrogen isotope Conclusions Results and Discussion We suggest the existence of two petroleum systems based on the ratios of n-alkanes (~C15-C30) (Guzzo et al., 2011). We have recently carbon isotope analysis of light hydrocarbons (C1 - C10) present in established and optimized an additional tool for the geochemical gases, condensates and oils of a northeastern Brazilian basin. This 13C values of the C -C and C -C hydrocarbons are plotted in characterization of light oils and condensates: the carbon isotopic δ 3 10 1 4 tool was particularly useful in this case, where biomarkers data and Figure 1 and Figure 2, respectively. determination (δ13C) of light hydrocarbons, ranging from 3 to 10 isotopic profiles of the n-alkanes (~C15-C30) could not be used to suggest the presence of such systems. carbon atoms (Torres et al., 2011; Torres & Ferreira, 2014). References This analytical technique is especially recommended for that kind Curiale, J., Morelos, J., Lambiase, J., Mueller, W., 2000. Brunei Darussalam of sample, as light oils and condensates which can incorporate characteristics of selected petroleums and source rocks. Organic Geochemistry 31, 1475–1493. biomarkers from less mature rocks during migration or by reservoir

contamination (Curiale et al., 2000), which in turn may mislead the Guzzo, J.V.P.; Santos Neto, E.V.; Ferreira, A.A., 2011. Improved genetic geochemical interpretation based on these compounds. characterization of Brazilian oils using combined molecular (biomarkers) and isotope geochemistry. International Meeting on Organic Geochemistry, 13 25. Interlaken, Switzerland. In this particular work, δ C values of light compounds. (C3-

C10) were measured for a set of oils and condensates in order Torres, C. L.; Ferreira, A. A., 2014. Compound specific carbon isotope to investigate the existence of two petroleum systems in the analysis of light hydrocarbons (C10- fraction): an improved method for correspondent study area. Biomarkers characterization and condensate characterization. South American Symposium on Isotope Geology, 9. São Paulo, Brazil. δ13C values of n-alkanes were not clear enough to confirm this

hypothesis. We complement the results with carbon isotopic data Torres, C. L.; Ferreira, A. A.; Silva, J. T.; Conde, S. A., 2011. Compound of C1 to C4 for each studied well. Specific Carbon Isotope Analysis of Gasoline Range Hydrocarbons in Light Figure 1.δ13CVPDB values of the 20 light compounds monitored in the Crude Oils. Brazilian Congress on Geochemistry, 13. Gramado, Rio Grande range of C3-C10 for oils and condensates. do Sul, Brazil. 24 25 protected from biodegradation, but they are rarely used because biodegraded whole oil, Faja-Z, shows a tight correlation with the non- Figure 2 HT-SimDis provides quantitative profiles of the entire n-C10 to AT08 of the more tedious protocols for their analysis. We found that biodegraded Cretaceous oil sample from Eastern Venezuela; whereas n-C boiling point/molecular weight range ofan oil.(A) High-Temperature alkanes, biomarkers and diamondoids released from asphaltenes 100 Novel geochemical technologies reveal by hydrous pyrolysis can be used to determine sources of the non-biodegraded Oligocene oil does not correlate. The severely Gas Chromatograms (HTGC) of related conventional (36 °API) and heavy everything you wanted to know about Heavy Oil severely biodegraded oil. Isotopic analysis of the biomarkers and biodegraded Faja-Q oil does not match any of the others and probably (13 °API) oils from the same Californian basin. (B) HT-SimDis profiles diamondoids and the fingerprints of diamondoids can delineate derives from a different source or source facies. (b) Comparisons of generated from the HTGC data reveal the heavy biodegraded oil contains a the oil sources over the charging history of heavy oil reservoirs. asphaltene pyrolysates from the same oil samples lead to the same much smaller C to C fraction than the relatedconventional oil. J. M. (Mike) Moldowana, Robert M. K. Carlsonb, Peter 10 100 Knowledge of all the heavy oil sources opens a window for basin correlation conclusions as (a), although the fingerprint graphs show Denisevicha, Jeremy Dahlb, Shaun Moldowana¬* modelers to identify deeper prospects and the less biodegraded different patterns.Differences seen in chart-(a) are confirmed by those Conclusions reserves of lighter oil. registered in chart-(b). Several novel geochemical technologies are used to characterize a Biomarker Technologies, Inc. (BTI), 638 Martin Avenue, Rohnert even the most severely biodegraded oils.CSIAand QEDA Park, CA 94928, USA; Stanford Institute for Materials and Energy Alkanes and biomarkers that can remain in biodegraded oil might High temperature simulated distillation (HT-SimDis, Figure 2) is of biomarkers, diamondoids and alkanes released from Science (SIMES), Stanford University, Stanford, CA 94305, USA be there due to mixing of multiple pulses of charge to the reservoir, and they could relate primarily to later charges that have not had a a powerful method for estimating the overall compositionsand asphaltenes by hydrous pyrolysis and CSIA and QEDA ofthe long duration in place. Typically the last charge to a reservoir will valuesof oil reserves and comparingthem in some detail to other biodegradation-inertdiamondoids in the maltenes are used [email protected] experience the least severity of biodegradation. reserves in the area or elsewhere (Altgeltand Boduszynski,1994). for source correlation. Combining thosewith biomarker acids website: www.biomarker-inc.com It provides profiles of the distillable compositionofoils (out to analysis and high temperature simulated distillation(HT-SimDis) We correlated heavy oi¬l from the two heavy-oil fields, Z and Q, in n-C100,i.e., 1328 °F atmospheric equivalent boiling point, AEBP, measurementsprovides unprecedented insight intothe origins, Copyright 2014, ALAGO. the Faja (Orinoco heavy oil belt) of Venezuela with non-biodegraded or ~1400 MW) and so complements geochemical analyses that transformations, and movements of petroleum resources within This paper was selected for presentation by an ALAGO Scientific Committee Cretaceous and Oligocene oil samples from the Eastern Venezuela measure molecular markers present at ppm concentrations. prospective provinces. Geologic knowledge can be provided following review of information contained in an abstract submitted by the author(s). Basin on order to evaluate these methods and possibly shed some light on the origins of the Orinoco Belt heavy oil. QEDA, CSIA-D and Thepercentagesofdistillable fractions account for the large share of where previously only guesswork was possible. CSIA of biomarkers (CSIA-B) of the oils, CSIA-B, CSIA of alkanes oil mass and value,andafford a record of geologic transformations. Introduction (CSIA-A), and QEDA were run on the HyPy oils. Heavy oil Z did not ComparisonsofHT-SimDis profiles of heavy biodegraded oil samples References Novel technologies have been developed to determine reservoir match perfectly with heavy oil Q, but there is an excellent match to those of related non-degraded oil samples yield a quantitative Altgelt, K.H. and Boduszynski, M.M., 1994.Composition and Analysis of charging history, quantify biodegradation history, correlate severely between Cretaceous oil and Heavy oil Z. Thus, heavy oil Q might be measure of which fractions have been diminished and increased Heavy Petroleum Fractions. Marcel Dekker, Inc., New York, 1994. biodegraded oil and determine multiple co-sources. All of these a mixture or derive from a different source or facies than Z. during the course of biodegradation.Figure2demonstrates how HT- Carlson, R.M.K.; Pena, M.M.; Boduszynski, M.M.; Rechsteiner, C.E.; factors are important to design correct petroleum system models. SimDis analyses of two related California oils are used to determine Shafizadeh, A.S.G.; Henshaw, P.C.,7th UNITAR International Conference, Here we describe new technologies to see past the effects of Methods that have recently been put into application to evaluate the reservoir history and composition of the oil include biomarker a 28 mass % difference due to biodegradation in the cumulative Beijing, Paper No.1998.203, 1998. biodegradation to the pristine oil from which it came and to evaluate acids analysis (BAA) and high temperature simulated distillation composition up to n-C20. HT-SimDis analyses can also provide Henshaw, P.C., Carlson, R.M.K., Pena, M.M., Boduszynski, M.M., the composition of the oil in place. The latter has implications for (HT-SimDis). data valuable in mappingviscosity distributions in heavy oil fields Rechsteiner, C.E., Shafizadeh, A.S., SPE 46205, (1998). better estimation of oil losses and determining its compositional (Henshaw et al., 1998)and estimating various heavy oil properties changes during biodegradation. Single-rank biodegradation scales usually provide only the (Carlson et al., 1998) using samples only a fraction of a gram in size. biodegradation level of the freshest charge to the reservoir; Although correlation of heavy oil can sometimes be accomplished whereas, biomarker acids analysis provides a history of multiple by standard biomarker fingerprinting methods, at other times the charging events along with their subsequent biodegradation to different levels and their relative importance to the composition of biodegradation alters those fingerprints and the left-overs are difficult the entire oil sample. Biomarker acids were analyzed in a selection to interpret. Furthermore, in many cases heavy oil accumulations of oil samples to calibrate their appearance and disappearance at have arisen from multiple sources making correlation more difficult. various levels of biodegradation severity. This technique allows We have applied several methods to difficult heavy-oil correlation the quantitative estimation of the fraction of an oil sample that has problems to demonstrate their efficacy in different situations. reached each of five levels of biodegradation. The combined totality of those fractions comprises the biodegradation profile of the oil. Results and Discussion Correlation based on compound specific isotope analysis of diamondoids (CSIA-D) and quantitative extended diamondoid analysis (QEDA, Figure 1) are the most universally applicable methods for heavy oil correlation since most diamondoid compounds are either very recalcitrant or inert to biodegradation. Full suites of diamondoids remain in even the most severely biodegraded oil and diamondoid correlation measures apply conveniently without any special consideration about biodegradation effects. Figure 1.QEDA can be run for any liquid sample or extract, regardless of severe biodegradation. (a) QEDA fingerprint data from the severely Asphaltenes are a storehouse of molecules that have been

26 27 AT09 older than previously describedmicrofossils fromPalaeoarchaean are no C, CN or S enrichments within these. The yellow arrows on the NanoSIMS micro-analysis of Carbon isotopic composition of organic matter. siliciclastic environments. The NanoSIMS permitted to map the 27Al+ map show less distinct microporous structures, resulting from higher The carbon isotopic fields for most of the solvent-extracted hydrocarbons degrees of decay and/or compaction of the microbial remains, these are The NanoSIMS: organic geochemistry at sub- distribution of carbon, nitrogen and sulfur with sub-micron lateral (white) and bulk organic matter (white) from the Roy Hill Shale Member also apparent in the 56Fe+ map. µm lateral resolution resolution, unachievable by X-ray analysis. have been included for comparison. The precision of individual data points is indicated by vertical lines (1s). NanoSIMS and TEM images and analyses are very complementary Daniel Andradea, Philippe Saliotb, François Horréardb* NanoSIMS carbon (a) and nitrogen (b) images, with optical image (c). for identification of organic roles at small scale: TEM has the highest Conclusion lateral resolution but lacks of light element sensitivity and is limited After a presentation of the technology, this poster presents and illustrates a CAMECA Business Unit – Ametek do Brasil Ltda., CEP 13337- to small field of view. The NanoSIMS can bring sensitivity especially through some examples the new capabilities in organic geochemistry for 300– Indaiatuba – SP, Brazil. on light elements, image larger fields in their context and allows in-situ analysis and mapping of trace elements and isotopes at sub-micron b CAMECA, 29 Quai des Grésillons, 92622 Gennevilliers, France. isotopic mapping. scale offered by the NanoSIMS.

*Corresponding author:[email protected] Isotopic in-situ microanalysis The localized isotopic analysis capability is illustrated in a References [1] Microfossils of sulphur-metabolizing cells in 3.4-billion-year-old rocks Copyright 2014, ALAGO. The NanoSIMS permits to detect and map electronegative elements third article [3] where the NanoSIMS was used to measure 13C/12C isotopic ratio in-situ, from small areas of 5 x 5µm on of Western Australia. David Wacey, et al . NATURE GEOSCIENCE, 21 This paper was selected for presentation by an ALAGO Scientific Committee (carbon, oxygen, nitrogen, sulfur…) as well as electropositive sections of metamorphosed shales with isotopic reproducibility AUGUST 2011 following review of information contained in an abstract submitted by the author(s). elements such as metals. In this second article [2], TEM-EDS and NanoSIMS were combined to study endolithic microfossils and precision sufficient to reassess the first appearance of [2] A combined TEM and NanoSIMS study of endolithic microfossils in eukaryotes and cyanobacteria on earth. The study eliminated the Introduction in altered seafloor basalt. Rounded to elongated pores 0.5–2 µm altered sea!oor basalt. N. McLoughlin et al, Chemical Geology 289 (2011) evidencefor oxygenic photosynthesis 2.7 Gyr ago and excluded [3] Reassessing the first appearance of eukariotes ans cyanobacteria. The NanoSIMS 50L is an original secondary ion mass spectrometer across were found embedded in compact palagonite that have previousbiomarker evidence for a long delay (300 million years) Birger Rasmussen et al, NATURE, vol. 455, 23 Oct 2008. (SIMS), also called Ion Microprobe, optimized to measure and map sizes and shapes comparable to microbial cells. In-situ elemental betweenthe appearance of oxygen-producing cyanobacteria and isotopic ratios or elemental composition from sub-µm areas with mapping revealed that the micropore rims are comparable in the rise inatmospheric oxygen 2.45–2.32Gyr ago. very high sensitivity. The NanoSIMS 50L is based on a parallel composition to the bulk palagonite and that some are enriched in Mattauch-Herzog magnetic sector mass analyzer allowing the manganese. Elevated concentrations of carbon and nitrogen were detection of seven masses (elements or isotopes) in parallel, with also found in some of the micropores. Hence these structures high mass resolution resolving the numerous mass interferences of were interpreted as fossilised bacteriomorphs of endolithic natural samples. microorganisms that inhabited fractures in the basaltic glass. The preferential accumulation of Mn in some of the cell encrustations

The NS50L uses one single immersion lens placed only 300µm suggests the mineralisation of Mn-oxidising bacteria. These data from the sample in order to focus the primary ion beam of Cs+ provide further evidence for the involvement of microorganisms in or O- into a spot size (= lateral resolution) of 50 nanometers, and the colonisation and chemical alteration of recent sea!oor volcanic to extract and refocus the sputtered secondary ions toward the glass and identify micro-scale Mn enrichments associated with spectrometer. micropores as a promising biosignature in such rocks.

After a description of the instrumentation principle we will illustrate a few of the various fields of organic geochemistry that have beneficiated from this unique combination of high lateral resolution, Reflected light photomicrographs of kerogen. a, Two bands containing high sensitivity and high mass resolution. abundant kerogen laminae (ker). b, Close-up of the kerogen-rich layer (top) in a, located between pyrite-rich (white) and kerogen-poor (dark Elemental in-situ microanalysis grey) matrix. c, d, Close-up of two areas in kerogen-rich band in b (two Sulfur isotope data from early Archaean rocks suggest insets) showing areas of analysis (white box) and their δ13C values. e, thatmicrobes with metabolisms based on sulfur existed almost3.5 Isolated streak of kerogen with three analytical areas (white squares) and billion years ago, leading to suggestions that the earliestmicrobial Above: NanoSIMS ion images from a palagonite filled fracture in recent correspondingδ13C values. ecosystems were sulfur-based. However, morphologicalevidence seafloor lavas from the arctic Mohns Ridge. The 48x48µm 28Si− map for these sulfur-metabolizing bacteriahas been elusive. The shows a central planar crack with dense banded compact palagonite (CP) presence of microstructuresfrom the 3.4-billion-year-old Strelley and an outer zone of microporous palagonite (MP) surrounded by epoxy Pool Formation inWestern Australia that are associated with resin; all the other maps show the boxed area. Irregular shaped areas are micrometre-sizedpyrite crystals was reported [1] based on visible in the C, CN and S maps and these contain no metals (lower row of measurements using different microscopies and isotopic and images). Sub-spherical micropores ~2µm across (white arrows) are visible elemental analysis. These microfossilsare about 200 million years in the Al, Mn, Fe, and Ti maps with especially pronounced Mn rims; there

28 29 AT10 Experimental One important feature arises from the full spectrum that this scale Dzou, L. I.; Holba, A. G.; Ramón, J. C.; Moldowan, J. M.; Zinniker, D., A set of 14 crude oil samples from the Llanos Orientales Basin, presents, whereby any pattern of oil mixture can be traced and 1999. Application of new diterpane biomarkers to source, biodegradation Increasing the resolution of biodegradation Colombia, were analyzed in a Solarix 9.4 T (Bruker Daltonics, compared to others. Oils with high SA Index values show some and mixing effects on Central Llanos Basin oils, Colombia. Organic scales with non-GC experiments Germany) apparatus using an electrospray ion source operated level of dispersion that demands more experiments. Nonetheless, Geochemistry 30, 515-534. in the negative ion mode. Mass spectra (m/z 200-1000) were these results ultimately suggest that the scale is ready for further testing in other petroleum systems. Larter, S.; Huang, H.; Adams, J.; Bennett, B.; Snowdon, L. R., 2012. A Renzo C. Silvaab*, Eustáquio V. R. de Castrob, Henrique L. B. obtained from 200 scans, achieving a resolving power of 530,000 practical biodegradation scale for use in reservoir geochemical studies of Penteadoc, Débora A. Azevedoa. at m/z 400. Data were processed using the Composer software (Sierra Analytics, USA). GC-MS and GC-FID were also used to biodegraded oils. Organic Geochemistry 45, 66-76. a Lagoa/Ladetec, Universidade Federal do Rio de Janeiro - Brazil; evaluate typical biodegradation parameters. Vaz, B. G.; Silva, R. C.; Klitzke, C. F.; Simas, R. C.; Lopes Nascimento, b LabPetro, Universidade Federal do Espírito Santo – Brazil; Results and Discussion H. D.; Pereira, R. C. L.; Garcia, D. F.; Eberlin, M. N.; Azevedo, D A., c E&P-EXP, Petrobras – Brazil; Whole oil chromatogram, demethylated terpane series (m/z 177) and 25NH/H30 information, when analyzed altogether, show very 2013. Assessing biodegradation in the Llanos Orientales crude oils by electrospray ionization ultrahigh resolution and accuracy Fourier transform *[email protected] erratic biodegradation patterns among the samples. Many Llanos Orientales crude oils are composed of variable mixtures of early- mass spectrometry and chemometric analysis. Energy and Fuels 27, 1277- 1284. Copyright 2014, ALAGO. charged biodegraded oils from Late Cretaceous source rocks and Figure 2. Scheme representing reservoir processes (relative biodegradation This paper was selected for presentation by an ALAGO Scientific Committee later charges of oils derived from Tertiary sections (Dzou et al., and recharge rates) effects to the sample position in the scale. following review of information contained in an abstract submitted by the author(s). 1999). Therefore, traditional GC parameters are not sufficient to evaluate differences of biodegradation extent and mixture in these Introduction samples. The use of this scale in petroleum system studies can also be approached. Estimated impacts of both biodegradation and The evolution of organic geochemistry as an autonomous discipline recharge rates are shown in Figure 2. In case of mixtures, less owes acknowledgements to the advances in analytical technology Previous studies used differences between double bond equivalent biodegraded oils have a lower impact on the resulting oil because that supported its keys achievements, e.g. gas chromatography (DBE) profiles of class O2 compounds as the basis for two of their lower acid content. Recharges of pristine oils would affect (GC) and mass spectrometry. Nowadays, novel analytical continuous biodegradation parameters, SA Index (∑DBE 1-6) and more the A/C than the SA Index since DBE 1 O2 species are slightly techniques with unmatched resolution allow a quasi-molecule- modified A/C Index (DBE 1 / ∑DBE 2-6), all obtained from FT- more abundant in them. Experimental efforts to check these and to-molecule analysis of petroleum fluids (petroleomics), which ICR MS experiments (Vaz et al., 2013). Briefly, the main effect of other assumptions are ongoing. can also offer nice tools for organic geochemistry assessments. biodegradation on DBE profiles is the increase of relative intensities One notorious example is the Fourier transform ion cyclotron of mono- to pentacyclic saturated acids. In this study, a new resonance mass spectrometry (FT-ICR MS), whose analytical sample set of highly biodegraded oils was very suitable to expand Conclusions The use of high resolution mass spectrometry techniques to probe features immensely improved the understanding of petroleum the scope of this biodegradation scale (up to 25NH/H30 ratio = acid species offers new dimensions to solve common problems compositional complexity, especially in the polar fraction. 5.36 in m/z 191) (Figure 1). of biodegradation scales based on gas chromatography. In this study, the biodegradation scale based on class O2 compounds Geochemistry assessments based on traditional oil biodegradation proposed previously is expanded with a heavily biodegraded crude scales have the point of view of removed or modified substances oils sample set and has its features and impacts explored. The next (typically hydrocarbons) during the biodegradation process. One of steps toward a full acceptance would be proofs of its usefulness their major drawbacks comes from their inability to classify mixtures to petroleum system studies as well as correlations with physical (Bennett and Larter, 2008). New scales (i.e. ‘Manco’ scale, Larter et properties, both of which are ongoing efforts. al., 2012) were developed to address these concerns by increasing the scale resolution, although still relying on results coming from traditional gas chromatography – mass spectrometry experiments. Acknowledgements The authors thank Ecopetrol SA for providing the samples. Nowadays, FT-ICR MS experiments offer the chance to analyze acid CNPq (Brazilian research council) for fellowships; ANP (Brazilian components produced by biodegradation processes. Therefore, Petroleum Agency), Petrobras S/A and for financial support. The new biodegradation metrics can be approached. The present help on FT-ICR MS experiments from W. Romão and G. Vanini is study takes the next step towards a biodegradation scale based acknowledged. on class O2 compounds as analyzed by ultrahigh resolution and accuracy mass spectrometry, which was previously proposed by Vaz et al. (2013). It shows results for heavily biodegraded samples, Figure 1. Biodegradation map comprising all 30 samples used (14 new References explores petroleum system implications and shows indications of ones). Proposed biodegradation metrics (x- and y-axis) for the new scale Bennett, B.; Larter, S. R., 2008. Biodegradation scales: Applications and further developments needed. are obtained from ESI(-) FT-ICR MS measurements. limitations. Organic Geochemistry 39, 1222-1228.

30 31 AT11 The application of these synthetic polymers as sorbents allows Dimethyl- phenanthrene 262.3 11.5 25.1 cleanup process. Besides larger PAH molecules, the procedure not only pre-concentration and cleaning of the sample but also Fluoranthene 313.2 13.8 11.9 was expanded to extract also smaller PAH molecules (2-3 rings). Isolation and analysis of polycyclic aromatic selective extraction of the target analyte, which is important, Pyrene 182.7 7.7 8.1 hydrocarbons (PAHs) in crude oil using particularly when the sample is complex and impurities can interfere Benzo(a)pyrene 304.7 11.4 20.8 Acknowledgements molecularly imprinted solid-phase extraction with quantification. The use of MIPs as SPE sorbents has led this Perylene 572.4 22.5 30.4 The authors thank Petrobras S/A for the financial support. (MISPE) coupled with gas chromatography- practice becoming known as molecularly imprinted solid-phase *n.d. = not detected; **coelution with internal standard. mass spectrometry (GC/MS) extraction, MISPE (Hu et al., 2013). References Firstly, the blank sample of the oil aromatic fraction was analyzed Hu, Y., Pan, J., Zhang, K., Lian, H., Li, G. 2013. Novel applications for the presence of background contamination. Figure 2(a) shows of molecularly imprinted polymers in sample preparation. Trends in Cristiane Rossi de Oliveira*,a, Cleverson José F. de Oliveiraa Experimental The MISPE used was SupeIMIPTM SPE – PAHs from Supelco. the full scan chromatogram of the oil aromatic fraction sample. The Analytical Chemistry 43, 37-52. method was applied to the spiked fraction and the recovery values a Division of Geochemistry, PETROBRAS Research and Initially, a standard mix of PAHs compounds was used to method were corrected for the background levels found in the blank fraction Tarley, C. R. T.; Sotomayor, M. D. P. T.; Kubota, L. T., 2005. Development Center (CENPES), PETROBRAS, Rua Horácio validation. The standard mix was prepared in cyclohexane and sample. The results are shown in Table 1. The manufacturer advice Polímeros biomiméticos em química analítica. Parte 1: preparação Macedo, 950, Ilha do Fundão, Rio de janeiro, RJ 21941-915, Brazil contained: methyl-naphthalene, ethyl-naphthalene, trimethyl- naphthalene, fluorene, dibenzothiophene, phenanthrene, methyl- the use of SupeIMIPTM SPE – PAHs to large PAH molecules. In e aplicações de MIP (“molecularly imprinted polymers”) em técnicas fact, the recovery was higher for the larger PAH compounds (more de extração e separação. Química Nova 28, 1076-1086. *[email protected] phenanthrene, dimethyl-phenanthrene, fluoranthene, pyrene, benzo(a)pyrene and perylene. than 4 rings). Moreover, the isolation of smaller PAH compounds (2-3 rings) were also able following this method protocol in lower Copyright 2014, ALAGO. recoveries. This paper was selected for presentation by an ALAGO Scientific Committee following Briefly, the MISPE was conditioned with 1 mL of cyclohexane. review of information contained in an abstract submitted by the author(s). 1.0 mL of standard mix solution at the level of 10 μg/mL was loaded into the MISPE. The MISPE was washed again with 1.0 mL Analyzing the full scan chromatogram of the oil aromatic fraction Introduction cyclohexane to remove the compounds that did not get inside the after the method procedure (Figure 2(b)) it was possible to see that the PAH isolation and concentration were achieved with success. A fast and simple solid-phase extraction (SPE) method using sorbent. The analyte elution was done with 3 x 1 mL of solvent. Furthermore, besides the spiked compounds, the MISPE was also molecularly imprinted polymer (MIPs) as selective material Acetone and toluene were tested as elution solvent. The analyte able to isolate other PAHs present in the oil aromatic fraction as: followed by gas chromatography-mass spectrometry (GC/MS) elution was dried under N2 steam. 5β-Cholane, Fluorene-d12 and methyl-fluorene (C1-fluorene), tetramethyl-naphthalene (C4-naph), was developed for isolation and analysis of polycyclic aromatic pyrene-d12 were spiked as the internal standard (IS) at the level of trimethyl-phenanthrene (C3-phen) and chrysene. hydrocarbons (PAHs) in crude oil sample. 30 μg/mL and the eluate was analyzed by GC/MS.

MIPs are tailor-made materials with high selectivity for a target A crude oil aromatic fraction sample was obtained from medium molecule. This selectivity arises from the synthetic procedure pressure liquid chromatography (MPLC) on silica column. The followed to prepare the MIP, in which a template molecule is linked, aromatic fraction was spiked with the standard mix of PAHs in by covalent bonds or non-covalent forces, to suitable monomer(s) duplicate at the level of 20 μg/mL and 0.5 g of the spiked fraction containing functional groups (Figure 1). This link is responsible for sample was extracted by the procedure described above. the subsequent specific binding sites imparted to the MIP (Tarley et al., 2005). Results and Discussion The PAHs recovery was evaluated using acetone and toluene as analyte elution solvent and is shown in Table 1. Although the values for acetone showed a significant error, it was chosen as analyte elution solvent due to the best chromatographic profile.

Table 1. PAHs recoveries from MISPE Recovery (%) Acetone Toluene Spiked Oil (with Acetone) Methyl-naphthalene n.d.* n.d. 0.1 Figure 2. Full scan chromatogram obtained by GC/MS from (a) crude oil Ethyl-naphthalene n.d. n.d. 0.3 aromatic fraction; and (b) isolated PAHs.

Trimethyl-naphthalene n.d. n.d. 1.5 Conclusions Figure 1. Schematic representation of the Molecular Imprinting Process: Fluorene ** ** ** The isolation and concentration of PAHs from a crude oil sample (a) self-organizing, (b) polymerization, (c) desorption/extraction; and (d) Dibenzothiophene n.d. 6.8 5.6 using MISPE and analysis by GC/MS were described. The isolation adsorption/recognition. Phenanthrene 42.4 n.d. 5.4 Methyl-phenanthrene 44.7 3.2 6.8 method is simple and includes only a few MPLC and MISPE

32 33 AT12 mg of organic matter already generated by kerogen’s cracking per Compared to the original rock, it was observed that the aliquots of Conclusions gram of rock (S1). rock extracted by ASE and SFE had not suffered any changing in Given the high closeness of the results for saturated and aromatic Comparative bitumen extraction from an its non-extractable organic portion measured (S2). The S2values biomarkers, total carbon isotopes and Rock-Eval pyrolysis immature petroleum source rock using The extraction in ASE was performed by an ASE system (Dionex, found for original rock and extracted rocks by ASE and SFE were obtained post SFE and ASE extractions, we concluded that SFE is SFE andASE ASE 350), where 10 g of rock were extracted in triplicate by the foundapproximatelythe same, inside the normal variation range for a promising application in extractive processes of bitumen of rocks injection of 100 ml of dichloromethane divided equally into five Rock-Eval analysis (±10%). when the purpose is performing geochemical analyzes over this

Rodrigo C. Silva1*, Beatriz X. C. Rocha1,Cleverson J. F. static cycles, at 75 °C and 1500-1700 psi (103-117 bar), totaling soluble organic fraction. Concerning to total carbon isotopic analysis over the bitumen Oliveira1,Gilberto P. Silva1, Rafael S. Mello1, Thiago A. D. Silva1 45 minutes of extraction. extracted by ASE and SFE, the results showed little variation Acknowledgements between the extracts δ13C values. The δ13Cstandard deviations 1Petrobras S.A., Centro de Pesquisas e Desenvolvimento The extraction in SFE was conducted in a SFE system (Jasco Inc., The authors thank Petrobras S.A. for all support provided. calculated among the triplicates of each type of extraction, and (CENPES), 21941-915, Rio de Janeiro, RJ, Brazil 2000 Plus Series) by submitting triplicates of 9 g of rock to 10% of dichloromethane in CO2, under a flow rate of 15 ml / min, at 65 °C also between the different extractions performed, were found lower References than 0.5 ‰. *[email protected] and 3190 psi (220 bar), during 15 minutes. McNally, M.E.P.,1995.Advances in Environmental SFE.AnalyticalChemis- try67, 308-315A. The Figure 2 shows the results of the percentage of saturated, Copyright 2014, ALAGO. The extracts obtained using both techniques, as well as the residue aromatic and NSO compounds, resulting from the submission Silva, R.D.V., Aguiar, P.F., Oliveira, C.J., Silva, R.C.,Capilla, R.,2010. This paper was selected for presentation by an ALAGO Scientific Committee following of extracted rock, were reserved for subsequent geochemical of the bitumen extracted via ASE and SFE to chromatographic Otimização de metodologia de extração de rochas geradoras para review of information contained in an abstract submitted by the author(s). analysis.Those extracts were analyzed using anEA-IRMSsystem (Thermo Scientific, Flash EA 1112 Series) and posteriorly had separation by MPLC.These results indicate a greater presence posterior análise de CL, CG-DIC e CG-EM. Abstract. Simpósio Brasileiro Introduction their fractions of saturated, aromatic and polar (NSO) compounds of polar compounds in the bitumen extracts derived from ASE de Cromatografia e Técnicas Afins, Campos do Jordão, p. 256. extraction.In parallel, it was perceived a relative increase of In Organic Geochemistry, the extraction of sedimentary rocks isolated by MPLC system (Margot KöhnemWillsch, MKWMPLC). saturated and aromatic portions isolated from the extracts obtained for bitumen isolation is very well known. Amongthe extraction The saturated and aromatic biomarkers profiles were determined by SFE, compared to those acquired via ASE.Moreover, even techniques the commonly applied are Accelerated Solvent by GC-MS (Agilent Technologies, GC 6890 and MSD 5973).In throughFigure 2, we observed high similarity of chromatographic Extraction (ASE) and Supercritical Fluid Extraction (SFE). addition, the residues of extracted rock were also analyzed in a Total Organic Carbon Content (TOC) analyser(Leco, SC-144)and profiles pertinent to GC-MS analysis of biomarkers as terpanes, steranes,monoaromatics and triaromatics present into saturated Concerning petroleum source rocks application, the ASE technique Rock-Evalpyrolysis system (Vince Technologies,Rock-Eval 6). and aromatic hydrocarbon fractions isolated from bitumencoming integrates the use of organic solvents under high temperatures and from ASE and SFE extractions. high pressures in order to reach a greater solvation for the soluble Results and Discussion organic matter content. Compared to conventional processes, By the following Figure 1, it can be noted that the removal of such as Sohxlet extraction, ASE requires a short period of time and soluble organic matter in both extraction process was 1% of the a reduced amount of solvent to achieve almost complete extraction organic matter originally present into the rock sample.Compared to of the bitumen intothe rock pores (Silvaet al., 2010). the potential of extraction in ASE for removing S1, SFE extraction reached 10% less of this potential.These values were calculated

The SFE is an environmentally friendly technique because it often from the equation: 1 - (S1Original Rock - S1SFE)/(S1Original Rock - uses an inert fluid in the process such as carbon dioxide (CO2). S1ASE). However, based on the results of bitumen concentration In general, the CO2 under a supercritical state is applied to rock on the aliquots of rock extracted by ASE and SFE was found samples due to its high potential of extraction.The high density, that the extraction technique performed by SFE showed a lower similarly to liquid, gives to the fluid a dipole moment rearrangement potential of extraction, 19% inferior than that obtained via ASE. for the constituent molecules, ensuring a higher solvating power. Resembling what happens in a gas performance, low viscosity and high diffusivity promote an easy and fast penetration into the matrix pores.The process is triggered in order to raise the solute mass transfer rates from the matrix to the supercritical fluid (Mcnally, 1995).

This work shows comparison results of ASE and SFE techniques in its application over bitumen extraction from source rock. Figure 1.Results of analysis for the aliquots extracted by ASE and SFE

Experimental regarding to TOC, pyrolysis in Rock-Eval, bitumen concentrationand total Figure 2.Biomarkers profiles obtained from the saturated and aromatic To fulfill the extraction tests we selected animmature petroleum carbon isotopes. All values refer to averages calculated from the analyzed hydrocarbon fractions isolated from the bitumen extracted by ASE and SFE. source rock pulverized to 60 mesh, containing 18% of TOCand 7.8 triplicates of rock and extract (bitumen).

34 35 AT13 (Molecular Composition of Inclusion) protocols developed by CSIRO AT14 (Commonwealth Scientific and Industrial Reseah Organisation; Oil-bearing Fluid Inclusion Biomarkers from detailed description of which can be forward at George et al. Flash pyrolysis coupled to GC×GC−TOF (1998, 2007). The results permit the direct geochemical correlation the Pre-Salt Succession, Offshore Brazil MS and GC−High Resolution TOF MS between inclusion and crude oils. A pre-requisite for the successful for chararcterization of crude oil and Carlos E. S. Coelhoa*, André L. S. Pestilhoa, Juliana A. Ieminia, analysis of the tiny amounts of oil trapped in FI is the complete Katia Wagnera, Ygor dos S. Rochaa, Sandra B. Jorgeb removal of oil and any other contaminants from the outside of the petroleum fractions grains prior to crushing of the rock under solvent to recover the a Division of Geochemistry, PETROBRAS Research and inclusion oil (off-line method). The oils were analyzed by GC-MS Figure 1.Two oil-bearing fluid inclusions under UV light hosted in quartz Clécio F. Klitzkea*, Joe Binkleya, Jeffrey Patricka Development Center (CENPES),Rua Horácio Macedo, 950, Ilha do using a DFS system, and quantification was carried out using from Pre-Salt carbonatic reservoir. single ion monitoring (SIM). Fundão, Rio de Janeiro, RJ 21941-915, Brazil a LECO Corporation, 3000 Lakeview Avenue, 48085 Saint Joseph, b FUNDAÇÃO GORCEIX,Rua Carlos Walter Marinho Campos, 57, Table 1. Biomarkers data for fluid inclusions and reservoired oil in an MI, United States Ouro Preto – Minas Gerais, MG 35.400-000, Brazil Oil-Bearing Fluid Inclusions Characterization offshore well. Oil-bearing fluid inclusions are brown to light-brown two-phase *[email protected] *[email protected] primary fluid inclusions hosted in quartz and calcitic cements from reservoir secondary porosity features. These FIs generally have blue

Copyright 2014, ALAGO. (Figure 1) to white fluorescence colors, with major calcitic hosted FI Copyright 2014, ALAGO. having oblate shapes while quartz hosted FI display oblate to more This paper was selected for presentation by an ALAGO Scientific Committee following This paper was selected for presentation by an ALAGO Scientific Committee angular shapes. review of information contained in an abstract submitted by the author(s). following review of information contained in an abstract submitted by the author(s). Introduction Molecular Composition of Inclusions Oil-bearing fluid inclusions (FI) are natural cavities in minerals Two suitable core samples and one free oil sample from the same Introduction filled with hydrocarbons that commonly occur within petroleum well were selected for analysis. Data from the FI oils and free oil reservoirs and along migration pathways. They are tiny droplets were interpreted with respect to its palaeo-depositional conditions Petroleum is the most complex matrix in nature, constituted by many (usually <10 μm) of oil encapsulated in defects in mineral grains of the same source rock, and thermal maturation. Acknowledgements thousands of compounds,and presents an analytical challenge. For The authors would like to thank Petrobras S/A, and all Petrobras/ and diagenetic cements. Therefore, they preserve oil in a closed comprehensive analysis we need a chromatographicseparation CENPES staff whose contribution was of a paramount importance system and consequently it is protected from secondary alteration Biomarker distributions show similar correlation between inclusion with high peak capacity and for mass spectrometry analysis we to establish our discussions and conclusions. processes such as biodegradation, water-washing or other oils and free oil for both terpanes and steranes (Table 1). Biomarkers need high resolvingpower and high mass accuracy. processes that may affect free oil after emplacement (e.g., George ratios suggest correlation with lacustrine source rocks. For example, C24 tetracyclic terpane/C26 tricyclic terpane ratios are References et al., 2007). Since fluid inclusion oils are trapped during low oil- As the world’s remaining deposits of petroleum become heavierit’s in relative low abundance, which is consistent with a low input of George S.C., Lisk M., Eadington P.J., Quezada R.A. 1998. water saturation they can be interpreted as representative of first important to understand the chemical nature of heavy crude oil terrestrial organic matter. C26/C25 tricyclic terpane ratios are high, Geochemistry of a palaeo-oil column: Octavius 2, Vulcan Sub- reservoir oil charges. This study aimed the application of oil-bearing and its fractions. The analysisof high boiling point constituents of basin, in The Sedimentary Basins of Western Australia 2. In: Purcell fluid inclusions molecular composition to the constraining of oil consistent with a lacustrine depositional environment (Sofer, 1993; P.G. & Purcell R.R. (eds) Petroleum Exploration Society of Australia crude oils adds a new dimension for the completecharacterization charge history from Pre-Salt carbonatic reservoir. Schiefelbein et al., 1999). The C23/C21 tricyclic terpane ratios are of crude oil. In this study we evaluated the use of a pyrolysis similar to lacustrine oils (Sofer, 1993). The gammacerane/C30 αβ Symposium, Perth, WA, p. 195-210. probe (Py) coupledto gas chromatography (GC and GC×GC) Analytical Procedures and Samples hopane ratios are low, certainly corroborating a lacustrine source. George S.C., Volk H., Ahmed M. 2007. Geochemical analysis time-of-flight (TOF) and GC high resolution time-of-flight(HRTOF) In order to perform this study, analytical procedures were as follows: Furthermore, the relative abundance of Tetracyclic Polyprenoids techniques and geological applications of oil-bearing fluid mass spectrometry (MS) for the characterization of crude oils and (i) Sample selection from drill cores; (ii) Fluid inclusion petrography; (TPP/TPP+DIA - tetracyclics polyprenoids/C27diasterane) strongly inclusions, with some Australian case studies. Journal of Petroleum (iii) Analysis of Molecular Composition of Inclusion. Sample selection confirms lacustrine-source for the three oils analyzed (Table 1). asphaltenefractions. Science and Engineering , 57. 119-138. was carried out in oil-prone reservoir zone aiming carbonate facies that displayed better porosities. Selected samples were used to Maturity-dependent ratios show small variation for inclusion oils in Experimental Roedder, E.1984. Fluid Inclusions. Mineralogical Society of doubly-polished thin section manufacture and a replicated sample comparison with free oil for Tri/Hop, NORNEO/C29 hopane, DIAH/ Crude oil and asphaltene samples obtained from several countries America, Reviews in Mineralogy, Virgínia, EUA: Mineralogical for each depth was saved for FI molecular analysis. C30 hopane and TS/(TS+TM) ratios, with relatively lower maturity were analyzed by Py−GC×GC−TOF MSandPy−GC−HRTOF MS. Society of America, v. 12, 644 p. as displayed by inclusion oils (Table 1). The samples were placed into a quartz tube of a Pyroprobe Model Fluid inclusions petrography was performed on a standard 5200 (CDS Analytical Inc., Oxford, PA, USA) interfaced to an Agilent Conclusions: Oil Charge History Constraints Sofer Z. 1993. Distribution of genetic oil families in West Africa petrographic microscope coupled to an ultra-violet source, 7890A GC (Palo Alto, CA, USA). Analyses were performed at 350 The geochemical data suggest that the oil trapped in fluid inclusions based on biomarker ratios. In: Latin American Congress on because oil-bearing fluid inclusions can be readily detected by oC and 500 oC for thermal desorption, and 800 oC for pyrolysis. Organic Geochemistry, 3rd, Manaus, Brazil, Extended abstracts, fluorescence microscopy due to its fluorescence color emission. in Well A is from the same source rock, generated at a relative p. 134-137. Interface, valve oven and transfer line were at 300 oC. Helium was FIuid petrography was performed on samples screening, identifying lower maturity than the average of the oil now produced from the used as carrier gas from the pyroprobe to the GC at a flow rate of the richest ones through distinct fluid inclusion assemblages reservoir. The relatively high proportion of inclusion oil trapped in Schiefelbein C.F., Zumberge J.E., Cameron N.R., Brown S.W. 1mL.min-1. (Roedder, 1984). The richest FI content samples showed the quartz and calcite happened soon after initial charge and stopped 1999. Petroleum systems in the South Atlantic margins. In: best inclusions, such fact enhanced the interpretations of the FI to be trapped due to an inhibition of diagenetic cementation as a Cameron N.R., Brooks JM., Bernard B.B., Zumberge J.E., Brown For Py−GC−HRTOF MS analysis a Pegasus GC−HRT (LECO chromatograms obtained. result of an emplacement of progressively higher maturity oil. Those conditions and the relatively small variation between inclusion oils S. (eds.) The oil and gas habitats of the South Atlantic. Geological Corporation, St. Joseph, MI, USA) was used in high resolution Society, London, Special Publications., v.153, p.169-179. The oil trapped within FI in the quartz-calcite cements of core and free oil suggest that reservoir charges occurred soon after the mode (≥25,000). Electron energy of 70 eV was applied. The mass samples was extracted and analyzed accordingly to the MCI first oil incursions. range was 35-510 m/z and the acquisition rate was 6 spectra/s.

36 37 Separation by GC was achieved with a Restek (Bellefonte, PA, USA) With only one dimension chromatography these same compounds References AT15 Rxi-5MS 30 m column in the condition of 1mL.min -1 of Helium at can be identified using high resolution mass spectrometry. High Chiaberge, S.; Fiorani, T.; Cesti, P., 2011. Methyldibenzothiophene isomer constant flow. The oven has a initial temperature of 50 oC held resolution and high mass accuracy increase the signal to noise ratio in crude oils: gas chromatography tandem mass spectrometry Analyses of bicyclic and tricyclic acids for 1 minute, raised to 320 oC at 5 oC.min-1and held at the final ratio discriminating interferences with the same nominal mass. analysis. Fuel Processing Technology. 92, 2196-2201. biomarkers in Potiguar Basin– Brazil Oils temperature for 10 min. The temperature of the inlet, transfer line Even co-eluted species can be easily identified and quantified by ESI- and APCI-TOF MS and ion source were respectively 280, 320 and 250 oC. using the exact mass. Sarmah, M.K.; Borthakur, A.; Dutta, A., 2010. Pyrolysis of petroleum a a a* asphaltenes from different geological origins and use of methylnaphthalenes Lucinaldo S. Silva , Marcio S. Rocha , Sidney G. Lima , José A. D. A Pegasus 4D (LECO Corporation, St. Joseph, MI, USA) was a a a and methylphenanthrenes as maturity indicators for asphalenes. Bulletin of Lopes , Antônia Maria G. L. Citó , Antônia L. da S. Santos , Igor used for Py−GC×GC−TOF MS analysis with the experimental V. A. F. Souzab Materials Science33, 509-515. conditions of 70 eV in the ion source, and acquisition rate of 200 spectra/s in the mass range of 40 to 700 m/z. The separationin the a Universidade Federal do Piauí – UFPI , Laboratório de Geoquímica first dimension used a 30 m Restek (Bellefonte, PA, USA) column Orgânica - LAGO, 64049-550, Teresina, PI, Brazil. Rxi-5MS. In the second dimension separation was done using a b Petrobras - Research and Development Center 1.25 m Restek Rxi-17MS column. The oven program has a initial temperature of 60 oC for 1 minute, raised to 320 oC at 4 oC.min- *[email protected] 1and held at the final temperature for 10 min. The temperature of the inlet, transfer line and ion source were respectively 280, 320 Copyright 2014, ALAGO. and 250 oC.Secondary oven temperature offset was 5 oC. The This paper was selected for presentation by an ALAGO Scientific Committee following quad-jet dual stage modulator had a temperature offset of 15 oC, review of information contained in an abstract submitted by the author(s). modulation period of 4 s, with 0.6 seconds long hot pulse. Introduction Results and Discussion Figure 2.Comparison of the analytical ion chromatogram (A), extracted ion Naphthenic acids comprise a complex mixture of alkyl-substituted Typically crude oil samples are analyzed in two steps of isothermal chromatogram (198 m/z) (B), and the extracted ion chromatogram for the acyclic and cycloaliphatic carboxylic acids. They are found in desorption (350 oCand 500 oC). After that the remaining residue petroleum because either the deposit has not undergonesufficient exact mass of the MDBTisomers (198.04977) (Cand D). is pyrolyzed at 800 oC. Isomeric ratios of polycyclic aromatic catagenesis or it has been biodegraded by bacteria (Peter et al., hydrocarbons (PAHs) and polycyclic aromatic sulfur hydrocarbons 2005). Working with marine evaporitic oils from Fazenda Belem, Figure 2 shows the comparison of the total ion chromatogram (A), (PASHs) were evaluated, and may reflect thediversity of organic Potiguar Basin, Lopes et al. (2005) found a good correlation extracted ion chromatogram for the nominal mass of 198 (B), and source input, thermal maturity, biodegradation level, and between acidic and neutral biomarkers. However the acidic the extracted ion chromatogram for the exact mass of the MDBT depositionalenvironments (Chiaberge et al, 2011; Sarmah et fraction requires laborious techniques of separation, purification isomers (C&D). al., 2010). An analytical difficulty normally observed using one and derivatization which considerably delay the analysis of these dimension GC is the co-elution of some PAHs and PASHs with the these compounds. same nominal mass. Pyrolysis of crude oil and asphaltene samplesshow distinct composition in terms of light and heavy PAHs, PASHs, and isomers, This study compared ESI and APCI methods in determining the To increase the chromatographic separation for better identification related to sample characteristics. Preliminary results show that molecular distribution of naphthenic acids (n-alkanes, byciclic and of co-eluted compounds analysis using GC×GC was implemented. the pyrolysis products of asphaltene samples havecompositional tryciclic) in crude oil and in acidicfraction,resulting from theliquid- Figure 1 shows the contour plot region of methyldibenzothiophene similaritywith the pyrolysis of the crude oil residue indicating that the liquid extraction. (MDBT) isomers in a Py−GC×GC−TOF MS analysis of a crude residue obtained after thermal desorption at500 oC is constituted oil sample.The signals with lower retention time in the second mainly by asphaltene. The composition of products obtained by Experimental dimension are alkyl naphthalenes (isobars that co-elute with MDBT asphaltene pyrolysis is very similar to the composition of the relative Studied oils: Oil samples used in this study were obtained from in the first dimension). Fazenda Belém field, in northwestern part of Potiguar Basin. More crude oil. detailed geological information on this Basin was presented by Lopes et al. (1999). Conclusions The pyrolysis of asphaltenes from discretecrude oil samples Liquid-liquid Extraction: About 500mgof oil samplewas dissolved shows distinct composition in terms of light and heavy aromatic indichloromethaneand extracted with 5% sodiumbicarbonate hydrocarbons and alkyldibenzo-thiophenes.The use of Py− solution. GC×GC−TOF MSis crucial for the determination of isomeric

composition, and Py−GC−HRTOF MS with high resolution and ESI and APCI MS TOF Analysis: The acidic fractions and crude high mass accuracy complements the identification by unequivocal oil were analyzed in a high resolution micrOTOF-Q II (BRUKER), chemical formula assignments.The study of the relationships of the small amount of sample was dissolved in 500 µL toluene:methanol crude oil and asphaltene composition are in progress. (1:1) and then, 20 µL of concentrated NH4OH was added. Electro- spray ionization (ESI) source was optimized as follows: negative Figure 1.Contour plot of methyldibenzothiophene isomers.

38 39 ionization mode, capillary voltage 3.0 kV, nitrogen was used as AT16 x 5 cm) and washed with dichloromethane:methanol (9:1, 250-350 nebulizing gas with a flow rate of 5 L/min and a temperature of mL). The extract was evaporated to dryness. Extract fractionation 200 oC at 0.3 bar. The atmospheric pressure chemical ionization Matrix solid-phase dispersion for into hydrocarbon families followed the D-6560 and D2007 ASTM (APCI) source was optimized as follows: negative ionization mode, hydrocarbon isolation from bituminous rock standards. capillary voltage 4.0 kV, nitrogen was used as nebulizing gas with a flow rate of 4 L/min, temperature of dry gas of 200 oC and Elena E. Stashenko*, Jairo René Martínez, Julián Castrillón The spectrometric and chromatographic data were obtained with temperature of vaporizer of 450 oC at 2.0 bar. a gas chromatograph GC 7890 (Agilent Technologies, AT, Palo

Universidad Industrial de Santander, Center for Chromatographyand Alto, CA, U.S.A.) equipped with a triple quadrupolemass selective GC/MS Analysis: The analyses were performed using a Thermo Mass Spectrometry, CROM-MASS, 680002, Bucaramanga,Colombia detector AT 7000 [Electron impact ionization (EI), 70 eV; AT, Palo Scientific TSQ Quantum XLS Ultra Triple Quadrupole GC-MS Alto, CA, U.S.A.], split/splitless injector (1:30 split ratio) and Mass- instrument. Capillary chromatographic column (Equity TM-1, 30 m, Hunter data processing software. A fused-silica capillary columns 0.25 mm ID). Initial temperature of 70 °C (4 min hold), followed by [email protected] DB-5MS ((J&W Scientific, Folsom, CA, U.S.A.) of 60 m x 0.25 mm a ramp of 2 °C/min up to a final temperature of 300 °C (20 min hold). The carrier gas was helium at a constant flow rate of 1.0 mL/ Copyright 2014, ALAGO. i.d., coated with 5%-phenyl polydimethylsiloxane (0.25 µm film min. Transfer line temperature was 310 °C. The quadrupole mass Figure 2. Expansion of highlighted region from previous Fig. 1. This paper was selected for presentation by an ALAGO Scientific Committee thickness)) was used. The GC oven temperature was programmed spectrometer was operated in full scan mode over the mass range following review of information contained in an abstract submitted by the from 120 °C (1 min) to 220 °C (3 min) at 6 °C min-1, then to 275 °C (15 Soft ionization methods (APCI- and ESI-TOF) produce one major 50–650 Da (EI mode at 70 eV). author(s). min) at 5 °C min-1. Helium (99.995%, Linde, Bucaramanga, Colombia) ion from each compound, with little further fragmentation, and it was used as carrier gas, with 155 kPa column head pressure and avoidsextraction,purification andderivatization steps, required for Results and Discussion 26.4 cm s-1 linear velocity (1 mL min-1, at constant flow). the analysis ofnaphthenic acids. Atmospheric pressure chemical Introduction Hydrocarbons were detected by GC/MS, and carboxylic acids ionization is a supplementary technique to electrospray. It is a soft For the analysis of organic matter contained in rocks, the isolation were obtained by liquid-liquid extraction and then detected by ionization technique but notas soft as ESI. Because charged ions of sufficient amount of the organic matter originally present in Results and Discussion ESI-TOF MS and APCI-TOF MS. The GC-MS analyses showed are not generated in APCI and it operates at high temperatures the sample is a fundamental prerequisite. The Soxhletextraction Although the MSPD lasted 1/6 the time required for Soxhlet or low hopane/sterane ratios, high gammacerane (>60) and this technique is used to analyze smaller, thermally stable polar technique is the method traditionally used. Ultrasound-assisted ultrasound-assisted solvent extraction, its extraction yields were bisnorhopane (>10). Ts/Tm, C35/C34 indices of the oils allowed and non-polar compounds. Signal suppression due to unknown solvent extraction has been the alternative method. There has generally higher for the various rock types processed. MSPD their classification as marine evaporitic type. Biodegradation was matrix interferences is a common problem in quantitative analysis, been recent interest in matrix solid-phase dispersion, MSPD, a has the additional advantage that the sample amount could be confirmed by the presence of 25-norhopane and the total loss of especially in ESI, so this is a limitation. increased by a factor of 4 (from 50 to 200 g) without changing the n-alkanes and isoprenoids. new technique which provides extraction yields similar to those glassware size or the procedure employed. Analyses by both methods showed that It was possible to evaluate obtained with the Soxhlet technique in shorter experimental time Naphthenic acids were also evaluated in crude oil by both ESI the distribution of n-alkane, bicyclic and tricyclic acidic biomarkers and with lower environmental impact (Laganáet al., 2010). In this and APCI MS techniques to simplify the analytical procedures, without laborious processes of purification and derivatization of oil work, MSPD, Soxhlet and ultrasound-assisted extraction were One of the goals of implementing the MSPD technique was to preserving the relative composition of compounds in the oils sample, for high to moderate level of biodegradation. employed to isolate hydrocarbons from sedimentary rocks from extract the largest amount of organic matter without discrimination samples and detecting higher homologues. The acidic oil fractions the Simití, La Luna, Umir, and La Paz formations, collected in the of any type of organic component in the sample. The OH groups Conclusions were analyzed in a high resolution ESI- and APCI-TOF MS by direct municipality of Girón, Santander, Colombia. Extraction yields and in silica gel could lead to increased retention of polar hydrocarbons LC-MS (ESI and APCI) is an analytical method for the sensitive infusion (Figure 1). Working with negative Electrospray Ionization- (asphaltenes, for example). However when alumina or sand were characterization of “molecular fossil” in crude oil. In general the distribution of hydrocarbons among the saturated, aromatic, ESI, we detected a series of bicyclic (C15-C20) and tricyclic acids used as dispersing agents instead of silica gel, the hydrocarbon naphthenic acids are known to be difficult to analyze; some respond resins, and asphaltene families were compared. The highly specific (C20-C26). well in ESI, and others respond better in APCI mode. ESI and APCI multiple reaction monitoring GC-QQQ-MS technique was used to distribution of the extracts obtained was the same, as well as the

- MS methods were evaluated for naphthenic acids analyses. monitor the changes resultant from passing through zeolites the extraction yields. Based on analyses of n-alkanoics, mono and sesquiterpenoids saturated hydrocarbon fraction, in order to improve the detection carboxylic acids, ESI in the negative ion mode was found to be of petroleum biomarkers. No significant differences in relative amounts of saturated, superior, howeverboth techniqueshavetheir specificity. asphaltenes, resins, and aromatic fractions were observed in extracts from the same rock obtained with the three techniques Acknowledgements Experimental under study. This indicates that MSPD is not selective towards a The authors thank CNPq (Brazilian research council) for fellowships; ANP (Brazilian Petroleum Agency), Petrobras S/A. Soxhlet extraction of powdered rock (50 g) employed a particular compound family and can be used to isolate organic dichloromethane-methanol (9:1 v/v, 150 mL) for 24 h. The extract matter from sedimentary rocks with higher yields and in shorter References was rotoevaporated to dryness. The same solvent mixture (200 time than the Soxhlet and ultrasound-assisted solvent extraction Lopes, J. A. D.; Santos Neto, E. V.; Koike, L.; Marsaioli, A. J., 1999. 3-Alkyl mL) was used in ultrasound-assisted extraction, performed under techniques. Another advantage of MSPD is its lower environmental and 3-carboxyalkyl steranes in marine evaporitic oils of the Potiguar Basin, reflux for 24 h. The extract was filtered over paper (red strip), impact due to the smaller amounts of solvent (1/5) that it requires, Brazil. Chemical Geology158, 1–2. washed 3 times with the solvent mixture (30 mL) and evaporated in comparison with the other two techniques. to dryness. For MSPD, the ground rock sample (50 – 200 g) was Peters, K. E.; Walters, C. C.; Moldowan, J. M., 2005. The biomarkers Figure 1.Comparison of ESI vs APCI results (Full scan negative ion mode, mechanically mixed (1:1 v/v) with a dispersing agent (silica gel, Guide, Cambridge University Press. scan range 100 – 1000 m/z). alumina or sand). The mixture was placed into a glass column (40

40 41 ARTIFICIAL MATURATION (hold for 2 min) at 8°C min-1, under a hydrogen pressure of 15 sterane and hopane distributions. As shown in Figure 2 HyPy of MPa. A hydrogen sweep gas flow of 5 l min-1, ensured that the the asphaltenes generated pristine, n-alkane, and sterane profiles, AM01 products were quickly removed from the reactor, with the products allowing for source and maturity characterisation of the seeps to trapped on dry ice cooled silica. be undertaken.

Recent developments in hydropyrolysis Results and discussion (HyPy) for petroleum geochemistry One aspect where standard techniques that concentrate on the free, solvent extractable phase cannot be applied is for the Will Mereditha*, Colin E. Snapea characterisation of heavily biodegraded oils and bitumens.

Figure 1. Hydrocarbon classes such as the n-alkanes and small alkyl- a Faculty of Engineering, University of Nottingham, Innovation Comparison of fragmentogramsof specific biomarkers isolated from substituted aromatic compounds are very susceptible to Park, Energy Technologies Building, Jubilee Campus, Nottingham, sedimentary rock with and without previous treatment with zeolite ZSM5. biodegradation, while more resistant compounds such as the Profiles obtained with the multiple reaction monitoring experiment to select NG7 2TU, UK. steranes and hopanes, which are widely applied in source, maturity metastable transitions characteristic of hopanes or triterpanes. and correlation studies, are vulnerable to alteration at higher levels. Figure 2.TIC and m/z 217 mass chromatograms of the aliphatic hydrocarbons *e-mail: [email protected]. Figure 1 shows that the treatment of the saturated hydrocarbon Once these compound classes have been irrevocably altered, the in the maltene fractions (free phase) and asphaltenes hydropyrolysates fraction with ZSM5 zeolites removes chemical noise (mostly biomarkers, covalently-bound into the macromolecular matrix of (bound phase) from the Ilubinrin tar sand bitumen (numbers refer to carbon paraffines) and permits reaching higher sensitivity in the Copyright 2014, ALAGO. the asphaltene faction, which are not bioavailable to the degrading chain lengths of n-alkanes) (from Sonibare et al., 2009). determination of petroleum biomarkers. The detection of This paper was selected for presentation by an ALAGO Scientific Committee following microbes, are thought to represent a remnant of the original oil. hopanesortriterpanesin these samples is used as an example of the review of information contained in an abstract submitted by the author(s). signal enhancement observed when zeolite-treated and untreated Molecular indices of thermal maturity are typically calculated from samples are compared with GC-QQQ-MS using the highly specific the biomarkers isolated from the free, solvent extractable phase of Introduction multiple reaction monitoring experiment. oils or kerogens. For kerogens, this free phase is representative of Continuous-flow pyrolysis conducted with a suitable catalyst at high only a small proportion of the total organic matter (typically <5%). Conclusions hydrogen gas pressures (15 MPa), termed catalytic hydropyrolysis Thus it does not follow that the distributions of the free biomarkers The use of matrix solid-phase dispersion for the extraction of or HyPy, was first utilised as a means to produce high yields of liquid organic matter from sedimentary rock is a viable alternative to are necessarily representative of those covalently-bound to the products from solid fossil fuels. It was later found that HyPy could solvent extraction techniques. MSPD is particularly convenient macromolecular structure (Love et al., 1995). A study by Murray be harnessed as an analytical technique for applications involving to laboratories with no sophisticated or expensive sample et al. (1998) observed a systematic change in epimer ratios with preparation equipment. Extraction yields are similar or superior the fragmentation of geomacromolecules and release of diagnostic increasing maturity for hopanes and steranes covalently-bound to those obtained with other techniques, solvent consumption is lipid biomarker structures. HyPy possesses the unique ability to in kerogens. While less mature in terms of isomerisation at both lower, and the experimental time is shorter. The zeolite treatment of produce high yields of hydrocarbon biomarkers from source rock the saturated hydrocarbon fraction of the extracts obtained does ring system and side-chain chiral centres, these biomarkers were kerogens, sediments and petroleum asphaltenes, whilst minimising increase the sensitivity and the selectivity of biomarker analysis. observed to undergo the same epimerisation reaction pathways structural alteration by isomerisation and cracking (Love et al., as their free counter-parts in the bitumen. Therefore, the range of Acknowledgements 1995). The technique can be used in petroleum geochemistry for ratios such as the moretane/hopane index for the HyPy products The authors thank financial support from the National Hydrocarbon applications where conventional biomarkers fail; e.g. characterising was found to be much larger than that for the bitumens (ca. 5 Agency (grant RC-747-2009) and from the Colciencias supervised heavily biodegraded oils, samples contaminated by oil-based donations program, grant 110254832637. times), indicating a much greater sensitivity to relatively small drilling mud, oil field solids such as tar mats/pyrobitumens, changes in maturity (Murray et al., 1998). and for deciphering basin filling history of migrated petroleum References fluids.HyPy has also gained prominence in geobiology studies Figure 1.Schematic of HyPy apparatus The ability of HyPy to provide meaningful information from samples ASTM D6560. 2012. Standard Test Method for Determination of informing the evolution of lifeon Earth. It has also been utilised Asphaltenes (Heptane Insolubles) in Crude Petroleum and Petroleum at elevated, post oil window maturity, where free phase biomarkers for the characterisation of the insoluble macromolecular material in Products. American Society for Testing and Materials.http://www.astm. HyPy is able to access these biomarkers in high yields, with appear in much lower concentration, and have often long since meteorites, andfor the isolation and quantification of black carbon org/Standards/D6560.htm asystematic study of the free and bound biomarkers obtained reached equilibrium was demonstrated by Lockhart et al. (2008). in soils. from heavily biodegraded petroleum undertaken by Sonibare et al. For a suite of Type II kerogen Kimmeridge Clay source rocks from ASTM D2007-11.2011.Standard Test Method for Characteristic Groups in (2009), who, following characterisation of the free, maltene fraction, the UK North Sea, with hydrogen index (HI) values as low as ca. Rubber Extender and Processing Oils and Other Petroleum-Derived Oils Experimental by the Clay-Gel Absorption Chromatographic Method, ASTM.http://www. subjected the asphaltenes isolated from three oil seeps from SW 50 mg HC/g TOC, it was found that the isomerisation reactions of HyPy wasundertaken using the apparatus described by Love et al. astm.org/Standards/D2007.htm Nigeria to HyPy. These seeps had been subjected to such severe the kerogen-bound biomarkers were retarded with respect to the (1995). Briefly, the asphaltenes (50 mg) were pyrolysed on a bed biodegradation that the maltene fraction contained no n-alkanes, free phase until a hydrogen index (HI) value of ca. 300. Beyond Laganà, A.;Cavaliere, C.; Giansanti, P.; Gubbiotti, R.; Samperi, R;Capriotti, of sulphided molybdenum catalyst (250 mg), with resistive heating few identifiable aromatic hydrocarbons, and significantly altered this point ring system isomerisation within the kerogen-bound A., 2010. Recent developments in matrix solid-phase dispersion extraction. from 50°C to 250°C at 300°C min-1, and then 250°C to 520°C Journal of Chromatography A, 1217, 2521-2532. phase is still retarded (until an HI of ca. 200), whilst the side chain 42 43 isomerisation for both hopanes and steranes is similar in the free AM02 Sampling and Methods C56+,the latter called PK10 to PK60 after di Primio & Horsfield and bound phases. Hydrous pyrolysis (HP) was applied to assess the products of (2006).Gas and liquid phase components vary systematically Compositional Description ofBrazilian petroleum generation in samples from the Tremembé Formation, with increasing TR, and do not present any evidence of oil to gas Conclusions Type-I Kerogen Using outcropping in São Paulo State (Brazil), in Taubaté Basin. The cracking. Catalytic hydropyrolysis (HyPy) has been demonstrated to be a Hydrous Pyrolysis Products Oligocene lacustrine sedimentswere deposited in a tertiary onshore highly versatile technique with a range of different applications rift in southeastern Brazil and can be considered a representative across petroleum geochemistry. Despite the obviously attractive Joelma P. LOPESa*, Regina BINOTTOa, Luciene S. JESUINOb, of a Type-I kerogen (TOC=10,1weight %; S2=74 mg/grock; capabilities of HyPy for analysing covalently-bound and highly Henrique L.B. PENTEADOc, André L.D. SPIGOLONa, Luiz F.C. HI=730mg/g TOC and Ro= 0,32%). functionalised lipid biomarkers, the technique has taken time COUTINHOa to become more widely used due to the specialist nature of the Each maturationexperiments consistedin 275gof crushed source- equipment required to perform this high pressure treatment safely a - Division of Geochemistry, PETROBRAS Research and Develop- rock chips ranging in size from 0.5to 2 cm, heated isothermally in 1 and routinely. Recently though, a commercially available system has ment Center (CENPES), PETROBRAS, Rua Horácio Macedo, 950, L reaction vesselsat temperatures between 280 and 360C for 36 been developed, with 9 systems are currently installed worldwide Ilha do Fundão, Rio de Janeiro, RJ 21941-915, Brazil to 144hr in the presence of liquid water, based on the methodology in both academic and commercial institutions. The efficacy of b - FUNDAÇÂO GORCEIX, Rua Carlos Walter Marinho Campos, presented by Lewan (1997). HyPy is founded upon optimised reactor design and analytical 57, Ouro Preto – Minas Gerais, MG 35.4000-000, Brazil run conditions that allow for excellent reproducibility of molecular c - E&P Exploration Division, Avenida República do Chile, 330, Total organic carbon (TOC) contents in source-rock aliquots, before Figure 1. profiles and retention of the major structural and stereochemical Centro, Rio de Janeiro, RJ 20031-170, Brazil and after the HP experiments, were determined by combustion in Quantitative Cumulative generation curves of compound classes produced features of biomarker hydrocarbon products. The key empirical a Leco carbon analyzer and the organic parameters were obtained by hydrous pyrolysis of a type I source rock (Tremembé Fm., Brazil). Gas biomarker lipid systematics, as demonstrated for recent and *[email protected] by Rock-Eval pyrolysis. and liquid phase components increase as with transformation ratios ancient kerogens, show that the kerogen-bound hopane and (yiYelds are reported as mg/g TOCoriginal). sterane biomarkers released by HyPy exhibit a slightly less mature Copyright 2014, ALAGO. Generatedgases and oils were collected and quantified.Molecular isomeric distribution than the corresponding free (extractable) This paper was selected for presentation by an ALAGO Scientific Committee following compositions of the gases were obtained by gas chromatography biomarker hydrocarbons. The kerogen-bound biomarker pool review of information contained in an abstract submitted by the author(s). (GC) with a Flame Ionization Detector (FID) for hydrocarbons,and is immobile and protected against alteration of structural and a Thermal Conductivity Detector (TCD) for non-hydrocarbons (O2, stereochemical features during thermal maturation reactions since Introduction N2, CO, CO2, H2S, NO, etc.). Quantitative GC analyses were carried this pool is sequestered by binding within a high molecular weight Oil and gas formation and accumulation result from theevolution out on the expelled oil samples. API gravities were measured only macromolecular matrix. of petroleum systems during geological time.Basin modellinguse in some samples because low-maturity experimental conditions kinetics of description of primary and secondary cracking reactions, did not yield enough oil for further analyses. References obtained by artificial maturation of source rock samples,to Lockhart, R.S., Meredith, W., Love, G.D., Snape, C.E., 2008. Release of bound reproduce, besides the migration paths and accumulations, the Results and Discussion aliphatic biomarkers via hydropyrolysis from Type II kerogen at high maturity. compositional aspects of oil trapped. Total organic carbon (TOC) contents,in the samples aliquots, varied Organic Geochemistry 39, 1119-1124. from 10.1 (non-heated sample) to 4.28%(most mature residual Figure 2.

The possibility of modeling petroleum composition during sample) as the transformation ratio (TR) increased from zero to 90 API gravity (a) and gas-to-oil ratio (GOR, b) of expelled petroleum obtained Love, G.D., Snape, C.E., Carr, A.D., Houghton, R.C., 1995. Release of covalently- generation, aswell as, the PVT behavior of the fluids during (%).The artificial maturation trend was corroborated by an increase by hydrous pyrolysis as a function of transformation ratio of a source rock bound alkane biomarkers in high yields from kerogen via catalytic hydropyrolysis. migration has only become availablerecently in modern basin in vitrinite reflectance, which varied from an original value of 0.32% containing type I kerogen (Tremembé Fm., Brazil). Organic Geochemistry 23, 981-986. modelling software packages. to a maximum value of 1.14%. API gravity values are almost constant (around 30⁰) with TR (Figure 2a), a featurethat correlates very well with API values of unaltered Murray, I.P., Love, G.D., Snape, C.E., Bailey, N.J.L., 1998. Comparison of It is noticeable the great similarity between the hydrous pyrolysis The mass-balance of productsindicates recovery factor over 90%. natural fluids from type I kerogen found at Campos and Santos covalently-bound aliphatic biomarkers released via hydropyrolysis with their products and the natural petroleum fluids, even into the physical Non-hydrocarbon gases such as N2, H2S and CO2 are part of basins. On the other hand, GOR first decreases and then slightly solvent-extractable counterparts for a suite of Kimmeridge clays. Organic and chemical properties. the compositional description of the gases,although they were not Geochemistry 29, 1487-1505. taken into account in GOR calculations. increases with TR. Modifications in the compositions of organic phases occur because of complex physiochemical transformations The aim of this work is to get new insights into petroleum during artificial maturation. In the early maturation stages (TR < Sonibare, O.O., Snape, C.E., Meredith, W., Uguna, Love, G.D., 2009. composition phases and PVT parameters, such as gas-to-oil ratio Cumulative generation curves are presented in Figure 1. The fluid 30%), there are no conditions for efficient oil generation and Geochemical characterisation of heavily biodegraded oil sand bitumens by (GOR) and API gravities, along an artificial maturation trend of a description consists of individual compounds as C1, C2 and C3, expulsion, and GOR presents the highest values, because the catalytic hydropyrolysis. Journal of Analytical and Applied Pyrolysis 86, 135-140. type I source rock submitted to hydrous pyrolysis experiments. and composite classes of compounds grouped by carbon number: C4, C5, C6-C15, C16-C25, C26-C35, C36-C45, C46-C55 and early gas is gradually being dissolved in the expelled liquid. A slight

44 45 increase in GOR (up to 80 m3/m3) was observed only at TR > AM03 and the signature of the converted petroleum generation potential 60%, when gas production appears to overcome oil generation (S2) acquired directly from open-system Rock-Evalpyrolysis. The kinetic parameters were obtained by non-linear regression (Figure 2b). New approach for comparing kinetic models using GeokinTM software (Lorant, 2001). The bulk kinetic models of petroleum generation based on Rock- Sampling and Methods presented in this study describe reactions based on a discrete Conclusions Eval and hydrous pyrolysis experiments Three rock samples were selected for this work containing each distribution of activation energies between 40 to 80kcal/mol witha A compositional model for hydrocarbon generation and maturation type of kerogen. Type-I is represented by an immature source step width of1kcal/mol and constant frequency factors (s-1). of a type-I kerogen was developed based on cumulative data from rock from Tremembé Formation, Oligocene of Brazil (TOC=10.1%, Results and Discussion Regina Binottoa*, André L. D. Spigolona, Luiz F. C. Coutinhoa,Rosane hydrous pyrolysis experiments. S2=74 mg/g rock, HI=730 mg HC/g TOC, 0.32%Ro). Type-II is A. Fontesa, Jefferson D. Baltara, Carlos G. C. Reetza, Luciene S. an early mature source rock from Itajaí-Açu Formation, Turonian The activation energies distribution, frequency factors (A) Jesuínob Gas and liquid phases increase systematically with transformation of Brazil (TOC=3.4%, S2=16 mg/g rock, HI=480 mg HC/g TOC, andgeological extrapolations (1oC/Ma) for each type of kerogen ratio (TR), and do not present evidence of oil to gas cracking up to 0.50%Ro). Type IIIis a lignitefrom Hambach mine, Miocene of are shown in figure 2. a Division of Geochemistry, Research& Development Center of a TR of 90%. Germany (TOC=51.2%, S2=90mg/g rock, HI=175 mg HC/g TOC, PETROBRAS, 0.32%Ro). b Fundação Gorceix API gravity values are almost constant (around 30⁰) with TR, a feature that replicates the distribution of API gravities of natural Nonisothermal open-system anhydrous pyrolysis experiments *[email protected] non-biodegraded petroleums derived from type-I kerogens, in were carried out in the Rock-Eval 6 Turbo apparatus (Behar et Campos and Santos basins. al., 2001) at different heating rates (5, 10, 15 and 25oC/min). The Copyright 2014, ALAGO. experimental data used in the numerical inversion correspond to This paper was selected for presentation by an ALAGO Scientific Committee following GOR presents the highest valuesat low TR’s because of the the petroleum generation rates (S2 curves). review of information contained in an abstract submitted by the author(s). contribution of early gas, then decreases during the main oil- generating phase, and increases again at TR > 60%. Introduction Isothermal closed-system pyrolysis experiments were performed in the presence of water (Lewan and Ruble, 2002).The hydrous One of the most important aspects to evaluate petroleum systems The compositional description presented in this work gives reliable pyrolysis experiments were conducted in the same isothermal is theextend and timing of petroleum generation that could be knowledge about the modification of the petroleum classes as conditions for Type-I and -II samples and in a different condition predicted bybasin modelling in which the calibrated thermal a function of increasing thermal stress. These data will be used for Type-III (Fig 1). The original and pyrolyzed rocksof each histories are coupled with appropriate kinetic parameters of organic to develop a compositional kinetic model to be applied in basin experiment were analyzed by Rock-Eval pyrolysis to S2 (mgHC/g matter transformation. modeling software to predict natural petroleum composition and rock) determination.The decomposition of reactant was monitoring Figure 2.Comparison of bulk kinetic models derived by open and closed- phase behavior. by the decrease of the remaining petroleum potential (S2residual) systems and geological extrapolations (1oC/Ma) for each type of kerogen. Kinetic parameters have been usually acquired by mathematical during the increase of thermal maturation. (A) Type-I, (B) Type II and (C) Type-III. inversion of thermogravimetric data obtained by artificial maturation Acknowledgements of source rocks and coals. Laboratory essays are carried out by The authors would like to thank Petrobras to allow publishing this The results of bulk kinetic models represent the best numerical heating immature samples at higher temperatures and shorter work. inversion of the input data associated with lower error function times than those involved in the natural process.The derived and reasonable geological extrapolation. Comparing open versus kinetic parameters depend not only on the pyrolysis experimental closed-system bulk kinetic models,similar geological extrapolations References conditions (open or closed, hydrous or anhydrous, isothermal or were obtained for the Type-I kerogen, despite of some differences non-isothermal) but also on the inversion method used. Lewan M. D.(1997) Experiments on the role of water in petroleum formation. in the frequency factors and activation energies distribution.

Geochimica et Cosmochimica Acta 61 (17), 3691-3723. However, open-system kinetic behaves slightly more reactive Despite of large number of work dealing with these pyrolysis Figure 1.Time-temperatureconditions employed in the hydrous pyrolysis than the closed-systemuntil 55% of conversion (Fig. 2A). Kinetic techniques, few studies have established a full comparison between DiPrimio R. and Horsfield B. (2006)From petroleum-typeorganofacies to experiments. model for the Type-II kerogen showed the largest differences in the kinetic models with respect to the reaction mechanisms, hydrocarbonphase prediction. AAPG Bull., 90, No. 7, 1031–1058. terms of frequency factor, activation energies distribution and generated products and geological extrapolations (e.g. Lewan and Hydrous pyrolysis experimental data used in the numerical inversion geological extrapolations. Closed-system kinetic model for Type- Ruble, 2002). correspond to the conversion into petroleum or transformation II kerogen shows fast conversions than open-system until 25%. ratios (TR) that were calculated for each experiment following the After that,open system kinetic model shows earlier generation (Fig. The propose of this study is present a new approach to compare equation:(S2 original – S2 residual / S2original)*100. This approach 2B). Similar behavior was also observed for the Type-III kerogen. bulk kinetic parameters using two types of experimental data: is the same applied by Tissot and Welt (1984) to describe the Moreover, activation energy distribution for the Type-III kerogen is the signature of the remaining petroleum potential (S2 residual) organic matter conversion into petroleum inthe natural series. broader than the others (Fig. 2C). monitored through residues of closed-system pyrolysis experiments

46 47 Intervals of non-reaction are characteristic of the closed-system AM04 n-heptane. The occluded biomarkers into the asphaltene structure kinetic models, in opposite way of the open-system, which shows were released according to the method described by Liao and a continuous activation energy spectrum (Fig. 2). Effect of hydrous pyrolysis in biomarker Geng(2002). Free and occluded biomarkers were characterized distribution of occluded compounds inthe by gas chromatography/mass spectrometry (GC/MS). The same Conclusions asphaltene structures methods were performed on the unheated sample. There are differences between kinetic parameters derived by the NoeliaFrancoa, Tais F. Silvaa, Milton C. Silvaa, Luiz Guilherme C. Results and Discussion open and closed-systems pyrolysis. Santosa, Regina Binottob,J.G. Mendonça Filhoa* Liquid products yields and geochemical characterization (Table 1) of the pyrolyzated samples evidenced that hydrous pyrolysis In general, kinetic models of the open-system Rock-Eval pyrolysis a Universidade Federal do Rio de Janeiro, Laboratório de conditions increased the thermal evolution of the Irati oil shale showed a more reactive behavior if compared to closed-system Palinofácies e Facies Orgânica, IGEO Ilha do Fundão 21941-909, obtaining expelled oil as a result. However, the TOC content hydrous pyrolysis for all kerogen types, although the differences are Figure 1.Mass chromatograms (m/z 85)of bitumen extracted from unheated Rio de Janeiro, RJ, Brazil. and hydrogen index (HI) indicate that the recovered sample at sample (a), occluded biomarker into asphaltene structures of this bitumen minor for the Type-I kerogen. The decrease of reactant (S2residual) b Geochemistry Sector, Petrobras Research & Development 340ºC/72h still preserve generation potential.At this condition the (b), expelled oil at 320ºC/72h (c) andoccluded biomarkers into asphaltene when compared with original S2is also an alternative to predict Center. sample is in the early oil window (Tmax, Table 1).These results are structures of this expelled oil (d). the timing of petroleum generation with reasonable geological in agreement with lacking variations in biomarker ratios such as:Ts/ extrapolation. [email protected] (Ts+Tm), 22S/(22S+22R), 20S/(20S+20R).Generated bitumens In theterpanes distributions was observed that tricyclic terpanes and oils do not show differences between biomarker ratios. were more abundant than pentacyclicterpanesin all the m/z Acknowledgements Copyright 2014, ALAGO. The free n-alkanes distribution in bitumen extracted from unheated 191mass chromatograms of occluded biomarkers in both

To PETROBRAS for the authorization to publish this research, as well as, to This paper was selected for presentation by an ALAGO Scientific Committee following sample (Fig. 1a) was compared with the occluded n-alkane generated bitumen and expelled oil.No remarkable differences were observed in the sterane distribution. USGS and UFRGS by the use of laboratory facilities. review of information contained in an abstract submitted by the author(s). distribution into its asphaltene (Fig. 1b). The same comparison was made for the expelled oil at 320ºC/72h (Fig. 1c and 1d). The main Introduction Conclusions References differences among these n-alkane distributions are the presence Despite of hydrous pyrolysis in Irati oil shale expelled oilsin all Hydrous pyrolysis is a technique to simulating oil generationduring of n-alkenes and the low concentration of low-molecular-weight Behar, F., Beaumont, V., Penteado, H.L.B., 2001. Rock-Eval 6 Technology: experiments, the thermal evolution was not enough to change basin subsidence. Lewan 1993 has shown that the heating n-alkanes in the occludedbiomarkers. The low concentration of Performances and Developments. Oil & Gas Science and Technology – the biomarkers distributions. Furthermore, the analyses of the ofwhole rocks in the presence of water generate oil-likesubstances these n-alkanes may be attributed to the loss of these compounds Rev. IFP 56 (2), 111-134. occluded biomarkersintoasphaltenes suggest that occlusion could whose chemical properties closely mimicthose of crude oils.The during the cleaning process of asphaltenes with n-heptane. On the protect these compounds from thermal alteration at least until early effects of thermal evolution on the main geochemical parameters other hand, the presence of n-alkenes into the asphaltene structures Lewan, M.D.and Ruble, T.E., 2002. Comparison of petroleum generation oil window. used in thecharacterization ofpetroleum source rocks and oils can suggests that during heating these n-alkenes are released from the kinetics by isothermal hydrous and nonisothermal open-system pyrolysis. also be studied from the products generated by hydrous pyrolysis. kerogen and when occluded insideof these asphaltene structures Acknowledgements Organic Geochemistry 33, 1457-1475. Changesin biomarkerdistributions, such as thoseof steranes and they are protected of the effect of temperature. The authors are gratefulto PETROBRAS-Brazil for the financial hopanes, during the hydrous pyrolysis of kerogensand whole rock supportthroughtheprojectentitled “Estudo Geoquímico de Resinas Lorant, F., 2001. Acquisition of Kinetic Data with GeokinTM Classic – samples are well documented(Abbott et al., 1990, Pan 2010). e Asfaltenos: Relação com a Composição do Querogênio e a Practical Aspects, Institut Français du Pétrole. However, the characterization of occluded compounds into the Evolução Térmica”. asphaltene structurehas not been reported until now. Based

Tissot, B.P., Welte, D.H., 1984. Petroleum formation and occurrence, on the usefulness of this technique, the main goal of this study References Abbott, G.D., Wang, G.Y., Eglinton, T.I., Home, A.K., Petch, second ed. Springer-Verlag, Berlin. was characterize and compare the occluded compoundsinto G.S., 1990. The kinetics of sterane biological marker release and the asphaltene structures of bitumens and oils generated during degradation processes during the hydrous pyrolysis of vitrinite hydrous pyrolysis experiments with their respective free biomarkers. kerogen. GeochimicaetCosmochimicaActa54, 2451-2461.

Experimental Lewan, M.D., 1993. Laboratory simulation of petroleum formation: Hydrous pyrolysis experiments wereperformedon a sample of Irati Hydrous Pyrolysis. In.: Engel, M.H. & Macko, S.A. (Eds.). Organic oil shale (Paraná Basin, Brazil), at temperatures range from 280ºC Geochemistry. Plenum Press, New York, 419-442. to 340ºC for 72h, using a Stainless Steel reactor (300 mL). The Liao, Z., Geng, A., 2002. Characterization of n-C7-soluble fractions expelled oil was collected from the water surface with a Pasteur Table1.Yieldsof liquid hydrocarbons products, biomarker ratios of original of theproducts from mild oxidation of asphaltenes. Organic pipette. The bitumen generated during the experiment was and generated bitumen, TOC and Rock-Eval parameters for unheated Geochemistry33, 1477-1486. extracted from the residual source rock with Soxhlet using CH2Cl2 sample and pyrolyzed samples of Irati oil shale, Paraná Basin, Brazil. All

as solvent. Total Organic Carbon (TOC) contents and Rock-Eval experiments were performed for 72h. Pan, C., Geng, A.,Zhong, N., Liu, J., 2010. Kerogen pyrolysis in analyses were conducted in unheated and pyrolyzated samples. the presence and absence of water and minerals: steranes and The asphaltenes of these products were precipitated using triterpenoids. Fuel 89, 336-345.

48 49 AM05 For the analyses of bitumen the samples were extracted in a soxhlet Table 2: Yield of bitumen and expelled oil generated by AM06 extractor and were then analysed for n-alkanes and isoprenoids hydrous pyrolysis at 350 °C for oh, 20 and 50 h. Artificial Maturation Applying Hydrous by chromatographic and GC-MS techniques. GC-MS techniques Time (h) Expelled oil (g) Bitumen (g) Changes in oil properties with the advance were also applied to determine the hydrocarbon characteristis of 0 h 0,2 5,418 Pyrolysis Experiments on Organic- Rich of thermal maturation induced by hydrous the expelled oils. (bitumen and oil). 20 h 4 1,636 pyrolysis for a Brazilian source rock Shales From The Ipubi Mbr., Santana Fm., 50 h 4,7 0,766 containing a Type-I kerogen Araripe Basin, Brazil The hydrous pyrolysis experiments were conducted in a closed At or prior to these apparent maximum yields, the bitumen system (350ºC at 0, 20, 50 h), which allowed calculations of the André L. D. Spigolona,d*, Michael D. Lewanb, Henrique L. B. decomposes to oil that is expelled from the bitumen-impregnated Tânia Valéria de O. Delgado1*, Marleny B. Gonzalez1, Simone quantitative distributions of various organic fractions with increasing Penteadoc, Luiz F. C. Coutinhoa, João G. Mendonça Filhod rock as was observed by the distinct compositional differences Barrionuevo1, João Adauto de Souza Neto2, Wolfgang Kalkreuth1 thermal maturity. The sample was crushed and homogenized to between the polar–rich bitumen and the expelled oil rich in saturate chips (1-2 cm) and was not pre-extracted prior to the experiments. a Division of Geochemistry, PETROBRAS Research and Development and aromatic fractions and characterized by less polar fractions An average bulk density was determined for the rock chips and used Center (CENPES), 21941-915, Rio de Janeiro, RJ, Brazil 1 Universidade Federal do Rio Grande do Sul, Laboratório de (Table 3). b United States of Geological Survey (USGS-Denver) Análise de Carvão e Rochas Geradoras de Petróleo, Porto Alegre- to calculate the amount of water needed to maintain liquid water c Basin and Petroleum System Modeling of PETROBRAS in contact with the rock before, during, and after the experiments Table 3:Relative chemical distribution of total hydrocarbon RS d Universidade Federal do Rio de Janeiro, Instituto de Geociências, in 250 ml reactors composed of stainless steel. For each of the fraction under the selected T/t conditions.O.R.: original shale 2Center for Technology and Earth Sciences, Federal University of 21.949-900, Rio de Janeiro, RJ, Brazil hydrous pyrolysis runs 45 g of rock and 86 ml of distilled water sample,H.R.: pyrolyzed shale sample, Bitumen (B), expelled Pernambuco, Recife-PE were used. After loading and sealing the reactor, the remaining oil (E.O.). F1% = saturated HC; F2% = aromatic HC; F3% = *[email protected] headspace was evacuated and filled with 30 psi of helium. hetrocompounts. *tania_rocha [email protected] Copyright 2014, ALAGO. Introduction Products (pyrolyzed rock, expelled oil, bitumen) were recovered, This paper was selected for presentation by an ALAGO Scientific Committee following The Araripe Basin is located in the interior of the northeasten quantified and characterized from each experiment, allowing review of information contained in an abstract submitted by the author(s). region of Brazil. The basin covers the most southern part of Ceará, to determine the thermal evolution of the pyrolyzed rock, and to F1% F2% F3% and parts of Pernambucoand Piauí states, and geologically is determine the fractional composition and geochemical properties Introduction and goal O.R. 5,9 17.6 76.5 characterized by a predominantly Mesozoic succession. The of the generated expelled oils and retained bitumen. To understand the thermochemical transformation of kerogen H.R. development of the basin is directly linked to the opening of with increasing maturation and the compositional variation of the 0h (B) 2.4 7.3 90.2 the South Atlantic, with deposition during the post–rift fase of a Results and Discussion generated products, the petroleum industry has used laboratory 20h (B) 9 24.4 66.7 sequence of organic-rich shales associated with evaporitic rocks pyrolysis experiments to artificially mature source rocks at relatively The results of the organic petrological and geochemical examination 50h (B) 12.7 24.1 63.3 of the Aptian Ipubi Formation, Group Santana. high temperatures and short times under an inert atmosphere. of the original sample showed the following characteristics: TOC 0h (E.O) 28.4 28.4 44.6 Because of the use of several pyrolysis conditions, such as content of 25.7 wt.%, S1 yield of 15.2 mg HC/g rock, remaining 20h (E.O) 30.8 25.6 43.6 The objectives of this study were to evaluate a) the thermal open or closed system, hydrous or anhydrous and isothermal or HC generative potential (S2) of 126.0 mg HC/g rock, Hydrogen 50h (E.O) 14.3 48.8 36.9 evolution of the organic-rich rocks; b) their hydrocarbon generating nonisothermal pyrolysis, significant differences are observed in Index (HI) of 489 mg HC/g TOC and Tmax of 408 ºC. potential via hydrous pyrolysis experiments The experiments were the generated petroleum products. However, the composition of carried out using the same maximum temperature (350º C) with Conclusions oils generated and expelled in hydrous pyrolysis are the closest to The results from the hydrous pyrolysis experiments showed that time increments of 0h, 20h and 50h. Specific aspects of this The maturation effects caused by the hydrous pyrolysis experiments that of natural oils (Lewan, 1997; Ruble et al,. 2001; Lewan et al., by increasing experiment time the rate of transformation from study (Delgado, 2012) include a quantitative assessment of the were firstly observed by significantly reduced source rock potential 2006), and therefore, provide the best method to evaluate changes kerogen into hydrocarbons increased, as indicated by the increase generative potential of the organic-rich rocks, the determination in the pyrolized shale, with S2 values ranging from 126.0 mg HC/g in oil properties with thermal maturity. in hydrocarbon yields (bitumen and expelled oil). At the same time of the composition of liquid hydrocarbons generated from the rock in the original sample to 12 HC/g rock, after 50 hr at 350°C. hydrogen indices (HI) and hydrocarbon generation potential (S2) shale at various time, and the determination of geochemical and A similar trend was observed in the Hydrogen Index that showed This research investigates changes in expelled oil generated of the pyrolyzed rock were significantly reduced with increasing petrographical changes of the organic matter in the residual rocks a maximum of reduction at 350°C at 50 h experiment time, where by hydrous pyrolysis from an immature organic-rich lacustrine experiment time. after the hydrous pyrolysis experiments. Preliminary results of this the HI was lowered to 124 mg HC/g TOC (Table 1). source rock (TOC=28.8%; HI=892 mg HC/g TOC; 0.3%Ro) of study were published by Aptian age from the Araripe Basin (NE-Brazil). The tested sample The results on chemical composition of the expelled oils indicated is representative of a Type-I kerogen and can be considered a Table 1: Rock-Eval/TOC data of selected Ipubi Formation enrichment in the saturated fraction, whereas the bitumen retained The experiments were performedunder specific conditions such reasonable analog for Brazilian lacustrine source rocks of Lower shale rock sample:O.R.: original shale sample,H.R.: pyrolyzed in the rock was characterized by enrichment of the heavier fraction as sample mass, reactor volume, mass ofwater added, andthe Cretaceous age, which are responsible for most of the oil generated shale sample. S1= mg HC/g rock; S2 = mg HC/g rock; S3 = mg (heterocomponents). reaction temperatureto ensure theliquid phaseduring heating in the Brazilian continental margin. (Lewan, 1993; 1997). CO2/g rock; HI = mg HC/g TOC References Analytical Methods Delgado T.V.O. 2012. Trabalho de Conlusão: Maturação Artificial Sampling and Sample Preparation TOC (wt.%) S1 S2 S3 Tmax (°C) HI The hydrous pyrolysis experiments were conducted under de Rochas Geradoras de Petróleo-Caracterização Geoquímica e The shale samples were collected by the Center for Technology and O.R 25,7 15.2 126 1.87 408 489 isothermal conditions at twelve different temperatures for 72 hours Petrografia de Folhelhos do Membro Ipubi da Formação Santana, Earth Sciences, Federal University of Pernambuco. The samples H.R (280, 300, 310, 320, 325, 330, 340, 345, 350, 355, 360, 365°C) Bacia do Araripe, PE/CE, 90p. were crushed, homogenized and and representative sub-samples 0h 8,89 1.06 61.9 1.11 415 696 and at 310, 325, 340, and 355°C for different times (e.g., 12, were prepared for the various hydrous pyrolyses experiments. 20h 8.95 0.8 19.5 2.16 437 218 24, 30, 36, 48, 72, 96, 104, 120, 132 hours) to simulate the full Lewan, M.D. 1997. Experiments on the role of water in petroleum The original samples were also analysed by TOC and Rock Eval 50h 10 1.01 12 2.06 444 120 range of petroleum generation from early bitumen generation to formation: Geochimica et Cosmochimica Acta, v. 61: 3691– 3723. Pyrolysis parameter (Weatherford Laboratories, Texas). maximum oil generation. Lewan, M.D. 1993. Assessing natural expulsion from source rock Table 2 show the product yields of bitumen and expelled oil for by laboratory pyrolysis; p 201-210. In: Magoon B.L., Dow G.W. The original samples were also prepared and analyzed by the hydrous pyrolysis runs (0, 20, 50 h at 350 ºC). The maximum Generated gases were characterized by molecular composition The petroleum system-from source to trap. Tulsa Oklahoma. 1994. petrographic incident light analyses (vitrinite reflectance and maceral bitumen yield occurs at 0 h. Yields of expelled oil have a maximum including C1-C6 saturated and unsaturated hydrocarbons, H2S, analysis); and petrographic transmitted light analyses (spore color of 4.7 mg HC/g at 350 ºC and 50 h experiment time. CO2, O2, N2, He and Ar. The expelled oils were characterized index and qualitative analysis of organic matter by fluorescence). by their bulk properties (sulfur content, API gravity, stable carbon

50 51 isotopes and SARA fractions) and molecular properties (alkane show a 12C depletion with increasing transformation ratio from AM07 chips (1-2 cm) and was not pre-extracted prior to the experiments. distribution and biomarker signatures). Product yields in mg/g -30.65‰for the low temperature (280oC) to -28.48‰ for the high An average bulk density was determined for the rock chips TOC and gas/oil ratios (GOR m3/m3) were calculated for each temperature (365oC) for 72 hours. Hydrous pyrolysis experiments on a and used to calculate the amount of water needed to maintain experiment. Based on the maximum expelled oil yield at 360°C Permian coal sample from the liquid water in contact with the rock before, during, and after the for 72h, the transformation ratios (TR) for generation of expelled Although the results show pristane/n-C17 and phytane/n-C18 Leão-Butiá Coalfield, Paraná Basin experiments in 250 ml reactors composed of stainless steel. For oil were determined for all the experiments. Physico-chemical ratios decrease with increasing transformation ratios, the pristane/ each of the hydrous pyrolysis runs 45 g of rock and 86 g of distilled properties of expelled oils were evaluated in a function of TR (Fig. 1). phytane ratio remains nearly constant (Fig. 1B). During oil Leandro S. Putti, Marleny B. González, Simone Barrionuevo, wate were used. After loading and sealing the reactor, the remaining generation, the concentration of Stigmastane in the expelled oils Wolfgang Kalkreuth, Thaysa L.C. de Morais headspace was evacuated and filled with 7 Mpa of helium. Results and Discussion decreases with increase transformation ratio and is associated The petroleum yields (oil + hydrocarbon gases) increase linearly with low concentrations of 3-4 Methyldiamantanes. At maximum Instituto de Geociências, UFRGS, Rua: Bento Gonçalves 9500, Products (pyrolyzed coal, expelled oil, bitumen) were recovered with the advance of transformation ratio at a maximum of 728.23 oil generation (360°C/72h), the concentration of Stigmastane is CEP: 91501-970, Porto Alegre, Rio Grande do Sul, Brasil. quantified and characterized in each experiment, allowing mg/g TOC. The hydrocarbon gases (C1-C5) generated at the oil zero, and the concentration of diamandoids is still very low, which determining the thermal evolution of remaining coal, fractional peak represent 9% of total (Fig. 1A). The beginning of oil generation indicates no oil cracking to gas according to Dahl et al. (1999). e-mail: [email protected] composition, geochemical properties of the generated and stage corresponds to 0.2TR, when the bitumen is effectively Final Remarks expelled oils and retained bitumen. decomposed (320-325oC). Introduction In the case of Type I kerogen-bearing source rock, bulk properties In Brazil, the most important coal bearing sedimentary succession Results and Discussion In general, the geochemical results indicate that there are some (API gravity, δ13C, sulfur content, SARA fractions) of expelled oils occurs in the Permian Rio Bonito Formation, Paraná Basin, located The results 0f the organic petrological and geochemical studies changes in bulk parameters of the expelled oils, mainly related to from the hydrous pyrolysis experiments show some systematic in the states of Rio Grande do Sul(RS) and Santa Catarina (SC). of the original sample (S2/S3 seam) showed the following API gravity, SARA fractions, and whole-oil stable carbon isotopic changes during the oil generation stage. Among molecular ratios, The objectives of this study were the determination of a) the physic- characteristics: TOC content of 44.19 wt.%, S1 yield of 1.08 mg composition (δ13C). The molecular properties like the distribution pristane/n-C17 and Phytane/n-C18 are strongly controlled by chemical variability between the coal seams that constitute the São HC/g rock, remaining HC generative potential (S2) of 75.68 mg of n-paraffins and isoprenoids also change systematically with the thermal maturation and show a consistent behavior with the Vicente Norte Mine, Leão-Butiá Coalfield; b) to determine changes HC/g rock, Hydrogen Index (HI) of 171 mg HC/g TOC, Oxygen increasing thermal maturation (Fig. 1B). advance of transformation ratios during the oil generation stage. in chemical composition and petrographic parameters caused by Index of 5 mg HC/g TOC, Tmax of 418 ºC, vitrinite reflectance of As indicated by gas/oil ratios, biomarkers, and diamandoids, no oil artificial maturation of the organic matter contained in seam S2/ 0.45% Rr. However, relatively small variations are observed in gas/oil ratios. cracking to gas was observed under the experimental conditions S3 using hydrous pyrolysis experiments at 350 °C with experiment GOR initially decreased from 500 to 80 m3/m3 and then remained employed. times ranging from 0 – 50 hours; c) to evaluate the hydrocarbon The maturation effects caused by the hydrous pyrolysis experiments essentially constant until the oil peak. The high GOR values occur potential of this Permian coal. were firstly observed by significantly reduced source rock potential during early bitumen generation at the onset of oil generation (Fig. Acknowledgements in the pyrolized coal, with S2 values ranging from 75.68 mg HC/g 1C). Similar trends were obtained by Lewan and Henry (2001) The authors are grateful to PETROBRAS and USGS for financial and The Hydrous pyrolysis experiments refer to the thermal rock in the original sample to 18.60mg HC/g rock, after 50 hr at for different types of kerogens (Type-I, -II and -IIS) during the oil analytical support of this research within the PhD of the first author. decomposition which takes place when organic matter is heated 350°C. A similar trend was observed in the hydrogen Index that generation by hydrous pyrolysis. to high temperatures in the presence of water (Lewan, 1993, 1997; showed a maximum of reduction at 350°C at 50 h duration where References Ruble et al., 2001; Franco et al., 2010). Pyrolysed coal, bitumen the HI was lowered to 54 mg HC/g TOC. Dahl, J.E., Moldowan, J.M., Peters, K., Claypool, G., Rooney, M., Michael, and expelled oil were recovered, quantified and characterized G., Mellos, M., Kohnen, M., 1999. Diamondoid hydrocarbons as indicators from each hydrous pyrolysis run, allowing determining the thermal Tmax values ranged from 418 (original sample) to a maximum of of oil cracking. Nature 399, 54–56. evolution of the coal sample and to study the effect on the amounts 469°, whereas vitrinite values ranged from 0.45 (original sample) to and distribution of hydrocarbons generated during the experiments. a maximum of 1.14 %Rrandom; Lewan, M.D., 1997. Experiments on the role of water in petroleum Both rank parameter indicate immature stage for the original formation. Geochimica et Cosmochimica Acta 61 (17), 3691–3723. Sampling and Sample Preparation sample, whereas the pyrolysed coal are well within the oil window Coal samples were collected from the São Vicente Norte Mine, based on the level of vitrinite reflectance and at the transition to the Lewan, M.D. and Henry, A.A., 2001. Gas:Oil Ratios for Source Rocks Leão-Butiá coalfield (Putti, 2012).From the base to the top of overmature stage based on Tmax values. Containing Type-I, -II, -IIs, and –III Kerogens as Determined by Hydrous the coal-bearing sequence, the coal seams are named: camada Pyrolysis. In: Dyman, T.S. and Kuuskraa, V.A. (Ed.). Geologic Studies of Inferior 2 (I2), camada Inferior (CI), Leito 4 (L4), camada Superior 3 Figure 1 shows the product yields of bitumen and expelled oil for Deep Natural Gas Resources. USGS Digital Data Series DDS-67, version (S3), Leito 3 (L3), camada Superior 2 (S2), Leito 2 (L2), Leito 1 (L1), the hydrous pyrolysis runs (0, 20, 50 h at 350 ºC). The maximum 1.0. and camada Superior 1 (S1). bitumen yield occurs at 20 h. Yields of expelled oil have a maximum of 0.700 mg HC/g at 350 ºC and 50 h experiment time (Fig. 1) Lewan, M.D., Kotarba, M.J., Curtis, J.B., Wieclaw, D., Kosakowski, The coal samples were prepared for petrographical and chemical P., 2006. Oil-generation kinetics for organic facies with Type-II and -IIS analyses according to standardized procedures (Bustin et al, At or prior to these apparent maximum yields, the bitumen kerogen in the Menilite Shales of the Polish Carpathians. Geochimica et 1989), and the sample from the S2/S3 interval was prepared for decomposes to oil that is expelled from the bitumen-impregnated Cosmochimica Acta 70, 3351–3368. hydrous pyrolysis experiments rock as was observed by the distinct compositional differences between the polar–rich bitumen and the expelled oil rich in saturate Figure 1. Relationship between the geochemical parameters of expelled Ruble, T.E., Lewan, M.D., Philp, R.P., 2001. New insights on the Green River Experimental and aromatic fractions and characterized by less polar fractions. oils generated by hydrous pyrolysis with their transformation ratios. Yields petroleum system in the Uinta basin from hydrous pyrolysis experiments. This coal used in the hydrous pyrolysis runs was subjected to organic of expelled oil and hydrocarbon gas are given in mg/g of original TOC (A), American Association of Petroleum Geologists Bulletin 85, 1333–1371. petrologic and geochemical studies prior to the experiments that molecular ratios (B), and gas/oil ratios in m3/m3 (C). included vitrinite reflectance measurement to determine the rank of Spigolon, A.L.D., Lewan, M.D., Mendonça Filho, J.G., Penteado, L.H.B., the coal; determination of maceral composition; Chemical analysis; Variations in the API gravity ranging 22° to 32° show a complex Coutinho, L.F.C., 2013. New insights on changes in the oil quality during TOC; Rock-Eval pyrolysis. relationship with transformation ratios. As expected, increasing petroleum formation by hydrous pyrolysis on a Brazilian source rock API gravities correlate with increasing saturates and decreasing containing Type-I kerogen. Abstracts. 26th International Meeting on The hydrous pyrolysis experiments were conducted in a closed asphaltenes (Spigolon et al., 2013).Sulfur contents ranging of Organic Geochemistry 1, Costa Adeje, Tenerife, Spain, p. 417-418. system (350ºC at 0, 20,50 h);, which allows calculations of the 0.82 to 1.55 wt% and systematically decrease with the advance quantitative distributions of various organic fractions with increasing of TR. Stable carbon isotope composition (δ13C) of whole oils thermal maturity. The sample was crushed and homogenized to

52 53 Figure 1. Changes in hydrous pyrolysis products generated at 350 ºC for 0, AM08 Acknowledgements 20 and 50h experimental time for the S2/S3 sample, Leão-Butiá coalfield. The authors thank to Petrobras for sponsorship of this study as Fluorescence Behavior of Alginites in well as authorization for its publication. The results on chemical composition of all expelled oils indicated Artificial Maturation Experiments enrichment in the saturated fraction, whereas the bitumen retained References Araujo, C.V., Vieth-Redemann, A., Pradier, B., Kalkreuth, W., in the coal was characterized by enrichment of the heavier fraction a* b Carla Viviane Araujo , Renata Brenand Alvarenga das Chagas , Gomez Borrego, A., Gurba, L., Hagemann, H., Hufnagel,W., Koch, (heterocomponents), an effect of the mineral matrix, retaining a, , Jaques Soares Schmidt M., Kuili, J., Laggoun-Defarge, F., Lo, H., Newman, J., Spanic, D., preferentially molecules of larger size in the bitumen fraction, Igor Viegas A. F. de Souza.a Suarez-Ruiz, I., Thompson-Rizer, C., 1998. Interlaboratory exercise whereas the lighter hydrocarbons are being expelled). on the application of microspectral fluorescence measurements as a PETROBRAS/CENPES/PDGEO/GEOQ maturity parameters. Revista Latino Americana de Geoquímica Conclusions b FUNDAÇÃO GORCEIX Orgânica 4, 41-49. The results from the hydrous pyrolysis experiments showed that *[email protected] by increasing experiment time the rate of transformation from Araujo, C.V, Borrego, A., Brenand, R., Cardott, B. Flores, D., coal into hydrocarbons increased, as indicated by the increase in Gonçalves, P. , Hackley, P., Hower, J., Kern, M., Kus, J., Mastalerz, Copyright 2014, ALAGO. hydrocarbon yields (bitumen and expelled oil). At the same time M., Mendonça Filho, J.G. Mendonça, J., Menezes, T., Newman, This paper was selected for presentation by an ALAGO Scientific Committee following hydrogen indices (HI) and hydrocarbon generation potential (S2) of J. Suarez-Ruiz, I., Sobrinho, F & Viegas, I., 2014. Petrographic review of information contained in an abstract submitted by the author(s). the pyrolyzed coals were significantly reduced. thermal indices of a Devonian shale maturation series, Appalachian Basin, USA. ICCP Thermal Indices Working Group interlaboratory Introduction exercise. Manuscript under review. Maturity parameter such as vitrinite reflectance and Tmax oC The objective of this study is to investigate fluorescence properties indicate immaturity for the original sample prior to the experiments, Figure 1 – Fluorescence microspectrophotometry of prasinophyte alginites of alginites, as maturity parameters, in artificial maturation Baranger, R., Martinez, L., Pittion, J-l., Pouleau, J., 1991. A whereas at 50 h experiment time at 350 oC the pyrolyzed sample is from the 350ºC isotherm experiments at 1 and 20 h. Raw data presented experiments, as well as compare these properties with those new calibration procedure for fluorescence measurements of well within the oil window as indicated by vitrinite reflectance and/ derived from natural maturation series. in red and adjusted data by the correction function in blue. sedimentary organic matter. Organic Geochemistry 17, 467-475. or at the transition mature/overmature as indicated by the Tmax Visual observation reveals that alginites are gradually less abundant oC value. Fluorescence microscopy has become an important tool in Jacob, H., 1965. Neue erkenntnisse auf dem gebiet der with increasing duration of experiments. Furthermore, they tend to maturation assessment of source rocks since spectral fluorescence lumineszenzmikroskopie fossiler brennstoffe. Fortschr. Geol. present a halo between the alginite body and the matrix suggesting The quantitative hydrous pyrolysis data from this study provide a methods were presented in pioneering studies by Jacob (1965), Rheinld. u. Westf.12, 569-588 a shrinkage process due to possible condensation reactions. useful means to evaluate compositional variations in bitumen and van Gijzel (1967, 1975, 1981), Teichmuller and Ottenjann (1977) Alginites are present in experiments up to 20 h (fig.2). No alginites Souza, I.V.A.F.; Araujo, C.V.; Menezes, T.R.; Coutinho, L.F.C.; expelled oils generated from coal with increasing thermal maturity. among others. Quantitative methods such as spectral fluorescence were observed in experiments from 50 up to 200 h. Santos Neto, E.V.; Binotto, R.; Spigolon, A.L.D.; Cioccari, G.; The data also offer insights into the physiochemical processes that and its derivative parameters (λmax, red-green Quotient) are very Lewan, M.D.; Rondon, N.; Mendonça Filho, J.G., 2011. Hydrous take place during hydrous pyrolysis useful when vitrinite is rare absent or ambiguous (Wolf & Corrêa da Spectral fluorescence measurements carried out on immature pyrolysis experiments: new insights about generation, saturation Silva, 1984 and Stasiuk, 1994). The evaluation of λmax has shown and petroleum expulsion through organic petrographic evidences. Acknowledgements organic-rich rock of the Oligocene-Miocene Tremembé Formation great applicability as a maturation parameter in natural series IMOG Meeting. Interlaken, Switzerland, Abstract. in the Taubaté Basin (Brazil) revealed a similar behavior with no The authors acknowledge and appreciate the analytical support (Araujo et al., 1998 and Araujo et al., 2014). Nevertheless, when significant change in max with increasing experimental temperature provided by the Laboratory for Coal and Source Rocks, UFRGS. studies on fluorescence parameters are carried out on artificial λ Stasiuk, L.D., 1994. Fluorescence properties of Paleozoic oil- and time run. Furthermore a disappearance of alginites in the more maturation series derived from hydrous pyrolysis experiments no prone alginite in relation to hydrocarbon generation, Williston basin, severe experiments was noticed (Souza et al., (2011). References consistent results are obtained. Saskatchewan, Canada. Marine and Petroleum Geology 11(2), Franco, N., Kalkreuth, W.; Peralba, M. C., 2010. Geochemical 219-231. Characterization of Solid Residues, Bitumen and Expelled Oil Experimental 50 µm Teichmüller, M., and Ottenjann, K., 1977. Liptinite und lipoid Stoffe Based on Steam Pyrolysis Experiments from Irati Oil Shale, Brazil: Spectral fluorescence measurements were carried out on in einem Erdölmutterdestein . Erdöl und Kohle, 30, 387-398. A preliminary study. Fuel 89: 1863 – 1871. prasinophyte alginites from two isothermal series of hydrous pyrolysis experiments. For this purpose a Devonian sample from Lewan, M.D. 1997. Experiments on the role of water in petroleum van Gijzel, P., 1967. Autofluorescence of fossil pollen and spores Ponta Grossa Formation of Parana Basin was selected. Sixteen with special reference to age determinationand coalification. Leids formation: Geochimica et Cosmochimica Acta, v. 61: 3691– 3723. 1 h experiments of 1 up to 200 h at 350 and 360ºC were performed. 5 h geol. Meded. V.40 p.263-317. Lewan, M.D. 1993. Assessing natural expulsion from source rock Polished blocks from samples derived from these assays were i° 2.5 h by laboratory pyrolysis; p 201-210. In: Magoon B.L., Dow G.W. analyzed in fluorescence mode, as well as the original rock sample. van Gijzel, P., 1975. Polychromatic UV-fluorescence The petroleum system-from source to trap. Tulsa Oklahoma. 1994. Fluorescence intensities from 400 to 750‪‪ nm were obtained and microphotometry of fresh and fossil plant substances, with special Putti L. C. 2012. Caracterização petrológica, geoquímica e corrected with a correction function (Baranger et al., 1991 and reference to the location and identification of dispersed organic maturação artificial de carvão da mina São Vicente Norte, jazida Araujo et al., 1998). material in rocks. In: Alpern, B., (ed.), Pétrographie de la matiere Leão-Butiá, Formação Rio Bonito, Bacia do Paraná, RS. Trabalho organique des sediments. Relations avec la paleotemperature et le 10 h 20 h 50 h de Conclusão de Geologia, Instituto de Geociências, Universidade Results and Discussion potential pétrolier, CNRS, Paris, 67-91. Federal do Rio Grande do Sul, Porto Alegre, p.103. Figure 2 - Photomicrographs of prasinophyte alginites in fluorescence mode. The λmax derived from spectral fluorescence measurements van Gijzel, P., 1981. Applications of the geomicrophotometry carried out on prasinophyte alginites of original sample is at 590 nm Presenting the original sample (iº) and the 350ºC isotherm experiments of of kerogen, solid hydrocarbons and crude oils to petroleum Ruble T.E., Lewan M. D., Philip R.P. 2001. New Insights on the and Ro% is 0.57%. However, unlike the behavior observed in the 1 to 50h. Green River Petroleum System in the Uinta Basin from Hydrous exploration. In: Brooks, J. ed., Organic Maturation Studies and study of the natural series the gradual advancement of the λmax Fossil Fuel Exploration, Academic Press, London, 351-377. Pyrolysis Experiments. AAPG Bulletin, v.85 (8): 1333 – 1371. of the green to red region is not observed as would be expected Conclusions The observation of phenomena such as no change of λmax and with increasing maturation. The λmax remains predominantly Wolf, M., Corrêa da Silva Z.C., 1974. Petrographic description red-green quotient suggests that the severity of hydrous pyrolysis unchanged in experiments of 1 to 20 h (fig. 1), as well as the red- and fácies analysis of some samples from the oil shale of the Irati experiments does not allow the evaluation of maturation increase green quotient. Nevertheless, vitrinite reflectance reaches up to Formation (Permian). In: Congresso Brasileiro de Geologia, 28, by fluorescence properties that show a severe degradation in 1.29%. Porto Alegre. Anais, Sociedade Brasileira de Geologia 1, 159-170. experiments of long duration and high temperatures in contrast to

that observed in the natural series.

54 55 AM09 palynofacies according Mendonça Filho et al. (2011), cyanobacterial References content analyses was conducted using optical microscopy, the taxa Anagnostidis, K.; Komárek, J., 1988. Modern approach to the classification Geochemical characterization were identified as described by Anagnostidis and Komárek (1988) system of cyanophytes 3 – Oscillatoriales. Archiv Hydrobiologie Algological of the Hydrous Pyrolysis Products and geochemical characterization was performed by total organic Studies, Supplement, 80 (1-4): 327-472. from a recent Microbial Mat carbon (TOC) and gas chromatographic-mass spectrometric (GC- MS) methods. DasSarma, S.; Arora, P., 2001. Halophiles. In: Nature Publishing Group /

Mendonça Filho, J.G.a*, Franco, N.a, Silva, T.F.a, Stojanović, K.b, www.els.net.Enciclopedia of life sciences.1-9. Carvalhal-Gomes, S.B.Va, Silva, F.S.a, Fontana, L.F.a, Furukawa, Hydrous pyrolysis experiments were performed at temperatures G.G.a of 280ºC and 330ºC for 20h, using a Stainless Steel reactor (300 Grimalt, J.O.; Wit, R.; Teixidor, P.; Albaiges, J., 1992. Lipid biogeochemistry mL). TOC content was determined in pyrolyzated samples. Liquid of Phormidium and Microcoleus mats. Organic Geochemistry 19, 509-530. a Universidade Federal do Rio de Janeiro, Laboratório de hydrocarbons products, expelled oil and extractable organic matter Mendonça Filho, J.G.; Chagas, R.B.A.; Menezes, T.R.; Mendonça, J.O.; Palinofácies e Facies Orgânica, IGEO, Ilha do Fundão 21941-909, (EOM), were analyzed by GC-MS. da Silva, F.S.; Sabadini-Santos, E., 2010. Organic facies of the Oligocene Rio de Janeiro, RJ, Brazil. lacustrine system in the Cenozoic Taubaté basin, Southern Brazil. b University of Belgrade, Faculty of Chemistry, Studentski trg 12- International Coal Geology 84, 166-178. 16, 11000 Belgrade, Serbia. Mendonça Filho, J.G.; Menezes, T.R.; Mendonça, J.O.; Oliveira, A.D.; [email protected] Carvalho, M.A.; Santana, A.J., 2011. Kerogen: Composition and Figure 2. Mass chromatograms (m/z 85, 191, 217) of (a) the extractable classification. In: Flores, D.; Marques (Eds.), M. ICCP Training Course on

Copyright 2014, ALAGO. organic matter (EOM) from original unheated sample and (b) the expelled oil Dispersed Organic Matter. Plenimagem, 17-23.

This paper was selected for presentation by an ALAGO Scientific Committee following at 330ºC/20h. *Isomeric phytenes. review of information contained in an abstract submitted by the author(s). Experimental conditions used in hydrous pyrolysis experiments Introduction were enough to obtain expelled oil (591.12 mgHC/gTOCo at Microbial mats are multi-layered microbial communities spatially 330ºC/20h) from the studied sample. The effect of temperature organized as a result of physicochemical gradients. They typically on geochemical parameters determined on the pyrolyzated have steep gradients of oxygen and sulfide, and characteristically samples was evidenced by the decrease of TOC content in the are dominated by only a few functional groups of microbes: original unheated sample from 3.88 wt% to 2.20 at 330ºC for cyanobacteria, colorless sulfur bacteria, purple sulfur bacteria, Figure 1. Microbial mat sample collected from Lagoa Vermelha, Rio de 20h. Biomarkers of liquid products also confirm the increase of and sulfate-reducing bacteria. The organic matter of the Janeiro, Brazil. thermal evolution of the organic matter content in the sample. The hypersaline microbial mats, including the lipid content, must also biomarker profile shown in Figure 2b strongly suggests the release be distributed according to this fine stratification which patterns Results and Discussion of compounds from the organic matter and the transformation to may be complicated by strong seasonal salinity fluctuations in the The cyanobacterial content characterization of microbial mat sample the most stable structure at experimental conditions (e.g. Hop- overlying water column. These variations may even involve shifts identified fourteen species of cyanobacterias being the Microcoleus 17(21)-ene in the original unheated sample to ββ-Hopane, βα- of the predominant cyanobacterial species (e.g. from Microcoleus chtonoplastes the predominant specie. This specie is known to be Hopane and αβ-Hopane in the expelled oil at 330ºC/20h). to Aphanothece and vice versa) which represents a considerable a halophilic species able to bear high concentrations of salinity (Das increase in complexity when studying the biogeochemical Sarma & Arora, 2001). Its predominance in the fabric of this type of Conclusions processes of these fluctuating environments (Grimalt et al., 1992). microbial mat is justified by the fact that it develops predominantly The occurrence of expelled oils and their biomarkers profile Consequently, study of these mats may provide reference data for in the supralittoral zone and withstands long periods of subaerial during hydrous pyrolysis experiments, using a microbial mat the understanding of the depositional processes occurring in the exposure with increasing salinity and temperature conditions. sample, evidenced the efficiency of this technique to simulate the mats formed under seasonally fluctuating conditions. Therefore, Results of palynofacies analyses showed that bacterial amorphous transformation of organic matter content into liquid hydrocarbons the main goal of this work is simulate the transformation processes organic matter (AOM) is the most abundant group with 97.1%, as well as, the potential of this type of organic material to generate of organic matter in microbial mats from Lagoa Vermelha, Rio de following by 1.7% of palynomorphs and 1.2% of phytoclasts. hydrocarbons. These results will allow a possible correlation with Janeiro, Brazil. Two different AOM were observed in this sample pelicular (84.3%) ancient microbial carbonates in Brazilian and foreign sedimentary and in plates (19.1%), according Mendonça Filho et al (2010). basins for understanding their processes of formation and Experimental Geochemical characterization of microbial mat shows that total sedimentary diagenesis. A sample of microbial mat (Fig. 1) was collected from Lagoa organic carbon content in the sample is 3.88 wt%. This value Vermelha, a small shallow hypersaline lagoon located on the coast can be attributed to the fact that this microbial mat is composed Acknowledgements east of Rio de Janeiro, Brazil. by alternating carbonate, and non-lithified organic layers (Fig. 1). The authors are grateful to PETROBRAS-Brazil, FAPERJ and CNPq Hydrocarbon fraction of the EOM shows the expected profile for for the financial support. We would like to thank Dr. Rosane Nora The sample was freeze-dried to geochemical characterization and this type of sample,n-C17 was the most abundant n-alkane. The from UFRRJ for her help in the protocol development for biomarker fixed in a 4% formaldehyde solution for microscopical analyses. The occurrence of terpenes and sterenes and biological configurations analysis organic content characterization of the sample was performed by was also observed (Fig. 2).

56 57 BIODEGRADATION of a two-dimensional chromatogram whenever combined Acknowledgements with chemometric treatment may become an innovative and The authors thank CAPES (Brazilian research council) for advantageous tool in the search for assessment of biodegradation fellowships,Petrobras S/A andCPG – UNICAMP for financial BD01 of crude oils.The application of these tools involving the fingerprint support. of environment samples were developed. With the application of

New Strategies Chemometric for Evaluation these tools regions of the chromatogram or peaks with higher References of Biodegradation of Crude Oils By Gcxgc importance in the description of biodegradation are estimates. 1 Abbas, O.; Rebufa, C.; Dupuy, N.; Permanyer, A.; Kister, j., 2008. Assessing petroleum oils biodegradation by chemometric analysis of Figure 1. Profile of a non-biodegraded oil. Experimental spectroscopic data. Talanta75, 857-871. a Paloma S. Prata, Noroska G. S. Mogollón, Fábio Augusto. Four Brazilian crude oil samples were selected because of their

difference in biodegradation (A,B, C and D Sample). For sample 2 Sierra-García, I. N.; Alvarez, J. C.; Vasconcellos, S. P.; Souza, A. P.; Neto, a Universidade Estadual de Capinas, Instituto de Química, 13083- processing and analysis chromatographic grade n-hexane E. V. S.; Oliveira, V. M., 2014. New Hidrocarbon Degradation Pathways 970, São Paulo-SP, Brazil. and n-pentane from TediaBrazil (São Paulo, Brazil) was used. in the Microbial Metagenome form Braziliam Petroleum Reservoirs. PLOS

Approximately 100mg of each crude oil were weighed and ONE9(2), 1-13. [email protected] desasphatated with 10 mL of n-pentane (4x). The concentration of

15 mg/mL was maintained for all samples. 3 Peters, K. E.; Walters, C. C.; Moldowan, J. M., 2005, The Biomarker Copyright 2014, ALAGO. guide: Interpreting Molecular Fossils in Petroleum and Ancient Sediments, This paper was selected for presentation by an ALAGO Scientific Committee following The lab-made GC×GC-FID prototype was based on HP-6890 second ed., New Jersey. review of information contained in an abstract submitted by the author(s). Figure 2. Profile of a biodegraded iol. Series II GC-FID (Agilent, Santa Clara – CA, USA). The column

set used consisted on a 30 m × 0.25 mm × 0.25 µm SLB-5 ms 4 Oliveira, C. R.; Oliveira, C. J. F.; Ferreira, A. A.; Azevedo, D. A.; Aquino Introduction The model had as objective the discrimination of oils for (5% phenylmethysiloxane) column (Supelco) connected through Neto, F. R., 2012. Characterization of aromatic steroids and hopanoids Biodegradation of oil is a physicochemical process, which alters biodegradability, separated into two distinct groups (biodegradable a capillary of 1 m × 0.20 mm to a middle polar Rxi-17 (50% in marine and lacustrinecrude oils using comprehensive two dimensional the composition and quality of the oil, increasing the concentration and non-biodegradable). The validation was carried out by applying phenylmethysiloxane) column (Restek) 1.0 m × 0.15 mm × 0.15 gas chromatography coupledto time-of-flight mass spectrometry (GCxGC- of asphaltenes and resins, reducing the amount of saturated and samples with different levels of biodegradability. As expected, µm. The modulation period was set to 8.0 s and data acquisition TOFMS). Org. Geochem.53, 131-136. aromatic hydrocarbons1.Bacteria and microorganisms responsible samples from the calibration set were correctly predicted. It was was performed at 100 Hz. The oven temperature was programmed for biodegradation of oil in their tanks in the distance of millions of found that all chromatograms employed in the model building held from 70°C for 330°C at 2.5°C min-1 with split 1:1; the injector and years. The degradation of compounds by processes of microbial a high range of information and were extremely diversified among detector temperatures were set at 300°C and 350°C, respectively. activities and factors that enhance biodegradation are studied today themselves. Moreover, it was possible to identify compounds which Hydrogen at 0.6 mL min-1 was used as carrier gas. The modulator because of the degree of difficulty encountered in microbiological have been degraded and compounds that appear with increased used was the Loop with two turns using nitrogen gas, and sampling of some species, and access to the oil reservoir2. biodegradability. Based on this model, the regression coefficients pressures in the cold jet valve 4 psi and 100 psi hot jet valve. thus facilitating the visualization of the variables of greatest The chromatograms generated by GGxGC-FID of crude oils Oil composition as measured by gas chromatography is dependent relevance in the model building NPLs-DA, which were correlated were used to build the multivariate calibration model based on upon the biodegradationOil composition carried out by gas with the compounds responsible for the biodegradation, using the chemometric tool NPLs-DA, and were aligned routine developed chromatography is dependent on the level biodegradation, and calculated retention index was obtained. at the Laboratory of Chemometrics in Analytical Chemistry, the higher this level, the greater the unresolved complex mixture UNICAMP. For the data processing Matlab version 2011and PLS- (UCM)3. Because of the great number of individual components The application of chemometric tools was essential in the toolbox software. contained in the UCM, is particularly difficult to correlate oils using evaluation of data of a complex nature. Its application enabled gas chromatography. Because of the great number of individual the simplification of data, highlighting the relevant information and Results and Discussion components contained in the UCM, is particularly difficult to reducing noise. The figures below show the chromatographic profiles of the correlate oils using gas chromatography3. By using comprehensive samples. It is possible to observe the disappearance of lighter two-dimensional chromatography, these problems could be Conclusions compounds, as well as reducing color that demonstrates the low solved4. Comprehensive two-dimensional gas chromatography The chemometric tool NPLs-DA was essential to correlate the concentration of these compounds. withflame ionization detection (GCxGC/FID) applied to oil samples level of biodegradability with the information obtained from the surpasses typical GC, and so have been applied for more accurate two-dimensional chromatograms, due to its greater increase in determination of the level of biodegradation. detectability, offered by the compression of the chromatographic band modulator. So this worked presented a potential tool for Given the wealth of information obtained from the data acquisition predicting the level of biodegradation in large sample sets.

58 59 BD02 tarball sample deposited at Taipus de Fora beach, located in the Conclusions southeastern state of Bahia, Brazil. The region is located near We conclude that the tarball sample has higher abundance of Tarball Characterization by Esi(-) Ltq Xl active offshore oil production and shipping routes. oxygen classes, but the oxygen species are not useful as conserved Orbitrap internal polar markers to identify origin of tarballs. We also estimate Experimental that the time after the oil spill that originates the tarball sample is

Laercio L. Martinsa, Hilda L. A. Bastosa, Célio F. F. Angolineb, Anita The tarball sample collected at Taipus de Fora beach was more than 511 days. Other tarball samples from Taipus de Fora J. Marsaiolib, Eliane S. de Souzaa, Georgiana F. da Cruza* crushed and pulverized before oil extraction with dichloromethane beach will be analyzed in a higher resolution and higher mass solvent using Soxhlet system. The oil obtained was fractionated Figure 1. Distribution of heteroatom classes determined by ESI(-) LTQ XL accuracy analytical techniques to confirm the results obtained in a Laboratory of Engineering and Petroleum Exploration, Darcy in asphaltene and maltene fractions using n-pentane, and Orbitrap mass spectra to asphaltene fraction of tarball sample. this study, and also to assess potential species (i.e. NS class) as Ribeiro North Fluminense State University – LENEP/UENF, Macaé, the asphaltene was purified in Soxhlet system3. The tarball a conserved internal polar markers to indentify the origin of these RJ, Brazil; asphaltene and maltene fractions were dissolved at 0.5 mg mL-1 tarballs. b Chemistry Institute, University of Campinas - UNICAMP, POB in toluene:methanol (1:1 v/v) with 0.5% of NH4OH prior to LTQ XL 6154, 13084-971 Campinas, SP, Brazil. Orbitrap analysis. Acknowledgements The authors thank PRH20-ANP, LENEP/UENF and IQ/UNICAMP,

*[email protected] Results and Discussion and Petrobras/Rede de Geoquímica for providing the necessary The relative abundance of heteroatom classes in the asphaltene infrastructure to conduct research.

Copyright 2014, ALAGO. and maltene fractions of the tarball sample is presented in Figure 1

This paper was selected for presentation by an ALAGO Scientific Committee following and Figure 2, respectively. The compound classes indentified are Figure 2. Distribution of heteroatom classes determined by ESI(-) LTQ XL References review of information contained in an abstract submitted by the author(s). characterized by the type and the number of heteroatoms. Only Orbitrap mass spectra to maltene fraction of tarball sample. 1 Wang, Z., Fingas, M., Yang, C., Hollebone, B., 2004. Biomarker the detected heteroatom classes of >1% of the total summed Fingerprinting: Application and Limitation for Correlation and Introduction relative abundances are presented (O2, O3, O4, N, NO, NO2, In a study with weathered samples collected as oil residues from Source Identification of Oils and Petroleum Products. Prepr. Pap.- Due to the wide variety of geological conditions and ages under NO4, N2O4 classes). The relative abundance for the N and N2 are the motor vessel (M/V) Cosco Busan oil spilled4, it was found that Am. Chem. Soc., Div. Fuel Chemistry 49 (1), 331. which oil has formed, every crude oil exhibit an essentially unique also showed, although these classes have low relative abundance compounds which contain one nitrogen (N1) generally decrease biomarker “fingerprint”. Therefore, chemical analysis of source- (<1%), since these are important for the distinction of potential spill in relative abundance with increased exposure, whereas classes 2 Stout, S. A., Uhler, A. D., McCarthy, K. J., Emsbo-Mattingly, S., characteristic and environmentally-persistent biomarkers generates sources according to a previous work4. containing oxygen increase in relative abundance with increased in: Introduction to Environmental Forensics (B. L. Murphy and R. D. information of great importance in determining the source of spilled length of exposure. In this work, we also observed higher abundance Morrison, eds.), Academic Press, London, 2002, Chapter 6. oil, differentiating oils, monitoring the degradation process and The O2 and O4 classes represent acidic compounds, presumably of oxygen compounds (like O2, O4, NO classes abundances weathering state of oils under a wide variety of conditions1,2. carboxylic and dicarboxylic acids, and it is expected that these showed in Figure 1 and Figure 2) which is in agreement with the 3 Azevedo, D. A., Silva, T. F., Silva, D. B., 2009. Avaliação The spilled oil generally form tarballs, which are soft clumps of classes present higher relative abundance in the tarball sample fact that this kind of compounds are products of biodegradation geoquímica de biomarcadores ocluídos em estruturas asfaltênicas. weathered oil, mingled with sand, and other beach material, and the N and N2 classes present least relative abundance, since and photo-oxidation, which are processes that weathered samples Química Nova, 32 (7), 1770-1776. ranging from the size of a pinhead to larger chunks. this sample is severely biodegraded. Among the OO classes, like tarballs have undergone. Thereby, oxygen species in oils spilled the O1 class showed the lowest abundance. Alcohols, mainly not remain consistent into marine environment after the oil release 4 Corilo, Y. E., Podgorski, D. C., McKenna, A. M., Lemkau, K. L.,

Normally, the identification of spilled oil source is performed using phenols, which are considered as intermediates in a number of and this kind of compounds are not useful as a conserved internal Reddy, C. M., Marshall, A. G., Rodgers, R. P., 2013. Oil Spill Source biomarker diagnostic parameters obtained by GC analysis1. biodegradation pathways of petroleum components, dominate this polar marker to identify oil spill source of tarballs. Identification by Principal Component Analysis of Electrospray However, GC-based analytical techniques are restricted to light class5. These intermediates compounds may be almost completely Ionization Fourier Transform Ion Cyclotron Resonance Mass petroleum components and have limited application for polar consumed during further biodegradation. The relative abundance According to the cited study about M/V Cosco Busan oil spilled4, Spectra. Analytical Chemistry, 85, 9064−9069. compounds analysis such as the N, NO, NS, O2 heteroatom of N1OO classes is high to this sample, which is in agreement the relative abundance of N species remains consistent up until species. Thus, biomarker diagnostic parameters fail to identify with the fact that the compounds in these classes appears to be day 511 and after 617 days, the relative abundance of nitrogen- 5 Liao Y., Shi Q., Hsu, C. S., Pan, Y., Zhang, Y., 2012. Distribution weathered products generated after the spill, such as oxidized biodegradation products of N-containing compounds, it being containing classes (NS, NO and N1) decrease concomitantly and of acids and nitrogen-containing compounds in biodegraded species. Thus, electrospray ionization (ESI) high-resolution mass formed, for example to the N1O2 class, from ring opening of coincide with an increased abundance of O2 species (naphthenic oils of the Liaohe Basin by negative ion ESI FT-ICR MS. Organic spectrometry such as LTQ Orbitrap can be used for characterize oil hydroxyl dibenzocarbazoles with additional of a carboxyl group5. acids). The higher concentration of oxygen species in the sample Geochemistry 47, 51-65. spilled (tarball) and can be useful to monitor compositional changes effectively suppresses the ionization efficiency for less acidic in polar fractions in order to estimate the time after oil spills. species, such NS, N and N2 heteroatom class compounds. This effect can be observed in the Figure 1 and Figure 2, which show

The main goal of this study is polar fraction characterization to lower relative abundance to the N and N2 classes. Based on this, examine the time after the oil spill, and the possible origin of one it can be estimate that the time after the oil spill that originated this tarball sample is more than 511 days. 60 61 BD03 widened the range of analyzed compounds. Here we selected four Acknowledgements BD04 different oil samples sharing the same source rock and of similar CNPq; ANP (Brazilian Petroleum Agency),FAPESP Using O-containing acidic polar compounds maturity level, of different biodegradation levels(Figure 1) Microbial degradation of phenanthrene and of biodegraded petroleum as biomarker of References methylphenanthrenes in biodegradation Cruz, G.F.; Angolini, C.F.F.; Dellagnezze, B.M.; Garcia, I.N.S.; Oliveira, W.M.; laboratory conditions Santos Neto, E.V.; Marsaioli, A.J. 2011,Could petroleum biodegradation be

Célio Fernando Figueiredo Angolinia, Ramsés Capillab, Anita a joint achievement of aerobic and anaerobic microrganisms in deep sea Gabriel V.de Sousaa, Laercio L. Martinsa, Georgiana F. da Cruzaa*, Jocelyne Marsaioliaa* reservoirs? AMB Express 1, 47. Bruna M. Dellagnezzeb, Valéria M. de Oliveirab a State University of Campinas, Chemistry institute, P.O. Box Head, I.M., Jones, D.M., Larter, S.R., 2003. Biological activity in the deep a Laboratory of Engineering and Petroleum Exploration, Darcy 6154, CEP 13083-970, Campinas-SP. B) Organic Geochemistry / subsurface and the origin of heavy oil. Nature 426, 344–352. Ribeiro North Fluminense State University – LENEP/UENF, POB CENPES Petrobrás Figure 1. The O2 class abundance increased with biodegradation. 119562, 27910-970 Macaé, RJ, Brazil; Kim, S.; Stanford, L. A.; Rodgers, R. P.; Marshall, A. G.; Walters, C. C.; b Microbial Resources Division, Research Center for Chemistry, [email protected] Qian, K.; Wenger, L.M.; Mankiewicz, P. 2005,Microbial alteration of the Biology and Agriculture (CPQBA), University of Campinas – In non-biodegraded samples there is a predominance of linear acidic and neutral polar NSO compounds revealed by Fourier transform ion UNICAMP, CEP 13148-218, Paulinia, Brazil.

Copyright 2014, ALAGO. carboxylic acids (DBE 1), but in our samples of biodegradation cyclotron resonance mass spectrometry. Organic Geochemistry 36, 1117- level equal 2, the aliphatic carboxylic acids were not so abundant. This paper was selected for presentation by an ALAGO Scientific Committee following 1134. *[email protected] review of information contained in an abstract submitted by the author(s). Additionally we observed that their depletion increased at higher biodegradation levels as these compounds are in turn biodegraded Larter, S., Wilhelms, A., Head, I., Koopmans, M., Aplin, A., Di Primio, R., Copyright 2014, ALAGO. after the hydrocarbons In general, each DBE class abundance Introduction Zwach, C., Erdmann, M., Telnaes, N., 2003. The controls on the composition This paper was selected for presentation by an ALAGO Scientific Committee following increase at the beginning of the biodegradation process followed Microorganisms degrade petroleum following different biological of biodegraded oils in the deep subsurface-part 1: biodegradation rates in review of information contained in an abstract submitted by the author(s). pathways (Widdel and Rabus, 2001; Prince et al., 2002) at rates by an abundance decrease at higher biodegradation levels (Figure petroleum reservoirs. Organic Geochemistry 34, 601–613. that strongly depend on the availability of inorganic and organic 2). Those oscillations synchronize with those observed in the Introduction analyses of the corresponding hydrocarbon electron acceptors (Head et al., 2003; Larter et al., 2003).. These Prince, R.C., 2002. Petroleum and other hydrocarbons, biodegradation Many compounds present in petroleum, like polycyclic aromatic biological transformations lead to the systematic alteration of the of. In: Britton, G. (Ed.), Encyclopedia of Environmental Microbiology. John hydrocarbons (PAHs), are recalcitrant and may long persist in crude oil chemical and physical properties e.g., degraded oils Wiley, New York, pp. 2402–2416. the environment. The PHAs, including phenanthrene (P) and have higher specific gravity, viscosity and heteroatom-containing methylphenanthrenes (MP), are generated in large quantities and compounds are more abundant (Kim et al., 2005), which are are Vasconcellos, S. P; Crespim, E.; da Cruz, G.F.; Senatore, D.B.; Simioni, introduced in the environment mainly due to the use of oil-related more resistant to microbial catabolism than pure hydrocarbons. K.C.M.; dos Santos Neto, E. V.; Marsaioli, J.M.; Oliveira, V.M.; 2009. activities and derivatives. These compounds are less susceptible In particular, the carboxylic acids which are produced during the Isolation, biodegradation ability and molecular detection of hydrocarbon to biodegradation than other hydrocarbons due to the complexity biodegradation have a correlation with this process, prompting us degrading bacteria in petroleum samples from a Brazilian offshore basin. of their chemical structure and low water solubility1. Currently, the to use them as marker of biodegradation extension in petroleum Organic Geochemistry, 40, 574-588. bioremediation is the most applied strategy for the removal of such samples. compounds from the environment. This technique employs living Widdel, F., Rabus, R., 2001. Anaerobic biodegradation of saturated and organisms aiming at the mineralization of pollutants, resulting in the

Experimental aromatic hydrocarbons. Current Opinion in Biotechnology 12, 259–276. removal or attenuation of the pollutant compounds to less harmful In this work we used four oil samples obtained in July 2005 from a Figure 2. products in the contaminated area2. In this context, the aim of Pampo Sul Oilfield production platform in the Campos Basin.These this study was to investigate the PHAs degradation ability of four samples showed distinct biodegradation levels (Figure 1), and were Conclusions bacterial strains, four metagenomic clones and clone consortium. Similar to the biodegradation ofthe hydrocarbons we understand previously studied by Vasconcellos et al. (2009) and Cruz et al. The evaluation was performed in artificial seawater microcosms that biodegradation of O-containing compounds occurs in a (2011).The acidic fractions all oil samples were extractedwith silica by comparison between the composition of samples which were sequential way, with biodegradation of less complex structure / KOH (25g KOH for 200g of silica) in a soxhlet apparatus. exposed to the microorganisms and the control samples using (lower DBE) over more complex structure (higher DBE). Also crude oil as carbon and energy source. Results and Discussion the O-containing classes are more recalcitrant than their The relationship between the carboxylic acids and biodegradation corresponding hydrocarbons, but they are quickly biodegraded Experimental when their precursors are depleted. These classes were pointed has been a topic of research in our lab for the last 15 years, and the The metagenomic clones (2B, 1A, 9E and 10A), bacterial out biodegradation biomarkers. access to fast analyses like petroleomics (Rodger et al., 2005) has strains (Dietzia maris, Micrococcus sp, Bacillus subtilis and

62 63 Achromobacter alcanovirax) and the consortium (clone pool) were revealing great potential for further biotechnological applications. microbial catabolism under varying conditions6. The metagenomic BD05 derived from Brazilian petroleum reservoirs (Campos Basin, RJ and Furthermore a considerably high biodegradation potential was clones (individually or in consortium), in general, showed the Potiguar Basin, RN). The assays were performed in triplicate and confirmed for phenanthrene and methylphenanthrenes mainly following order of susceptibility of biodegradation of the MPs: Orinoco Oil Belt Crudes Produced by incubated in rotational shaker, 120 rpm, at 37 °C for the clones by clones 2B and 10A and the bacterial strains D. maris and 3-MP>2-MP> 1-MP~9-MP. No preferred order of degradation for Differential Biodegradation and at 28 °C for the bacterial strains. The microcosms were Micrococcus sp. (Figure 2). the bacterial strains was observed. CARMONA VERÓNICA and TORÍN LENNY monitored for 21 days, being evaluated for petroleum degradation Conclusions each seven days. Triplicate erlenmeyer flasks were sacrificed [email protected] y [email protected] Results showed that under the conditions used in this experiment, at each time point (0, 7, 14 and 21 days) and oil extraction was clones 2B and 10A, bacterial strains Micrococcus sp. and Dietzia Copyright 2014, ALAGO. carried out following the methodology previously described by maris (CBMAI 705) and clone pool exhibited a considerably high This paper was selected for presentation by an ALAGO Scientific Committee following da Cruz et al. (2008)3. The extracted oil was then separated into review of information contained in an abstract submitted by the author(s). bioremediation potential in the biodegradation of phenanthrene SARA components: saturated, aromatic and polar fractions using and methylphenanthrenes. Introduction silica gel column chromatography. Phenanthrene (m/z 178) and During the process of quantification and certification of reserves methylphenanthrenes (3-MP, 2-MP, 9-MP and 1-MP, m/z 192) Acknowledgements of the Orinoco Oil Belt (FPO), a set of samples of crude oil (100), core and wall (262), were collected. Also, geochemical were analyzed by CG-MS using SIM mode. The authors thank CNPq for fellowships, PRH20-ANP, LENEP/ characterization was performed. With the precedent data, it was UENF for financial support and Petrobras/Rede de Geoquímica established the presence of oil groups having different degrees Results and Discussion for providing the necessary infrastructure to conduct research. of altering compounds highlighting two trends of homohopanes Severely biodegraded oils are generally enriched in polar B.M.D. was supported by grants from FAPESP (process number biodegradation. The first trend involves the formation of 25 nor- hopanes, while the second one implies the absence of 25 nor- compounds and depleted in saturated hydrocarbons. Results 2010/52247-1). hopanes, as it has previously been reported by Peters et al., 1996, obtained from SARA analysis allowed to evaluate the proportion of for other basins.S ASdditional samples were identified where the these compounds and estimate qualitatively which microorganisms Figure 2. Biodegradation rate of the phenanthrene and MPs from the References order of alterSed compounds, commonly employed in determining the level of biodegradation of crude oil, appears to differ from that are potentially degraders. This analysis showed a predominance extracts of the control sample and all microcosms evaluated during the 1 Alexander, M., Biodegradation and Bioremediation, Academic Press, proposed by the traditional scales. New York, 1994. of polar components in all samples after 21 days, revealing that biodegradation experiment. The aim of this study isS(sin coma), Sto define the implications of all microorganisms are potentially degraders, especially clones 2B biodegradation in the generation of different groups of crudeSs in 2 Fernandez-Luqueno et al., 2011. Microbial communities to mitigate the Orinoco Oil Belt. and 10A and the bacteria D. maris and Micrococcus sp. (Figure 1). During the biodegradation experiment, the most distinct change in abundance of phenanthrene was observed for the metagenomic contamination of PAHs in soil-possibilities and challenges: a review. Methodology Environmental Science and Pollution Research 18, 12-30. clones 2B and 10A, that consumed more than 90% of this API gravity and concentration of S, V, and Ni were determined in compound after 21 days. Among the bacterial strains, Micrococcus crude samples. Extracts were obtained from wall-core samples with sp. was the most efficient in biodegrading phenanthrene with rates 3 Da Cruz, G. F., Santos Neto, E. V., Marsaioli, A. J., 2008. Petroleum dichloromethane. Both, the extract and Scrudes were separated into fractions of saturates, aromatics, resins and asphaltenes > 99% compared to the control sample. degradation by aerobic microbiota from the Pampo Sul Oil Field, Campos Basin, Brazil. Organic Geochemistry 39, 1204-1209. (SARA) using the HPLC technique. The saturated fraction was analyzed Swith a gas chromatograph with a FID detector and GC- The degree of alkylation is a critical factor controlling the rate of MS, while the aromatics, were analyzed by GC-MS. PHAs biodegradation. Normally, the rate decreases with increasing 4 Huang, H., et al., 2004. The effect of biodegradation on polycyclic Results and Discussion number of alkyl substituents4. However, in this study, when using aromatic hydrocarbon in reservoired oils from the Liaohe basin. NE China. In this study, only samples that are thought to have a common D. maris and A. alcanovirax, MPs concentrations decreased faster Organic Geochemistry 35, 1619-1634. origin and that show no evidence of crude mixtures were analyzed. 5 Budzinski, H., et al., 1998. Aerobic biodegradation of alkylated aromatic than that of phenanthrene. MPs abundance also underwent a This has been done for the purpose of determining the sole effect significant decrease during this experiment. The clones 2B and hydrocarbons by a bacterial community. Organic Geochemistry 28, 337- of biodegradation on the generation of different oil types. 10A also were more efficient in this case, but not as prominent 348. Based on the different stages of biodegradation, the oils were classified into four groups according to the characteristics observed as that of phenanthrene, since after 21 days they biodegraded 70 in the gas chromatograms C15 +, analysis of fragmentograms m/z: 6 Peters, K. E., Walters, C. C., Moldowan, J. M., 2005. The Biomarker and 64%, respectively, compared to the control sample. On the 191, 177, 217, 218, and 412 of the saturated fraction and m/z: other hand, D. maris was the most efficient in the degradation of Guide. Biomarkers and Isotopes in Petroleum Systems and Earth History, 192, 198, 178, and 184 of the aromatic fraction. This allowed S to MPs compared to the phenanthrene, consuming more than 99% vols. 1 and 2, Cambridge University Press, USA, p. 1155. group the oils as follows: after 21 days. The clone pool biodegraded more than 80% of Group 1, presents steranes unchanged, 25-norhopanes and phenanthrene and about 60% of MPs after 21 days. demethylated terpanes. (Fig 1 A)

Figure 1. Ternary diagram of SARA analysis. Studies of crude oil biodegradation in reservoir and in laboratory Group 2 shows presence of 25-norhopanos and no steranes. (Fig 1 B) conditions5 indicate that the 9-MP is less susceptible to The investigated microorganisms also showed high percentages biodegradation than other MPs isomers, as observed in this study, of biodegradation of n-alkanes and isoprenoids (data not shown), Group 3, shows partly-altered hopanes, unaltered steranes and except for the D. maris, reflecting differences in the rate of the the first members of the 25-norhopanes (C31 - C33).

64 65 demethylated terpanes in the m/z 177. B - Steranes removed in the m/z CHEMISTRY OF The sample path started in the injection port at 250 °C where it is Group 4, presents 25-norhopanSes, steranes and hopanes 217 and presence of 25-norhopanSeos in the m/z 177. volatilized and introduced into the capillary column (OV-1, 60m x completely removed and demethylated tricyclic terpanes. GEO-ORGANIC MOLECULE 0.32 mm ID, 0.25 µm film thickness) with a gas flow drag of 1.5 ml / Conclusion min at an initial temperature of 30 °C for 3 min. Subsequently, three An important feature is that in group 2, the quality parameters such Four oil groups were found to be generated by different processes heating ramps were used starting at 10 °C / min to 100 °C for 1 as API gravity, viscosity and %S and SARA are similar. However, of biodegradation. CG01 min then with 4 °C / min to 220 °C for 1 min and finally 10 °C / min the samples of group 3, having similar values of API gravity, and until 300 °C for 10min. After separation of sample components, SARA composition have viscosities at 40 ° C ranging from 14149 The process that generates the most significant changes in the Evaluation of crude (COL) as a standard in the products are directed towards the oxidation reactor at 980 °C to 318232 mm2/s; this could indicate that, although they seem oils of the FPO, seems to be the differential biodegradation of compound-specific isotope analysis of C15+ according to their retention time, where they are oxidized producing compounds. CO2, NOx and H2O. Successively, these gases are passed to a to have the same degree of biodegradation, according to the in saturated fraction of crude oils parameters studied, a number of compounds that are preferentially reduction reactor at 650 °C where NOx are transformed into N2 biodegraded in various crudes. This biodegradation seems to This work revealed at least three distinct stages of biodegradation and excess of O2 is eliminates before that, the products pass Delfín E. Rivas, Miriam M. Díaz, Felipe R. Quintero depend on the areal and vertical location of the samples. This for the same level of biodegradation of the Peters and Moldowan through a water trap comprising a tubular Nafion membrane which in turn, could be caused by specific bacterial communities and scale. is responsible for removing H2O.Finally, the sample is introduced to Petróleos de Venezuela PDVSA-Intevep, Gerencia General de reservoir conditions, as pointed Peters et al., (2005). the IRMS through a open Split system where carbon isotope ratios Exploración, Gerencia Departamental de Investigación Estratégica The correlation between quality parameters and oil groups in the form of CO2 were analyzed for each separate compound. (EYIE), Caracas 1070-A, Republica Bolivariana de Venezuela Similarly to homohopanes, alteration of tricyclic terpanes appears generated by biodegradation could be useful for exploitation to follow two trends. The first one involves an alteration which schemes. *[email protected] Results and Discussion starts during the homohopanes demethylation or before and Figure 1 shows gas chromatogram of C15+ saturated fraction continuing even when these compounds have been completely Copyright 2014, ALAGO. of COL-5X obtained with the GC-C-IRMS. good separation of removed; in this case demethylated tricyclic terpanes are present. Acknowledgments This paper was selected for presentation by an ALAGO Scientific Committee following The second trend involves the degradation of steranes, prior to the The authors would like to thank PDVSA - Intevep / CVP for allowing n-alkanes from n-C15 to n-C32 including isoprenoids as pristane review of information contained in an abstract submitted by the author(s). homohopanes and no apparent signs of degradation of tricyclic the publication of the data and the conduct of this study. (Pr ) and phytane (Ph) was observed. Furthermore, the absence of terpanes in demethylated; in this case tricyclic terpanes are not Unresolved Complex Mixture (UCM) suggest that COL-5X has not Introduction observed. Although some authors such as Connan (1984) and Lin References Compounds-specific isotope analysis (CSIA) consists essentially suffered apparently biodegradation process. This is an excellent et al. (1984), indicate that tricyclic terpanes are altered at a similar Alberdi M., Moldowan J.M., Peters K.E. and Dahl J.E. (2001). Stereoselective on the separation of complex mixtures with help of gas finding because the COL-5X can be proposed as a potential internal level of biodegradation as diasteranes (> 8 pm), we found in this biodegradation of tricyclic terpanes in heavy oils from the Bolivar Coastal chromatography (GC), followed by the combustion (C) or pyrolysis standard for the PDVSA Intevep CSIA stable isotope laboratory. area biodegradation that is consistent with the proposal by Alberdi Fields, Venezuela. Organic Geochemistry, 32, pp. 181–191 (P) of each of the separated compounds. Finally, the isotope ratios et al., (2001), who concluded that demethylation of terpanes of these compounds are analyzed individually in the isotope ratios occurs during the destruction of steranes and demethylation of Connan, J. (1984) Biodegradation of crude oils in reservoirs. In: Advances mass spectrometer (IRMS). hopanes, although at a lower rate. in Petroleum Geochemistry, Vol. 1 (J. Brooks and D. H. Welte, eds.), Academic Press, London, pp. 299-335. CSIA has been widely used in the characterization of crude oils

Hudges W.B. (1984). “Use of thiophenic organosulphur compounds in which provide important indication of the origin and represents characterizing of oils derived from carbonate versus siliciclastic sources”. a possibility to correlate crude-crude and crude-source rock. In: Palacas G., ed., Petroleum Geochemistry and Source Rock Potential of In addition, it provides the opportunity to identify processes of Carbonate Rocks: AAPG Studies in Geology, No. 18, 181-196. maturation, migration and biodegradation because of individual isotopic composition changes in these events. Furthermore, it has

Lin, L. E., Michael, G. H., Kovachev, G., et al. (1989) Biodegradation of tar- been demonstrated that δ13C individual values, of n-alkanes and sands bitumens from the Ardmore and Anadarko basins, Carter County, isoprenoid saturated oil fraction, show a variation with maturation Oklahoma. Organic Geochemistry, 14, 511-23. (Bjorøy et al 1992, 1994a, b). For this reason, the study of this fraction of crude oil is very important while cyclic and aromatic

Peters K., Moldowan M., McCaffrey M. and Fago F. (1996). Selective hydrocarbons isotopic values are not affected in the maturation biodegradation of extended hopanes to 25-norhopanes in petroleum process. Biodegradation studies have shown heavy isotopic values reservoirs. Insights from molecular mechanics. Organic Geochemistry. Vol. of n-alkane because biodegradation processes are preferential for 24, No. 8/9, pp. 765 - 78. removing the lighter isotopes(Clayton, 1991).

Peters, K., Clifford, W. y Moldowan, J. (2005). The biomarker guide (V. II), This paper shows the first steps of PDVSA-Intevep in the 2ª Ed. Cambridge: Press Syndicate of the University of Cambridge. 1155 p. development of methods for Compounds-specific isotopic Figure 1.Gas chromatogram of C15+ saturated fraction of COL-5X obtained analysis for different mixtures of geochemical interest. The purpose by GC-C-IRMS. of this work is the evaluation of crude COL-5X as a standard in compound-specific isotope analysis of C15+ in saturated fraction After optimizing the chromatographic conditions for the separation of crude oils using GC-IRMS for isotope measurement. of C15+ saturated fraction of COL-5X, the reproducibility of δ13C measurements were evaluated for each separate n-alkanes Experimental including isoprenoid. For that, 30 measurements were made Sample pretreatment involves weighing the C15+ saturated fraction obtaining a standard deviation of ± 0.5 ‰which is characteristic of COL-5X and dilution in hexane (HPLC reagent grade, Honeywell) for this type of analysis.Furthermore, Figure 2 shows that δ13C to a final volume of 1ml for subsequently injecting 5 µl in the GC- measurements for different n-alkanes and isoprenoids were similar C-IRMS where the gas chromatograph (GC) used was Trace GC to each other with an average and standard deviation for all values Ultra with the GC combustion (C) III as interface coupled to (IRMS) of -29.4 ± 0,4 ‰. Fig.1. A - Steranes unchanged in the m/z 217, 25-norhopanSeos and model Delta V plus, all these equipment manufactured by Thermo.

66 67 The potential of CSIA for determining source is shown in Figures 1 and CG02 chloride, bromide, sulfate, carbonate, bicarbonate, acetate and components of analyzed waters in this study. Since acetate and 2. Can be seen in Figure 1, the gas chromatogram shows that the formiatewere determined. For cation analysis was prepared 20 bicarbonate are different chemical species, it is expected that n-alkane distribution is characteristic of a crude oil of marine source. mL aliquot of each sample. Prior to analysis these samples were the chemical behavior of water to be different, depending on the This observation is consistent with Figure 2 which shows a linear trend Acetate in formation waters at the filtered using 0.20 µm poreTeflon membranes, in order to exclude proportion of these anions. If each of these species are quantified typical of the crude oil of marine source (Guthrie et al., 1996). southeast of the Maracaibobasin colloidal species. independently, is obtained that for M2 and M3, the major anion is the chloride and acetate M1. Beatriz Anguloa*, Frank Cabreraa, José Centenoa, Ramón Ca, Mg, Na and K were analyzed using inductively coupled Monterob, Eyleen Riveroc plasma optical emission spectroscopy (ICP-OES) technique with a A direct consequence of discriminating alkalinity components is Teledyne Prodigy equipment. to know the actual concentration of bicarbonate in the samples, a PDVSA INTEVEP, Gerencia de Investigación Estratégica en allowing a more accurate way to estimate rates of carbonate Exploración y Yacimientos; Los Teques, Venezuela, Analyses of carbonate and bicarbonate were performed according mineral saturation. b Instituto de Ciencias de la Tierra, Universidad Central de to titrationtechnique, during the first 72 hours. Titrations were Venezuela, Caracas, Venezuela carried out with sulfuric acid (Hach standardized 0.16 N) and Determining concentrations of acetate is useful for generating c PDVSA INTEVEP, Gerencia de Química Analítica, Los Teques, phenolphthalein and bromocresol green indicators (Hach). models of carbonates saturation indexes more accurate in various Figure 2. δ13C values of C15+ saturated fraction of COL-5X . Venezuela areas of the oil industry. Conclusions Chloride, bromide, sulfate, acetate and formiate anions were These models allow us to estimate the possibility of formation The results obtained shows that the COL-5X can be used as a *[email protected] analyzed from an aliquot of 20 mL of each sample, previously standard in Compounds-specific isotopic analysis. filtered using 0.45 µm poreTeflon membrane and analyzed by liquid of carbonate precipitates around wells and pipes. Also generate Carbon isotopic analysis of individual hydrocarbon compounds is information that facilitates decision-making in the field of Copyright 2014, ALAGO. chromatography using a DIONEX equipment ICS-3000 with a 4 an useful tool used to determine the source of an oil environmental management and studies of secondary oil recovery. This paper was selected for presentation by an ALAGO Scientific Committee following x 250mm IonPac AS18 column and KOH as mobile phase with gradient concentration. The amperage was modified of 120mA to Furthermore, these anions of carboxylic acids associated with oil Acknowledgements review of information contained in an abstract submitted by the author(s). The authors thank to Strategic Research Department in Exploration 15mA specifically for the detection of formiate and acetate. reservoirs can play an important role in processes of diagenesis to (EYIE) and the Stable Isotope Laboratory of PDVSA-Intevep for Introduction act as ligands which facilitate formation of complexes of elements providing full support to this work. Results and Discussions such as aluminum, iron, lead and zinc(Kharaka y Harnor, 2003). Anions of carboxylic acids (AAC) can be present in high The five waters are considered Na-HCO3 type as is shown in Figure References concentrations in oilfields, constituting 99% of the alkalinity 1 (a). This however, would be different when discriminating the Bjorøy,M.,Hall,P.B.,Hustad,E.,Williams,J.A.,1992. Variation in stable carbon reported in some formation waters(Kharaka y Harnor, 2003). Conclusions contribution to alkalinity by carboxylic acid anions, see Figure 1 (b), isotope ratios of individual hydrocarbons as a function of artificial maturity. Carboxylic acid anions acetate and formiate contribute between 48 given that the determination of bicarbonate anion using the titration Organic Geochemistry 19,89–105. and 70% of total alkalinity for the 5 wells tested. Their presence is not detected since generally the most abundant Bjorøy,M.,Hall,P.B.,Moe,R.P.,1994a. Variation in the isotope composition technique is indirect and does not allow distinguish between the of single components in the C4–C20 fraction of oils and condensates. of all carboxylic anions, acetate anion has an equivalent point equivalence point of bicarbonate and acetate. The determination of the anions of organic acids in petroleum Organic Geochemistry 21,761–776. similar to bicarbonate anion. This is why it is wrongly assumed that reservoirs at temperatures between 80 ° C and 160 ° C is important the alkalinity is provided exclusively by carbonate and bicarbonate Bjorøy,M., Hall,P.B.,Moe,R.P., 1994b. Stable carbon isotope variation of because its estimate allows a better understanding of processes as anions when is determined by titration method. n-alkanes in Central Graben oils. Organic Geochemistry 22,355–381 mineral dissolution and precipitation, affecting models of porosity and permeability of the reservoir. Clayton,C.J., 1991. Effect of maturity on carbon isotope ratios of oils and An over-estimation of bicarbonate values in water alters the results condensates. Organic Geochemistry 17,887–899. of geochemical modeling of water for prediction of formation damage by clogging or carbonate scales, estimating support for Guthrie,J. M., Trindade, L. A. F., Eckardt, C. B. and Takaki, T. 1996. This leads to better predictive models of the behavior of the water, water injection secondary recovery processes and estimation of Molecular and carbon isotopic analysis of specific biological markers: which in turn allow better management of reservoir productivity and evidence for distinguishing between marine and lacustrine depositional fouling behavior of produced waters intended for reuse (Zhang y produced water management. environments in sedimentary Brazil. Presented at the Annual Meeting of the Dawe, 1995; Kharaka y Harnor, 2003; Cantucci et al. 2009). American Association of Petroleum Geologists.

Additionally, the action of organic acids as ligands has important Acknowledges Authors want to thanks PDVSA Occidente for its support during implications in the reactive metal transport (Fein, 1991). sample collection.

Experimental Five producers oil wells were selected in a depth range from4734mto References Cantucci, B.; Montegrossi, G.; Vaselli, O.; Tassi, F.; Quatrocchi, F. 5444mand temperatures between 96oC and 120oC with water y Perkins, E.,2009. Geochemical modeling of CO2 storage in deep cut higher to 30% depending on their potential to present organic reservoirs: The Weyburn Project (Canada) case study, Chemical anions dissolved in water. Figure 1.AAC contribution in the composition of waters Geology,265, Nº 1–2, 181-197.

Cationssodium, potassium, calcium and magnesium and anions As shown in Figure 1, acetate is one of the major anionic

68 69 Fein, J., 1991. Experimental study of aluminum-, calcium-, CG03 In this work, compounds (3b), (4b), (5b), (6b) and (8b) were (8a) in the oil sample, even though the less abundant.Furthermore, and magnesium-acetate complexing at 80°C, Geochimica et synthesized and co-injected with an oil sample derivatized to compound (4b) was observed, so identifying acid (4a), which was Cosmochimica Acta, 55, Nº 4, 955-964. Synthesis of 3-n-propylergostane biomarkers. hydrocarbons to confirm the structures proposed by Lima et not previously reported. Structural proof of 3-n-propylergostanoic al.(2010) for the new biomarkers. Kharaka, Y. y Harnor, J., 2003. Deep fluids in the continents: I. acids identified in Campos basin oils. As co-injection did not confirm the structures of majority Sedimentary Basins, Treatise on Geochemistry. 5, 5.16. Elseiver, Experimental compounds, we tried to evaluate alternative structures that do not 7800. Felipe R.Sampaioa, Eugênio V. Santos Netob, Francisco de A. M. Once three-dimensional structure of biomarkers is crucial, possess clear differences in fragmentations. In order to test the Reisa¬* stigmasterol was chosen as starting material. The synthetic route presence of 5α, 14α, 17α and 20S epimers, co-injection was made Zhang, Y. y Dawe, R.,1996. Effect of organic acids on the consisted in a series of stereo and regioselective reactions leading with racemic mixture (20R + S) of compound (8b), but it was not determination of carbonate species in solutions, Analytica Chimica a Universidade Estadual de Campinas, Instituto de Química, to formation of compounds with different side chains attached to identified. Analyzing mass spectra of HHA, we may conclude that 13083-970, Campinas, SP, Brasil. Acta,318, 2, 239-249. C-17. First of all, synthesis was based on obtaining a hydroxy- stereochemistry of compounds is 5α(H) (m/z 191 ion) and 17β(H) b Petrobras/Cenpes/PDGEO, Av. Horácio Macedo 950, Cidade aldehyde, which was the key intermediate. In a second step, this (m/z 259 ion). For C-17, mass spectra show a signal more intense Universitária-Ilha do Fundão, 21941-915, Rio de Janeiro, RJ, Brazil intermediate was used in a set of Wittig reactions with different for m/z 301 than for m/z 299, suggesting a 17β(H) configuration. *[email protected] alkyl groups, followed by dehydration and catalytic hydrogenation. Another possibility is the existence of regioisomers at A ring. Lima et al. (2010) fixed the propyl group at C-3 by analogy to a whole Analysis by 13C NMR and mass spectrometry confirmed the Copyright 2014, ALAGO. series of alkyl-steranes with substitution at that position. These stereochemistry 3β-propyl, 5α(H), 14α(H), 17α(H) and 20R. This paper was selected for presentation by an ALAGO Scientific Committee following alternatives can only be confirmed by the synthesis of those

review of information contained in an abstract submitted by the author(s). compounds and co-injecting with oil sample. The oil sample was fractioned, obtaining the acidic fraction which Conclusions was submitted to a derivatization processaccording to Lima et al. Introduction In this work, 5 standards nor-ergostanes were synthesized with Working with saline lacustrine oils from Campos basin, Lima (2010) and references cited therein. good yields and purity. These compounds are a homologous et al. (2010) identified a family of biomarkers composed of3-n- series of ergostanes having different side chains attached to propylergostanoic acids. 14 compounds were first detected by Co-injections were realized in an Agilent GC7890A/7000 MS Triple C-17 and 5α(H) configuration. These standards are the respective hydrocarbons of 3-n-propylergostanoic acids found in oils from GC-MS and GC-MS/MS of the respective hydrocarbons. For Quad. The oven temperature programming was: 60 °C (10 min); Camposbasin and their structures were proposed by Lima et compounds (3a), (6a) and (8a)each methyl ester were analyzed by 10 °C/min to 190 °C; 1 °C/min to 250 °C; 2 °C/min to 300 °C (30 al. (2010). These acids, besides being unpublished, might be GC-MS. min). Nitrogen was used at collision chamber, at 10 eV. The MMI- connected to a biodegradation process, in which is the C-17 side type automatic injector was at 300 °C with a split rate of 10:1. chain that suffers microbial attack. These results are important not only because they are originals, but Auxiliary temperature was configured to 300 °C. Separation was The co-injections confirmed the presence of (3a), (5a), (6a) and also they may indicate a biodegradation process taking place in the (8a). Compounds of greater relative concentration reported by carried out with CPSIL-8CB column (60 m x 0,25 mm x 0,25 μm). reservoirs. It was found that the compounds relative composition Lima et al. (2010) did not co-elute with standards, despite having He was used as carrier gas at 1,0 mL/min. MRM method was used close retention times and the same fragmentation, suggesting the varied according to biodegradation level (Lima et al., 2010). In in co-injection. presence of isomers. Furthermore, it could identify a new biomarker (4a). the biodegradation process, microorganisms attack carbon chains in the sequence: linear hydrocarbons, isoprenoids, cyclic Acknowledgements Results and Discussion hydrocarbons, etc (Peters et al., 2005).In Campos basin’s oils, The authors thank CNPq (Brazilian research council) for fellowships; a homologous series of steranoic acids derived from ergostane Identification of 3-n-propylergostanoic acids was made by Lima et Petrobras S/A andInstitute of Chemistry - UNICAMP for financial (Figure 1) was found, in which the side chain at C-17 goes through al. (2010) based on fragmentation in mass spectrum of the methyl support. progressive biodegradation, as evidenced,for the first time, by esters, hydrocarbons (HHA) and deuterated hydrocarbons (HDA) References Lima et al. (2010). derived from acids. In this identifications, the n-propyl group was Lima, S. G.; Steffen, R. A.; Reis, F. A. M.; Koike, L.; Neto, E. V. S.;

fixed at C-3 position and the stereochemistry of α5 (H), 14α(H) and Cerqueira, J. R.; Lopes, J. A. D.; 2010. Propyl ergostanoic acids: Possible 17α(H) centers was established, but the configurations at C-20 (R new indicator for oil biodegradation. Organic Geochemistry 41, 325-339. or S) and C-24 (R or S) could not be determined. Carboxyl group Peters, K.E., Walters, C.C., Moldowan, J.M., 2005. The Biomarker Guide, was settled at side chain based on fragmentation of deuterated second ed. Cambridge University Press, Cambridge, UK. hydrocarbons derivatives. Nevertheless, authors did not accurately determine its position. Therefore, diastereoisomerically pure synthesis of standards was made to confirm the structures.

Co-injections showed that the most intense peaks do not correspond to synthesized compounds. However, the presence of adjacent peaks, of lesser abundance, with the same retention times and precursor ion → product ion transitions of synthesized Figure 1: Structure of 3-n-propylergostanoic acids and their derivative standards confirmed the presence of the acids (3a), (5a), (6a) and hydrocarbons. 70 71 ENVIRONMENTAL MangueChannel (CM). The samples were filtered using 142 mm PAHs, with predominance of alkylated over parental compounds a) GEOCHEMISTRY diameter and 0.7μm porosity glass-fiber filters After filtration, the suggesting degraded oil presence (C0 0.05). Figure 2ashowsthe first three from 30ng.L-1to 12,468 ng.L-1, with an average of 613ng.L- factorscontributions to the average concentration of each station 1±1,459ng.L-1. In general, rivers in the eastern bay region (CB, Cristiane R. Mauada*, Letícia Lazzaria,Mayara da S. Anicetoa, The highest average concentrations of PAHs, according MLR GM and SU) were less contaminated than the rivers in the western Carlos G. Massonea,Renato S. Carreiraa, Cássia de O. Fariasb, model, were found in the IR (1,143 ng L-1), followed by IG and portion. Angela de L. R. Wagenera (843 ng.L-1) and CC(556 ng.L-1). Figure 2. Contributions of each factor on the predicted concentrations (a)

and the contributions of each factor in the cumulative variance of the first Pontifícia Universidade Católica do Rio de Janeiro,LABMAM/ GM station showed predominance of recent oil contamination (142 three factors (b) Departamento de Química,20453-900, Rio de Janeiro, RJ, Brazil. ng.L-1) representing 52.7% of PAHs contributions (figure 2b). For Universidade do Estado do Rio de Janeiro,LAGON/Departamento CM, IG and SJM, the contribution of recent oil accounted only 0.9%, Acknowledgements de Oceanografia, 20550-013, Rio de Janeiro, RJ, Brazil 3.9% and 1,5%, respectively.The highest average concentrations The authors are grateful to CAPES (Coordenação de of degraded oil were found in IG (744 ng L-1 / 72.5%) and IR (518 Aperfeiçoamento de Pessoal de Nível Superior) for funding the *[email protected] ng L-1 / 37.2%), being less representative in GM station (30.4 ng project.

Copyright 2014, ALAGO. L-1 / 11.3%). References This paper was selected for presentation by an ALAGO Scientific Committee following Sofowote, U.M., McCarry, B.E., Marvin, C.H., 2008. Source review of information contained in an abstract submitted by the author(s). Combustion processes were clearly evidenced in IR, CC and CM Apportionment of PAH in Hamilton Harbour Suspended Sediments: stations, being the main source of PAHs to the last two stations. Comparison of Two Factor Analysis Methods. Environmental Introduction This can be seen as a result of high vehicular traffic near these Science & Technology 42, 6007-6014. The understanding of the sources and fate of contaminants, like stations, with main roads such Avenida Brasil and João Goulard Figure 1. Sampling stations surrounding Guanabara Bay. polycyclic aromatic hydrocarbons (PAHs) to estuaries in large highway (Linha Vermelha), nearIR and CC stations, and the high Wagener, A.L.R., Meniconi, M.F.G., Hamacher, C., Farias, C.O., urban settlements is of fundamental relevance to the management traffic flow in the downtownand Novo Rio intercity bus terminal The PCA/MLR approach (Sofowote, et. al., 2008) was used da Silva, G.C., Gabardo, I.T., Scofield, A.L., 2012. Hydrocarbons of these aquatic systems. Whereas in temperate systems such (near CM station). in sediments of a chronically contaminated bay: The challenge of knowledge is relatively high, less information is available for tropical to identify the main sources of PAHs in the river end-members Conclusions source assignment. Marine Pollution Bulletin 64, 284-294. systems. In part, the difficulty derives from the limited application contributingwith an average of 70% of continental water discharge of diagnostic ratios among selected compounds for source to GB. Although combustion processes have been observed in all assignment of PAHs in warmer climates (Wagener et. al. 2012). stations, the introduction of petrogenic PAHs from the SPM to GB Here, we used the composition of PAHs insuspended particulate The factor analysis showed distribution of variables in five is well representative, distinct previous studies which indicate the matter (SPM) of river end-members and a multivariate statistical factors(eigenvalues>1), contributing to a total of 89.5% of data combustion events as the most relevant contribution of PAH. This approach (principal component analysis with multiple linear variance. However, only factors 1, 2 and 3 were responsible for interpretation confirms the intense degradation processes of the regression – PCA/MLR) to characterize the input of PAHs from the proposing possible sources of PAHs in the SPM. Those accounted more labile petrogenic compounds in GB. drainage basin to Guanabara Bay (GB), Rio de Janeiro. for 82.2% of the total variance, which 50.6% was explained by factor 1. This factor showed a positive correlation with PAHs of Experimental higher molecular weight and parental preference with lower The samples were collected in eight water bodies surrounding abundanceof the alkylated compounds (with C0>C1>C2>C3>C4 the GB(Figure 1) once a month for eleven months–Caceribu River sequence), representing the pyrolytic processes.Factor 2 explained (CB), Guapimirim River (GM), Suruí River (SU),IguaçuRiver (IG), São 24.9% ofdata variance showing positive correlation to petrogenic João de MeritiRiver (SJM), IrajáRiver (IR), Cunha Channel (CC)and

72 73 EG02 methylene chloride: methanol (9:1) each time. Before the extraction, Environmental Protection Agency (USEPA): anthracene (An), References a standards solution was added with n- tetracosane-d50. The phenanthrene (Phe), fluoranthene (Fl), pyrene (Py), chrysene (Chr), USEPA – U.S. Environmental Protection Agency. 1984. Summary Aromatic Hydrocarbons in extracts were subjected to liquid chromatography using silica benzo[b]fluoranthene [Bz(b)] and benzo[k]fluoranthene [Bz(k)]. of the Issues with Regard to the Carcinogenicity, Mutagenicity, and Sediments of the Amazon Region gel. The aliphatic and aromatic hydrocarbon fractions and polar The PAH concentrations found in the samples are well below Exposure of Polycyclic Organic Matter (Pom). Washington, D.C., compounds were eluted with hexane, hexane:methylene chloride those established by the legislation, indicating an uncontaminated EPA/600/8-88/076 (NTIS PB88220371). environment. Marcela M. Berga, Celeste Y.S. Siqueirab, Luiz Landaua, Francisco and methylene chloride:methanol, respectively, and later analyzed R. Aquino Netob for GC/FID and GC/MS. The Fe/An ratios from all of the samples had values less than 10, and the An/ (An +Phe) ratio was greater than 0.1 for all of the points. a Universidade Federal do Rio de Janeiro, LAMCE/COPPE, 21941- Results and Discussion These results indicate the contribution of pyrogenic sources in the 909, Rio de Janeiro, RJ, Brazil. In the ten analyzed samples, 31 aromatic compounds were sediments. The pyrogenic origin of the PAHs was also indicted by b Universidade Federal do Rio de Janeiro, Instituto de Química, identified. The total concentration of aromatic hydrocarbons in the the Fl/Py ratio: the values of this ratio for all of the samples were 21941-909, Rio de Janeiro, RJ, Brazil. samples varied from 46.33 ng/g to 1253.66 ng/g of dry sediment. The majority of the aromatic compounds identified were of biogenic greater than 1. Moreover, the Fl/(Fl+ Py) ratio indicates that the combustion was derived from the burning of coal (Figure 1). [email protected] origin.

Copyright 2014, ALAGO. The points sampled in the Solimões River showed a large

This paper was selected for presentation by an ALAGO Scientific Committee following perylene concentration, varying from 173.34 ng/g to 219.70 ng/g review of information contained in an abstract submitted by the author(s). of sediment; however, the points from Coari Lake did not exhibit the same behavior: their concentrations varied between 0.82 and

Introduction 10.31 ng/g of sediment. In the Solimões River, the points sampled The Amazon region has great global importance due to its biodiversity are surrounded by plants on both riverbanks, which may explain and freshwater reserves. The increase in industrial activities and the greater contribution of perylene to the sediments. The lowest the discovery of the Urucu oil province made prevention measures perylene concentration among these three points is located exactly and monitoring of this area necessary to avoid possible damage to in front of TESOL, where the contribution from plants is the least. the environment. The geochemical analysis of biomarkers allows distinctions to be made between the contributions of biogenic and Polycyclic aromatic hydrocarbons (PAHs) of biogenic origin, such anthropogenic sources to the organic matter. as retene, cadalene and monoaromatic lupane, were also identified. Retene (1-methyl-7-isopropyl-phenanthrene) derives from abietic

Polycyclic aromatic hydrocarbons (PAH) are hydrophobic organic acid, a natural diterpenoid constituent of the resin of plants. In Figure 1: Plot of the ratios (a) Phe/An, (b) An/(An + Phe), (c) Fl/Py, and (d) compounds consisting of two or more fused aromatic rings. They addition to its natural occurrence, retene can also be a marker Fl/(Fl + Py) emerge from incomplete combustion of organic material and are of wood combustion. Retene was not found in large quantities thus ubiquitous in the environment. The main emissions of PAH compared to the perylene concentration in the samples in the Conclusions Several compounds were detected such as n -alkanes, Polycyclic are from anthropogenic sources like fossil fuel combustion and study, having a maximum concentration of 8.84 ng/g. Cadalene Aromatic Hydrocarbons (PAHs) but PAH concentrations found in petrochemical production, refineries, power plants, asphalt, and is the final product of the diagenetic degradation of compounds of the samples are well below those established by the legislation, tire wear debris. Due to the toxicity and partial carcinogenicity of cadinene-type compounds and, as a consequence, is the most indicating an uncontaminated environment. these compounds, the United States Environmental Protection common sesquiterpene reported in sediments. The cadalene Agency listed 16 of them as pollutants of high priority (EPA concentration varied from 0.19 – 8.79 ng/g, with the exception PAH),that are thus monitored very frequently. This study focuses of the sampling three sites, where cadalene was not detected. Acknowledgements The authors thank ANP (Brazilian Petroleum Agency), Petrobras on the identification of aromatic organic compounds, especially Monoaromatic lupane is a pentacyclic triterpenoid derived from S/A, PEC/COPPE/UFRJ and IQ/UFRJ for technical andfinancial Polycyclic Aromatic Hydrocarbons (PAH) in the sediments of Coari lupeol and is formed through the diagenesis of plant precursors support. Lake and Solimões River in the Amazon region, Brazil. and natural products.

Experimental Among the aromatic compounds found in the samples, seven are Samples were extracted using ultrasonic agitation with 50mL of included on the list of priority pollutants from the United States

74 75 EG03 for extraction of PAHs and their analysis. Samples extraction fluoranthene (13%). The %Rec obtained in the organisms samples References processes followed the 3550C method described by USEPA was >>100% indicating a matrix effect, but it just reduce the GREGÓRIO, A.M.S.; MENDES, A.C. 2009. Batimetria E Sedimentologia Occurrence of Polycyclic Aromatic (2007) and the clean up process, the 3630C method described by quantitative accuracy of results not affecting the qualitative result. Da Baía Do Guajará, Belém, Estado Do Pará, Brasil. Amazônia: Ciência e Hydrocarbons in Recent Sediments and USEPA (1996). The sediments ΣHPAs seems to influence the benthic organisms Desenvolvimento 5, 53-72. Benthic Organisms of an Amazon Estuary ΣHPAs in both qualitative and quantitative ways (Table 1). GCMS equipment Shimadzu QP2010 was used under the following SANTOS, C.C.; SILVA, C.D.L.; DAMASCENO, F.C.; CORREA, J.A.M. 2013.

Camila C. Santosa*, José Augusto M. Correaa, Flaviana C. operating conditions: helium (He) as the carrier gas; capillary Métodos CLAE e CG/EM na Determinação de Hidrocarbonetos Policíclicos Damascenob column NST-05 (30 m × 0.25 mm × 0.25 µm) from J & W Scientific; Aromáticos em Sedimentos Estuarinos Amazônicos. Anais de Artigos do flow rate of 0.8 ml min-1; detector operated with zero relative II Simpósio de Estudos e Pesquisas em Ciências Ambientais na Amazônia a Universidade Federal do Pará, Laboratório de Cromatografia, energy (1.5 kV); modes of operation SIM and splitless; and manual 2, 223 - 231. Belém, PA, Brazil. injection of 1μL. The temperature ramp used was as follows: the b Universidade Federal de Sergipe, Lab. de Análises de Compostos initial temperature was 40°C oven for 2 min, increasing at a rate of SOARES, L.C.T.; SANTOS-NETO, A.J. 2012. Protetores de Analitos e Orgânicos Poluentes, Aracajú, SE, Brazil. 25°C min-1 to 100°C, then increased again to 5°C min-1 to 230°C, Efeito de Matriz em CG. Scientia Chromatographica 4,139-152. and finally increased to a rate of 2°C min-1 up to 260°C keeping

*[email protected] this temperature for 5 min. The total time of the chromatographic USEPA. U.S. Environmental Protection Agency Method 3630C: Silica Gel run was 50 min. Clean Up. 1996. Available in: www.epa.gov. Accessed on: June 19th, 2013.

Copyright 2014, ALAGO. USEPA. U.S. Environmental Protection Agency Method 3550C: Ultrasonic This paper was selected for presentation by an ALAGO Scientific Committee following Results and Discussion Extraction. 2007. Available in: www.epa.gov. Accessed on: June 19th, review of information contained in an abstract submitted by the author(s) The fine sediments (%Fines) dominated in both sampling periods and it has a direct relation to the organic matter concentration 2013.

Introduction (%OM). From the 16 PAHs studied, 10 of them were detected in The Guajará bay, located at the mouth of Amazon River, near sediments samples during the wet season and 8 during the dried Belém city the capital of Pará state. In this area occurs an intense season. Even with a low diversity of aromatic compounds, dried boat traffic, as well as transportation and sale of fuels in floating season sediments presented greater HPAs total concentration docks and activities related to the storage and transportation of (ΣHPAs), 1351.43 ng g-1. In wet season the total concentration of Table 1. Occurrence of polycyclic aromatic hydrocarbons in petroleum products in a harbor named Miramar Petrochemical PAHs was 263.99 ng g-1, which can be related to the increased sediments and benthic organisms of the Guajará bay sediments Terminal (TEMIR). hydrodynamic in the estuary this last period. during two differents seasons.

Small spills and discharges of oil in water are sources of punctual Correlation analysis indicated that ΣPAHs were not influenced by pollution by polycyclic aromatic hydrocarbons (PAHs). PAHs are %Fine and %Organic Matter (OM). Benzo(a)pyrene corresponded Conclusions There is a predominance of higher molecular weight PAHs, which is organic compounds generated by the incomplete combustion to 87% of ΣHPAs during the wet season, whereas the others due to a lower volatility and higher stability of these compounds in of organic matter (OM) and are one of the contaminants of most PAHs had ≤ 3%. During the other period stood out: pyrene (18% the environment. The origin of PAHs in both arrays is predominantly interest in environmental studies due to their mutagenic and of ΣHPAs) fluoranthene (16%), the chrysene, benzo(b)fluoranthene pyrogenic, and can be directly related to anthropogenic activity. carcinogenic potential. (15%) and benzo(a)pyrene (11%). Based on geochemical ratio it was possible to confirm the predominance of aromatics from Anthropogenic activities that originated the PAHs levels observed This study aimed to evaluate the occurrence of the 16 PAHs pyrolytic origin. in sediments and benthic organisms are the discharge of untreated considered as priority by the Environmental Protection Agency of the domestic sewage and emissions of particulates from cars and United States in sediments and benthic organisms (Namalicastys The ΣPAHs seems to influence the density of polychaetes in small/medium boats. abiuma Grube, 1872) of TEMIR harbor. sediments. Reduction of about 50% in the number of organisms was observed during the dry season, when there was the greater

Methods amount of ΣHPAs in their body structure. Eleven PAHs were Acknowledgements The authors thank the Post-Graduate Program in Geology and Field expeditions in the studied area were carried out in December detected in the polychaetes during the dry season (ΣHPAs = Geochemistry of UFPA, the National Council for Scientific and 2012, March, May and June 2013 representing the dried, wet (two 848.71 ng g-1) and 10 of them in the wet season (ΣHPAs = 141.85 Technological Development (CNPq) and the Laboratory of Organic samples) and dried seasons, successively. ng g-1). PAHs stood out during the dried season: indene(1,2,3- c,d)pyrene (47%) and pyrene (23%). During the wet season the Compounds Pollutants Analysis of UFS.

There were used 0.5 g of benthic organisms and 4 g of sediment major were: pyrene (23%), chrysene (17%), fluorene (17%) and

76 77 EG04 (station 4) and BCCF10–09 (station 9) were sampled at 120 m and relative to dissolved sulfate. The sulfur isotopic composition of the an ideal system for the re-oxidation of the sulfur species, and 117 m water depths and the last core (BCCF10–15) was retrieved humic acids in the Cabo Frio sediments suggests the incorporation generate the sulfur intermediates species which react with the Isotopic evidence for sulfurization of humic from the inner-shelf area (station 15) at 80 m water depth(Figure 1). of the diagenetic sulfur in the OM, thought reactions of the organic OM to complete the sulfurization process. The presence of the acid in sediments of the tropical upwelling The sediment samples were processed within an O2-free glove bag matrix with reduced species of sulfur produced by dissimilatory benzothiophene in the humic acids also indicate the sulfurization system of Cabo Frio (RJ). and were sliced in high resolution (1 cm). The extraction of the humic sulfate reduction. of the OM, but further analysis and interpretation must be done to substances was made using the basic extraction with NaOH 0.1M understand the absence of sulfur compounds with low molecular The incorporation of sulfur into OM appears to be most favorable weight compounds. Rut A. Díaz1, Manuel Moreira1, Ursula Mendoza1, Wilson and the precipitation of the humic acids using HCl 6M. The isotope under conditions where partially oxidized aqueous species of Machado1, Michael E. Böttcher2, Christelle Anquetil3, Sylvie compositions were measured by means of combustion isotope- sulfur such may be present. The sediments off Cabo Frio were Derenne3, Ramses Capilla4, Ana L. Albuquerque1 ratio-monitoring gas mass spectrometry (Thermo Finnigan™ MAT Acknowledgements 253) coupled to a Thermo Flash elemental analyzer via a Confl o IV deposited under highly dynamic redox conditions in the surface This work was funded by the Geochemistry Networkof layers beneath oxic bottom waters, and this condition maintains a PETROBRAS/CENPES and the Brazilian NationalPetroleum and 1 Departamento de Geoquímica, Universidade Federal Fluminense, split interface. For the analysis with Py-GC-MS, the humic acid was constant process of re-oxidation of the sulfur species, which favor the Biofuels Agency (ANP). Niterói, RJ 24020-150; extracted with dichloromethane (DCM) and ethanol (MeOH) using a the sulfurization of the OM. 2 Marine Geologie, Institut für Ostseeforschung Warnemünde, proportion of 2:1 (v/v). Rostock, Germany; References 3 BIOEMCO, Université Pierre et Marie Curie, France;4Petrobras/ BRÜCHERT, V., 1998. Early diagenesis of sulfur in estuarine sediments: The Cenpes/Geoquímica, Ilha do Fundão, RJ role of sedimentary humic and fulvic acids. Geochimica et Cosmochimica Acta 62, 1567-1586.

*[email protected] Díaz, R., Moreira, M., Mendoza, U., Machado, W., Böttcher, M.E., Santos,

H., Belém, A., Capilla, R., Escher, P., Albuquerque, A.L., 2012. Early Copyright 2014, ALAGO. diagenesis of sulfur in a tropical upwelling system: Cabo Frio, southeastern This paper was selected for presentation by an ALAGO Scientific Committee following Brazil.Geology 40, 879.882. review of information contained in an abstract submitted by the author(s).

Introduction Zhu, M., Chen, L., Yang, G., Huang, X., Ma, C., 2014. Humic sulfur in Among a variety of sulfur forms in marine sediments, organic sulfur eutrophic bay sediments: Characterization by sulfur stable isotopes and is quantitatively the second most important sulfur pool (only behind K-edge XANES spectroscopy. Estuarine, Coastal and Shelf SciencE 138, pyrite), frequently accounting for 35% of the total sedimentary sulfur 121-129. in marine environments. The sulfurization of the organic matter (OM) results from the incorporation of reduced inorganic sulfur species Figure 1: Locations of study area and core sampling stations. Figure 2. Downcore Profiles: δ34S of Chromium Reducible Sulfur (CRS), into sedimentary OM. This process is an important mechanism pore water sulfur (SO42-) and Humic Acid (HA). for the preservation of functional organic compounds during Results and Discussion In the molecular characterization of the humic acids by Py-GS- early diagenesis. In the course of the diagenesis, the sulfurization The atomic ratio (S/C) in the humic acids ranges between 0.035 MS were identified compounds like linear n-alkanes and alkenes, of the OM generates a gradual increase in the molecular weight and 0.23, according to reported atomic ratios for several marine branched-alkanes, alcohols, aromatic compounds and some of the compounds produced within the sedimentary OM, which sediments and sedimentary rocks (0.006–0.38). The fact that compounds with oxygen and nitrogen.The sulfur compound inhibits the degradation of the OM by bacteria and contributes to S/C ratio in the humic acids is larger than the algal ratio in marine identified was a micro-peak of benzothiophene with the principal the preservation of organic compounds in a geologic time scale. plankton (0.004-0.010) suggests the uptake of sulfur into the ion m/z 134. This compound is a sulfur compound with high The present work aims to characterize the OM focusing on the organic matter. molecular weight, and generally indicates an advance maturity in sulfurization of the OM during the early diagenesis,using the sulfur the sediments with a high aromatization process, what contrast with isotopic composition (δ34S) of the humic acids and the molecular The sulfur isotope composition of the humic acids cover a range the local sediments type. The presence of this sulfur compounds characterization by Curie-Point Pyrolysis-Gas Chromatography- between -8 and +5 ‰, being significantly enriched in the lighter may indicates the sulfurization of the OM. Mass Spectrometry (Py-GC-MS). isotope compared to pore water sulfate (about +21‰), but depleted with respect to co-existing pyrite (CRS) (between -27

Methods and -42‰) (Figure 2). The δ34S of sulfur that is biosynthesized by Conclusions The S/C ratio and the sulfur isotopic composition of the humic In the upwelling system of Cabo Frio, Southeast Brazil, four box-cores marine organisms is close to seawater sulfurfrom which it is formed acids ( 34S) indicate the OM sulfurization in the sediments from were collected across the continental shelf. The shelf-edge core and the diagenetic sulfur produced by the dissimilatory sulfate δ the upwelling system of Cabo Frio. These sediments represent BCCF10–01 (station 1) was collected at 142 m, cores BCCF10–04 reduction has an isotopic composition highly depleted in 34S

78 79 EG05 on a Agilent 6890N GC equipped with a Agilent 7683B Split/ Figure 1GC-MS Chromatograms at m/z 191 and 217 of oilyresidue Uhler, A.D., Stout, S.A., Douglas, G.S. Chemical heterogeneity in spliteless injector and interfaced to a Agilent 5975B quadrupole collected from a turtle specimen (Chelonia mydas). modernmarine residual fuel oils. In: Wang, Z., Stout, S.A. (Eds.), Oil Spill Oil Spill Characterization Using mass selective detector (electron voltage 70 eV and quadrupole EnvironmentalForensics: Fingerprinting and Source Identification. Academic Organic Geochemistry Case Studies temperature 150°C). The samples were analyzed in selected ion Incident 2 Press, Boston (2007). monitoring mode (SIM). The residue sample from penguin feathers (Spheniscus

magellanicus) was submitted to oil hydrocarbon fingerprint Wang, Z.; Yang, C.; et al., Petroleum Biomarker for Oil Spill Characterization Wagner L. BASTOS, Carlos A. CARBONEZI,Jarbas V. P. GUZZO, Separation was performed on a DB-5MS fused silica capillary analysis. The chromatogram showed a nearly normal distribution and Source Identificartion, in Wang, Z.; Stout, S.; Eds: Oil Spill Environmental Fabiano G. LEAL, Laura B. B. RIGO, Michelle S. GAMA, Patricia L. column. The GC oven was temperature programmed from of n-alkanes in a carbon range of C19 to C28 on a prominent UCM. Forensics, Academic Press: Oxford (2007). CAVALCANTE. Petrobras method.Helium was used as carrier gas. Diagnostic ratios of target biomarker compounds HOP/EST, H29/ H30, TET/26Tri, H35/H34, prevalence of %27 R&S, in addition Division of Geochemistry, PETROBRAS Research and Development αββ Compounds were identified on the basis of mass chromatographic with n-alkane GC profile indicated a heavy fuel, maybe obtained Center (CENPES), PETROBRAS, Rua Horácio Macedo, 950, Ilha responses and relative retention times by comparison with a from Cuba oil (figure 2). do Fundão, Rio de Janeiro, RJ 21941-915, Brazil standard sample.

Copyright 2014, ALAGO. Results and Discussion This paper was selected for presentation by an ALAGO Scientific Committee following In this work, two different samples, collected in different days, review of information contained in an abstract submitted by the author(s). were obtained from aGreen Sea Turtle (Chelonia mydas) and MagellanicPenguin feathers (Spheniscus magellanicus). Samples

Introduction wereanalyzed from geochemical point of view. Biological markers or biomarkers are molecular fossils, meaning that these compounds are derived from formerly living organisms Incident 1 An oily residue collected from a green sea turtle specimen (Chelonia (Peters et al., 1993). Biomarkers are complex organic compounds mydas) was submitted to GC fingerprint analysis. Thechromato- composed of carbon, hydrogen, and other elements (Peters et gram profileobtained from residue showed a distribution of n-al- al., 1993). They are found in rocks and sediments and show no kanes with maxima around C-20 on a UCM (unresolved complex change in structure from their parent organic molecules in living mixture). Diagnostic ratios of target biomarker compounds HOP/ organisms (Peters et al., 1993). Furthermore, due to the wide EST (Hopanes/Steranes), H29/H30 (C2917 (H),21 (H)-30-nor- Figure 2: GC-MS Chromatograms at m/z 191 and 217 of oilyresidue variety of geological conditions and ages under which oil has α β hopane/C3017 H),21 (H)-hopane), TET/26Tri (C24 tetracyclic collected from penguin feathers (Spheniscus magellanicus). formed, every crude oil may exhibit an essentially unique biomarker α( β terpane/C26 tricyclic terpanes S+R), H35/H34 (C35 pentakisho- fingerprint (Wang et al., 2007). This allows characterize and identify mohopaneS+R/C34 tetrakishomohopaneS+R), prevalence of the several petroleum systems in the sedimentary basin, and Conclusions %27 R&S(% of C27 14 ,17 cholestane S+R/C27+C28+C29 In both cases was possibleto conclude that the origin of consequently, the oils spills occurred in all nationwide, becoming αββ β β- cholestanes S+R), absence of methyl-steranes, in addition with a contamination refer to heavy fuels produced from foreigner crude the biomarkers a powerful tool. presence of 2-methylanthracene in the aromatic fraction indicated oils. These facts occur frequently due to several ocean currents a heavy fuel (Uhleret al., 2007), probably obtained from Middle East which these marine animals are subjected and intense navigation Based on these characteristics, two cases studies were carried out oil (figure 1). in the Brasilian Coasts. in Brazilian territory showing it is possible to use biomarkers and geological information to identify the origin of theseevents. Acknowledgements

Experimental The authors thank Petrobras S/A for financial support. Oil samples were fractionated using a semiautomated medium pressure liquid chromatography technique to provide saturated References and aromatic hydrocarbons fractions. Peters, K. E.; Moldowan, J. M., The Biomarker Guide: Interpreting Molecular Fossils in Petroleum and Ancient Sediments, Prentice Hall, New

Gas chromatography coupled to mass spectrometry (GC-MS) York (1993). analyses of saturated hydrocarbon fractions were performed

80 81 EG06 residents and operators and is another issue that clearly needs to through a saturated solution AgC2H3CO2. This was allowed to be resolved. GAS AND SURFACE bubble the gas phase until the formation of solids of Ag2S (black Energy and the environment-relating releases GEOCHEMISTRY color). This solid was filtered using a 0.45 µm Millipore membrane. Finally another aspect of hydrofracking is related to disposal wells Finally, the samples were analyzed using Isotopic Relation Mass to sources with environmental forensics necessary to dispose of co-produced formation waters. Much Spectrometry (IRMS) of Thermo Scientific, Delta V plus model, of this water is pumped back into the subsurface. However in coupled to Elemental Analyzer (EA) of Thermo Scientific, Flash EA R. Paul Philp GS01 Oklahoma in particular with the dramatic increase in the amount 1112 model. The standards used were PSO_1 y PSR_1 which of drilling that has occurred over the past 5 years, there is a lot are referenced with international standard NBS-127. Results are School of Geology and Geophysics, Uni. of Oklahoma, Norman, Origin of H2S in Franquera, Moporo and La more water being reinjected into the subsurface. At the same time presented as δ34S relative to Vienna Canyon Diablo Troilite (VCDT) OK. 73019. there has been a significant increase in the number of earthquakes Ceiba oilfields: Evidence from sulfur isotopes standard. The reproducibility for δ34S measurements is ± 0.3‰. in the same areas. Now at this point no direct relationship has and chemical analysis of fluids The sulfur isotopic relations were analyzed like SO2 in IRMS. [email protected] been established between the earthquakes and the disposal wells. However the circumstantial evidence is very strong. Cabrera Franka*, Vásquez Jhaissonb, Rivas Delfína, Angulo Beatriza, Results and Discussion Copyright 2014, ALAGO. Duno Laurysb, Guerrero Blancab Several mechanisms were initially considered for Franquera, This paper was selected for presentation by an ALAGO Scientific Committee following The second part of the talk will be devoted towards oil spills and Moporo and La Ceiba oilfields. Sulfur isotopic compositions of H2S review of information contained in an abstract submitted by the author(s). releases of refined hydrocarbon products. There are many parallels a Venezuelan Technological Institute of Petroleum (PDVSA Intevep), (g), SO42- (ac) and R-S (organic sulfur) did not identify uniquely between the increased drilling activity and environmental incidents Department of Strategic Research, 76343, Caracas 1070-A, Introduction a single process for H2S source in the study area, probably due involving transportation of hydrocarbon products resulting from this Venezuela With the ever increasing demand for all forms of energy both in to the potential that had Maracaibo Basin, in particular Upper increased activity. One area in particular is related to transportation b Oil Company of Venezuela (PDVSA Occidente), Department of this country and would wide, it is inevitable that there will be more Eocene B reservoir, for fluid mixing and their subsequent effects of these products via trains vs. pipelines. In the past two years in N. Reservoir Integrated Studies, Maracaibo, Venezuela and more releases of energy related products into the environment. of rock-water interaction during the geological history. Particularly, America there have been a number of significant incidents involving These releases may be oil or gas-even coal-or products related it believed that H2S generation was marked initially by organic crude oils being transported by rail. The unfortunate problem here *[email protected] to exploration and production activities. In terms of exploration matter thermal cracking of marine origin (La Luna Formation). is that in many cases it is not simply the release of the oil following there are many issues associated with hydraulic fracturing which Later, reservoir conditions could favor the microbiological activity the spill but the fact many of these spills are also accompanied by Copyright 2014, ALAGO. will be discussed elsewhere at this meeting. This will inevitably of sulphate-reducing bacteria (SRB). Evidences of these proposed explosions and fires. This paper was selected for presentation by an ALAGO Scientific Committee following lead to increasing levels of litigation requiring more and more review of information contained in an abstract submitted by the author(s). mechanisms, as well as ruling out other processes are described sophisticated techniques to relate releases to their point of origin. Conclusions below: These releases may be accidental and unintentional or in some In summary this talk will discuss two major environmental areas Introduction cases even deliberate. Further complicating the issue is the fact related to the oil industry. The first is related to hydrofracking Reservoir souring is a common problem during waterflooding Absence of evaporite sequences: Thermochemical Sulphate that in many areas releases may occur in the same area as natural issues now that is been used extensively in the industry. The operations into sweet reservoirs. In this case, the mechanism Reduction (TSR) from anhydrite layers (CaSO4) is not a possible seeps or areas with significant tanker traffic that also contribute impacts of this approach are wide-ranging from ground water that produces the hydrogen sulfide (H2S) is related to sulphate- source for H2S since evaporitic sequences were not deposited in to the overall contamination background. Every release will have contamination to earthquakes. The second issue to be discussed reducing bacteria (SRB). Similarly, the steam injection into heavy its own specific set of characteristics. These will depend on such this area and H2S concentrations recorded at wellhead are very will be environmental issues related to transportation of crude and extra-heavy oil reservoirs (with high sulfur content) can produce features as the nature of the product and environmental conditions low for this type geological mechanism in which the decomposition oils and refined products. This has become an important area of significant amounts of H2S due to acuathermolysis reactions. where the release occurred. of anhydrite systematically introduce large amounts of H2S. discussion in recent years with issues related to new pipelines vs. transportation by train. Several major environmental issues related On the other hand, the production of H2S can also be linked to Results and Discussion Type of organic matter: The generation of H2S due to presence of to transportation by rail led to this discussion. geologic past, a phenomenon named “geologic souring”. These In the first part of this presentation the primary focus will be on sulfur-rich organic matter in the source rock (La Luna Formation) “indigenous” mechanisms are associated with some elements issues related to unconventional oil and gas exploration, in other of petroleum system. At the present day, the Upper Eocene B may be a possibility. The kerogen in the source rock has marine words hydrofracking. Hydrofracking and related activities can reservoir has concentrations of 20-80 ppm H2S and 4-12% characteristics associated with a reducing depositional environment have many potential impacts on the environment. First I think it CO2, suggesting the same source due to their close geographic with significant sulfur content to generate H2S. is important to emphasize that despite the large numbers of wells association for Franquera, Moporo and La Ceiba (FRAMOLAC) that have been drilled in the US in the past decade, there are oilfields. The Franquera, Moporo and La Ceiba (FRAMOLAC) Biodegradation of crude: The studied crude oils are partially relatively few examples of groundwater contamination following to oilfields situated onshore and assigned to Sur Lago Trujillo Division biodegraded, suggesting that sulphate-reducing bacteria (SRB) the hydrofracking. The two issues here are first the presence of the are located between Trujillo and Zulia States of Venezuela. The chemicals that comprise a very small percentage of the drilling fluid. possibly contribute to H2S formation in the geological past. isotopic composition of sulfur in H2S(g), SO42- from formation One big issue here is the wide variety of chemicals that are used water and crude oil allows to generate a map with the values of and the fact that the oil companies are very reluctant to publish Reservoir temperature: The average temperature in FRAMOLAC δ34S in the interest area in order to study the main processes lists of these compounds. The second issue whether any of these is 273 °F (133 °C) for Unit B-1 and 287 °F (141 °C) for Unit B-4. controlling biogeochemical cycle of sulfur in the reservoir and chemicals or any oil or gas released from the shales actually enters Therefore, these values deny the possibility that H2S is currently understand the predominant mechanism for generation of H2S in the groundwater. I think it is important to remember that is in the caused by sulphate-reducing bacteria (SRB) since these bacteria oil reservoir. best interests of the oil companies not to fracture the ground water only survive at temperatures <170 °F (77 °C) (Machel, 1995), which aquifers. By doing so they will end up producing large amounts Experimental is less than the vast majority of values reported in the study area. of water, which of course is not in their best interest and certainly Several samples of crude oil, formation water and H2S were means loss of profits for them. collected in head well and analyzed for sulfur isotopic relations Correlation δ34S (SO42-) and δ34S (H2S). Figure 1 shows that (34S/32S or δ34S). Crude oil and formation water samples were sulfur isotopes are slightly fractionated during the reduction process Another aspect of the hydrofracking is the need for very large taken in plastic recipients. Separated water samples were filtered (if the cause is due SRB). Therefore, sulfur isotopic composition of amounts of freshwater for the fracking operation. This is an issue through 0.45 µm Millipore membrane and sulfate (SO42-) was H2S produced is different to precursor inorganic-sulfur species. All that has to be addressed since many of these fracking operations precipitated with BaCl2 solution. The gas samples were collected in are underway in areas where there is a severe shortage of values fall below the ranges reported for crude oil and sulfate. well head using a biphasic separator. The gas stream was passed freshwater. This in turn frequently results in friction between local

82 83 isotope ratios. comparison between our method and the NMR method from GS02 University of Nantes, France. Our results show high consistency Results and Discussion for the two methods analyzing propanol (e.g., -28.9 vs. -29.3+/-0.9 The Innovative Applications Of Stable (1) Production Decline Prediction Model per mil for the side carbon of a known standard, Figure 3). However, In the past, production decline trend has been mainly predicted Isotopes In Petroleum Geochemistry the NMR method cannot be readily used for the propane-converted by Arps’ equation (Arps, 1944).However, the b value is poorly propanol from natural gas, due to the low purity. For each chemical constrained and the uncertainty can be significantly large. Our reaction, we closely monitor the isotope values of reactants and YongchunTanga,*, Li Gaoa, Sheng Wua, PanqingHea, Andrei Deeva method provides a new dimension to constrain the production products. This method has been applied to our laboratory natural decline trends. The Barnett Shale Gas well shows large carbon gas and synchronized gas standards from different sources. a GeoIsoChem Corporation, Covina, CA, USA isotope variation (up to 2 per mil) during the study period of time (up to 1 year). The application of our model to this well leads to an [email protected] estimate of the production rate change curve in the next several decades (Figure 1). Copyright 2014, ALAGO. Figure 1. Sulfur isotopic values for crude oil, SO42- of formation water and H2S This paper was selected for presentation by an ALAGO Scientific Committee following (2) On-site Isotope Logging for C1,C2 and C3 gases review of information contained in an abstract submitted by the author(s). Isotopic fingerprint of H2S is more depleted in 34S than SO42- The evolutionary instrument GC-IR2 (Figure 2a) is now scheduled in formation waters, within a relatively small range. A maximum Introduction isotopic fractionation of 3.5‰ suggests that bacterial activity inside for the first field trial in a Utica Field. The data can be presented Carbon and hydrogen isotopes have been widely used in petroleum a “close system” could be involved in the redox process at some in the mud log for direct comparison with other geological data Figure 3.The protocol scheme of analysis of propane intra-molecular geochemistry. Carbon isotopes of hydrocarbon gases provide time of basin evolution. Larger values of isotopic fractionation can (Figure 2b). isotopes (procedures in the box are vigorously calibrated with NMR valuable information of gas origin, maturity, formation temperature, be achieved when the bacterial activity is carried out inside an method). reservoir compartment and many other major aspects of petroleum “open system” (Cavallaro et al., 2006), which is not the case of systems. Hydrogen isotopes provide key constraints on gas FRAMOLAC. Conclusions maturity and gas origin. Use of the C and H isotope ratios has thus We presented a series of novel methods and instruments for the been a routine in exploration and production. Correlation δ34S (crude oil) and δ34S (H2S). The values of application of hydrocarbon gas isotopes in petroleum exploration 34S relatively similar for H2S and crude oil samples (figure 1); and production. Based on advanced isotope modeling and real- δ In addition to the “classic” use, we have developed a series of suggest that hydrogen sulfide was produced in part during the time isotope logging, we have better constrained production decline innovative methods/techniques based on extensive and proprietary transformation of kerogen to hydrocarbons. Later, H2S along prediction; we have made it true for real-time onsite isotope logging research in our group. We’ll present three of them: (1) The innovative hydrocarbons should migrate from source rock to reservoir rock. for the C1, C2 and C3 gas isotope analysisby constructing the interpretation tool for production decline prediction using real-time first field-deployable isotope analyzer; We have also fully calibrated isotope analysis, (2) the world’s 1st real-time, onsite InfraRed Conclusions the method of intra-molecular isotope analysis, which may provide isotope analyzer for C1, C2 and C3 gases and (3) Intra-Molecular The origin of H2S in Eocene B Superior reservoir suggests a mixture new power for hydrocarbon source delineation and origin. isotope method - a new tool for gas isotope geochemistry. of processes that occurred in geologic past, each independent of Acknowledgements the other. The presence of sulfur relatively high in crude oil (1.5- Experimental 1.9%), the quantity of H2S measured (15-80 ppm), the sulfur The funds for this work include DOE, GeoIsoChem Joint (1) Production Decline Prediction Model isotopic compositions similar between crude oil and H2S and Figure 1.Production decline prediction by Arp’s (blue line) and exponential Industrial Consortium, PetroChina fund (13HT10500000038) and We established our model based on our published work in carbon other evidences, allow conclude that: i. H2S was initially formed equations (orange line) for the study well, where t1 is the end time of International Science &Technology Cooperation Program of China isotope fractionation during diffusion and desorption (Xia and Tang, by thermal cracking of organic matter (carbonate source rock) and measuring production rates, and t2 is the predicted time when Arp’s (ISTCP) (2010DFB64070). 2012). The inputs for our model are carbon isotopes of methane ii. Bacterial sulfate reduction (BSR) occurred when the system equation won’t fit. Q1, Q2 and Q3 are the total production amounts in and the production rate record from a production well. The study conditions favored the growth of bacteria. different time windows. References site was a Barnett shale gas well. The δ13C values of C1 were Xia, X.; Tang Y., 2012. Isotope fractionation of methane during natural measured by our field-deployable gas isotope analyzer (NGIA). The Acknowledgements gas flow with coupled diffusion and adsorption/desorption. Geochim. production rates were recorded by our field geologists. Thank to PDVSA INTEVEP (Venezuelan Technological Institute of Cosmochim. Acta77,489-503. doi:10.1016/j.gca.2011.10.014. Petroleum) and PDVSA OCCIDENTE (Petroleum of Venezuela). (2) On-site Isotope Loggingfor C1,C2 and C3 gases Arps, J.J., 1944. Analysis of decline curves. Trans. AIME. 160, 228-247. We constructed the first of its kind field-deployable compound- References specific isotope analyzer, the gas chromatography-InfraRed Cavallaro A. N., Cerroni M., Alberdi M. I., Ostera H. H2S Associated With Isotope Ratio (GC-IR2) analyzer. In this novel instrument, we use Heavy Oils in Reservoirs Under Primary Production: Cases of Grimbeek and the transformative mid-Infrared sensing technology (i.e., the Hollow El Alba Fields in Gulf of San Jorge Basin, Argentina. SPE 103920, 2006 Waveguide) and the latest semiconductor IR lasers to achieve microliter sample injection volume and high accuracy (better than Machel H. G., Krouse H. R., Sassen R. Products and distinguishing criteria 0.5 per mil without the standard gas calibration). of bacterial and thermochemical sulfate reduction. Applied Geochemistry 10, p. 373 – 389, 1995 (3) Intra-Molecular Isotope analysis 2a 2b We established the analytical procedures for intra-molecular

isotope analysis (position-specific instead of compound-specific) Figure 2.The GC-IR2 instrument and the isotope logging data on surface log. for propane. We first purify propane from natural gas (up to 99%), and use a special enzyme to convert propane to propanol. We (3) Intra-Molecular Isotope analysis then use a series of well-controlled chemical methods to convert Compared with previous efforts, our protocol is well-constrained propanol to acetic acids. The position-specific carbon isotopes and complete. For example, we conduct an inter-laboratory can thus be calculated based on bulk propane and acetic acid

84 85 GS03 presence in the subsurface of substance of economic interest as indicate the location of thermogenic gases (above) and the maturity of the GS04 hydrocarbon or metal deposits. As a matter of fact, it has been hydrocarbons (below), with a gas charge in the West and an oil charge in the center of the area. Oil Versus Gas Charge in the Solimões Basin used extensively in both mineralization search and oil and gas The origin of H2S in prospection. In the Solimões basin, around 10,000 points of soil sampling have been studiedfor the amounts and proportions of Conclusions Brazilian Presalt reservoirs Prinzhofer A., Rostirolla S. Magnier C., And Takaki T. hydrocarbon gas (Mello et al, 1996). The two main parameters Surface geochemistry confirms the presence of thermogenic a* a which need to be assessed are the quantification of the superficial gases in the northwestern part of the basin, as already known Erica Tavares de Morais / Eugenio Vaz dos Santos Neto / Hrt-O&G, Ipex bacterial background, hiding the possible presence of deeper through numerous wells. However, the main gas seeps are located Alexandre de Andrade Ferreiraa¬ thermogenic gases, and the understanding of the thermogenic gas in the west of the Urucu fields, and in non-drilled areas, South and [email protected] composition, associated to the usual processes of a petroleum Southeast of Urucu, where no real knowledge of source rocks and a Petrobras R&D Center system (source, maturity, Prinzhofer et al., 2000).Also, the process maturity may be assessed directly, because of the lack of wells. Copyright 2014, ALAGO. of fractionating evaporation of the gas compounds in the soils must The hydrocarbon maturity calculated from surface geochemistry *[email protected] This paper was selected for presentation by an ALAGO Scientific Committee following be modeled. The removal of the main bacterial contribution in the confirms the extremely high maturity observed in the western part review of information contained in an abstract submitted by the author(s). sampled gases is done through a statistical filtering of the data of the basin, with only gas charge. On the contrary, going to the Copyright 2014, ALAGO. (Figure 2a). From the remaining gas samples considered to contain center of the basin, around the Urucu field and in the more southern This paper was selected for presentation by an ALAGO Scientific Committee following Introduction a significant proportion of thermogenic fluids, a model of retention/ areas, the assessed maturity decreases and is associated with oil review of information contained in an abstract submitted by the author(s). The Solimões Basin is located in the remote Brazilian Amazonia evaporation in the soils has allowed to characterize the most active or condensate charges. sedimentary basin. Itcombinesimpressive geological complexities Introduction microseeps (Figure 1). An estimate of the hydrocarbon maturity and difficult logistics which may be comparable in many ways to H2S is a highly corrosive and toxic gas that can cause serious of these active microseeps gives a map of repartition of maturity Acknowledgements deep offshore exploration (Murakami et al., 1993). In order to find damage to health and metals even in tiny concentrations. During through the whole basin (Figure 2b). The authors thank HRT-P and Rosneft for the authorization of adequate exploration guidelines in such a vast, protected and E&P activities in the southeastern offshore Brazilian basins, H2S was presenting these data. inhabited land (450,000 km2), first hand geochemical field data found in some petroleum accumulations within presalt reservoirs. may be considered as paramount to begin to sort out the working References Each possible concern on geological conditions must be taken petroleum systems and to assess the best possible locations for Eiras J.F. and Lima C.C.A. (2008): Petroleum exploration in the Solimões into account because it would govern fluid composition and can oil or gas accumulations. For a good hydrocarbon exploration basin. PetroGeo, May 2008, Manaus, Brazil, 5p. bring impact in development costs of accumulations. This is even campaign, there are two main routes for petroleum geochemistry. more strategic when petroleum exploration is targeting increasingly One, the careful study ofexisting drilled wells and compiled Mello M.R., Gonçalves F.T., Babinski N.A. and Miranda F.P. (1996): deeper carbonate reservoirs, more and more distant from geochemical data of collected fluids in reservoirs together with Hydrocarbon prospecting in the Amazon Rain Forest: Application of coastline in presalt reservoirs. Therefore, representative samples source rocks, cuttings and cores studies. The second main input surface geochemical, microbiological and remote sensing methods. In D. were collected, H2S precipitated and analyzed for measurement comes from surface geochemistry. Quite often, as will be presented Schumacher and M.A. Abrams, eds., Hydrocarbon migration and its near- of δ34S. Results were conclusive and made possible to identify in this study,the latter confirms the information in wells and outlines surface expression: AAPG Memoir 66, p. 401-411. the process (TSR) that generated H2S as well as its respective new and valuable zones of exploration where no wells can serve as S-source (sulfate evaporites). proxies (Mello et al. 1996). Murakami, C.Y., Gonçalves, F.T.T., Eiras, J.F., Becker, C.R., Lima, M.P., Daniel, L.M.F. (1993) Habitat of petroleum in the Solimões Basin, Brazil. 3rd The main objective of this work was to identify the origin of H2S and Well results summary Latin-American Congress on Organic Geochemistry, Extended Abstracts, the respective sulfur source using δ34S of representative samples. In the area of the HRT blocks, the large majority of the wells have Mello, M.R. and Trindade, L.A.F. (eds.), p. 113-115. been drilled in the Northern part. The southern half of the area Experimental presents hardly one or two old wells. As the new HRT wells have Natural gas with hydrogen sulfide was bubbled in a solution of zinc Figure 1: Position of gas wells and thermogenic superficial gases in a C2- Prinzhofer, A. and A.Y. Huc, 1995, Genetic and post-genetic molecular and been also drilled in the already known area, the direct information acetate (2 %) during approximately 30 minutes. Silver sulfide was C3-nC4 triangle. A leakage model allows distinguishing the soil gases isotopic fractionations in natural gases: Chemical Geology, v. 126, no. 3-4, about the stratigraphy of the basin is only available in this area, precipitated as a black solid residue, after the addition of silver linked with the more active microseeps p. 281-290. the southern part being only known by geophysics and through nitrate to the solution; it was filtered and dried in an oven (100 °C surface geochemistry. Prinzhofer A., Mello M.R., da Silva Freitas L.C. &Takaki T. (2000): New during 1 hour). geochemical characterization of natural gas and its use in oil and gas Two Devonian main siliciclastic marine source rocks (Frasnian and evaluation, in M.R. Mello and B.J. Katz, eds., Petroleum systems of South Aliquots of ≈0.5 mg of silver sulfide were weighted in tin capsules Famennian) predominate in the Solimões Basin. The Frasnian aged Atlantic margins : AAPG Memoir 73, p. 107-119. with ≈0.5 mg of vanadium pentoxide. These samples were sediments have been characterized as more oil-prone as compared analyzed in a Flash EA 1112 (Thermo Fisher Scientific) elemental to Famennian shales. The later extension and richness of these two analyzer coupled to a MAT 253 (Thermo Fisher Scientific) mass source-rocks throughout the basin imply a high gas potential in spectrometer for measuring d34S. Sulfur dioxide was used as the the western part of the studied area. This trend is enhanced by a reference gas. severe secondary cracking occurring in the Northwest, due to a local proximity of a magmatic sill with the petroleum system (Eiras The silver sulfides IAEA-S-1 (d34SV-CDT = −0.30 ‰), IAEA-S-2 and Lima 2008). (d34SV-CDT = +22.6 ‰) and IAEA-S-3 (d34SV-CDT = −32.30 ‰) and zinc sulfide NBS-123 (d34SV-CDT = +17.09 ‰) were The extreme thermal stress associated with this part of the basin, used as primary standards for daily correction of the d34SSO2 in associated with the presence of destabilized ferrous minerals, order to obtain the d34S values for the samples. A standardized increases the gas charge by a factor two, and induces unusual cadmium sulfide (d34SV-CDT = +21.9 ‰) was used for calibration geochemical pattern for the gas, as rollover and carbon isotope of the analytical system. Results of d34S are reported in parts per inversion (Prinzhofer & Huc, 1995). thousand (‰) against the international standard Canyon Diablo

Troilite (V-CDT). The precision of d34S values is ±0.2 ‰. Gas surface geochemistry Figure 2: Statistical treatment of surface gas data (projection of gas compositions on the two first Eigen Vectors of a PCA). These parameters Surface geochemistry is the only direct way to assess the Results and Discussion

86 87 The values of d34S measured for H2S recovered in presalt Conclusions GS05 were placed in zip-lock plastic bags and frozen to minimize possible reservoirs gas samples have shown d34S values between ≈ +10 The methodology precipitating Ag2S from H2S makes easier the microbial activity. Iodine, soilEh/pH, elements concentration and ‰ to ≈ +21 ‰ that are considered isotopically enriched in 34S storage, transportation and sample handling. Also it preserves the Preliminary Results of a Surface C5-C17 hydrocarbons extraction samples were collected in the and also typical of thermochemical sulfate reduction (Herbert et original isotopic signature of the sulfur. same manner and left unfrozen. al., 1985). These results overlap the values obtained for anhydrite Geochemistry Studyusing Multiple Methods in samples collected from the Aptian evaporite sequence, ≈ +17 d34S values indicated that the H2S recovered from the studied the Cinzento Diapir Seep, Recôncavo Basin, Passive hydrophobic adsorbent modules were buried and exposed ‰ < d34S < ≈ +22 ‰ (Figure 1). In nature there is no significant presalt reservoirs was generated by thermochemical sulfate State of Bahia, Brazil for approximately seven days, after which they were retrieved and isotopic fractionation between H2S and the sulfur source (Worden reduction (TSR). sent to the laboratory for analysis. et al., 2012). Thus, similar values of δ34S suggest that evaporites Carlos S. Bandeira de Melloa*, Antônio Fernando M.Freireb, Dennis (anhydrite) are the most likely sulfur source for TSR. The correlation between H2S (≈ +10 ‰ < d34SH2S < ≈ + 21‰) J. Millera, Ronaldo C. S. Gonçalvesa, Ana Cristina S.Serrac. Preliminary Results and Discussion and CaSO4 (≈ +17 ‰ < d34SCaSO4 < ≈ +22 ‰) suggests that the Results obtained so far refer to chemical elements, direct gas The reservoirs that gas samples were collected have temperatures anhydrites from the Aptian evaporites were the source for the H2S. a PETROBRAS Research and Development Center (CENPES), measurements,soilEh/pH, microbiology and extraction methods. lower than 100 °C indicating that they were not places suitable for Rua Horácio Macedo, 950, Ilha do Fundão, Rio de Janeiro, RJ Analyses pertaining to the remaining methods are in progress. H2S generation via TSR. This scenario indicates that the generation The relatively low temperatures of the reservoirs where gas samples 21941-915, Brazil. of H2S occurred in deeper parts of the basin and that such gas were collected indicate that TSR reactions took place in other areas b PETROBRAS, Exploration&Prodution, Avenida Chile, 330, Geochemical concentrations were analyzed statistically using the migrated up dip towards shallower reservoirs in the southeastern with higher temperatures. Consequently, H2S may have migrated Centro, Rio de Janeiro, RJ 20031-170, Brazil. Statistica program. The normal and log-normal populationbehaviors offshore Brazilian basins. from deeper beds to traps over significant distances. c fundação GORCEIX wereobtained. The latter, common to the most of the studied variables, were convertedto logarithms and transformed to Z-score Additionally, reactions of petroleum fluid and H2S are other possible Acknowledgements Rua Carlos Walter Marinho Campos, 57, Ouro Preto –Minas Gerais, values to facilitate comparison between different concentration processes that can scrub the H2S from reservoirs as already We acknowledge PETROBRAS for the permission to publish MG35.400-000, Brazil. measurements. The variables were then analyzed through Principal observed in Central Tarim Basin, China. The compelling evidence this paper, to the colleagues of the Geochemistry and Recovery Component Analysis (PCA). The Surfer program was employed to for this type of reactions is the positive correlation between sulfur Technology Laboratories for the analyses and PVT gas sample *[email protected] producenearly 180 maps of geochemical contours, in Z-scores, to content in petroleum and whole oil d34S (Cai et al., 2001). Such collection, and to Clarisse Lacerda Torres for the critical review of determine which variables relate direct or indirectly to the oil seep feature has not been observed yet in the studied basins. Therefore, the manuscript and d34S laboratory analyses. Copyright 2014, ALAGO. at the Cinzentodiapir. this information seems to corroborate that the relatively low This paper was selected for presentation by an ALAGO Scientific Committee following concentrations of H2S in petroleum accumulations in the presalt References review of information contained in an abstract submitted by the author(s). The geochemical contour maps were divided in two main groups, reservoirs found in the southeastern offshore Brazilian basins are Cai, C.; Hu, W.; Worden, R.H., 2001.“Thermochemical sulphate reduction i.e. apical and haloanomalies. The best apical anomalies were originally low. in Cambro-Ordovician carbonates in Central Tarim”, 2001, Marine and Introduction indicated by Z-score sum of Sc, Ce, Rb and K. Beyond these Petroleum Geology 18, 729-741. The CinzentoDiapiris located in the Recôncavo Basin, state variables, F (Figure 2), U, Cu, Pb, Zn, Cd, Ni, Eh and pH also ofBahia, Brazil. The diapir consists of shalesbelonging to the showapical anomalies. The halo anomalies were pointed out by Herbert, B.N.; Gilber, P.D.; Stockdsle, H.; Watkinson, R.J., 1985. “Factors IlhasGroup, whichintruded sandstones and conglomerates of 2,4-Dimethyl Pentane, 1-Heptene and 1-Nonane. Ba, Be, Ca, Ce, controlling the activity of sulfat-reducing bacteria in reservoirs during water the São Sebastião Formation, both Lower Cretaceous in age. Co, K, La, Li, Lu,Mg, Mn, Na, Rb, Sr, Tb, Y and Ybanomalies correlate injection”, Society of Petroleum Engineers, SPE 13978. Conspicuous oil seeps occur primarily at the outcropping contact with the outcropping diapir, which corresponds to an area of finer between shales of the Ilhas Group and conglomerates of the São grain size (silt-clay).Ratios of U, Th and K also show correlation with Worden, R.H.; Smalley, P.C.; Fallick, A.E., 2012. “Sulfur cycle in buried Sebastião Formation(Fig. 1).The purpose of this study was to test the hydrocarbon seep at the diapir, U/Th normalization indicated evaporites”, Geology 25 (7), 643-646 different surface geochemistry methods at a well exposed onshore an apical anomaly and the K/Th normalization pointed out a halo oil seep. anomaly.

Thediapir area was studied employing the following methods: Direct gas measurements in soil indicated anomalous values traditional soil headspace sampling, direct gas readings from for total gases and CO2 within and surrounding the diapir. The probe samples, adsorbed gases (acid extraction), iodine microbiology method did notproducesignificant anomalies in the concentration, geomicrobiology, molecular biology, extraction for studied. higher molecular weight compounds (C15+), fluorescence, soilEh/ pH, elements concentration,passive adsorbent modules and Conclusions aC5-C17 hydrocarbons extraction method.Soil grain size was also This preliminary study sheds light on the possibility of detecting determined to better understand the distribution and dispersion of geochemical anomalies using methods other than the traditional geochemical results. surface geochemistry methods such as headspace, through which light gases (methane, ethane, propane, butane and pentane) are Sampling procedures measured for oil and gas exploration. It was possible to increase Sampling was performed in 97 stations located throughout the the robustness of the geochemical results employing multiple diapir and its surroundings (Fig 2).Soil samples for headspace methodswhich correlate directly or indirectly with the oil seep. analysis were collected in plastic containers with metal lids (Isojars) adding water and a bactericide solution.A soil probe was used to Acknowledgements The authors thank PetroleoBrasileiro SA – Petrobras and the Figure 1. Sulfur isotopic composition of H2S from presalt reservoirs and of penetrate the soil in order to collect gases for direct measurements. For microbiological analyses soil samples were collected with Brazilian Petroleum Agency - ANP for permission to publish. anhydrite (Aptian evaporites). Notice the overlap between the d34S of both propersterilized equipment to warrant asepsis.All samples We also thankFernando Pellon de Miranda for suggestions and groups of samples suggesting that anhydrite is the most likely source of were frozen, including a selected number of samples for DNA revision. sulfur for TSR. Non overlapped part of the d34S of precipitated from H2S sequencing. References can be, probably, derived from evaporite facies not yet sampled. Soil samples for adsorbed gases, C15+ extraction and fluorescence Bandeira de Mello, C.S., Gonçalves, R. C. S., Miller, D. J., Freire, A. F. M., Suaznabar, B. R. 2014.Levantamento Geoquímico de Superfície na região

88 89 do Diápiro do Cinzento na Bacia do Recôncavo, BA. Relatório Técnico Final GS06 Figure 2. Plot of 84Kr/4He vs CO2 content (%) for the different analysed para a ANP. Results and Discussion reservoirs (reservoir baseline, circles), the different analysed soil samples Geochemical monitoring: baselines for the Concerning in situ measurements on soil points, the average CO2 (soil baseline, triangles) and the future injected CO2 (hypothesis, crosses) flux obtained was equal to 0.06±0.04 mol.m-2.day-1 during the M1 in the cases of 1) an oxycombustion capture process and 2) an amine Silliman, A. H. & Anderson, H. S., 2014. Geochemical Survey of an Onshore surface (soils) and for reservoir fluids of the MacroseepDiapirodoCinzento, Reconcavo Basin, Brasil, Technical Report survey campaign and equal to 0.056±0.053 mol.m-2.day-1 during capture process. for Petrobras. “Zapatos-Mata R” field, “Area Mayor Anaco”, the M2 survey campaign. The carbon isotopic composition of CO2, Eastern basin, Venezuela. δ13CCO2, of the 10 soil samples analysed during both the M1 and Conclusions M2 survey campaigns are comprised between -11.9±0.3‰ and In the event of a leak, the appropriate monitoring strategy includes Bruno Garciaa, Virgile Rouchona, Victor Alcobiab, Mercedes -22.3±0.3‰. The air/soil mixing model process (for the calculation a good knowledge of the reservoir geology and particularly of the Cavanic¬ of the δ13CCO2 values of soil samples) gives a range of δ13CCO2 structural aspects. Structural drains (where leaks can probably from -18‰ to -26‰ (figure 1). occur) must be identified and typified together with associated a IFP Énergies nouvelles (IFPEN), Direction Géosciences, 1 et 4 geo-fluids. 4 different geo-fluids are identified as end members avenue de Bois-Préau, 92852 Rueil-Malmaison Cedex – France The compositions of the different reservoirs sampled during the and must be typified for an efficient monitoring survey (reservoir, b Beicip-Franlab, 232, Avenue Napoléon Bonaparte, 92502 Rueil- M1 and M2 survey campaigns (from well-heads) follow the same aquifer, injected CO2 and soil). Depending on structural features Malmaison Cedex - France trend: CH4 is the major gas component ≈ 70%vol, followed by of reservoir and specific natural compositions of the fluids, different c PDVSA GAS. Nueva Esparta Avenue, PDSVA GAS Building, South C2 ≈ 10%vol, CO2 and C3 in the same order of concentration ≈ strategy can be applied that will have to be determined during Hill Sector, 6001 (zip code) Barcelona, Anzoátegui, Venezuela 8%vol, and finally C4 and C5 represent ≈ 1-2%vol. The carbon- baseline determinations. isotopic composition of these reservoirs provide information on [email protected] gas sources. The carbon isotopic composition of CH4, δ13CCH4 In our case, the gas compositions obtained at the surface and displays a value of ≈ -45‰ (M1 and M2 survey campaign for all field subsurface, together with the natural CO2 fluxes and contents Copyright 2014, ALAGO. samples) suggesting a thermogenic source. For CO2, δ13CCO2 from soils can be used as a basis of methodological guidelines: This paper was selected for presentation by an ALAGO Scientific Committee following values are range from ≈ -2‰ to -15‰. These values can result review of information contained in an abstract submitted by the author(s). from a mixed thermogenic/inorganic source. For the other HC Leak detection at surface level: i) low natural CO2 fluxes and contents compounds, δ13C values ranging from ≈ -32‰ to -26‰ are not are well suited to surface leak detection. ii) isotopic composition Introduction discriminatory. of carbon (δ13CCO2) for soil samples has been identified as the PDVSA is launching an industrial project of Enhancing Oil Recovery most discriminatory geochemical signature to detect an eventual by CO2 injection (EOR-CO2). In a second phase, this project CO2 leakage. Finally, iii) the methane isotopic composition of the will probably gear up as a candidate for a pilot study involving reservoir, much lower than atmospheric methane composition is carbon capture and storage (CCS) if prerequisites are met. In a well suited to leak detections at the surface. context of safety and public acceptance for EOR process and underground CO2 storage, a surface background of natural CO2 Leak detection at both reservoir and aquifer levels: i) the CO2 Figure 1. Geologic map and planned sample stations of the shale diapir area. content and surface fluxes prior to the EOR-CO2 and/or CCS isotopic composition of the reservoir, much heavier than biological need to be performed. Complementary to the surface monitoring, CO2 composition is well suited to track injected CO2 occurrence in an integrated geochemical study of subsurface elements, including soils. ii) high He abundances in reservoirs (compared to atmosphere) fluid reservoirs, was performed. It compiles data and sets up a will trace efficiently leaks at both the surface level and aquifers. reference geochemical baseline, an absolute prerequisite step in Noble gas composition of reservoirs is the most discriminatory the preparation of any EOR-CO2 project. geochemical signature to detect an eventual CO2 leakage at any reservoir level or aquifer (figure 2). From two survey campaigns (M1 and M2) accomplished in 2012, the gas composition of soils, the control of the variability of this Figure 1. δ13CCO2 (per mil) in function of 1/ (CO2%vol) in a log scale, for References natural composition through time as well as the geochemical soil samples. Garcia, B., Hy Billiot, J., Rouchon, V., Mouronval, G., Lescanne, composition of different reservoir fluids have been performed. A M., Lachet, V., Aimard, N. A Geochemical Approach for Monitoring complete baseline has be obtained and will serve as reference to The noble gas compositions of the fluids from reservoir and soil a CO2 Pilot Site: Rousse, France. A Major gases, CO2-carbon characterize potential CO2 leakage during future injection and then points display specific signatures and provide information in term isotopes and Noble Gases Combined Approach (2012). Oil Gas assess the safety of the storage processes. of early identification of gas breakthrough (figure 2). Science and Technology, vol. 67; pp. 341-353.

Experimental The IFPEN methodology for geochemical monitoring: Description This methodology developed these last years is a major-gases, CO2-carbon-isotopes and noble gases combined approach Figure 2.Z-score contour of the fluorineanomaly. The orange area correlates (Garcia et al., 2012). roughly with the outcropping diapir. In this project, - in situ measurements of i) HCs and CO2 contents and ii) CO2 fluxes for the surface (soils) were realized. Moreover, samplings of gas were performed for i) CO2-carbon isotope and ii) noble gas analyses at laboratory. For each M1 and M2 survey campaign, a total of 50 soil points were measured in situ and, 10 soil points together with 10 wells (reservoir fluids) were sampled for complementary laboratory analyses.

90 91 GS07 of X-ray diffraction (Siemens XD-8 Advance) and sulfur content, in the samples, where the main mineralogical phases are calcite, vanadium and nickel concentrations by inductively coupled plasma quartz, kaolinite, illite, montmorillonite, plagioclase, and traces of OIL GEOCHEMISTRY atomic emission spectroscopy (ICP-AES). Bitumen was extracted pyrite minerals. Both montmorillonite and illite could be responsible Recognition of Onshore Surface Seeps with dichloromethane in a Soxhlet extractor, and then quantified. for catalyzing the conversion of sterenes to diasterenes (with and Microseeps by Determination of Soil OG01 In the bitumen extract, after asphaltenes precipitation, the maltene a rearranged structure), which are then reduced to diasteranes. Diamondoid Concentrations fraction was separated into its saturated, aromatic and resin Thus, in agreement with our findings, oils from clastic source rocks fractions by means of adsorption chromatography, using alumina tend to be rich in diasteranes. The concentrations of V (187-3840 Jeremy Dahl1, J.M. Moldowan2, Micaela Nali3, and Roberto Hydrocarbon Generation Potential in The as the stationary phase. The saturated hydrocarbon fractions were ppm) are higher than those of Ni (40-246 ppm), and the values of Galimberti3 Talara Basin, Peru eluted with n-hexane, the aromatic hydrocarbon fractions with the V/(V + Ni) ratio are in the range of 0.7-0.9. Sulfur contents are in toluene, and the resin fractions with a toluene:methanol mixture. the range of 0.7 to 1.5%. These results are typical of sedimentation Stanford University Liliana López,Sandra Casado, Johnatan Soto and Salvador Lo Detailed analyses of the saturated and aromatic biomarkers were under suboxic conditions with low availability of S. Biomarker Technology International Mónaco performed by gas chromatography-mass spectrometry (GC-MS) ENI coupling a network gas chromatograph (Model 6890N, Agilent Conclusions ENI Instituto de Ciencias de la Tierra. Facultad de Ciencias. Universidad Technologies) to a mass spectrometer (Model 5975, Agilent The core rock samples were identified as possible source rocks Central de Venezuela Technologies). In this case, the GC system was equipped with a with the following overall characteristics: (a) siliclastic lithology, Recognition of onshore and offshore hydrocarbon seeps and type DB-1 or a type DB-5 fused silica capillary column (60m x 0.25 (b) mixed marine-terrigenous organic matter (type II-III kerogen), microseeps has been a fundamental aspect of petroleum [email protected] mm x 0.25 μm) to analyze the saturated and aromatic fractions (c) marine shale depositional environments with suboxic to oxic exploration since the inception of the industry. Thousands of respectively. The monitored ions were: m/z = 113, 191, 177, 217, conditions, (d) early mature to onset of oil window maturity, and (e) years ago, oil was collected for use where it leaked out of the Copyright 2014, ALAGO. 218 for n-alkanes and acyclic isoprenoids (pristane and phytane) regular to very good generating potential. ground. Later many of these same sights were targeted for drilling This paper was selected for presentation by an ALAGO Scientific Committee following terpanes, steranes and diasteranes; m/z = 178, 192, 184, and 198 and became some of the first oil fields. Success onshore was review of information contained in an abstract submitted by the author(s). for phenanthrene, methylphenanthrenes, dibenzothiophene and Acknowledgements duplicated offshore, with the recognition of subsea seeps generally methyldibenzothiophenes, respectively. This work was funded by the Consejo de Desarrollo Científico y through the analysis of piston cores. Introduction Humanístico, Universidad Central de Venezuela, under the research The Talara Basin is located in the NW coast of Peru and includes Results and Discussion grant N° PG-03-8204-2011 and Fondo Nacional para la Ciencia y With most of the major onshore seeps already mapped, it became sedimentary sequences containing rocks from the Paleozoic to the All the samples presented TOC contents in the range 0.9-2.9%, Tecnología, under the research grant N° 2012002299. We thank necessary to recognize and map microseeps. A variety of Tertiary ages. The Muerto (COT = 1.0-4.5%) and Redondo (COT < reaching TOC contents > 5% only in a few cases. Lateral and the Laboratory ChemiConsult of Venezuela for donating the drilling methods have been employed for this end including subjecting soil 1.0%) formations from the Cretaceous age, which contain kerogen vertical variations in the TOC contents were observed, where the LA cuttings samples from the Talara Basin. References samples to hydrocarbon gas and liquid extraction and analysis type II and II-III, have been considered as possible source rocks and OL wells presented TOC contents in the order of 6% whereas and microbial studies including DNA analyses. (Martínez et al., 2005). Moreover, the Heath Formation from the the TOC contents in the CO and ZA wells reached maximum Fildani, A., Hanson, D.H., Zhengzheng, C., Moldowan, J.M., Tertiary (Oligocene) age, which is characterized by the presence values of 2%. This result indicates the wide variability of the organic Graham, S.A., Arriola, P.R., 2005. Geochemical characteristics of Recently, we showed that the measurement of diamondoid of high input of terrigenous organic matter, was also proposed matter input of the basin. Samples with TOC content ≳ 1% can oil and source rocks and implications for petroleum system, Talara concentrations in piston core samples could be a valuable tool for as a possible source rock (Fildani et al., 2005). Although these be considered good source rocks, and those with TOC content Basin, northwest Peru. American Association of Petroleum Bulletin recognizing offshore oil and gas seeps. In many areas, even though studies indicated the high potential for hydrocarbon generation > 4% are considered excellent source rocks. The TOC content 89, 1519-1545. other methods fail to detect gas seeps, diamondoid concentrations in the Talara Basin, it is necessary to further identify the possible values obtained suggest that the samples are potentially good can rise an order of magnitude above the background. As such, source rocks through a detailed evaluation of oil-oil and oil-source source rocks. On the other hand, the samples are characterized Martínez, E., Fernández, J., Calderón Y., Hermoza, W., Galdos, measuring diamondoid concentrations in piston core extracts rock correlations of different stratigraphic sequences, in addition by the presence of kerogen type II and II-III, with Tmax value in the C., 2005. Tumbes and Talara Basins Hydrocarbon Evaluation. can be a highly valuable method of mapping offshore seeps and to establishing the petroleum systems. Here, we present the range of 443-440°Cindicating that these samples are early mature PERUPETRO S. A. microseeps. study of drilling cuttings samples extracted at different depths to onset of oil window maturity. The bitumen concentrations in from four wells in the Talara basin for source rock evaluation and the samples are distributed within a wide range from 300 to 4000 As a result of this success, we were curious as to whether we determination of the depth intervals with potential for hydrocarbon ppm. The hydrocarbon/resin ratios as determined from the SARA might be able to map out onshore surface seeps of oil and gas generation. The potential of the samples as source rocks was compositions are close to 1. Figure 1 shows a typical example of using diamondoid concentrations in soil. To test this method we determined through the evaluation of lithology, organic matter a mass chromatogram for n-alkanes and acyclic isoprenoids (Pr = mapped diamondoid concentrations over a known oil accumulation type, depositional redox environment, thermal maturity level, pristane and Ph = phytane), terpanes and steranes. All analyzed the and compared the values to surrounding areas. We showed that and hydrocarbon-generating potential, using a combined suite samples presented Pr/Ph in the range from ≤ 1.0 to 1.9, the high diamondoid concentration over the oilfield are generally higher than of rock analyses: (1) mineralogical composition, (2) total organic pristane/phytane ratio and plot pristane/n-C17 vs phytane/n-C18 in the surrounding area, in some cases by an order of magnitude. carbon content, (3) bitumen concentration, (4) SARA (saturated, indicate that these source rock contain mixed terrigenous and We believe this method could become a powerful tool for the aromatic, resins and asphaltenes) composition in bitumen extracts, marine type II-III and terrigenous type III organic matter deposited recognition of onshore microseeps. Furthermore, we believe this (5) biomarkers in saturated hydrocarbon fractions, (6) aromatic under suboxic to oxic conditions (Figure 2). Additionally, in will be the best method for mapping seeps of high-maturity fluids markers in aromatic hydrocarbon fractions, (7) rock-eval pyrolysis, homohopanes distribution (C35< C34), is, typical of suboxic to oxic like gas and condensates, which contain high concentration of and (8) trace elements (e.g., V and Ni). conditions during source rock deposition. The correlation between diamondoids, especially since many of the other methods have dibenzothiophene/phenanthrene and Pr/Ph ratios suggests that the limitations for recognizing these types of fluids. Experimental samples come from marine shale. On the other hand, the regular Forty two drilling cuttings samplesin fourwells(LA,CO, OLandZA) steranes distributions and the abundance of C27 steranes relative from the TalaraBasin(Peru) were analyzed. The total carbon to C29 steranes, as well as the presence of for tricyclic terpanes, (TC) contents were determined using a carbon analyzer (LECO, suggest a contribution of marine organic matter input. In addition, C-144). The inorganic carbon or carbonatic carbon contents the presence of 18α(H)-oleanane in some intervals, indicates the were measured using the Bernard calcimeter method and total presence angiosperm plants during the sedimentation of source organic matter (TOC) was determined by difference. Kerogen type rocks from the Cretaceous to the Tertiary ages. The relationship and maturity level were determined on a standard Rock-Eval-6 between steranes and C27-diasteranes [C27-diasteranes/(C27- following basic methods for whole rock analysis. For ten selected diasteranes+steranes)] suggests the presence of siliclastic lithology samples, mineralogical composition was determined by means

92 93 OG02 following method was applied: API gravity and elements (V, Ni and hydrocarbon’s thermal evolution must be located in a maturity Figure 1. Mass chromatograms of the n-alkanes and acyclic isoprenoids S) determination, GC of C15- fraction, SARA composition, δ13C range of 0.9% ≤ Ro ≤ 1.3 - 1.6 (Pirela et al., 2013). determination of whole oil, saturated and aromatic fractions, and (m/z = 113, top) terpanes (m/z = 191, middle) and steranes (m/z = 218, New gas-condensates reservoir on Golfo de bottom) in the saturated hydrocarbon fractions isolated from the bitumen specific compounds determination (diamondoids). Regarding hydrocarbons origin, assessed by steranes, seems to of sample from OL. Venezuela Basin, Offshore, Venezuela. Source be associated with type III/II kerogen with terrestrial predominant rock and fluids geochemical characterization On the other hand, rocks samples (cuttings and core) were collected organic matter input. However, isotopic correlations between from 12 wells located offshore and onshore on Golfo de Venezuela saturates and aromatic hydrocarbons suggest a marine origin. Pirela, M.a; Berrios, Ia Basin. These wells grouped samples from Tertiary and Cretaceous Steranes also indicates that lithology associated is siliciclastic, . intervals. Samples were characterized based on results coming and isotopic data (total 13Coil δ-23 ± 0.3 ‰) suggests a Miocene a E&P General Management, PDVSA Intevep, S.A. Los Teques, from Rock Eval Pyrolysis, organic petrography, and biomarkers source rock (Peters et al., 2005). P.O. Box 76343 1070-A, Venezuela according to organic matter’s content, type and thermal maturity. Results and Discussion Previous results correlate with rock’s geochemical characterization e-mail: [email protected] which suggests Miocene (TOC>2%; type II kerogen; immature) and Gas sample’s results (Well-2, -3 and -4) reflect values below 95 Oligocene (TOC 0.5 -1%; type II/III kerogen; immature) intervals Copyright 2014, ALAGO. % in CH4 (wet gas) along with a value greater than 4% for C2H6 as potential source rocks on offshore wells located on (Well-1,- This paper was selected for presentation by an ALAGO Scientific Committee following (ethane) and more than 7% of compounds C2+, also indicates 2,-3,-4 and -5). However, Cretaceous intervals (TOC 3%; type II/ review of information contained in an abstract submitted by the author(s). the source of generation is associated with hydrocarbon type III kerogen; mature to overmature) were main potential source rock condensate. on onshore wells (Well-9,-10,-11,-12). Introduction Offshore exploration studies are currently one of the main objectives On the same way, C2-C5 alkanes (including iso-butane) δ13C All geochemical results are consistent with Golfo de Venezuela of the Venezuelan oil industry; these have been extended in several isotope suggests that gas were originated from type III-II kerogen basin geological literature (e.g. Contreras, 2011; VIPA, 2000) areas: East, Nor-east, Center and Western (Golfo de Venezuela thermal cracking (thermogenic gas). Difference between ethane and about existence of two regions (North Eastern and South Western) Figure 2.Pristane/n-C17 versus phytane/n-C18 showing the type II-III and Basin) regions of country. propane also indicate that gas in reservoir has been generated by separate by a tectonic feature known as Urumaco Through (Figure type III kerogen in samples from Talara basin. organic matter’s primary cracking, and it is maturity is equivalent to 1) and Lagarto system fault. On first region, absence of Cretaceous In 2009 was drilled the first wells on northeast of Golfo de Venezuela 1.1 % Ro and required a temperature above 180°C for generation. intervals suggests that tectonic events (possibly movement of the Basin (Cardon IV Field; Figure 1) and confirms the existence of gas On same reservoir, liquid petroleum (condensates, type crude Caribbean plate during Paleocene-Eocene; Escalona and Mann, and light oil on Tertiary carbonate facies. Due to this discovery, has oil paraffin) displayed API gravity values equal to 49° correlating 2011) associated with Urumaco Through and Golfo de Venezuela been of great interest since it is estimated that more than 10 TFC with SARA composition: saturated hydrocarbons (70 wt%) and basin formation have caused erosion of older Oligocene sequences. remain on the area, generating an intense exploration activity that aromatics (30 wt%), with no concentration for asphaltenes and This is supported by high maturity degree reached by Cretaceous including drilling new wells in order to understand the petroleum resins fractions. In fact, distribution pattern suggests a greater sequences in South Western region and correlates with maturity system on the area and to assess the genesis of hydrocarbons prevalence of lower molecular weight compounds

Cretaceous sequences absence on North East region along with presence of same age sequences (potential source rocks) in ` South Eastern region suggest existence of at least two petroleum systems in Golfo de Venezuela basin. First one Tertiary-Tertiary (totally different and new) and second one made up of Cretaceous- Figure 1. Golfo de Venezuela basin’s relative location Tertiary (traditional petroleum system found onshore).

In this sense, this work presents rocks and fluid geochemical Acknowledgements characterizations with main objective to establish oil-oil, and some The authors thank PDVSA Intevep for permission to publish this cases oil-rocks correlations to determine if there are more than one work. oil family or source rocks on the area. References Experimental Pirela, M.; Pérez, A.; Berrios, I., 2013. Geochemical characterization Gas and condensates samples were collected from Wells 2,3 and of discovery new gas-condensates reservoir on Golfo de Venezuela 4 to characterize fluids present in Cardón IV field. Interval evaluated Basin, Offshore, Venezuela. On: 26th International Meeting on Organic corresponds to a sequence calcareous from early Miocene Figure 2. Well-2, -3 and -4 total oil crude chromatogram Geochemistry (IMOG), Tenerife, España, September 2013. (Cuauderalito Member) with a thickness of approximately 750 ft, located (by electric logs) between 9000 - 9700 ft to depth. On the other hand, various geochemical parameters related to Peter, K., Walters, C.; Moldowan, M., 2005. Biomarkers and Isotopes in Gas samples were analyzed by chemical and molecular oil maturity (diamondoids, isoprenoids relations and n-paraffins, Petroleum Exploration and Earth History, Cambridge University Press. composition based on the procedure described in analytical norm n-heptane and iso-heptane indexes) show no clear definition as Stanford. COVENIN 2569-89 and δ13CH4 was determined using isotope to this aspect is concerned. Considering all maturity parameters, ratio GC (GC-C-IRMS). Furthermore, for oil characterization

94 95 Escalona, P.; Mann, P., 1995. Tectonics, basin subsidence mechanisms, OG03 fractions and bitumen extractions supported version of marine bituminous shale of Bazhenov formation. The differences could be and paleogeography of the Caribbean-South American plate boundary (type II) or mixed (type II/III) source rock (Peters et al., 2004). explained by regional variations in source rock properties toward the zone, Marine and Petroleum Geology. 28, 8-39. Normally oils from Bazhenov source rock have generally higher borders of the basin, where Bazhenov was deposited in shallower Origin of oil in western Shaim region, sulfur content (>1.0 wt.%) and result from sulfate-reducing bacteria depositional environments. Absence of strong arguments in biomarker’s characteristics in favor of significant input of terrestrial Contreras, D.R., 2011. Defining the Northeastern boundary of the West Siberian Basin, Russia activity, primarily in anoxic marine sediments and low Pr/Ph ratio organic matter from the Ural Mountains can be explained by their supergiant Maracaibo foreland basin, Venezuela. Geos 41:94-95. Master (<1.1 or even lower). Whilst typical oils from Tyumen fm show lower a b* relatively low relief and predominance of chemical weathering. Dissertation. University of Texas. Makarova A. , José R. Carballo sulfur content (0.01 wt.%) and higher Pr/Ph = 4 (Peters et al., 1994). Oils from both intervals show medium sulfur content = 0.4 Conclusions a Repsol-Russia Visión Integrada del Potencial Petrolífero de Venezuela, 2000. PDVSA. wt. %, and from Yereminskoye field = 0.9 wt.%. Results of geochemical analyses provide evidence that b Repsol Sinopec Brasil Internal Report. hydrocarbons from Lower Cretaceous Vikulovo and Leushinskaya The regular stair-step progression of C31-C35 homohopanes in reservoirs are genetically related to oils from Shaim region and [email protected] combination with value of ratio C31 22R/C30 hopane ranging were generated from Upper Jurassic - Lower Cretaceous organic from 0.38 to 0.41 are consistent with suboxic bottom water during facies analog to bituminous shale of Bazhenov formation. These Copyright 2014, ALAGO. deposition under marine shelf condition. Relative depletion of accumulations of oil rims with gas caps in Karabashskiy area result This paper was selected for presentation by an ALAGO Scientific Committee following 28,30-Bisnorhopane compared to typical high-sulfur Bazhenov- from the process of separation-migration of originally single-phase review of information contained in an abstract submitted by the author(s). sourced oils also indicates oxic-suboxic environment. fluid deposits, containing oil and trapped in Jurassic reservoir. Strike-slip faulting in Pre-Jurassic basement in Oligocene time caused pressure release followed by phase separation, fluid Introduction A ternary diagram of 20R epimers of 5α(H),14α(H),17α(H) forms of West Siberian Basin (WSB) is a quite mature basin and new C27-C28-C29 steranes (“regular” steranes) was used to distinguish migration into shallower position and retrograde condensation. discoveries are rare. However, some areas, particularly in the groups of crude oils from different source rocks. Oils from Tyumen Shallow depth favored microbial activity in Vikulovo reservoir resulting in nonhomogeneous biodegradation of oil within the western and eastern borders, remains basically unexplored source rock are more abundant in C29 regular steranes due to reservoir. as they have been classified as “low potential”.Recent drilling high contribution of terrestrial organic matter to the sediments. results in the westernmost area WSB show that Jurassic and As distinct from them oils from Bazhenov source rock are rich in It has to be pointed out that the results presented in this study Cretaceous petroleum plays extend further to the west from the C27-C28 streranes. All oils from Shaim region, including oils from Karabashskaya area have C27-C28-C29 steranes in nearly equal are not conclusive and on-coming drilling campaign should help known hydrocarbon accumulations. Existing geochemical models concentration. Also ternary diagram of C27-C28-C29 diasteranes in solving problems such as reservoir continuity, oil and gas (Kontorovich, et al.) indicate that Jurassic organic reach facies, (rearranged steranes) was used to support oil-oil correlation. composition changing, level of biodegradation, which can impact which represent the major sources of hydrocarbon in the basin, greatly the economic value and producibility of petroleum. significantly degrade toward the borders of the basin showing poor During burial and maturation R configuration at C-20 steranes are TOC content and generally being immature to barely mature for gradually converted to a mixture of R and S configuration, causing References hydrocarbon generation. A detailed geochemical study based on an increase in ββ/ (ββ+αα), until equilibrium is reached (Peters et GC-MS, biomarker and stable δ13C isotope analysis of oil samples al., 2004). On the same basis isomerization at C-22 in C31-C35 Haworth, J., M. Sellens, and A. Whittaker, 1985, Interpretation of has been performed in order to establish genetic relationships homohopane takes place, resulting in increasing of 22S/ (22S+22R) hydrocarbon shows using light (C1-C5) hydrocarbon gases from mud-log with the known hydrocarbon source rocks and oils in the western ratio. In order to evaluate oil maturity two plots were used: 20S/ data: AAPG Bulletin, v. 69, p.1305-1310. G. Gogonenkov, A.Timurziev “Strike-slip faulting in the West Siberian border of the basin. (20S+20R) vs %C29ββ/(ββ+αα) for the C29 sterane; %C3222S/ (22S+22R) vs %C2920S/(20S+20R). In comparison with oil related Platform: Insights from 3D seismic imagery”, C. R. Geoscience 344 (2012) 214–226 Experimental to Tyumen source rock and majority of oils related to Bazhenov source rock, oils from Vikulovo and Leushinskaya reservoirs are Three samples of crude oils, including 2 tested oils from the first less mature and correspond to early-middle oil window. The ratio A. Kontorovich et al. “Main oil source formations of the West Siberian exploration well and one heavy oil from Yeremenskoye field have Basin”, Petroleum Geoscience, Vol. 3 1997, pp. 343-358 of C30 17β,21α (H)-moretane to their corresponding 17α,21β (H)- been analyzed by standard GC on Agilent Technologies 7890A GS hopane decreases with thermal maturity from ̴ 0.8 to 0.15 (and System. GC-MS analyses of crude oils and rock bitumens were even less), these values for Vikulovo = 0.13, Leushinskaya= 0.13 A. Milkov “Methanogenic biodegradation of petroleum in the West Siberian performed using CLARUS 500 (PerkinElmer) gas-chromatograph- and Vikulovo (Yereminskoye field) = 0.07 are coincide with values Basin (Russia): Significance for formation of giant Cenomanian gas pool”, mass spectrometer after separations into saturated and aromatic typical for mature oils. AAPG Bulletin, V.94, No.10, October 2010, pp. 1485-1541 hydrocarbons. Calculation of relative content of each compound was done by method of simple peak area normalization. GC of three related oils show different degree of biodegradation. K.E. Peters, C.C. Walters, J.M. Moldowan “The biomarker guide” Volumes Compared with the non-biodegraded oil of Leushinskaya fm, the 1,2, 2004 Also geochemical analyses results of 23 oil samples from wells in oil of Vikulovo fm is slightly biodegraded as indicated by the loss of K.E. Peters, A.Eh. Kontorovich, B.J. Huizinga, J.M. Moldowan, and C.Y.Lee Shaim region (from Neftex research company) and published data n-alkanes. While the moderately biodegraded oil from Yereminskoye “Multiple oil families in the West Siberian Basin”, AAPG Bulletin, V.78, No.6 of 32 oil samples (Peters, Kontorovich et al., 1994) of the entire field (Vikulovo fm) shows a more severe biodegradation evidenced by the loss of both n-alkanes and acyclic isoprenoind.API gravity (June 1994), p.893-909 WSB widely distributed by geographic locations and reservoir age decreases with increasing biodegradation among oils: 33 API in were selected andintegrated in the study for correlations. Leushinskaya, 28 - Vikulovo, 19 - Vikulovo (Yereminskoye field). V.A. Savenko, “Paleogeography and paleomorphology of Upper Jurassic Comparison of GC of oils from Vikulovo reservoir from different – Neocomian sediments in Shaim oil and gas bearing region and adjoining Results and Discussion depth show excellent vertical biodegradation gradients, with areas of West Siberia”, Lithosphere, 2011 Analyzed oils from Vikulovo and Leushinskaya fm show degree of biodegradation increasing toward the OWC, because of geochemical characteristics that indicate deposition under marine presence of water. Shallow depth of the reservoir as well favors S.R. Silverman “Migration and segregation of oil and gas”, conditions. GC of saturated fraction of oil from Leushinskaya fm biodegradation, because of low temperature and sufficient porosity has an unimodal n-alkanes distribution maximizing at n-C17-C18, to allow the diffusion of nutrients and bacteria activity. A.Timurziev “Strike-slip neotectonic in sedimentary basins: tectonophysics abundance of which gives the evidence of algal contribution to As indicated by similar distribution of n- and i-alcanes, steranes and and fluid dynamics”, ScD theses, 2009 source rock and relatively high thermal maturity. Oils from Vikulovo diasteranes, triterpanes, monoaromatic and triaromatic steroids, A.V. Vyssotski, V.N. Vyssotski, A.A. Nezhdanov “Evolution of the West and Leushinskaya fm have Pr/Ph ratio in the range 1.15-1.2, oils from Vikulovo y Leushinskaya reservoirs are genetically related Siberian Basin”, Marine and Petroleum Geology, 23 , 2006 which as well very typical for low-wax oils from marine source to oils from Shaim region. Therefore, HC from Karabashskiy area rock. Analysis of Pr/nC17 versus Ph/nC18 for crude oils, saturated most likely were generated from Jurassic organic facies analog to

96 97 OG04 temperature was 310 °C. The quadrupole mass spectrometer OG05 was operated in full scan mode over the mass range 50–650 Da Identification of aryl isoprenoids in oils from (EI mode at 70 eV). Collision Energy 10 eV. Collision Gas Ar. For Geochemical evaluation of oil migration in data acquisition by selected reaction monitoring (SRM) the masses Sergipe–Alagoas Basin, northeastern Brazil Stromatolites Samples: influence of water according to Figure 2(a) were used for the two compound groups formation salinity using Triple Quadrupole GC-MS/MS under investigation. The identification of biomarkers was done by comparison of elution order, retention times and mass spectra with Antônia L. da S. Santosa, Edymilaís da S. Sousaa, Gustavo R. Rafael C. Pachecoa*/ Eliane S. DeSouzaa/ LeonamBragaa literature data (Summons and Powel, 1987; Peter et al., 2005; Santos Júniorab, Marcio dos S. Rochaa, Zhang et al., 2011; Santos Júnior et al., 2013) José A. D. Lopesa, Antônia M. G. L. Citóa, Francisco de A. M. PETROLEUM ENGINEERING AND EXPLORATION LABORATORY Reisb, Igor V. A. F. de Souzac, Sidney G. de Limaa*. (LENEP/UENF), MACAÉ, BRAZIL. Results and Discussion a Universidade Federal do Piauí – UFPI , Laboratório de Geoquímica Figure 1 showed the distribution of aromatic hydrocarbon and aryl [email protected] Orgânica - LAGO, 64049-550, Teresina, PI, Brazil. isoprenoids, TIC typical of the saturate fraction; RIC of m/z 134 and Figure 2. SRM Transitions for TSQ Quantum XLS (a) and structures and b Universidade Estadual de Campinas – UNICAMP, Instituto de 120, pointing out the aryl isoprenoids and remaining diagenetic likely relationships between m/z 134 and 120 series (b). Copyright 2014, ALAGO. Química, 13083-970, Campinas, SP, Brazil. isorenieratane products. This paper was selected for presentation by an ALAGO Scientific Committee following c Petrobras - Research and Development Center, Brazil. The presence of diagenetic and/or catagenetic products of review of information contained in an abstract submitted by the author(s). The chromatographic profiles (TIC, Figure 1) and geochemical isorenieratane in source rocks and crude oils suggests photic zone *[email protected] parameters from the saturated fractions in this study indicate that anoxia during the deposition of organic-rich sediments. Additional Introduction confirmation of the origin of aryl isoprenoids from Chrobiaceae The compositional fractionation of petroleum accompanying they are not biodegraded and achieved similar thermal maturity Copyright 2014, ALAGO. in this oils can be obtained if these compounds are isotopically the migration process can be potentially used to infer distances levels (early to middle oil window) and that their source rocks were This paper was selected for presentation by an ALAGO Scientific Committee following heavier than their carotane counterparts of algal origin. However, petroleum may have travelled and the ratio of oil in the reservoir to deposited in a reducing depositional environment, under different review of information contained in an abstract submitted by the author(s). the presence of these compounds have been often related to that lost in the carrier beds1. Several researches have examined levels of salinity. anoxic depositional setting, and their structures are strongly the interaction oil components, mineral surfaces in reservoir rocks2 Introduction correlated to biological precursors derived from Chlorobiaceae and and the salinity of formation water that can have influence on Biomarker hydrocarbons in oils and sediments have considerable Figure 1 shows the chromatographic profile of the saturated and Chromatiaceae. wettability and oil recovery3. Therefore, the purpose of this study potential for assessing the nature of biological processes in the aromatic fraction (m/z 120 and 134). m/z 134 mass chromatogram was to investigate the distribution of petroleum compounds during past, but only a few can be uniquely related to particular organisms. showing distribution of trimethyl aryl isoprenoids, and m/z 120 Conclusions the migration in recent analogues of Albian carbonate rocks of the We complemented previous studies (Sousa Júnior et al, 2013) In analysis of Sergipe-Alagoas basin, related to the lacustrine and mass chromatogram showing the novel series of dimethyl aryl Brazilian pre- salt stromatolites, and to highlight theeffect of the and identified a new series of dimethyl arylisoprenoids in oils of salinity level of synthetic formation waterduring the compositional marine evaporitic source rocks, we identified a large range of isoprenoids. To m/z 120 series can be generated from the m/z 134 the Sergipe-Alagoas Basin - Northeast of Brazil, saline lacustrine, fractionation. diagenetic and catagenetic products of the aromatic carotenoid counterparts through loss of a methyl from the aromatic ring at C-6 by GC-MS-MS (EI and CI). The co-occurrence of the dimethyl aryl isorenieratene, including C40, C33, and C32 diaryl isoprenoids and or C-3 or C-4 (Zhang et al., 2011). (m/z 120) and structurally related trimethyl aryl (m/z 134) series Experimental aryl isoprenoid derivatives (Sousa Júnior et al., 2013). may indicate that the former likely derive from the latter by way of a Initially, it was realized a mineralogical characterizationofstromatolites demethylation process, as suggested by (Zhang et al., 2011), but samplesthrough X-ray diffraction. They were saturated with In this paper we re-evaluate the serie of trimethyl aryl and dimethyl this this specificity needs to be further investigated. syntheticformationwatersof different salinities: W1- 143 g/L aryl isoprenoids by GC-MS and GC-MS-MS (EI, CI). In addition we and W2- 286 g/L (postand pre-salt Brazilian water formation, Acknowledgements identified the co-occurrence of the dimethyl aryl, structurally related respectively). The migration process was performed by gravitational The authors thank CNPq (Brazilian research council) for fellowships; trimethyl aryl series may indicate that the former likely derive from ascension,in duplicates. It was used API gravity of 26o oil andfour ANP (Brazilian Petroleum Agency), Petrobras S/A. the latter by way of a demethylation process. rocks samplessaturated withdifferent types of formationwater, References W1 and W2. After 60 days of migration in carbonate rock Experimental Sousa Júnior, G. R.; Santos, A. L. S.; De Lima, S. G.; Lopes, J. A. D.; Reis, samples, at room condition, the four stromatolitessampleswere Sample preparation: F. A. M.; Santos Neto, E. V.; Hung K. Chang., 2013. Evidence for euphotic divided into 3 parts (Bottom, Middle and Top), and the oils were removed by a Soxhlet extractor. Each extracted sample (free Oil) About 80 mg of oil were subjected to PTLC on silica gel impregnated zone anoxia during the deposition of Aptian source rocks based on aryl isoprenoids in petroleum, Sergipe–Alagoas Basin, northeastern Brazil. was fractionated by liquid chromatography to obtain saturated with 5% AgNO3 and then the silica was developed using 98:1 (v:v) Organic Geochemistry 63 94–104. and aromatic hydrocarbons. The fractions were analyzed by n-hexane:ethyl acetate. The plates were then selectively scraped Gas chromatography/ mass spectrometry, to investigate the oil and the silica was treated using dichloromethane:methanol 95:5 Peters, K. E.; Walters, C. C.; Moldowan, J. M., 2005, The biomarkers compositional fractionationthroughn-alkanes (m/z 85),polycyclic (v:v) for desorption of the constituents The fractions thus obtained Guide, Cambridge University Press. terpanes (m/z 191), steranes (m/z 217) and methyl-phenanthrenes (P1 – saturated and P2 – aromatic) were concentrated in a rotary Figure 1. TIC typical of the saturate fraction;RIC of m/z 134 and 120, (m/z 192), as result of salinity level influence. evaporator and analyzed by GC–MS and GC-MS-MS. Sumons, R. E.; Powel, T. G., 1987. Identification of aryl isoprenoids in showing the aryl isoprenoids and remaining diagenetic isorenieratane source rocks and crude oils: Biological markers for the green sulphur Results and Discussion products. bacteria. Geochimical et cosmochimica 51, 577-566. Acquisition Method for TSQ Quantum XLS: The result of stromatolite mineral characterization was Magnesian The compounds (Figure 2) were identified by their respective Zhang, C.; Zhang, Y.; Cai, C., 2011. Aromatic isoprenoids from the 25–65 Calcite, Quartz and Aragonite, respectively, 95.9%, 3.0% and The analyses were performed using a Thermo Scientific TSQ molecular ions, base peaks at m/z 134 (McLafferty rearrangement) Ma saline lacustrine formations in the western Qaidam Basin, NW China. 2.6% in the Top; 86.0%, 8.9% and 5.1%in the Middle; and 70.3%, Quantum XLS Ultra Triple Quadrupole GC-MS instrument. Capillary or m/z 133. In addition, m/z 119,120, 105, 91 and 77 were used Organica Geochemistry, 42, 851–855. 20.1% and 9.6% in the Bottom. chromatographic column (Equity TM-1, 30 m, 0.25 mm ID). Initial because they are typical of a poly substituted aromatic structure. It was observed the compositional fractionation ofthe n-alkanes, temperature of 70 oC (4 min hold), followed by a ramp of 2 oC/ For data acquisition by selected reaction monitoring (SRM) the whenit content decreased from Bottom to the Top. Moreover, the min up to a final temperature of 300 oC (20 min hold). The carrier masses according to Figure 2 were used for the two compound n-alkanes content inthe free oil of the subunits (Bottom, Middle gas was helium at a constant flow rate of 1.0 ml/min. Transfer line groups under investigation.

98 99 and Top) saturated with synthetic formation water W1 was higher phenanthrene; DIA: diasteranes. OG06 than obtained from stromatolites subunits saturated with synthetic According PAN et al. (2005), the selective adsorption oil formation water W2 (Figure 1). components on clay minerals in sandstones reservoir could also Distribution of hydrocarbon induce the variations of the (C23TTR+C30H)/C23-TTR. However, in the results obtained in this present research in carbonates rocks families in the central area of the didn’t show variations in this ratio during simulated migration Neiva Sub-basin, Colombia. Processes for independently of the salinity level of formation water(Table 1). migration and charge

During the simulated migration, the effect of salinity of the Henrry Rivera D., Roman E. González, Wilman F. Beltrán formationwater could be observed through the ration-C17 / 2-MP (Table 1). This ratio showed lower variations along the carrier bed ECOPETROL, COLOMBIA saturated with synthetic formation water W2when compared with subunits stromatolites saturated with synthetic formation water email: [email protected] W1.Thus,it might have occurred thepreferentialmigration of 2-MP Copyright 2014, ALAGO. when compared ton-C17 and the decreasing the interactionsof Figure 1.API gravity map in the Neiva area. This paper was selected for presentation by an ALAGO Scientific Committee following 2-MPwithmineralsurface andsyntheticformationwater (W2, of more review of information contained in an abstract submitted by the author(s). salinity), principally. The biomarkers interpretation for organic matter type suggests that the first oil family has siliciclastic inputassociated to Tetuan Fm., Introduction Conclusions which has more terrigenous facies in the area.The second oil family Since Neiva Sub-basin is recognized by its high petroleum The study of geochemical tracersto migration monitoring showed has more carbonate affinity than the first one,and correlateswithLa potential, reported low thermal maturity and its complex structural Figure 1: Compositional fractionation of n-alkanes through simulated a slight compositional fractionation of the oil during the simulated Luna Fm. source rock. setting challenges an explanation for the migration processes that migration in stromatolites samples. migration as was observed inthe behavior of n-alkanes andratios: charged considerable oil volume in its restricted area. phytane/n-C18, C21S/ (C21 +ΣC29) Sand n-C17/ 2-MP. Taking into account the oil families distribution and the source rock It was detected changes in the values of phytane/n-C18along interpretations, there are four petroleum systems present in the The main source rocks in the Neiva sub-basin are the Cretaceous the carrier bed, as consequence of the preferential migration of The ratios C27DIA /C27S, αββ / (ααα + αββ) S and (C23TTR+C30H)/ study area: 1) Tetuan-Caballos (!), 2) Tetuan-Honda (.), 3) La Luna- Tetuan and La Luna Formations shales, siltstones and limestones, phytane with respect to n-C18. Moreover, the ratio C21S/ (C21 C23-TTR couldn’t be recognized as sensitive indicators for oil Monserrate (!) and 4) La Luna-Honda (.). which represent the lower and upper part of the Villeta Group. These +ΣC29)Sincreased, about 50%, along carrier bed independently migration in this present research. Moreover, these ratios weren’t rocks have favorable geochemical properties for oil generation and of formation water salinity level (Table1). affectedbythe salinity level of formation water. expulsion in the central Neiva Sub-basin.

The steranesratios, C27DIA/C27S and αββ/(ααα+αββ),have been The salinity offormationwater can have proportionated The main reservoir rocks are the sandstones of the Cretaceous recognized as sensitive indicators for oil migration, based on field different waterfilms (W1 and W2) on the rock.This can have Caballos and Monserrate Formations, and Miocene Honda Group. observation for PAN et al. (2005) and SEIFERT&MOLDOWAN(1981). causeddifferentinteractions with oil compounds,influencingmainlythe Although two oil families have been identified in these reservoirs However, in this present research in carbonates rock these ratios migration of 2- methyl phenanthrene. (Sarmiento and Rangel, 2004), theirgeographical distribution and did notdemonstratethe compositionalfractionationof oil during the hydrocarbon migration and charge processes are not clear until simulated migration (Table 1). Acknowledgements now. The authors thank Petroleum Engineering and Exploration Figure 2. Structural cross section in the Neiva area showing petroleum Table 1:Saturated and Aromatic hydrocarbonsratios. Laboratory (LENEP/UENF),CAPES, FAPERJ,PETROBRAS/REDE systems and migration pathways (Ecopetrol, 2012). Experimental DE GEOQUÍMICAandAgência Nacional do Petróleo (ANP)for the Several geochemical studies over the last two decades show fellowships and financial support. Figure 2 shows that oil families distribution is controlled by structural good source rock potential for the Cretaceous sequence in the features. This is supported by a regional 3D hydrocarbon migration Neiva sub-basin. These analyses include: TOC, pyrolysis, organic References analysis, suggesting kitchen areas that could explain the existing oil petrography, bitumen extractions, crude analyses, liquid and [1] LARTER, S.R; BOWLER, B.F.J; CLARKE, E; WILSON, C; MOFFAT, fields and defined petroleum systems. gaseous chromatography, biomarkers and oil-rock correlations B;BENNETT, B; YARDLEY, G; CARRUTHERS, D. 2000. An experimental (Ecopetrol, 2001). investigation of geochromatography during secondary migration of According to basin modelling analysis,the maturity of these petroleum performed under subsurface conditions with a real rock. kitchen areas should be in the early oil window.However, there is This study uses previous analyses as input to identify spatial Geochemical Transactions 9. an inconsistence if the measured %Ro values are extrapolated in distribution of oil families for each reservoir taking into account these areas, where is expected thermal immaturity of the source their API gravity, sulfur content and biomarkers. The resulting [2] PAN, C; FENG, J; TIAN, Y; YU, L; LUO, X; SHENG, G; FU J. 2005. rocks. This discrepancy is supported by 1D geochemical models distributions along with burial history models and structural Interaction of oil components and clay minerals in reservoir sandstones. sugesting that the hydrocarbon generation/expulsion event in maps were used to propose the kitchen areas and hydrocarbon Organic Geochemistry 36, 633–6547. the Neiva syncline started in late Miocene timesand continues to migration pathways. Despite this model accounting for oil families [3]TANG, G, Q; FIROOZABADI, A. 2002. Relative Permeability Modification Present,with a maximum temperature at present day; nevertheless distribution, there are inconsistences with Ro maturity in the area. in Gas/Liquid Systems through Wettability to Intermediate Gas Wetting. the measured %Ro vs. Depth trend indicates that the oil window Results and Discussion Society Petroleum Engineer (SPE). Reservoir Evaluation & Engineering 5 only is reached at about 14.000’ (where is expected a temperature (6): 427-436. of 120°C). According to the API gravities and sulfur content trends, two main oil families are interpreted to be present; the first one with light oil [4] SEIFERT W. K. AND MOLDOWAN J. M. 1981. Paleoreconstruction by On other hand, there are other maturity parameters that are and low sulfur content is related to the Honda Group in a shallow biological markers. Geochimica et Cosmochimica Acta 45, 783-794. incompatible with measured %Ro values, such asTmax, which position (located east of Tenay fault) and Caballos Fm. reservoirs. shows a range between 430°C and 445°C that correlates with %Ro The second one with medium to heavy oil and high sulfur content, values higher than 0.5; and equivalent %Ro values from AFTA,that related to the Honda Group (located west of Tenay fault) and *TTR:tricyclic terpanes;H: Hopanes; S: steranes; MP: methyl also predicts higher maturity levels. Although this study does not Monserrate Fm. reservoirs.

100 101 pretend to evaluate the analytical methods, it is considered the OG07 presence of a vitrinite suppression effect (proposed originally by Results and Discussion Garcia & Carvajal 2006) that fits valid hydrocarbon migration routes Biomarker and n-alkanes isotope Two Miranga oil samples, 7MG and 9MG,pooled in sandstone that could explain the oil distribution in the area. profile study in oil samples from reservoirs, bothof lacustrine origin and different biodegradation Conclusions Recôncavo basin, Miranga field, Brazil. levels were selected forour study–casesto explain 7MG oil There are four petroleum systems in the Central area of Neiva resistanceto the biodegradation process, notwithstanding its Subbasin: Tetuan-Caballos (!), Tetuan-Honda (.), La Luna- Michel R. de B. Chavesa*, Celio F. F. Angolinia, Ramses Capillab, favorable conditions to microorganisms development. The analysis Monserrate (!) and La Luna-Honda (.). Anita J. Marsaiolia¬* of the bulk data of the saturated fractions of the samplesrevealed high wax content, n-alkane distributions with abundant high Oil accumulations in the Honda Group reservoir show that there is a Instituto de Química, Universidade Estadual de Campinas, PO molecular weight components and odd predominance, pristane a geographic variation in oil characteristics. East of Tenay fault the BOX 6154, 13084-971 Campinas, SP, Brazil. dominant over phytane (values 1.3- 1.6). TheC26tricyclic Tetuan-Honda(.) petroleum system is present, while to the west of b Organic Geochemistry Division, CENPES, Petrobrás, Ilha do terpanes over C25tricyclic terpaneswere relatively similar for that fault the Honda/La Luna petroleum system is found. Fundão, Rio de Janeiro, Brazil. both samples(C26TT/C25TT) (Table 1), confirming the Lacustrine

Distribution of oil families is controlled by structural features, which depositional environment. *[email protected] also determines the kitchen areas that could explain the existing oil accumulations. Table 1.Geochemical parameters obtained by GC-MS in SIM and SCAN mode. Figure 1. Isotopic composition distribution profile of n-alkanes in oil samples Copyright 2014, ALAGO. from Recôncavo basin, Miranga field. Vitrinite reflectance in potential kitchens areas seems to be This paper was selected for presentation by an ALAGO Scientific Committee following suppressed, as it is compared to present day thermal gradient and review of information contained in an abstract submitted by the author(s). other maturity parameters. Conclusions Introduction Using saturated biomarkers parameters obtained by GC-MS Acknowledgements combined with the isotopic distribution profile of the n-alkanes in a The Recôncavo basin, has11500km2, is located at the The present study is part of an Ecopetrol internal project on the GC-C-IRMS, we could characterize two oil samples from Miranga Upper Magdalena Valley Basin Petroleum Potential. We thank northeastern part of Bahia state and is considered one of the most oil field. These results are preliminary however depict different Ecopetrol S.A. for authorizing the publication of this information. petroliferous basins in Brazil. Miranga is among the seven biggest biodegradation levels which will be used in future biodegradation fields in this basin,andunderstandinghow biodegradation works in The oils samples showed different P/F ratios suggesting in few References assays using polar fractions. Miranga oil field is of economicinterest. The investigation required a changes in the depositional environment. Both samples were ECOPETROL, 2001. Proyecto evaluación regional de la cuenca valle superior previous geochemical characterization of the oil samples focusing thermally mature (Ts/(Ts+Tm)however 7MG was more, confirmed del magdalena implicaciones en los sistemas petrolíferos. Internalreport. the isotopic composition. The oil samples will be evaluated using Acknowledgements by its CPIlevel. The authors thank PETROBRAS and FAPESP for the fellowship the isotopic profile (δ13C) of the n-alkanes before and after ECOPETROL, 2012. Definición de los estilos estructurales presentes en la and financial support. biodegradation assays (future work).Knowing this, two oil samples Cuenca del Valle Superior del Magdalena, Gerencia de Exploración Centro Their biodegradation levels were also evaluated using the ratio Sur. InternalReport. from Miranga field in the Recôncavo basin, were evaluated in order between C29 25-nor-17α(H) hopano/C3017α,21β(H)hopano to recognize their maturation level, depositional environment and References together with analyzing the presence of n-alkanes, confirming the GARCIA-GONZÁLEZ, M. and H. Carvajal; 2006. La supresión de la reflectancia biodegradation levels. Gaglianone, P. C., Trindade, L. A. F., 1988, Caracterização geoquímica dos de vitrinita en las Formaciones La Luna y Hondita y sus implicaciones en la oil sample 9MG as the most biodegraded. óleos da bacia do Recôncavo. Geochimica Brasiliensis, 2 (1), 15-39. exploración de hidrocarburos en las Cuencas del VSM Y VMM, Colombia. 9th Experimental Simposio Bolivariano - Exploración Petrolera en las Cuencas Subandinas. The oil samples were selected based on their biodegradation levelsand The isotopic distribution of the n-alkanes wasobtained by GC-C- Ortiz, J.E., Torres, T., Delgado, A., Julia, R., Lucini, M., Llamas, F.J.,Reyes, E., Soler, V., Valle, M. 2004. The palaeoenvironmental and palaeohydrological SARMIENTO, L.F. and RANGEL, A., 2004. Petroleum systems of the Upper collected from reservoirsof different depths. Samplefractioning was IRMS showing the presence of the n-alkanes ranging from C10 to evolution of Padul Peat Bog (Granada, Spain) over one million years, Magdalena Valley, Colombia. Marine and Petroleum Geology 21 (pp. 373–391). performedusing a standard procedurewithdry silica gel column, C34. The aquatic origin n-alkanes (nC15, nC17, nC19) showed from elemental, isotopic and molecular organic geochemical proxies. eluted with 15-20 mL of n-hexane to obtain the saturated fraction values between -29,85‰ and -32,07‰ for sample 7MG and Organic Geochemistry 35, 1243-1260. which was analyzed byGC-MS usingSCAN and SIM mode -30,58‰ and -36,97‰9MG showing 13C contentfor the 9MG oil. Then-alkanes representing superior vascularized plants (nC27, n-alkane purification was achieved by crystallization of the aliphatic nC29, nC31) showed values ranging from -37,58‰ to -40,52‰ for fraction with a saturated solution of urea in methanol and analyzed oil 7MG and from -30,47‰ to -35,04‰ for sample 9MG, showing with a GC-C-IRMSThe isotopic values were measured in a Trace different ratios of wax lipids from leaves of higher plants.Most of the GC Ultra with a Delta V Advantage mass spectrometer from Thermo n-alkanes from C14 to C33in both oils showedhigher13C ratios in using splitless mode for analysis. The temperature programwas n-alkanes ofodd carbon numbers, although the difference in δ13C starting at 80°C (holding for 2 min.), increasing to 270°C at 40°C/ values was greater in sample 9MG. min., and then to 300°C (holding for 25 min.) at 10°C/min. using a DB-5 column (30m x 0,25 mm x 0,25μm) . The δ13C values werecompared to the PDB standard and calibrated by CO2pulses. The injector was kept at 300ºC, the interface at 350ºC and the combustion oven at 850ºC.

102 103 OG08 wells B and C is sealant character to level unit B4. Acknowledgements Compartmentalization analysis Experimental Thank to PDVSA INTEVEP (Venezuelan Technological Institute of of three crudes from Lake Maracaibo Basin Three wells were selected for analysis of compartmentalization (A, Petroleum) and PDVSA OCCIDENTE (Petroleum of Venezuela) B and C) located southeast of the Basin of Lake Maracaibo. In this Department of Reservoir Integrated Studies, Maracaibo, Venezuela.

Jhaisson A. Vásqueza*, Frank C. Cabrerab, Beatriz C. Angulob, sense, C15- samples were captured in amber bottles of 100 mL Victor. Hernández b, Ana K. Faracoa and seal lips of 20 mm with gum septum and aluminum cap. For References this, it was necessary to have a high pressure hoses connected Kaufman, R. L.; Ahmed, A. S.; Hempkins, W. B., 1987. A new technique for a Petroleum of Venezuela (PDVSA Occidente), Department of to biphasic pump, two leakage needles with coated copper of the analysis of commingled oils and its application to production allocation Reservoir Integrated Studies, Maracaibo, Venezuela 11/2” diameter one for injecting the fluid and the another to release calculations. Jakarta: Indonesian Petroleum Association, pp. 247-268. b Venezuelan Technological Institute of Petroleum (PDVSA Intevep), pressure and gun sealing septum. The samples were transported Department of Strategic Research, 76343, Caracas 1070-A, to the laboratory for analysis by gas chromatography of total oil Tocco, R; Alberdi, M., 1999. Geochemical study of Misoa Formation crude Venezuela (Whole Oil) in an equipment Agilent Technologies 6850 Series II. oils, Centro Lago Field, Lake Maracaibo, Western Venezuelan Basin. Marine From the results of the fingerprint were determined hundred eighty and Petroleum Geology 16 (1999) 135-150. [email protected] seven relations of which were chosen twelve with higher standard deviations for drawing diagrams stars. Therefore, a cluster analysis Dup: Duplicate Copyright 2014, ALAGO. of three samples of crude oil was carried out from the composition Figure 1. Cluster analysis between wells A, B and C, unit B4. This paper was selected for presentation by an ALAGO Scientific Committee following of the C15- fraction to establish the compartmentalization of the review of information contained in an abstract submitted by the author(s). reservoir.

Introduction Results and Discussion The economic growth constant worldwide has led to a growing C15- fraction corresponds to the light fraction of crude oil which demand for oil that has reached 90 million barrels a day of liquid is in the gasoline range and it is determined by the technique of hydrocarbon. The current economy is mainly based on a high gas chromatography of total oil (Whole Oil) which is widely used consumption of oil and according to estimates by the International for studies of oil-oil correlation, compartmentalization, maturity Energy Agency the situation will not change much over the next and establishes alteration processes within the reservoir as water 30 years. For this reason, it is vitally important geochemical washing, biodegradation and evaporative fractionation. In general, characterization of oil in order to optimize the exploitation plans. All for studies of compartmentalization are applied the relations of this has led to the geochemical analysis of oils from Basin of Lake organic compounds obtained by gas chromatography of total Maracaibo which is located western Venezuela and covers an areal oil and then are generated the polar plots taking into account surface 13210-13820 km2 representing one of the most important the relations with higher standard deviations. According to the reservoirs of oil. shape of them if they are equal for all oils analyzed it is said that the reservoir could be possibly connected and also come from

Organic geochemistry has played and important role in petroleum the same origin or even have similar post-genetics processes. exploration. Applications of organic geochemistry to reservoir studies Otherwise, if the polar plots are different is due to the presence of and production engineering have attracted a lot of attention in the compartmentalized reservoirs with differences in origin of the oils. petroleum wolrd (Kaufman et al., 1987; Tocco and Alberdi, 1999). Based on the basic principle of the reservoir geochemistry within In this sense, the results obtained by gas chromatography of total the same reservoir where there are permeability barriers (structural oil (Whole Oil) to the crudes A, B and C taking into account the and stratigraphic seals) occurs a compositional homogenization of twelve relations of organic compounds seem to indicate that the oil, therefore, in any part of the reservoir the same composition or oils are the same family due to the high grade of similitude of stars figerprints be presented and to the extent that these differences diagrams, although, these crudes have been subject to water Figure 2. Structural section (TVD) and stars diagrams from wells B and C, (subtle or noticeable) is observed in the crude might be attributed to washing which explain the compositional similarities. However, the unit B4. effects of compartmentalization. This research aims to perform an cluster analysis (figure 1) performed between the wells A, B and C analysis of reservoir compartmentalization in the Eocene B (Misoa using as criteria a cuttof five shows that the crudes A and C have Conclusions The compartmentalization analysis between wells A, B and C Formation) southeast of the Lake Maracaibo Basin, specifically in a similar composition to except the oil B. This may suggests that indicate that these crudes have been subject similar post-genetics the field belonging to La Ceiba Area, Trujillo state. For this, it was the fault that separates the wells B and C is type sealant which processes due to the similarities of stars diagrams. However, sampled the fraction C15- of three oils and it was conducted the even cut the Cretacic. Therefore, the original oil water contact to the cluster analysis suggests that wells A and C have a similar analysis of fingerprint of hundred eighty seven relations where were well B is higher deep than C supporting the compartmentalization composition to except B. In this sense, the fault that separates selected the twelve with higher standard deviation. The cluster of reservoirs (figure 2). the wells B and C is sealant character from the point of view analysis suggests that the oils A and C show a similar composition geochemical and petrophysical. to except the oil B. On the other hand, the fault that separate the

104 105 OG09 and source-rock lithology, such clay versus carbonate composition. 15, either the presence or absence of n-alkanes and isoprenoids Conclusions These source rock features represent key contributions to depict compounds, as well as the relationship between the 25-Norhopane/ Our fully-integrated geochemical study clearly differentiates a Source Facies diferenciation and Petroleum the source rock character, which usually includes kerogen typing C30Hopane and the saturates content (%), indicate that mixing multiple petroleum charge of Paleogene reservoir rocks in the Charge History In The Southwest Region (e.g., type II versus type III or II/III), oil versus gas potential, of pulses from different sources has taken place with a former oil southwest of the Llanos Basin and based on novel technologies, it of The Llanos Basin using High-Resolution depositional settings (e.g., deltaic versus marine; proximal versus severely biodegraded whose physical properties has been then poses the plausible age ranges for the various organic facies that Organic Geochemical Technologies distal), and potential hydrocarbon characteristics (e.g., sulfur-rich improved by a more recent refreshing process. The latter oil, where have controlled the petroleum charge in the study area. Furthermore, versus sulfur-poor; heavier versus lighter oil). interpretations were possible, suggested source facies deposited the level of understanding achieved on the biodegradation histories V. Blanco-Velandiaa*, Y. Blanco-Velandiab, E. Cardozo-Puentesb, within a proximal marine environment with a significant contribution using biomarker acids analysis has implications for petroleum J.M. Moldowanc, C. Orejuela-Parraa, W. Espitiab, J. Lelijveldd and Thermal maturity of the source sediments was also gleaned from of terrestrial organic material under oxic conditions. Unequivocal systems at regional scale in the Llanos, since its application has been O. Villarreald oil geochemistry and used as a proxy for the timing of oil generation evidence of mixing revealed by the screening techniques employed found useful in determining the overall composition of the oil and within the petroleum system, since such an attribute has a comes from the coexistence of prominent 25-Norhpane peaks, and its migration and charging for any given reservoir. This multifaceted a Instituto Colombiano del Petróleo-Ecopetrol S.A. Km7 vía fundamental effect on oil composition and its physical properties. the complete hopanes series in the same m/z 191 fragmentogram, research framework was complemented with a 2D petroleum Piedecuesta. Colombia Determination of the level of biodegradation and quantification of where such compounds are expected to be depleted in the system modelling which included the unprecedented utilization of b Gerencia de Exploración Regional Llanos. Vicepresidencia de oil mixtures in the various oil samples as well as their implications oil samples due to the intense palaeobiodegradation that has yield curves obtained from high-temperature simulated distillation, Exploración-Ecopetrol S.A. Bogotá. Colombia on the petroleum system in terms of volume of petroleum charged occurred in the reservoirs of the study area. to compare between biodegraded oil and non-biodegraded oil of c Biomarker Technologies, Inc (BTI). 638 Martin Avenue. Rohnert within Tertiary reservoir rocks have also been addressed herein. the same thermal maturity. This proxy for assessing the volumetrics, Park, CA 94928. USA More advanced techniques such as CSIA-B and QEDA reveal a ultimately aided determining the proportion of oil that has been lost d Schlumberger, Calle 100, Número 13-21 Piso 6-152. Bogotá Methodology remarkable divergence between compositional profiles for both the as a consequence of the biodegradation processes. Colombia The analytical program carried out on the oil samples consisted oil samples and the asphaltenes isolated from the HyPy oils, which of quantitative diamondoid analysis (QDA), saturate biomarkers by implies that such an analysis delivers the most useful outcomes Acknowledgment *[email protected] GC-MS, aromatic biomarkers by GC-MS, saturate biomarkers by for source differentiation. This is most likely due to the fact that the The authors thank the Vice- Presidency of Exploration, Ecopetrol GC-MS-MS, biomarker acids analysis (BAA), compound specific extended diamondoids fingerprints do not appear to be affected S.A. (VEX) and the Colombian Petroleum Institute for the

Copyright 2014, ALAGO. isotope analysis of alkanes-complete (CSIA-Ac),compound specific by biodegradation or oil cracking and they are present in the administrative and financial support to conduct the present study.

This paper was selected for presentation by an ALAGO Technical Committee following isotope analysis of diamondoids (CSIA-D) and QEDA for both, asphaltenes making them a universal source parameter. Figure 1 review of information contained in an abstract submitted by the author(s) the whole oils and the asphaltenes isolated from the appropriate shows the comparison between fingerprints of the whole-oil-QEDA References hydrous pyrolysate oils (HyPyoil). and the asphaltene-QEDA for each sample. Barbanti, S.M.; Moldowan, J.M.; Watt, D.S.; Kolaczkowska, E. (2011) Introduction New triaromatic steroids distinguish Paleozoic from Mesozoic oil. Organic Although a significant contribution of the geochemical work as a This comprehensive study includes biomarkers representing only The QEDA fingerprint for each asphaltene pyrolysis sample is Geochemistry 42, 409-424. part of the exploration process in the Llanos region has allowed the shallow source units, and QDA, which provides information on plotted together with that from the corresponding whole oil sample. development of an improved understanding of the habitat of the advanced maturity (extent of oil cracking), evaporative fractionation The various concentrations of diamondoids relative to triamantane Dahl, J.E.; Moldowan, J.M.; Peters, K.E.; Claypool, G.E.; Rooney, M.A.; petroleum accumulations, a complete explanation on the origin of (a phenomenon occurring during fluid migration) and the source for each sample indicate significant differences between the oils Michael, G.E.; Mello, M.R.; Kohnen, M.L. (1999) Diamondoid hydrocarbons the various petroleum types, as well as on the regional distribution of of the fluids, as well. We used CSIA-Ac as a method to correlate and the asphaltene QEDA fingerprints, suggesting that the three as indicators of natural oil cracking. Nature 399, 54-57. their physical properties, remains ambiguous. Such a fact of course, hydrocarbon sources ranging from the oil window into the wet gas samples have multiple sources. Therefore, this research provides has direct implications on both the mitigation of the exploration risk window. Once the various HyPy oils were obtained, each sample clear evidence of oil mixing in Tertiary reservoirs of the southwest Zinniker, D.A. (2005) New insights into molecular fossils: the fate of terpenoids and the reduction of exploitation costs within the study area. In was subjected to various analyses in order to determine whether Llanos with a distinctive proportion of the main pulses forming the and the origin of gem-dialkylalkanes in the geological environment. Ph.D. this work we aimed at producing and integrating conventional and the asphaltenes are related entirely to the rest of the oil sample oil sample 1 relative to samples 2 and 3 which appear to have a thesis, Department of Geological & Environmental Sciences, Stanford advanced high-resolution geochemical technologies in order to or if it can be shown a mixing effect. Further to this, comparisons common charge history and similar proportions of the mixture. University, Stanford, CA, USA, UMI Number: 3162337. better characterize the petroleum charge history in the petroleum between CSIA-B data from maltenes (whole oils) and from HyPy system under research. The ultimate target of this geochemical oils were performed to approach is to incorporate not only the relevant outcomes, but also the proposed work-flow into succeeding risk assessments for E&P illustrate the existing relationships and to suggest where either operations in the southwest portion of the Llanos. mixed or singly sourced oils might occur.

For this geochemical approach, a set of well-head samples Results and Discussion were carefully selected and sampled in order to reach the best Classic organic geochemical analyses were fundamental to understanding of the source rocks and source rock facies through evaluate the extent of biodegradation and its control on the oil-oil and oil-source rock correlations. The products obtained from various compound abundances that were used to perform further the geochemical characterization encompass the following aspects: interpretations on source and thermal maturity. Since the analyzed estimation of possible source ages; depositional environment, oils have experienced significant biodegradation the use of m/z including palaeowater conditions; organic matter input, such 177 and m/z 85 fragmentograms provided insights on the actual as the different types of organisms that have contributed to the distribution of N-alkanes and demethylated series of hopanes and Figure1. Quantitative extended diamondoid analysis (QEDA) of whole oils assemblages of the petroleum lipids and their relative importance; tricyclic terpanes respectively. Although API gravity varies from 8 to and HYPyoils generated from asphaltenes

106 107 OG10 CS2. Then the sample is placed in the automatic injector of chromatograph HP-6890 model, for analysis. There are slight compositional variations found by analyzing the Geochemical study of compartmentalization fraction C15- oil Block V-VI Field, differentiate them into two groups, in reservoirs of Block V-VI Lamar, Biomarkers in fractions saturated and aromatic hydrocarbons structurally separated by a fault. However, The compositional Maracaibo Basin, Venezuela. by GC-MS. saturated and aromatic hydrocarbons fractions are variations due to the response in the geochemical parameters, analyzed by gas chromatography coupled with mass spectrometry could be associated with the formation waters washing the sample VLE-F well. Natasha Acostaa*, Jacqueline Grobasa, Alejandro Martíneza, José equipment. Laboratory PDVSA Intevep uses an equipment model Durana, M. Lisandro Martíneza, Carmen Rodrígueza HP-6890 computer with a mass selective detector HP-5973 quadrupole MSD. Acknowledgements Thank to PDVSA-Intevep for letting me participate in this projectand a PDVSA-INTEVEP Chromatography of fraction C15-. Analysis of the light fraction of thank to the Laboratory of Geochemistry of INTEVEP for supporting me in the analysis performed in this work *[email protected] oil was performed on a HP-6890 chromatograph equipped with a capillary gas column type PNA of 1.05 m, with temperature References Copyright 2014, ALAGO. programming, helium as carrier gas and FID detector (ionization detector flame). The computer has software for the recognition of Agüero, A. 1998. Caracterización geoquímica de crudos del yacimiento This paper was selected for presentation by an ALAGO Scientific Committee following Figure 1.Polar diagram of oils studied VLE-305, Campo Bloque V-Lamar. Informe Técnico. Intevep. review of information contained in an abstract submitted by the author(s). the peaks corresponding to saturated and aromatic hydrocarbons present in each sample (DHA system: Detailed Analysis Hydrocarbons). Alberdi, M. 1995. Geoquímica de yacimientos y delimitación de Introduction Geochemistry applied to the study of reservoirs can be used to compartimientos en Bloque V-centro, Lago de Maracaibo. Informe Técnico. solve problems, such as, continuity in the reservoir, intervals Results and Discussion Intevep producer identification, identification of production problems, The reservoirs studied show oils with API gravities between 23.5 to and the presence of tarmats. (Kaufman, 1990). After the oil is 26.81° (medium oil), they have a higher proportion of the saturate Berrios, I., y Toro, C. Informe Técnico. Intevep. Estudio Geoquímico de entrapment, it is subjected to secondary processes, both chemical fraction and they are classified as paraffinic oils. According to the Yacimientos del área VLE-326 Bloque V, Campo Lamar Lago de Maracaibo. and physical, which can alter the composition of the oil, therefore, results suggest that biomarkers are oils mature, little altered from a 2000. the fluid in each compartment will have characteristics which allow source rock of marine origin. to differentiate it from the others. The study using light hydrocarbon Hernández, V. 2009. Caracterización geoquímica de crudos y agua de fractions (C15-) permit identify these compositional differences Analyses in the C15- fraction corresponds to the visual method formación de los yacimientos Cretácicos, Lago de Maracaibo. Informe acquired in each compartment and know the continuity of a of polar diagrams, which are calculated using 10 ratios of Técnico. Intevep. reservoir. compounds, which presented the highest standard deviation, which largely differentiates samples from the same population.

This paper shows the geochemical study of 7 oil samples from (Hernández, 2009). Figure 1 shows the polar diagram of crude oil Figure 2.Dendrogram of samples studied wells of Lamar Block V-VI, Maracaibo Basin; with the purpose of studied, where we can see that the sample from the well VLE-F (blue line) is slightly different from other wells, this sample (VLE-F) verify the level of communication between reservoirs from level the The dendrogram shows two families of oils, as suggested by had in several analyzes differences compared to the other samples sand C2. the diagram of stars; one family is represented by wells samples showed less maturity, lower API gravity, and slight compositional VLE-A VLE-B, VLE-C, VLE-D,-E and VLE-G and other family is differences. Experimental represented by the well sample VLE-F. The samples were taken from each wellhead, in hermetically In the dendrogram (Figure 2) is located on one axis, 9 oil samples sealed vials to preserve lightweight compounds (C15-). For the According the structural map at the top of the sand C2, the that are compared with each other, while the other axis is placed evaluation of these samples, in order to determine whether or sample from the well VLE-F is separated by faults of the other Euclidean distance between them. The difference between families not communication between the reservoirs wells, the following wells, suggesting it is in different compartments. Recommended to is given by a line (“Cut off), which indicates the Euclidean distance geochemical analyzes were carried out: check more detail the structural and seismic maps to explain this from crudes which are considered different. Cut off the analytical difference. Another explanation could be that the deposits are in location above is considered instrumental error of the method, Determination of composition saturates aromatics, resins and the same compartment, but the sample from the well VLE-F, has a which was calculated by performing the triplicate analysis of the asphaltenes. A HPLC equipped with a Waters 600 controller, small alteration in its composition depth vertical variations. a rotatable 486 nm absorbance detector and 410 differential sample (VLE-C). The second Cut off is considered above analytical Cut off, and taking into consideration the average and standard refractometer was used. Conclusions deviation of triplicate samples. The results of analysis of C15+ fraction and studied biomarkers

Gas chromatography, saturated fraction (C15+). For this analysis, in crude Block V-VI Field, suggesting they were generated by a a saturated hydrocarbon fraction is weighed and diluted with source rock of marine origin, thermally mature.

108 109 OG11 microscope equipped with a range of objective lenses (including a hydrocarbon migration. These HCFI contain oils characterized by x100 objective lens) was used for fluid inclusion microthermometry. API gravities between 40º-50º and homogenization temperatures Hydrocarbon migration history in the Its calibration was made using synthetic fluid inclusion standards between 92ºC and 113ºC. PVT modelling of coeval HCFI and Llanos Foothills Basin, Colombia, of pure CO2 and water. Precision is ± 0.2ºC at -56.5ºC and ± aqueous fluid inclusions hosted within quartz overgrowths indicates using fluid inclusions. 2ºC at 300ºC. The following fluid inclusion data was recorded: 1) trapping temperatures and pressures of ~120ºC and ~250 bars (Figure The homogenisation temperature (minimum trapping temperature 2). Isochores were constructed using VTFLINC programme. This software was developed to process microthermometric and volumetric J. Naranjo1, M. Feely2, A. Mesa1 of the fluid: TH) followed by the temperature of last ice melting (indication of the salinity of trapped fluid: TLM) ; 2) The number data from petroleum bearing fluid inclusions. The composition of the generic volatile oil reported by Burruss, (2003) was used as an input. 1 ICP-ECOPETROL, Colombian Petroleum Institute, ECOPETROL- of phases (liquid ± gas ± solid) present in each inclusion; 3) The program then created the saturation pressures (bubble point and ICP S.A Fluorescence colour of HCFI; 4) the volumetric proportion of liquid dew point curves) of this oil for a given homogenization temperature, 2 Department of Earth and Ocean Sciences, National University of relative to the total volume of the inclusion, at room temperature, using various equations of state. It also calculates the density of the oil Ireland, Galway. was determined using the Lucia software; 5) The salinity (calculated as equivalent wt% NaCl) was determined using the equation of and uses this to create an isochore (line of equal density) in PT space. Figure 3. Transgranular fluid inclusions with 40o – 50o API gravity, from the This isochore intersects the homogenization temperature (minimum Mirador Formation, Foothills 1 well, microphotograph under UV Light. e-mail: [email protected] state of Bodnar (1993). In the case of two-phase (liquid + vapour) aqueous inclusions isochores were constructed using the FLUID trapping temperature) of the coeval aqueous inclusions and is taken as an estimate of the true trapping temperatures and pressures of Microthermometric studies of the aqueous fluid inclusions hosted in Copyright 2014, ALAGO. programme (Bakker, 2003). Isochores for two-phase (liquid + these fluids. Integration of trapping temperatures with the burial history transgranular annealed fractures suggest at least two aqueous fluid This paper was selected for presentation by an ALAGO Scientific Committee following vapour) petroleum inclusions were constructed using VTFLINC of Cusiana field suggests that these fluids were trapped approximately migration events post-diagenesis. These fluids can be categorised review of information contained in an abstract submitted by the author(s). programme. during the Miocene (~10Ma). as follows: 1) A fluid with low to moderate salinity (2.0 – 12 eq. wt. It should be noted here that fluorescence colours displayed by % NaCl) and homogenization temperatures between 100ºC and Introduction Results and Discussion HCFI only provide at best a qualitative indication of the API gravity 137ºC; 2) An aqueous fluid with CH4 ± CO2 and homogenization Fluid inclusions (commonly < 15 µm in diameter) are samples of Fluids present within quartz overgrowths of oil trapped in the inclusions (Burruss, 1991; Goldstein and temperatures that range from 102ºC to 127ºC oil and aqueous fluids that circulated through a sedimentary basin Reynolds, 1994; Parnell et al., 1998; O’Reilly et al., 1998; Feely during its geological evolution. The presence of hydrocarbon Microthermometric data from aqueous fluid inclusions found in and Parnell,2003; Bodnar, 1990; Sellwood et al., 1993; Stasiuk Fluids present within veins. bearing fluid inclusions (HCFI) in authigenic cements and in annealed authigenic quartz (Figure 1) indicates that quartz overgrowths and Snowdon, 1997), however this premise does not always hold Fluid inclusion data from veins suggest a complex fluid migration fractures in detrital quartz grains in basin sandstones may reflects were precipitated by fluids with minimum trapping temperatures true (George et al., 1997; George et al., 2001). history in the Llanos Foothills basin. a history of petroleum migration and cementation during basin between 92ºC and 130ºC. Last ice melting temperatures (TLM) evolution (Burruss, 2003). Ultraviolet (UV) light microscopy is used indicate that both aqueous fluids with low salinities (0.5 to 4.8 eq. In a vein hosted within the Guadalupe Formation (Foothills 6 Well) to determine the presence of HCFI in basin sandstones and veins. wt% NaCl) and fluids with CH4 ± CO2 were present at the time of petroleum inclusions were found as both primary and secondary. This in turn identifies the stratigraphic levels where hydrocarbon quartz overgrowth formation. Primary hydrocarbon inclusions indicate that oil with an API gravity migration has occurred. Petrographic studies of HCFI and aqueous of 40º-45º and homogenization temperatures between 80ºC and fluid inclusions help develop a chronology of petroleum migration. 90ºC were present at the time of the vein formation. The presence We report the results of fluid inclusion petrography (aqueous and of secondary trails of petroleum inclusions may also indicate HCFI), UV microscopy and microthermometric studies (HCFI) of the later episodes of petroleum migration. Their homogenization Llanos Foothills Basin, Colombia. Furthermore we demonstrate the temperatures range from 40ºC to 82ºC. They have an API gravity use of fluid inclusion studies in the development of an oil charge of 45º-50º. However the similar characteristics in both fluorescence history framework for the Llanos Foothills Basin. Figure 2. Pressure-temperature diagram for the pretroleum fluid inclusions. colours and microthermometry data of primary and secondary inclusions may suggest a continuous hydrocarbon migration event. Experimental Rluids present within annealed microfractures. Nineteen fluid inclusion wafers from the following samples were Fluid inclusion data from annealed microfractures suggest that In the veins from the Lutitas de Macanal Formation (outcrop) a studied: 2 samples of outcrops, 9 samples of cuttings from the microfractures were important fluid conduits for petroleum and wide range of salinities and homogenization temperatures have Foothills 1 Well, 7 samples of core from the Foothills 3 Well, and aqueous fluids. HCFI occur as subparallel trails in detrital quartz been recorded. These fluids can be divided into three main groups 1 sample of core from the Foothills 6, (The names of the wells are grains and in trails that transect both detrital and authigenic quartz as follows: 1) A fluid with a high salinity (34 to 36 eq. wt.% NaCl) changed to comply with Ecopetrol-ICP´S request for confidentiality). Figure 1. Primary fluid inclusions trapped in quartz overgrowths, from (Figure 3). This indicates that hydrocarbon migration occurred post and homogenization temperatures between 240ºC and 290ºC. quartz overgrowth formation and that hydrocarbon bearing fluids These fluids are found as primary inclusions; 2) A fluid with A Nikon Diaphot microscope with an epifluorescence UV light the Une Formation, Foothills 1 well. Photomicrograph in plane polarized migrated along fractures. The fluid inclusions display a range of moderate salinity (10 to 17 eq. wt. % NaCl) and homogenization source attachment (designed to transmit 365 nm wavelength light) transmitted light. fluorescence colours from yellow (25º-30º API gravity) to blue-white temperatures between 178ºC and 227ºC. They are hosted as was used both to examine the petrography of fluid inclusions and (40º-50º API gravity), suggesting at least two separate hydrocarbon secondary inclusions, and 3) A fluid with moderate salinity (3.4-7.2 to determine the presence of HCFI. A Linkam THMS 600 heating– HCFI in quartz overgrowths are uncommon. This may indicate that migration events. eq.wt. % NaCl and 6.8–12.2 eq. wt. % CaCl2) and homogenization freezing stage mounted on a Nikon Labophot transmitted light the main phase of quartz overgrowth formation preceded significant

110 111 temperatures between 97ºC and 117ºC. They are found as eq. wt. %NaCl and 6.8–12.2 eq. wt. %CaCl2) and homogenization have been recorded from the fluid inclusions found within veins. P.F., Eisenberg, L.I. et al., (1997) Geochemicalcomparison of oil-bearing secondary inclusions. temperatures of between 97ºC and 117ºC; y 4) A hydrocarbon fluid These fluids can be divided into four main groups as follows: 1) A fluid inclusions and produced oilfrom the Toro sandstone, Papua New Discussion with API gravity of 40º-45º. Their homogenization temperatures fluid with a high salinity (34 to 36 eq. wt. %NaCl) and homogenization Guinea. Organ. Geochem, 26, 155-173. Based on the results of this study, an attempt has been made to range from 40ºC to 90ºC. temperatures between 240ºC and 290ºC; 2) A fluid with moderate build a fluid migration model for the Llanos Foothills Basin. salinity (10 to 17 eq. wt. %NaCl) and homogenization temperatures George S., Ruble T., Dutkiewicz A., Eadington P. (2001) Assessing the Conclusions between 178ºC and 227ºC; 3) A fluid with moderate salinity (3.4-7.2 maturity of oil trapped in fluid inclusions using molecular geochemistry data The first fluid event identified is associated with the formation 1. Fluid inclusion studies from the Llanos Foothills Basin reveal eq. wt. %NaCl and 6.8–12.2 eq. wt. % CaCl2) and homogenization and visually-determined fluorescence colours. Applied Geochemistry. 16, of quartz overgrowths. Microthermometric data indicates that the presence of aqueous and hydrocarbon fluids hosted within temperatures between 97ºC and 117ºC; and 4) A hydrocarbon 451 – 473 the fluids present in the formations at this time have minimum quartz overgrowths and in annealed microfractures, indicating that fluid with 40º-50º API and homogenization temperatures between temperatures between 92ºC and 130ºC. They have low salinities these fluids were present during cementation and also during later 40ºC and 90ºC. Goldstein, R. H. and Reynolds, T. J. (1994) Systematics of Fluid Inclusions (0.5 to 4.8 eq. wt % NaCl) and some also CH4 ± CO2. The low episodes of microfracturing. in Diagenetic Minerals. SEPM Short Course,31. U.S.A. Society for salinities indicate that they represent marine or meteoric waters Acknowledgements Sedimentary Geology. trapped within the pore spaces of these rocks. The presence of 2. Petroleum fluid inclusions within the overgrowths zone are rare The authors wish to thank to the research group Flujo Regional de Parnell, J., Carey, P., Duncan, W. (1998). History of hydrocarbon charge on CH4 ± CO2 may be due to their liberation from rocks rich in organic suggesting that the main phase of quartz overgrowth formation Fluidos and ECOPETROL-ICP for suppling the samples, funding the Atlantic margin: evidence from fluid inclusion studies, West of Shetland. matter during the maturation process associated with the burial preceded hydrocarbon migration. These oils are characterized by and authorization for the publication of this study. JN would like to Geology 26, 807-810. and consequent increase in pressure and temperature of the rocks. API gravities between 40º-50º and homogenization temperatures thank The Faculty of Science, National University of Ireland, Galway Hydrocarbon inclusions were only occasionally found in quartz between 92ºC and 113ºC. PVT modelling of coeval hydrocarbon for a two-year postgraduate fellowship which funded this research. Sellwood, B.W., Wilkes, M., James, B., (1993) Hydrocarbon inclusions in overgrowths indicating that the main phase of quartz overgrowth and aqueous inclusions hosted within quartz overgrowths indicates JN would also like to thank The Geofluids Research Group, late calcite cements: migration indicators in the Great Oolite Group, Weald formation preceded hydrocarbon migration. Rare HCFI hosted trapping temperatures and pressures of these fluids at ~120ºC and Department of Earth and Ocean Science, NUI, Galway for a fruitful Basin, S. England. Sediment. Geol. 84, 51 - 55. within overgrowths have minimum trapping temperatures of 92ºC- ~250 bars. Integration of trapping temperatures with the burial and pleasant working atmosphere. JN thanks to James Conliffe for 113ºC. They have a blue-white fluorescence colour (API gravity history suggests that these fluids were trapped during the Miocene the stimulating discussions about fluid inclusions. Stasiuk, L.D., Snowdon, L.R., (1997) Fluorescence micro-spectrometry of = 40º-50º). From modelling of petroleum and aqueous inclusions (~10Ma). synthetic and natural hydrocarbon fluid inclusions: crude oil chemistry, density it is believed that these hydrocarbons were trapped during the References and application to petroleum migration. Appl. Geochem.12, 229 - 241. Miocene (~10 Ma). 3. The majority of hydrocarbon inclusions are commonly found Bakker, R. J. (2003) Computer Programs (applied thermodynamic), in annealed microfractures. They occur both as subparallel trails University of Leoben, Austria. Online: www.unileoben.ac.at/~buero62/ The second fluid event identified corresponds to fluid inclusions in detrital quartz grains and as secondary inclusions in trails that minpet/Bakker/Programs/Computer.html hosted within transgranular annealed microfractures in the transect both detrital and authigenic quartz. This indicates that sandstones. These fluid inclusions have been recorded cutting the microfracturing was an important conduit for petroleum migration Bodnar, R.J., (1990). Petroleum migration in the Miocene Monterey quartz overgrowths. At least 2 aqueous and 2 hydrocarbon fluid . two types of hydrocarbon were found within microfractures: 1) Formation, California, USA: constraints from fluid inclusion studies. Mineral. migrations events were recorded: 1) fluid with low to moderate A hydrocarbon fluid with 40º-50º API gravity and homogenization Mag. 54, 295 - 304. salinity (2.0 – 12 eq. wt. %NaCl) and homogenization temperatures temperatures between 64ºC and 138ºC; 2)A hydrocarbon fluid with between 100ºC and 137ºC; 2) An aqueous fluid with small volumes 25º-30º API gravity. Bodnar, R.J., 1993. Revised equation and table for determining the freezing of either CH4 ± CO2. Their homogenization temperatures range point depression of H2O–NaCl solutions. Geochimica et Cosmochimica from 102 to 127ºC; 3) Hydrocarbon fluid with 40º - 50º API gravity 4. Microthermometric data indicates that quartz overgrowths Acta 57, 683–684. and homogenization temperatures between 64ºC and 138ºC; and were precipitated by fluids with minimum trapping temperatures 4) A Hydrocarbon fluid with 25º-30º API gravity, these inclusions between 92ºC and 130ºC. Last ice melting temperatures indicate Burruss , R.C., (1991). Practical aspects of fluorescence microscopy are typically < 3µm. Because of their size they are difficult to resolve that both aqueous fluid with low salinities (0.5 to 4.8 eq. wt% NaCl) of petroleum fluid inclusions. In Barker, C.E. and Kopp, O. (Eds)., and no precise microthermometric data could be obtained from and CH4 ± CO2 were present at the time of quartz overgrowth Luminescence Microscopy: Qualitative and Quantitative Applications., In these inclusions. The presence of inclusions within trails long formation. SEPM Short Course.25, 1-7. annealed fractures suggests that microfracturing was an important conduit for both petroleum and aqueous migration. 5. Microthermometric studies from the aqueous fluid inclusions Burruss, R.C. (2003) Petroleum Fluid Inclusions, an Introduction. In: Fluid hosted in transgranular annealed fractures, suggest at least two Inclusions Analysis and Interpretation. Samson I., Anderson A. and Marshall, The third and final event identified corresponds to the fluid aqueous migration events post-diagenesis. These fluids can be D. Mineralogical Association of Canada. Short Course 32, 159-174. inclusions found within the veins. At least three aqueous and one divided as follows: 1) A fluid with low to moderate salinity (2.0 – hydrocarbon fluid migration events were recorded: 1) Fluid with high 12 eq. wt.% NaCl) and homogenization temperatures between Feely, M and Parnell J. (2003) Fluid inclusion studies of well samples from homogenization temperatures (240ºC to 290ºC) and high salinities 100ºC and 137ºC; 2) An aqueous fluid containing CH4 ± CO2 and the hydrocarbon prospective Porcupine Basin, offshore Ireland. Journal of (34 to 36 eq. wt %NaCl); 2) A fluid with moderate salinity (10 to homogenization temperatures that range from 102ºC to 127ºC. Geochemical Exploration,78–79, 55– 59 17 eq. wt. %NaCl) and high homogenization temperatures (178ºC to 227ºC); 3) A CaCl2 bearing fluid with moderate salinity (3.4-7.2 6. A wide range of compositions and homogenization temperatures George, S.C., Krieger, F.W., Eadington, P.J., Quezada, R.A., Greenwood,

112 113 OG12 OG13 gas). The B Well gases are also of thermogenic origin. The C Well gases are of thermogenic origin (mixing of deep dry gases with associated gases). Biodegradation process apparently did not Geochemical Study of Reservoir Crude oil and gas from the Campos affect the sampled gases. Continuity in Cotoperí-Oritupano Field Basinof Brasil: a geochemical characterization Geochemical analyses of post-salt hydrocarbons from Late José A. García and Irenio Berrios Cretraceous and Tertiary reservoirs, are compared with the previous Rafael Tocco1*, Roger Baudino1 and Matthieu Pontet2 ones and allow revealing similities and differences. E&P General Management, PDVSA Intevep, S.A. Los Teques, P.O. Box 76343 1070-A, Venezuela 1 Repsol Exploration, Direction of Geology, Méndez Alvaro 44, Conclusions 28045, Madrid, Spain. The pre-salt oils are mixed oils with intermediate lacustrine-marine [email protected] 2 Repsol Sinopec Brasil, Praia de Botafogo 300, Rio de Janeiro, organic matter input, or oils generated by a source rock with mixed Brasil. organic matter (marine-lacustrine). The oils are mature to highly Copyright 2014, ALAGO. mature. Geochemical evaluation support oil-oil correlation between This paper was selected for presentation by an ALAGO Scientific Committee following *[email protected] A, B and C well oils. The analyzed gases are of thermogenic origin. review of information contained in an abstract submitted by the author(s).

Figure 2. Structural map of the study area. Copyright 2014, ALAGO. Acknowledgements Introduction The authors thank Repsol Sinopec Brasil for approving the The Cotoperí-Orocual field is located in Northern Monagas (Fig From Fig. 2 and according to the standard of continuity evaluation Introduction presentation of this study. 1). The reservoir is divided in five blocks by faults. The existence and the ΔPx data, there are some differences between the GC The Campos Basin is located in the Southeastern Brazilian Margin of those faults needs to be reevaluated, because the fault sealing peak ratios of the wells A, B and D, and the continuity of the fluid and has a total area of about 300000 km2. It is part of a series and reservoir continuity of different fault blocks are very important of the oil reservoir is good, while the wells D and E the continuity of basins formed along the Brazilian Atlantic margin during the issues for the study of oil filling histories and production (García et of the fluid of the oil reservoir is regular, which reflects that the breakup of Gondwana in Early Cretaceous times. The Campos al., 2008; Hou et al., 2004). continuity of the fluid is limited. basin is limited by the Vitória High, which separates it from the Espírito Santo Basin to the north, and by the Cabo Frio High, that Conclusion separates it from the Santos Basin to the south. The Campos The fluid continuity between Block 4 and Block 5 is limited. Basin has for long accounted for the largest reserves of Brazil in Therefore, the impact on fluid of the fault B4/B5 should be taken Late Cretaceous and Tertiary post-salt reservoirs and after the BM- into consideration in future development of Cotoperi-Orocual field. C-33 Repsol operated block, pre-salt discoveries also revealed to be the place of large pre-salt accumulations. Acknowledgements The authors would like to acknowledge PDVSA Intevep, S.A. for Results and Discussion permission to publish this paper and thank reviewers for their The pre-salt oils are mixed oils with intermediate lacustrine- useful comments. marine organic matter input, or oils generated by a source rock with mixed organic matter (marine-lacustrine). These crude oils Figure 1. Relative location of the fields in the North Monagas. References were generated by a clay-rich source rock. Two oil groups (A and García J. A., Vargas A. and Canale G. Estudio Geoquímico de B wells) show presence of moderate-high relative concentration Experimental Compartamentalización de Yacimientos en la Costa Oriental del Lago of gammacerane compound, being the major concentration in Four dead oil samples were purchased in duplicate, taken at the de Maracaibo. XI Latin-American Congress on Organic Geochemistry the B Well oils. Gammacerane indicates that increased water wellhead according to API RP 44. The samples were dried and November 2-6, 2008. Margarita Island, Venezuela. salinity during deposition of the source rock. The m/z 191 terpane then removed the sediment according to ASTM D1796-97. C15- chromatograms for C Well oils show low signal-to-noise ratios. fraction was analyzed in a gas chromatograph Agilent Technologies, Halpern H. I. (1995) Development and application of light-hydrocarbon- Highly mature oils have low concentrations of biomarkers (very low model 6850 Series II. based star diagrams. AAPG Bull, 79(6): 801-815. relative concentrations of branched saturate hydrocarbons). C Well oils are more mature than A and B well oils. Results and Discussion Hou D., Zhang J., Long Z., Zhu J., Tang Y., Xu X. and Huang B. (2004) Based on the basic principle that within a reservoir where there Study of fault sealing by geochemical techniques: Fault sealing evaluation in Geochemical evaluation support oil-oil correlation between A, B are permeability barriers occur compositional homogenization of petroleum migration and reservoir continuity. Proceedings of the 6th AAPG and C well oils. oil therefore anywhere in the reservoir will be presented the same International Conference. 201-208. composition or fingerprint (Kaufman et al., 1990) and, to the extent Hunt J. M. (1995) Petroleum Geochemistry and Geology. W. H. Freeman Some geochemical signals suggest that the oils are affected that there are compositional differences, they may be attributed to and Company. New York, 743 by biodegradation. The only explanation for biodegradation the effect of compartmentalization (Hunt, 1995). The GC peak ratios evidences could be that the oils have been affected by microbial of the oil samples were analyzed and studied. Fifteen representative Kaufman, R. L., A. S. Ahmed, and R. J. Elsinger, 1990, Gas Chromatography processes before the reservoir reached temperatures of 80ºC parameters (P1-P15) were selected (after Thompson, 1987) and as a development and production tool for fingerprinting oils from individual (paleo-biodegradation). Generally oil accumulations which contain posted in a star plot (after Halpern, 1995; Fig. 2). reservoirs: applications in the Gulf of Mexico, in D. Schumaker, and B. F. a number of distinct charges or charge over time at different

Perkins, eds., Proceedings of the 9th Annual Research Conference of the rates, exhibit mixed geochemical signatures: mixing of fresh and Society of Economic Paleontologists and Mineralogists, October 1, 1990: degraded oils . The biodegradation is not a significant feature that New Orleans, p. 263-282. affect the oil quality.

Thompson K.F.M. 1987 Fractionated aromatic petroleums and the Gas samples from both Post- and Pre-Salt series were analyzed. generation of gas-condensates. Org. Geochem., 11(6): 573-590 The A Well gases are of thermogenic origin (Post Salt gases: mainly oil associated gas; Pre-Salt gases: mainly condensate associated

114 115 OG14 from the Colombian Institute of Petroleum (ICP) and recent studies where Tmax values are predominant below 435°C, ICE 5.0-5.5, OG15 that were done within the context of this research. IAT 2+ to 3+ and Ro values of 0.4-0.6% indicating an immature thermal state of the organic material for this sequence. Geochemical characterization Quality control: A revision of the whole information was ran in order Geochemical characterization of from the northern area of the Eastern to eliminate the data with error or lack of information such as depths S2 and S1 values are low in this area of the Basin, indicating low oil seep and oil samples from wells of Llanos Basin, Colombia. and pyrolysis data with total organic content (TOC) < 0,5%wt which generator potential. adjacent areas, in order to determine the can cause problems at the moment of data interpretation. origin, by oil-oil correlation, two study Nelson Sanchez1,Felipe de la Parra1,Diego A. Martinez2*¬, Jenny P. Conclusions. Biostratigraphic correlation: time intervals were identified from a cases, Monagas, Venezuela 2 3 In this area of the Basin, the Mesozoic and Cenozoic section, shows Ramirez ,Henry Suarez palinology research made by the biostratigraphy group of the ICP and the available electrical registers for each well. an immature thermal state and through the Paleozoic section we Y. J. Rincones1*, C. Rodríguez 1, J. Arenas 1 1Instituto Colombiano del Petróleo ICP-ECOPETROL, Piedecuesta, observed an increase of the thermal maturity of the rocks towards Colombia Geochemical characterization: after the compilation of information SW-NE direction, which goes from Immature-early mature in 1 PDVSA, Intevep, Los Teques, 76343, Venezuela 2 Natfrac Corporation, Bucaramanga, Colombia and identifying the time intervals in the correlation, the geochemical Santa Maria-1 and Joropo-1 wells to late mature in Agualinda-1, 3 Empresa Colombiana del Petróleo ECOPETROL, Bogotá, characterization was made for each time interval from each well, La Heliera-1, Chiguiro-1 and La Coral-1 wells. It’s observed that [email protected]; [email protected] Colombia taking into account the standards from Peters & Cassa, 1994. the compiled thermal maturity data from different studies shows variations, depending on the material that was taken to perform the Copyright 2014, ALAGO. *[email protected] Integration of the information: after relating the geochemical analysis or the techniques that were applied. This paper was selected for presentation by an ALAGO Scientific Committee following interpretation for each time interval and the correlation made on review of information contained in an abstract submitted by the author(s). step 2, the correlation for each time interval was made, which Copyright 2014, ALAGO. The intervals with conditions for the best hydrocarbons generator allowed us to see the variations along the researched transect and This paper was selected for presentation by an ALAGO Scientific Committee following potential are placed to the NE between La Heliera-1, Chiguiro-1 Introduction to identify the intervals with potential for hydrocarbons generation. review of information contained in an abstract submitted by the author(s). and La Coral-1 wells in Coniacian age rocks, with good-very good The geochemical characterization is a specialty widely used in the organic contents and good-very good generator potential with type oil industry, with multiple applications that help to understand the Results and discussion Introduction II kerogen mainly to the SW. In Santa Maria-1 well, two intervals with petroleum system in the area. Below are two study cases, in which Organic material content: the Paleozoic interval showed poor to The main sources of hydrocarbons in the Eastern Llanos Basin good geochemical properties were identified; the first to the top of geochemical characterization was applied to determine the source regular organic material content with values that were between are cretaceous age rocks that belong to Gacheta Formation. Early Oligocene sequence with good organic contents, regular to of oil seeps, in the area North of Monagas in Venezuela (figure 1). 0.2-0.9%wt. In the Late Cretaceous interval the TOC contents Nevertheless, due to the increase in the demand for hydrocarbons, good generator potential mainly associated to type II kerogen and The samples were analyzed by general and special geochemical increased from regular to good with values between 0.6-2.37%wt it’s necessary to explore for new sources that would improve the second to the middle part of Late Miocene interval, with good techniques, to determine the origin and maturity of these, as well as towards Santa María-1 and La Heliera-1 wells, reaching very good production. to very good organic content, good generator potential, type I and any possible oil-oil correlation, to determine the source of the spill. values in Chiguiro-1 well mainly in the interval known as Coniacian. II kerogen. Finally within the Cenozoic interval are the best TOC values Within this context, it’s necessary the research and exploration of between 0.5-5.6%wt which indicate regular to very good organic new areas that weren’t taken into account before, which can have References material contents mainly towards Mid Miocene. new source rocks with conditions for hydrocarbons generation. Brown; Ruth Laboratories, INC. Geochemical evaluation for Among these new locations is the northern area of the Eastern hydrocarbon source potential, Sun Chiguiro No.1_Colombia, Quality of the organic material and generator potential: The tools Llanos Basin. South America. Final report. to establish the kerogen type in the Paleozoic and Proterozoic sections are the IH rates, which were associated to type III Kerogen This research is focused on Santa Maria-1, Joropo-1, Agualinda-1, Dow, W. G.; Gonzalez, E., 1979. Geochemical evaluation of Rondon-1, (gas generator). Organic petrography results (visual analyses of La Heliera-1, Chiguiro-1 and La Coral-1 wells, as shown in Corozal-1 and La Heliera-1, Wells, Llanos Basin, Colombia. Robertson Kerogen) indicate a predominance of liptinites and phytoclasts. figure 1, with the purpose of characterizing each time interval Research (US) Inc. From this information was established that the Late Cretaceous from geochemical information, kerogen visual analyses and interval has type II Kerogen (gas and oil generator), related to biostratigraphy to identify the generator potential of these rocks in Dunn, M. E., 1986. Geochemical data for the well La Coral, Llanos Basin, marine sediments where the mixture of organic material derived this area of the Basin. Colombia. Research Center. from phytoplankton, zooplankton and bacteria took place; the

Cenozoic interval is characterized by a mixture of type I and II Duddy, I. R.; GEOTRACK, 2013. Organic petrography analysis (vitrinite Figure 1. Geographical Location kerogen (oil generator) associated to a mixture of lacustrine and reflectance and visual kerógeno analysis), in cutting samples from 3 wells. marine sediments. Report prepared for ICP-ECOPETROL, Colombia. Methods For the evaluation and characterization of the samples collected, Maturity of organic material: the evaluation of the maturity for ICP-ECOPETROL, 2013. Integración de resultados geoquímicos y the following geochemical analyzes were carried out: SARA, GC on Paleozoic and Proterozoic intervals was hard to discriminate litológicos correspondiente a los pozos del proyecto palinoestratigrafía. saturates fraction and GC-MS of saturates and aromatic fraction because vitrinite reflectance data (%Ro) was dismissed due to the Reporte interno, 64p. (figure 2). absence of flora within these intervals, hence there weren’t any vitrinites to perform the analysis; the evaluation for this interval was Peters, K., 1986.Guidelinesforevaluatingpetroleumsource rock using made taking into account the values of the color index for acritarchs programmed pyrolysis. AAPG Bulletin 70, N° 3, 318-329. such us Leiosphere, Cymatiogaleaspp, Dictyotidiumspp among others from the same age. These analysis suggest an immature Figure 1. Location of the Wells used for this research, placed on the Peters, K.; Cassa, M., 1994.Applied source rock geochemistry the to early mature state for the area between Santa Maria-1 and northern area of the Eastern Llanos Basin. petroleum system from source to trap. AAPG Memoir 60, 93-120. Joropo-1 wells with SCI values between 5.0-6.5 (Roeq 0.6-0.7%) Staff of E&P Operations, 1981. Final Well Report Santa María N°1, Ariporo with and increase towards Agualinda-1, La Heliera-1, Chiguiro-1 Methodology área, Colombia, 217p. and La Coral-1 wells, with states of Late Maturity getting out the The phases developed for this research were as follow: generation window with SCI values between 8.0-9.0 (Roeq 0.9- García, D. F.; Giraldo, B. N., 1999 Geoquímica del sector Capachos- 1.3%). On the other hand for the Mesozoic and Cenozoic sequence \Compilation of bibliography: the main sources for this research Cuenca Llanos Orientales. Instituto Colombiano del Petróleo. we could count on Tmax, SCI, TAI and vitrinite reflectance data, were the final reports that were made for each well, the database

116 117 Figure 2. Methodological diagram of oil characterization References OG16 Gulf of Mexico province. In contrast the heavy oils from Colombia [1] Peters, K., Walters C., and Moldowan, M., 2005, The Biomarker Guide. were generated by several pulses of biodegradation. Results and discussions Biomarkers and Isotopes in Petroleum Exploration and earth History. Vol. 2. This paper presents two cases of oil leaks from old fields of NE THE ORIGIN OF HEAVY CRUDE OILS IN Cambridge University Press. Acknowledgements Venezuela. The first Case is about geochemical characteristics of MEXICO AND COLOMBIA The authors thank ECOPETROL and PEMEX for allowing to an oil sample A-1 from a spill in the area C, and an oil sample [2] Rullkötter, J. and Wendish, D., 1982, Microbial alteration of 17α(H)- present this work. B-1 from well B located in the area C. The results showed clear hopano in Madagascar asphalts: Removal of C-10 methyl group and ring differences between the samples, indicating a negative oil-oil Mario A. Guzmán Vegaa, Diego F. García-Bautistaa, Leonardo opening. Geochimica et Cosmochimica Acta, Vol. 46, p. 1534-1553. correlation between oil samples A and B, which indicates that Mogollón-Galvisa, Robert E. Marquez-Romeroa the oil sample A does not come from wells in the area, although [3] Seifert, W. K., and Moldowan, J. M., 1979, The effect of biodegradation samples are associated with a carbonate rock deposited under a ECOPETROL on steranes and terpanes in crude oils. Geochemical et Cosmochemica anoxic conditions and a marine origin, the differences were found e-mail: [email protected] in the maturity and biodegradation. Acta, Vol. 43, p. 111-126.

Copyright 2014, ALAGO. The second Case is about geochemical characteristics of oil This paper was selected for presentation by an ALAGO Scientific Committee following seepage samples E-1, E-2, E-3, E-4, E-5, E-6, detected in the field D and an oil sample F-1, from well F, located in the field D, in order to review of information contained in an abstract submitted by the author(s). conduct an evaluation to determine if these oil samples correspond to oil seepages or oil spills caused by abandoned wells in the area. Introduction The results suggest that the oil seepage samples and the well oil 64% of world reserves are related to heavy and extra heavy crudes sample are positively correlated, indicating that the abandoned well reservoirs. We analyzed here the formation of heavy oil in two is leaking oil, in addition, the characterization determined that the different tectonic environments: Extensional (case of Mexico) and a samples are associated with a carbonate rock deposited under compressive foreland (case of Colombia). anoxic conditions, a marine origin and maturity is between early and oil window. Besides the lack of paraffins and isoprenoids and Results and Discussion the presence of the compound 25-Norhopane established that the The Tithonian source rocks contain large amounts of organic sulfur samples show a high degree of alteration (grade 8) due to the effect compounds and are considered the most important generative of biodegradation and/or oxidation of the compounds. subsystem in Mexico. Kerogens from Tithonian natural series and related oils suggest that hydrocarbon generation in these rocks Conclusions begins and ends about 0.5% and 0.9% respectively, with peak * In case 1, the results indicate that the oil samples A-1 and B-1 generation of about 0.8% Ro. are associated to organic matter type II of marine origin, deposited under reducing conditions, but the oil sample B-1 is more mature In the central and southern portion of the Llanos Orientales and less biodegraded than the oil sample A-1. In addition, basin have been recognized at least 2 families of oils, a family sample A-1 showed an abundance of branched and naphthenic associated with Cretaceous marine source rocks and a second compounds that are not in the sample B-1, which could indicate family associated to source rocks of continental affinity. The a possible mixture of predominantly marine oil source with a lower presence of unmethylated compounds is considered as a common proportion of a biodegraded oil. These results indicate that the characteristic of oils produced by marine rocks which is diagnostic samples A-1 and B-1 do not have a positive correlation, therefore of advanced biodegradation processes . Samples analyzed in the oil sample A-1 does not come from wells in the area. these compounds coexist with n -paraffins showing a complex filling history. The distribution of heavy oils is not related to the * In case 2, the results indicate that the oil seepage samples (E-1 depth and the current temperature of the reservoir. These fluids to E-6) and the well oil sample (F-1), are associated to organic were trapped in shallow and cold reservoirs (temperature <80 ° matter type II of marine origin, deposited under reducing conditions C ) before the burial of the deposits to its current position These and a maturity between medium to oil window, in addition, the facts suggest the presence of a paleo - oil biodegradation affecting characterization determined that the oil seepage samples and pulses accumulated during early migration, being biodegraded to the oil well sample are positively correlated, indicating that the oil temperatures above 80 ° C. seepages samples (E-1 to E-6) taken around the well (F-1) are the result of a spill of this. Besides, the lack of paraffins and isoprenoids Conclusions and the presence of the compound 25-Norhopane established The mineral matrix of the source rocks is an important factor that that the samples show a high degree of alteration, this is because, controls the quality of the crude. In rocks with clay matrix, iron is the samples of oil seepages were taken at the surface, and the well abundant and reacts with the sulfur in the sedimentary environment, has been closed for a long time. giving rise to pyrite and chalcopyrite, whereas in source rocks with

carbonate matrix, free sulfur reacts with organic matter giving rise Acknowledgements to sulfur rich kerogens which produce an early generation. The authors thank to PDVSA Intevep all their support that made possible to carry out this research. This early generation process would be responsible for the heavy oil deposits present in some of the Mexican reservoirs in the Mexican

118 119 OG17 i.d., 0.1 μm df) was used as the second-dimension column (2D). OG18 The selected samples were pre-fractionated to saturated Another HRMOG example is related to the separation of C30 24-n-propylcholestanes - derived from 24-n-propylcholesterols, High-Resolution Molecular hydrocarbon and aromatic fractions. Due to the high content of Vertical variability in crude oil composition: n-alkanes, some of the saturated fractions were treated with urea which are biosynthesized by sea water Crysophyte algae (Peters Organic Geochemistry for the to achieve the branched and cyclic hydrocarbon fraction (B/C). The et al., 2005) -, from interferents like the C30 4-methyl-24- Es-Soc Well, Socororo Field, Eastern Depositional Paleoenvironment saturated hydrocarbon, B/C and aromatic fractions were dissolved ethylcholestanes. Venezuelan Basin Classification of Brazilian Crude Oils in dichloromethane before chromatographic analysis. The presence of these compounds in crude oil is an important tool Salvador Lo mónaco and Liliana López Results and Discussion to identify marine organic material input in the source rock. Positive Alessandro Casilli1, Félix T. Gonçalves1,Jaakko Laakia1, Maria The use of a powerful analytical technique such as GC×GC-TOFMS identification of the 24-n-propylcholestanes by GC-MS/MS in Instituto de Ciencias de la Tierra. Facultad de Ciencias. Universidad Regina B. Loureiro1,Débora A. Azevedo1, Francisco R. Aquino accesses new opportunities forgeochemical data analysis, which MRM mode (414>217) can be difficult due to low concentrations Central de Venezuela Neto1 may be considered as a step towards a High Resolution Molecular and coelutions with C30 4-methyl steranes. On the contrary, as Organic Geochemistry. Recent results from our group have shown reported in Figure 2, the GC×GC-TOFMS permitted its separation *[email protected] 1 Universidade Federal do Rio de Janeiro, Instituto de Química, how non-conventional compounds are important to differentiate and reliable identification. LAGOA-LADETEC, Ilha do Fundão, 21941-909, Rio de Janeiro, paleoenvironment depositional conditions. In fact, in a group of 20 Copyright 2014, ALAGO. RJ, Brazil. oils from the same basin, minor differences in the GC×GC-TOFMS This paper was selected for presentation by an ALAGO Scientific Committee following data analysis have been observed (Casilli et al., 2014). In another review of information contained in an abstract submitted by the author(s). [email protected] example, Kiepper et al. (2014) differentiated samples with 3β- and 2α-methyl-hopane series (as suggested by Farrimond et al., 2004) Copyright 2014, ALAGO. Introduction and onocerane isomers, present at trace level, as proxies of the This paper was selected for presentation by an ALAGO Scientific Committee following The determination of producing intervals and oil quality in a reservoir different depositional paleoenvironment. review of information contained in an abstract submitted by the author(s). requiresthe studyof different geochemical parameters. In particular, In this work, GC×GC-TOFMS has been used as an important oil quality reflects the compositional characteristics of hydrocarbons Introduction tool in biomarker investigation, paving the path for a true HRMOG that impact the economic viability of an exploration, development, The geochemical analysis of crude oils demands a lot of information approach. The oils investigated allowed the characterization of including vast characterization of its chemical constituents. or production opportunity. In general, oil quality may affect the different depositional paleoenvironment and their mixtures. The This task historically has involved different analytical techniques, direct economic value of the crude oil. Typical oil-quality properties biomarker ratios for H30/St ααα (S+R), Tr26/Tr and % 3βMH31/ predominantly capillary gas chromatography (GC) in many cases H30 are, respectively: Oil A: 9, 1.74, 2; Oil B:12, 1.48, 2; Oil C: Figure 2.EIC m/z 414 showing the separation of 24-alkylcholestanes include API gravity, viscosity, sulfur, asphaltene, and metals (e.g., coupled to mass spectrometry (MS; MS/MS). Due to the lack of 8.99, 1.42, 1.93; Oil D: 7.53, 1.33, 1.87; Oil E: 9.3, 1.97, 1.73; Oil and mass spectra of 4α-methyl-24-ethylcholestane (a) and vanadium, nickel) contents, and acidity. Biodegradation can information related to chromatographic coelutions and the limited F: 3.59, 1.3, 1.47; Oil G: 2.36, 1.21, 1.72; Oil H: 1.89, 0.9, 0.18; 24-n-propylcholestane (b) access to the spectral data of the SIM and MRM modes, in the last significantly impact essentially all oil-quality properties of crude oils Oil I: 0.79, 0.82, 0.66; Oil J: 1.01, 1.03, 0; Oil K: 1.57, 1.25, 0; years the investigation of complementary techniques have been in producing zones. More specifically, oil biodegradation typically Oil L: 1.68, 1.41, 0.55. Plotting these values, the classification in Conclusions considered. three depositional paleoenvironments was not clearly obtained by GC×GC-TOFMS allowed the separation and identification of non- (a) decreases API gravity, (b) reduces the content of saturated and conventional parameters (H30/St27 ααα (S+R) vs Tr26/Tr25) (Figure conventional biomarkers, besides the usual ones. It is evident aromatic hydrocarbons relative to polar compounds (c) increases Comprehensive two-dimensional gas chromatography (GC×GC) 1a). On the other hand, the oils have been easily differentiated by the outstanding contribution of non-conventional compound hyphenated to time of flight mass spectrometry (TOFMS) provides oil viscosity, (d) increases oil acidity and (e) increases the sulfur combining a non-conventional parameter (%3β-MH31/H30) and a for the classification of Brazilian oils from different depositional interesting results, mainly due to its higher separation capabilities, content and the concentration of certain metals (e.g., V and Ni). conventional one (H30/St27 ααα (S+R)) (Figure 1b). paleoenvironment. the availability of the mass spectrum of each component and reliable As a consequence, the residual oil resulting from biodegradation quantitative data. GC×GC-TOFMS raises the analytical capability Acknowledgements becomes enriched in NSO compounds (resin and asphaltene beyond the presently known biomarkers, leading to the possibility Petrobras SAP 4600349302, CNPq, FAPERJ. fractions), sulfur and metals (Connan, 1984; Wenger et al., 2002; of refining the application of High-Resolution Molecular Organic Geochemistry(HRMOG) to distinguish more subtle differences Larter et al., 2006). Knowledge of the lateral and vertical variations References in composition. This could lead to a better understanding of the in the oil-quality properties as a consequence of biodegradation Casilli, A., Silva, R.C., Laakia, J.,Cleverson, C.J.F., Ferreira, A.A., Loureiro, geochemical depositional paleoenvironment of complex petroleum M.R.B., Azevedo, D.A., Aquino Neto, F.R., 2014. High Resolution is an important key to the development and implementation of systems. Molecular Organic Geochemistry Assessment of Brazilian Lacustrine Crude enhanced oil recovery methods. Oils. Organic Geochemistry, 68, 61-70. In this study, a representative number of crude oils from different Brazilian basins were selected and deeply investigated. GC×GC- Venezuela has one of the world’s largest reserves of heavy and Kiepper, A.P., Casilli, A., Azevedo, D.A., 2014. Depositional TOFMS allowed the determination of minor molecular differences paleoenvironment of Brazilian crude oils from unusual biomarkers revealed extra heavy biodegraded crude oils in the Eastern Venezuelan resulting in their depositional paleoenvironment characterization. using comprehensive two¬dimensional gas chromatography coupled to Basin, which includes the widely studied Orinoco Oil Belt and the time-of-flight massspectrometry.Organic Geochemistry, in press. Experimental Socororo Major Area in the Maturin sub-basin. The Socororo field, Analyses were performed on a Pegasus 4D (Leco, St. Joseph, MI, and in particular the ES-SOC oil well, in the Socororo Major Area Farrimond, P., Talbot, H.M., Watson, D.F., Shulz, L.K., Wilhelms, A., 2014. USA) GC×GC-TOFMS, composed of an Agilent 6890 GC (Palo is the subject of this study. Here, we describe the vertical variability Methylhopanoids: Molecular indicators of ancient bacteria and a petroleum Alto, CA, USA) equipped with a secondary oven, a non-moving correlation tool. GeochimicaetCosmochimicaActa, 68 (19), 3873-3882. in the extractable organic matter (EOM) of sidewall core samples quad-jet dual-stage modulator and a Pegasus III (Leco, St. and oil composition. The latter was correlated to the characteristics Joseph, MI, USA) time of flight mass spectrometer. A DB-5 column Peters, K.E., Walters, C.C., Moldowan, J.M., 2005. The Biomarker Guide, (Agilent Technologies, Palo Alto, CA, USA), 5%-phenyl–95%- of the source rock (e.g., lithology, organic-matter input, redox Figure 1. Plot reporting the separation of 12 Brazilian oils formed in different Biomarkers and Isotopes in Petroleum Exploration and Earth History, Vol 2., methylsiloxane (30 m, 0.25 mm i.d., 0.25 μm df) was used as the depositional conditions, and thermal maturity) in order to establish depositional paleoenvironments based on conventional parameters (a) and p. 527. Cambridge University Press, Cambridge, UK. first-dimension column (1D). A BPX-50 column (SGE, Ringwood, adding a non-conventional one (b). oil quality as a consequence of biodegradation. VIC, Australia), 50%-phenyl–50%-methylsiloxane (1.5 m, 0.1 mm

120 121 Experimental Connan, J., 1984. Biodegradation of crude oils in reservoirs. In: Brooks, OG19 The samples suites consisted of a freshly recovered crude oil Alteration by biodegradation J and Welte, D (Eds.)Advances in Petroleum Geochemistry. V. 1 Aademic sample and sixteen sidewall core samples from the ES-SOC The EOM concentrations in the core samples exhibited values lower Press, London, 299-335. Carbon isotope analysis of than 0.1% (0.02-0.89 %), except for a sample taken at the depth well obtained from a relative depth interval of 878 m to 1373 m. specific biomarkers in Brazilian oils: Organic carbon concentration (LECO, C-144), and sulfur content interval of 1360 m were EOM reached a value of 2.4% (Figure 2). Larter, S., Huang, H., Adams, J., Bennett, B., Jokanola, O., Oldenburg, (LECO SC-432) were determined. Extractable organic matter The analyzed crude oil with 14° API and a sulfur content of 2.5%, novel patterns and limitations T., Jones, M., Head, I., Riediger, C., Fowler, M., 2006. The controls on the (EOM, %m/m) was obtained using Soxhlet extraction technique presented a SARA composition of 24% saturated hydrocarbons, composition of biodegraded oil in the deep subsurface. Part II – geological ¬* ¬ a with dichloromethane. The oil samples were de-asphaltened to 36% aromatic hydrocarbons and 40% polar compounds (resins + Jarbas V. P.Guzzoa , Mario D.Rangela , Eugenio V.Santos Neto , controls on subsurface biodegradation fluxes and constraints on reservoir- a¬ b¬* obtain a maltene fraction, which was subsequently separated asphaltenes). Figure 2 shows the n-alkanes and pristane phytane Ygor S. Rocha , John M. Moldowan fluid property prediction. American Association of Petroleum Geologist into its saturated, aromatic and resin fractions by means of distributions for the crude oil. The distributions are characterized Bulletin 90, 921-938. adsorption chromatography, using packed columns with alumina by a wide unresolved complex mixture (UCM) contribution under a PETROBRAS Research & Development Center, Rio de Janeiro, as the stationary phase. The saturated hydrocarbons were eluted a resolved peak envelope showing the presence of acyclic Brazil Peters, K.E., Moldowan, J.M., 1993. The Biomarker Guide. Interpreting with n-hexane, the aromatic hydrocarbons with toluene, and the isoprenoids (phytane and pristane) and variations in the relative b Biomarker Technologies, Inc.,Rohnert Park, California, USA Molecular Fossils in Petroleum and Ancient Sediments, Prentice Hall, polar compounds (resins) with a mixture of toluene and methanol. intensity of n-alkanes, indicative of alteration by biodegradation. Englewood Cliffs, New Jersey. Analyses of the saturated biomarkers were performed by gas e-mail: [email protected], [email protected] chromatography-mass spectrometry (GC–MS) on a network gas The abundance of C23 tricyclic terpanes, the slight alteration of Wenger, L.M., Davis, C.L., Isaksen, G.H., 2002. Multiple controls on chromatograph (Model 6890N, Agilent Technologies) coupled to steranes, and the absence of 25-norhopanes (Figure 1) indicate Copyright 2014, ALAGO. petroleum biodegradation and impact on oil quality. SPE Reservoir a mass spectrometer (Model 5975, Agilent Technologies). The GC that the crude oil is biodegraded to at least a PM level 5 (Peters This paper was selected for presentation by an ALAGO Scientific Committee following Evaluation & Engineering 5, 375-383. system was equipped with DB-1 fused silica capillary column (60 and Moldowan, 1993). In contrast, crude oils from other wells in review of information contained in an abstract submitted by the author(s). m x 0.25 mm x 0.25 μm). The monitored ions were m/z = 113 for the Socororo field showed the presence of isoprenoids pristane n-alkanes, pristane and phytane; m/z = 191, 177 for terpanes; and and phytane, absence of n-alkanes and traces of 25-norhopanes, Introduction m/z = 217, 218 for steranes and diasteranes. indicating different loadings of oils to the reservoir, which were Compound specific isotope analyses of biomarkers (CSIA-B) were subsequently biodegraded. carried out in a set of Brazilian oils with well constrained molecular Results and Discussion (biomarkers) and isotopic (CSIA-n-alkanes profiles) genetic based classification. Factors that control carbon isotopic composition of Crude oil type individual biomarkers are determined by paleobiologic origin and Analysis of the C24/C23 and C26/C25 tricyclic terpanes ratios paleoenvironmental conditions during deposition of the source and C27-C29regular steranes abundance indicates that the crude rocks (Hayes et al. 1990). oil originated from marine organic matter. The ratio C35/C34≥ 1 suggests anoxic-suboxic conditions during source rock deposition Carbon isotopic ratios of hopanes, tricyclic terpanes, steranes and (Figure 1). Additionally, the calculated values for the C24/C23, C22/ isoprenoids were investigated in representative oils of the three main C21 and C26/C25 tricyclic terpanes ratios and C31R/C30Hop tectono-sedimentary stages of the Brazilian continental margin: a) hopanes ratios suggest that the analyzed oil originated from either freshwater to saline lacustrine oils of the rift stage; b) evaporitic a marine-carbonate or a marine-marl source rock. The calculated oils of the Proto-Atlantic transitional/sag stage, and c) restricted values for the C29 sterane isomerization ratios C2920S = 54.5% to open marine oils of the drift stage. This combined approach and C29ββ = 52.5% indicate that the endpoint has not been provides advantages for the developing methodology (CSIA-B), reached (C2920S = 52-55% and C29ββ = 67-71% at endpoint; which is compared to a previous classification scheme. CSIA-B Peters and Moldowan, 1993). These results suggest that the crude adds new significant genetic and paleoenvironmental attributes to oils were generated prior or at the beginning of the oil window. a multivariate geochemical database.

Results and Discussion Great differences within hopane C-isotope ratios (generally > 10‰, figure 1) occur between marine and lacustrine oils. Lacustrine oils have characteristically 13C depleted hopanes (up to -39‰), Figure 2. Concentration (%m/m) of extractable organic matter (EOM) as a reflecting significant bacterial methane cycling (Summons et function of well depth; SARA composition; and mass chromatogram for al. 1994), restricted circulation and widespread water column n-alkanes and acyclic isoprenoids of the analyzed crude oil. stratification during Brazilian Lower-Cretaceous episodes of lacustrine source-rock deposition. Normal marine oils have 13C Conclusions enriched hopanes (up to -14‰) which is concordant with molecular The crude oil extracted from the ES-SOC well, Socororo field, (biomarker) paleo-environmental inferences of non-stratified and was originated from either a marine-carbonate or a marine-marl sub-oxic bottom waters during late drift phase. Pristane, phytane source rock with marine organic matter input deposited in anoxic- and steranes generally show similar isotopic compositions (around suboxic conditions and at an early oil window level of maturity. After -27‰) between oil families, which is concordant with their presumed generation, the oil was biodegraded at a PM level 5. phytoplanktonic origin. None of the oil families, except the normal marine oils, present indications of important terrestrial organic Acknowledgements matter input. Thus, -27‰ can be considered as representative This work was funded by the Consejo de Desarrollo Científico of the isotopic composition of primary producers of the euphotic y Humanístico, Universidad Central de Venezuela, under the zone (Schouten et al. 1998), for example, during Turonian times Figure 1. Mass chromatograms of the terpanes (m/z = 191 and 177, top) research grant N° PG-03-8204-2011 and Fondo Nacional para la in South Atlantic. Interestingly, the “orphan” biomarkers tricyclic and steranes (m/z = 217, bottom) in the saturated hydrocarbon fractions Ciencia y Tecnología, under the research grant N° 2012002299. terpanes tend to follow the same range of values of isoprenoids isolated from ES-SOC oil samples. References and steranes.

122 123 The carbon isotopic profiles of hopanes follow a pattern which OG20 Results and discussions is indistinguishable among oils generated by freshwater/saline or Falcón Basin’s crude oils are characterized for having an API gravity between 25° and 55°. The sulfur content is low (<0.5%). Oils can hypersaline source-rocks. These hopane isotopic profiles show a Origin and maturity of crude oils and oil seeps recurrent feature represented by a large difference (characteristically be classified as paraffinic, and oil seeps are paraffinic-naphthenic > 4‰) between the isotopic composition of C29 hopane (the most from Falcón Basin, Western Venezuela product of alteration by microorganisms. 13C depleted hopane) and C30 hopane. These two compounds show quite similar isotopic compositions in the oils of marine origin. Leonardo Sánchez-Carrasco a¬* Vanadium (V)/ Nickel (Ni) and Pristane (Pr)/ Phytane (Ph) The representative oils of Lower Cretaceous inland waterbodies correlations allowed differentiating crude oils and oil seeps (generated by rift and sag source rocks) also have a remarkable a PDVSA EXPLORATION, PUERTO LA CRUZ, ANZOÁTEGUI according to the depositional conditions of the source rock. heavy sterane (C304-methylstigmastane), generally 4‰ heavier STATE, VENEZUELA Important differences were identified amongst the available than C27-C28-C29 regular co-occurring desmethyl steranes, information. These dissimilarities suggest that, there is more than suggesting a distinct primary producer in continental waters [email protected] one source rock in Falcón Basin. Figure 2 shows the relation Pr/Ph recording episodic algal blooms. The 4-methylsteranes are largely vs. Dibenzothiophene (DBT)/ Phenantrene (PHEN) (Hughes et al., derived from dinoflagellates, of which certain species can thrive in Copyright 2014, ALAGO. 1995) where a group of crude oils originated from a fluvial/deltaic evaporitic environments. This paper was selected for presentation by an ALAGO Scientific Committee following source rock is observed followed by other group derived from a review of information contained in an abstract submitted by the author(s). siliciclastic marine source rock. Maracaibo’s Basin oils are located Figure 3. Spatial distribution of crude oils correlated according to Conclusions in the zone of anoxic- euxinic conditions associated to marine paleoenvironmental conditions of the sedimentary environment of the We observed a general agreement between paleoenvironmental Introduction carbonate and lacustrine source rocks. source rock using Pr/Ph and V/Ni. scenarios provided by thetraditional geological and geochemical Falcón Basin is a secondary oil and gas basin in Venezuela (Figure approaches and those derived from the isotopic analysis of specific 1). Recent discoveries of excellent quality crude oil offshore Falcón, Figure 3 shows the spatial distribution of the redox conditions of The maturity at the moment of generation and expulsion from biomarkers. CSIA of biomarkers is thekey tool to correlate isotopic have reactivated the exploration and the interest for the basin; the sedimentary environment were source rock was deposited, the source rock for the crude oils varies according to the relative and molecular data directly to a particular paleobiologic source and/ therefore a better understanding of the active petroleum systems according to the crude oils and oil seeps studied. To the North of location on the basin. Maturity was estimated from biomarkers or biosynthetic pathway. It has shown great potential to add new is necessary. the basin, crude oils are associated to a source rock deposited in the saturated fraction (C29 Steranes, Ts/Tm, Moretane, C32 and refined attributes to the paleoenvironmental reconstruction of in a disoxic sedimentary environment. Another group is related Homohopane) and aromatic fraction (MPI, %Rc, %Rm, TAs, MAs). ancient ecosystems and for the investigation of mechanisms of to a source rock deposited in a suboxic-anoxic sedimentary The maturity varies from early oil window (0.55%Ro) up to oil hydrocarbon generation. environment at the northeast and west of the basin. Finally a third generation peak (0.9%Ro). Maturity of crude oils and oil seeps in group was evidenced associated to a source rock deposited in Falcón Basin changes from East to West and from North to South References an anoxic environment in the Agua Salada Sub-Basin at the (Figure 4), suggesting different stages of maturation for the different Hayes, J. M., Freeman, K. H., Popp, B. N., and Hoham, C. H., 1990. Southeastern part of Falcón. source rocks. These changes could help to identify different Compound-specific isotopic analyses: a novel tool reconstructionof ancient events that could have taken place during the basin evolution like biogeochemical processes. Organic Geochemistry16, 1115–1128. differences in sedimentation rates and heat flow patterns, basin tilting, and migration directions of crude oils. Integration of crude oil Schouten S., Klein Breteler, W. C. M., Blokker P., Schogt N., Rijpstra W. I. C., characterization with geochemical rock data will allow establishing Grice K., Baas M. and Sinninghe Damsté, J. S., 1998. Biosynthetic effects the oil systems in the basin. on the stable carbon isotopic compositions of algal lipids: implications for deciphering the carbon isotopic biomarker record. Geochimica et Six crude oil families were identified based on their origin and Cosmochimica Acta, 62, 1397–1406. maturity. A1 and A2 come from a type III fluvial-deltaic source rock A1 generated at early oil window and A2 at oil peak. B1 and B2 Summons, R. E., Jahnke, L. L., and Roksandic, Z., 1994. Carbon Figure 1. Relative location of the Falcón Basin showing its main structural from a type II-III marine siliciclastic source rock having the first a isotopic fractionation in lipids from methanotrophic bacteria: relevance characteristics, Western Venezuela (from Baquero et al., F. 2009). minor maturity. C1 and C2 family are related to a marine anoxic for interpretation of the geochemical record of biomarkers. Geochimica et type II source rock with differences in the maturity level. Cosmochimica Acta, 58, 2853–2863 Numerous studies have taken place in the basin with the main goal of characterizing crude oils and oil seeps. However, many of them have focused on analyzing individual samples or making correlations with a limited amount of data. The differences of this Figure 2. Pr/Ph vs. DBT/PHEN for crude oils from Falcón and Maracaibo Basin. work from the others is that a regional scale study was applied in order to show the family distribution of crude oils in the basin and Another parameters used like n-alkane distribution, oleanane obtain the characteristics of the possible source rocks; therefore the index, steranes distribution and isotopes suggest that some crude main goal of this work was to compile all the existing geochemical oils and oil seeps were generated from a type III kerogen, others information related to crude oils and oil seeps in the basin and carry from a type II-III kerogen and southeast crude oils from a type II out an oil- oil correlation study. That way similarities and differences kerogen. A similar distribution as Figure 3 was acquired for source among these oils could be established and their origin and level of rock kerogen type. maturity determined.

Experimental Figure 1.Carbon Isotopic composition of specific biomarkers recorded in Information from 24 crude oils and 63 oil seeps was collected. Brazilian oils of diverse origin. The data set includes lacustrine (freshwater The available analyses were API gravity (19), SARA composition and saline) oils from Campos, Santos and Espirito Santo basins; evaporitic/ (78), %S (52), V/Ni (26), GC (25), GCMS (69) and isotopes (14). hypersaline (sag lakes) oils of Ceará, Campos and Santos basins; and This information was used for oil-oil correlation and compared Figure 4. Spatial distribution of the maturity from crude oils and oil seeps, restricted to normal marine oils from Campos, Santos, Espirito Santo and with information from Maracaibo’s Basin crude oils. Results were Falcón and Maracaibo Basin. Para-Maranhão basins. represented in graphic, tables and classification maps according to correlation parameters.

124 125 Conclusions OG21 gammacerane, dinosterane, C27-C28-C29-sterane distribution, Based on the available information the existence of more than one and TPP. 3. Recognizing and correlating the deep sources Based on quantitative diamondoid analysis (QDA, Figure 2) it is source rock for Falcón Basin’s crude oils and oil seeps is evident. Advanced Geochemical Technologies Six crude oil families were identified. A1 and A2 generated by a C30-steranes (24-n-propylcholestanes) are only observed in evident that the pre-salt oil samples have undergone little, if any, type III kerogen fluvial-deltaic source rock differentiating each other for Determining Multiple Sources, Facies marine oils by using the m/z 414 → 217 in GC-MS-MS (Moldowan cracking (Dahl et al., 1999). Among the remaining oils one appears in the maturity level. B1 and B2 families generated by a type II-III and Oil-Mixtures of Oil Produced in the et al., 1990), butinterferences can occur by“cross-talk” from to be non-cracked, and its biomarkers give a Late Cretaceous marine siliciclastic source rock also with maturity level differences. Santos Basin, Brazil 4-methylsteranes when lacustrine oil is present. This situation marine depositional environment signature. Finally C1 and C2 families originated by a type II marine anoxic occursfor end-member Lagoa Feia sourced oils and in mixtures source rock with differences in the maturity level being the first with a minor marine-source component. In order to correlate the deep sources of this oil suite we applied the Silvana M. Barbantia,b, J. M. (Mike) Moldowanc, Jeremy E. Dahld, generated at early oil window and the second at the oil peak quantitative extended diamondoid analysis (QEDA) which shows Geoffrey Botte, Tikae Tikakia, Shaun M. Moldowanc (similar for the other families). C25-HBI along with oleanane provide an important source age three different patterns for these oil samples. The QEDA patterns boundaries for Brazilian oil (Moldowan et al., 1994; Damsté et al., all together (Figure 2a) for comparison with break-out graphs a Integrated Petroleum Expertise Company, IPEXco, Rio de References 2004, Barbanti et al., 2006). HBI derives fromrhizosolenid diatoms depict the purely lacustrine-sourced oils (Figure 2b) in contrast to Janeiro, Brazil; Baquero, M., Acosta, J., Kassabji, E., Zamora, J., Sousa, J., Rodríguez, that evolved and radiated in the Turonian and HBI is reported only two distinct patterns for the marine sourced oils (Figure 2c). The b current affiliation: Schlumberger, Reservoir Sampling and Analysis J., Grobas, J., Melo, L. Scheider, F. 2009. Polyphase development of the known to be in source rocks and oils of Turonian and younger latter appears to indicate that two different marine sources within Laboratories, Houston, USA. Falcón Basin in northwestern Venezuela: implications for oil generation. ages. Recent analytical advances allow HBI concentrations to be the middle to upper Cretaceous sedimentary sequence have c Biomarker Technologies Inc., 638 Martin Avenue, Rohnert Park, Geological Society, London, Special Publications 328, 587-612. measured down to a few ppm, previously only to about 100 ppm. effectively generated the marine-sourced oils, respectively.The pre- CA 95472 USA; salt oil samples show a nearly perfect correlation of their QEDA d Stanford Institute for Materials and Energy Science (SIMES), Hughes, W., Holba, W., Leona, D. 1995. The ratios of dibenzothiophene 2. Advanced geochemical technologies to determine source fingerprints. Because the pre-salt oils are not seen by QDA to be Stanford University, Stanford, CA 94305, USA; to phenanthrene and pristane to phytane as indicators of depositional mixtures cracked, they serve as the QEDA trace of the pre-salt lacustrine e GB Scientific, Inc., 1090 Industrial Avenue, Suite B, So. Lake environment and lithology of petroleum source rocks. Geochimica et CSIA data distinguishes, with very strong isotopic differences, source formation. Some highly cracked post-salt reservoired oil Tahoe, CA 96150 USA Cosmochimica Acta 59, 3581-359. the marine and lacustrine oil sources. These are a powerful samples show the same trend in QEDA establishing these mixed- combination, together with diamondoid analyses used to determine source oils as having a lacustrine Lagoa Feia deep source. Some [email protected] deep sources and mixtures. thermally cracked oil samples that have an overall marine oil website: www.biomarker-inc.com (corresponding author) biomarker signature show the QEDA signature of the pre-salt oils Oil sourced from the Lagoa Feia Formation shows isotopically light implying they are mixed from a marine source in the oil-window and Copyright 2014, ALAGO. hopanes characteristic of a depositional environment featuring a a lacustrine source from deep. This paper was selected for presentation by an ALAGO Scientific Committee following stratified water column with anoxic bottom waters. Occurrence of review of information contained in an abstract submitted by the author(s). chemoautotrophy and probably a carbon cycle of methanogenesis- methanotrophy result in the isotopically light hopanes. Introduction

Marine oil has isotopically heavy hopanes characteristic of a well- One of the principal sources in the Brazil Margin is in the syn- mixed water column without stable euxinic stratification or anoxic rift section, sometimes referred to as the pre-salt or the Lagoa bottom waters. The hopanes in this depositional system were Feia Formation, which is deposited in a lacustrine depositional contributed by cyanobacterial phototrophs that incorporate CO2 environment. In Santos Basin the rift sources are lower Aptian from the atmosphere as a carbon source (Figure 1). and Barremian. The other sources are broadly grouped as marine sources for this discussion. They are younger in age, throughout the rest of the lower (or middle) and upper Cretaceous. Biomarker analysis can determine much about the source affinity of the oil- window portion of the oil. However, many of the oils are cracked and consist of contributions from both a deep and shallow source. Oil mixtures, in general, and cracked-oil mixtures, in particular, are difficult to unravel by using biomarker fingerprints alone. Here we first examine biomarker parameters to determine the principal Figure 2. Diamondoid analyses show oil cracking and determine affinities shallow-source affinities and diamondoids to determine whether of deep sources. (a) QDA shows most Santos Basin oils are mixtures from deep sources are also represented in each individual oil sample. A shallow and deep sources. The ans oils (pre-salt) andsample #39 show set of advanced geochemical technologies is applied to unravel the low diamondoid concentrations typical oil generated only from a shallow oil mixtures in this sample suite.Oil samples in the study included source. (b)Extended-diamondoid fingerprints show three patterns in the oil three from deep-water pre-salt production and nine from the set. (c) Pre-salt and related oils show one unique pattern. (d) Oils with central Santos Basin from post-salt reservoirs. a marine source show two different patterns, which could be used to Results and Discussion Figure 1. Isotopic ratios of hopanes strongly differentiate the marine and distinguish two different marine sources. 1. Some key biomarker parameters lacustrine sources in Brazil.Co-source contributions can be made for mixed Conclusions There is evidence for co-sourced oil in several cases by means oils, such as Sample 14. Shallow sourcesin the Santos basin are defined by compound of age-related and paleo-environmentally controlled biomarkers. n-Alkane isotope ratios for lacustrine oils typically show a “boat” specific isotope analysis of biomarkers (CSIA-B) coupled with These parameters refer only to the shallow (Oil Window) pattern as determined for the three pre-salt oil samples in this study. age-related and taxon-specific biomarkers. Shallow-sourced oil sources. Possible deep sources are not considered in this initial Facies differences are seen that distinguish the isotopic trace of mixtures are determined mostly by using CSIA-B and CSIA-A. interpretation. The following biomarker indices are considered to one pre-salt oil from those of the other two. Isotopic traces for the The occurrence of deep-sourced contributions and co-sourced be the most important for source identification in this basin: C30- alkanes isolated from the marine oils show a flat profile signaling mixtures is common in the basin shown by QDA. The deep sources steranes, C25-highly branched isoprenoid (C25-HBI, new method), a similar algal input across the spectrum of carbon chain lengths. are correlated by using QEDA and linked to source-rock families by

126 127 end-member non-cracked, non-mixed oils. Three deep-sourced oil OG22 into saturated, aromatic, and polar fractions and analyzed by Figure 2.Gammacerane Indices (gammacerane/C30 hopane) are generally families, two marine and one lacustrine, have been indicated by GC, GC-MS and GC-MS-MS, mainly in Selected Ion Monitoring low (<0.1) conforming to normal saline marine water during source rock (SIM) and Multiple Reaction Monitoring (MRM) modes. Because formation. Higher values are caused by biodegradation and preferential using the QEDA diamondoid fingerprinting method. Geochemical composition of crude oils of considerable biodegradation emphasis was put on biomarkers removal of C30 hopane. References and biodegraded seepage oils in Belize resistant to alteration. The source rock samples were in addition Barbanti, S.M., Guzzo, J.V.P., Rangel, M.D.;et al.(2006) The C25 highly and Guatemala: evidence for charging from subjected to standard geochemical screening analyses and the A yet unexplored and completely different petroleum system may branched isoprenoid as a specific tool for differentiating the African and Cretaceous carbonate source rocks kerogen qualitatively investigated by reflected light microscopy. exist offshore Belize. Slicks and sea bed seeps are common, Brazilian oils from Lower to Late Cretaceous [abs.], in Proceedings of and at Rocky Point on Ambergris Caye tar mats are found on the 10thALAGO, Salvador, Brazil, p. 133-134. H.I. Petersena*, B. Hollandb, H.P. Nytoftc, A. Chod, J. de la Cruze, Results and Discussion reef. These have been claimed to contain angiosperm biomarkers The crude oils are non-biodegraded, whereas the seepage oils are J.H. Cornecf indicating an Upper Cretaceous or younger source. Further Dahl, J.E.; Moldowan, J.M.; Peters, K.E.; et al. (1999) Diamondoid moderately to severely biodegraded. The oils were charged from analyses are required to resolve this and to exclude potential marine carbonate source rocks with comparable thermal maturity hydrocarbons as indicators of natural oil cracking. Nature 399, 54-57. a Maersk Oil, Esplanaden 50, DK-1263 Copenhagen K, Denmark contamination from oil spills from ships. and with some possible contribution from a lacustrine source in the b Blue Creek Exploration Ltd., P.O. Box 30, Punta Gorda, Belize South Petén Basin. High C35 Homohopane Index values in most Damsté, J.S.; Muyzer, G.; Abbas, B.; et al. (2004) The Rise of the c Geological Survey of Denmark and Greenland (GEUS), Oester Conclusions samples but low Gammacerane Indices (Fig. 2) indicate source Rhizosolenid Diatoms. Science, 304(5670), 584-587. Voldgade 10, DK-1350 Copenhagen K, Denmark Crude and seepage oils in the greater Petén Basin can be divided rock deposition under reducing conditions in normal marine water. d Geology and Petroleum Department, Ministry of Natural into three main groups, but they were all charged chiefly from Based on subtle variations in biomarker composition three main Moldowan, J.M.; Fago F.J.; Lee C.Y.; et al. (1990) Sedimentary Resources and the Environment, Market Square, Belmopan, Belize carbonate-rich source rocks, likely the Lower Cretaceous Cobán groups of oils were defined: (i) Group 1 includes oils from the North 24-n-propylcholestanes, molecular fossils diagnostic of marine algae. e Perenco Guatemala Ltd., 5a. Av. 5–55 Zone 14, Europlaza Torre Fm limestones. A possible lacustrine facies contribution is present Petén Basin and the western Corozal Basin and are characterized Science 247, 309-312. 4, Nivel 14, Guatemala City, Guatemala in the South Péten Basin. Seeps are spread over Belize and the by high amounts of C28 steranes and very high tricyclic terpane f Consultant, 1867 South Marion Street, Denver, CO 80210, USA seepage oils are mostly severely biodegraded. However, they share Moldowan, J.M.; Dahl, J.; Huizinga, B.J.; et al. (1994) The molecular fossil T22/T21 ratios, (ii) Group 2 contains oils from the South Petén a common source with the crude oils in the area. The location of Basin; intermediate TPP ratios could suggest contribution from record of oleanane and its relation to angiosperms. Science 265, 768-771. *[email protected] kitchen areas in Guatemala is relatively well-known, whereas in lacustrine facies, (iii) Group 3, a heterogeneous assemblage of oils Belize these remain unresolved, although charging from the eastern from the southern part of the Corozal Basin with some oils possibly part of the North Petén Basin updip into the western Corozal Basin Copyright 2014, ALAGO. derived from more marine shaly facies . seems likely. The location of the kitchen area for the seepage oils in This paper was selected for presentation by an ALAGO Scientific Committee following the Belize Basin is still speculative. A possible, younger petroleum review of information contained in an abstract submitted by the author(s). system may be present offshore Belize. Introduction The petroleum geology of Guatemala and, in particular, of Belize Acknowledgements is poorly documented. The E-W trending La Libertad arch and The study was carried out while the first author was employed at the Maya Mountains divide Guatemala into the North and South the Geological Survey of Denmark and Greenland. The Ministry of Petén Basins and Belize into the northern Corozal Basin and the Natural Resources and the Environment (Belize) and the Ministerio southern Belize Basin. Together, these subbasins constitute the de Energia y Minas (Guatemala) are thanked for providing the oil greater Petén Basin. Oil production is mainly from the Xan Field in samples. We are grateful for logistical support provided by Blue North Petén Basin with lesser amounts produced by small fields in Creek Exploration Ltd. both basins in Guatemala, (Bishop, 1980; Peterson, 1983; Dengo, 2007). The hydrocarbons are believed to have been charged References from Lower Cretaceous organic-rich carbonates of the Cobán Bishop, W.F., 1980. Petroleum geology of northern Central America. Formation. The petroleum system(s) is thus significantly different Journal of Petroleum Geology 3, 3–59. than the nearby Reforma area and Campeche Shelf in the Gulf of Mexico that are charged from Upper Jurassic marine shales. Figure 1. Bitumen (left) and oil in vug (right) in freshly broken Lower Dengo, C.A., 2007. Chapter 30. Petroleum geology. In: Bundschuh, J., Belize is significantly underexplored and has only two recently Cretaceous limestone, Belize Basin. Alvarado, G.E. (Eds.), Central America: geology, resources and hazards. discovered small fields in production, viz. the Spanish Lookout and Taylor & Francis Group, London, 895–916. The biodegraded seepage oils from the Corozal and Belize Basins Never Delay fields, both in the Corozal Basin. However, numerous show geochemical features mainly related to Group 2, although onshore seeps have been known for a long time in Belize but until Petersen, H.I., Holland, B., Nytoft, H.P., Cho, A., Piasecki, S., de la Cruz, they constitute sub-groups. recently the types, composition and sources of the seep and crude J., Cornec, J.H., 2012. Geochemistry of crude oils. Seepage oils and source rocks from Belize and Guatemala: indications of carbonate-sourced oils were virtually unknown (Petersen et al., 2012). Lower Cretaceous Cobán Fm source rocks have been drilled in petroleum systems. Journal of Petroleum Geology 35, 127-164. the North Petén Basin in Guatemala, but both source and kitchen The present study describes the geochemical composition of areas for the crude and seepage oils in Belize are unknown. Some crude and seepage oils, and a number of source rock samples Cobán Fm limestone samples from the Belize Basin show good Peterson, J.A., 1983. Petroleum geology and resources of southeastern from onshore Belize and Guatemala. It documents the presence quality oil-prone kerogen, but the TOC content is low. Mexico, northern Guatemala, and Belize. U.S. Geological Survey, Geological of carbonate-sourced petroleum system(s) in the greater Petén Survey Circular 760, 44 pp. Basin, and suggests potential charge areas.

Experimental Nine Crude oils from Guatemala and Belize were acquired for analysis together with 17 seepage oils collected during fieldwork in Belize. The seep oils ranged from sticky bitumen to oil (Fig. 1). In addition a number of source rock samples from the study area were collected and analyzed. Asphaltene-free samples were separated

128 129 OG23 Samples excluded from the training set included: (1) heavily biodegraded oils (rank 5 or more on the 1–10 scale of Peters Anoxic Upper Miocene (M.-U. Puente) marl source rock generated tribe 3 west of NIFZ. Chemometric Recognition of and Moldowan, 1993), and (2) highly mature condensates, where biomarkers are low (e.g.,<10 ppm steranes). Source-related Genetically Distinct Oil Families biomarker and carbon isotope ratios for the remaining 112 non- or Anoxic Mohnian(?) marl generated tribe 4 west of NIFZ. in the Los Angeles Basin, California mildly biodegraded oil samples were used to definethe training set. >12,000 ft Anoxic M.-U. Miocene (L. Puente “nodular shale”) marl with K.E. Petersa,b*, T.L. Wrightc, L. Scott Ramosd, J.E. Zumbergee Chemometric (multivariate statistics) software (Pirouette and significant terrigenous plant input generated tribe 5 southwest of Family

InStep; Infometrix, Inc.) was used to create a multi-tiered decision 11, 12, 13 PALOS VERDES NIFZ. 21, 22 HILLS a Schlumberger Information Solutions, Mill Valley, CA 94941 tree that identifiesgenetic oil families. We used geochemical 31, 32, 33 b Department of Geological & Environmental Sciences,Stanford expertise and principal component loadings to select 24 source- 41, 42 Anoxic M.-U. Miocene (L. Modelo “nodular shale”) marl with 5 University, Palo Alto, CA 94305 related parameters that differentiate the samples (details of the 6 significant terrigenous plant input generated tribe 6 at low maturity c Chevron Corporation (retired), San Anselmo, CA 94960 method are described in Peters et al., 2005, 2007). northwest of NIFZ. d Infometrix, Inc., Bothell, WA 98011eGeoMark Research, Houston, TX 77095 Results and discussion Figure 2. Map of the Los Angeles basin shows depth contours on base Conclusions Hierarchical cluster analysis and the decision tree identify six tribes Mohnian (~14 Ma; Late Middle Miocene) >12,000 ft in pink. Oil tribes 1-2 Six genetically distinct Miocene petroleum systems (12 families) *[email protected] and 12 genetic oil families (Figure 1). are east of the Newport-Inglewood Fault Zone (NIFZ), while tribes 3-6 are occur in different parts of the Los Angeles basin. The Newport- to the west. Base map is from Wright (1991). Inglewood Fault Zone separates tribes 1-2 (families 11-12, 13, Introduction 21-22) to the east from tribes 3-6 (families 31-33, 41-42, 5, 6) to Oil Tribe The prolific Los Angeles basin is a classic transform-margin 112-Sample the west.Chemometric analysis of biomarker and isotope ratios basin that may be the most petroliferous province on Earth per 1 Training Set BENTHIC SANTA PALOS LOS ANGELES BASIN anddistinct stratigraphic occurrence help identify the source rock FORAM MONICA VERDES WEST EAST EPOCH STAGE MOUNTAINS HILLS

volume of sedimentary fill. Since Brea-Olinda in 1880, 67 fields NIFZ for each family. Oil familiesin the Los Angeles basin retain the TIMMS PT. SAN PEDRO LA HABRA

East of NIFZ of East HALLIAN

LATE SLT. FERNANDO were discovered, including three super-giants at Wilmington, Long 2 UPPER UPPER Oil-like shale geochemical fingerprint of the vertical and lateral organofacies PLEIST LOMITA MARL Similarity E WHEEL. MIDDLE MIDDLE hydrocarbons PICO line PICO (NOT EXPOSED) not observed Beach, and Huntington Beach.Little exploration has occurred VENT. LOWER LOWER variations in their source rocks.

LATE (Philippi, 1965) 3 11 11 since the early 1970’s, although significant potential likely remains REPETT. 13 REPETTO REPETTO REPETTO E PLIOCENE MALAGA 32 in deep, especially offshore areas. Because most exploration in 4 DELMONT. UPPER UPPER MUDSTONE ~4 wt.% TOC, up Acknowledgements UPPER

West of of NIFZ West 5 31 to 16 wt.%, Type I

the basin occurred prior to the advent of modern geochemical LATE VALMONTE We thank L.B. Magoon (USGS, retired) and Tess Menotti (Stanford MIDDLE MIDDLE and II kerogen DIATOMITE MOHNIAN PUENTE (Global Geochem. methods, genetic relationships among the various petroleum PUENTE LOWER 6 LOWER Corp., unpub.) University) for useful discussions. M OM D E L O UPPER “NODULAR’ LOWER SHALE 5 Repeatability 6 M O N T E R E Y accumulations and their source rocks remain speculative. TOPANGA line CALABASAS MIDDLE TOPANGA

Cluster Distance MIDDLE LUISIAN ALTAMIRA GP.

M I O C E O E C E N I M GROUP LOWER SCHIST CONEJO VOL. CONG. References VOLC. SD. RELIZIAN

TOPANGA GP. TOPANGA TOPG. CYN

This paper uses source-related biomarker and isotope ratios to EARLY Figure 1. Hierarchical cluster analysis dendrogram based on 24 source- NIFZ Blake, G.H., 1991. Review of the Neogene biostratigraphy and stratigraphy evaluate genetic relationships among ~150 crude oil samples related biomarker and isotope ratios identifies six oil tribes. of the Los Angeles basin and implications for basin evolution. AAPG from the basin. The extent of biodegradation for each sample was Figure 3. Distinct stratigraphic occurrence of oil families supports their Memoir 52, 135-184. assessed in order to identify a “training set” where the source- The families within each tribe have different bulk properties (e.g., origins from different organofacies of Miocene Monterey source rock. Base related ratios are unaffected and can be used to identify genetic API gravity, sulfur, and metal content) that were previously explained chart modified from Blake (1991). Unpublished data (Global Geochemistry Jeffrey, A.W.A. et al., 1991. Geochemistry of Los Angeles basin oil and gas oil families. The training set was used to create a chemometric as mainly due to secondary processes, such as biodegradation or Corporation) indicate that the Middle-Upper Miocene section contains systems. AAPG Memoir 52, p. 197-219. decision tree (multivariate statistics) that allows automated genetic thermal maturity (e.g., Jeffrey et al., 1991). However, the decision- source rock due to high total organic carbon (~4 wt.%) and type I-II oil- classification of additional oil or source-rock extracts that might tree classification is based on differences in genetic properties that prone kerogen. The shallower Pliocene and Pleistocene units cannot be Peters, K.E.;and Moldowan, J.M., 1993. The Biomarker Guide--Interpreting be collected, including samples where some of the source-related reflect distinct petroleum systems. source rock due to low thermal maturity (Philippi, 1965). Molecular Fossils in Petroleum and Ancient Sediments. Prentice-Hall, ratios were altered by biodegradation.The chemometric analysis Englewood Cliffs, New Jersey, 363 p. also allows quantitative assessment of the degree of certainty The oil families occur in different reservoirs from different parts of Stratigraphic positions of the oils in each family help to identify for each genetic assignment. Finally, the geochemical data and the basin, consistent with origins from distinct pods of active source their source rocks. For example, family 13 (tribe 1) and tribe 6 Peters, K.E.; Walters, C.C.;and Moldowan, J.M., 2005. The Biomarker stratigraphic occurrence of each oil family were used to infer their rock (Figures 2-3). The source-rock depositional environment for occur in Lower Pliocene reservoirs in the northern portion of the Guide. Cambridge University Press, Cambridge, U.K., 1155 p. source-rock organofacies. each oil family can be inferred using biomarker and isotope ratios basin, suggesting that family 13 originated from Delmontian black (e.g., Peters et al., 2005). Carbon isotope data for saturate and shale near the top of the organic-rich Miocene section. Tribe 6 oils Peters, K.E. et al., 2007. Circum-Arctic petroleum systems identified using Methods aromatic hydrocarbons in the samples suggest Miocene marine appear to originate from the Lower Modelo Formation (“nodular decision-tree chemometrics. AAPG Bulletin 91, 877-913. Procedures are similar to those in Peters et al. (2007). Asphaltenes source rocks. Tribes 1-2 straddle the Central Trough, occur shale” equivalent; Figure 3). The distributions of families 11 (tribe 1), were removed from the oil samples using n-hexane. Saturate and mainly east of the Newport-Inglewood Fault Zone (NIFZ), and 31 and 32 (tribe 3), and tribe 5 in the southern portion of the basin Peters, K.E. et al., 2013. Chemometric differentiation of crude oil families in aromatic hydrocarbons were separated by column chromatography show evidence of clay-rich source rock deposited under suboxic suggest that family 11 originated from theUpper Puente Formation, the San Joaquin Basin, California. AAPG Bulletin97, 103-143. using hexane and dichloromethane, respectively. Stable carbon conditions with elevated higher-plant and angiosperm input. Unlike tribe 5 is from “nodular shale” in the basal Puente Formation, and isotope ratios were determined using a Finnigan Delta E isotope tribes 1-2, tribes 3-6 occur west of the NIFZ and show evidence families 31 and 32 are from intermediate positions. These results Philippi, G.T., 1965. On the depth, time and mechanism of petroleum ratio mass spectrometer. C15+ saturated biomarkers were of more distal, clay-poor source rocks deposited under anoxic parallel those from the San Joaquin basin, where similar Miocene generation. Geochimica et Cosmochimica Acta 29, 1021-1049. analyzed on a Hewlett-Packard (HP) 5890 gas chromatograph conditions. Tribes 3-5 include the giant Wilmington, Long Beach, oil families retain the geochemical fingerprint of vertical and lateral interfaced to a HP 5971 mass spectrometer. The HP-2 column (50 and Huntington beach fields, which account for ~60% of the organofacies variations in their source rocks (Peters et al., 2013). Wright, T.L., 1991. Structural geology and tectonic evolution of the Los m x 0.2 mm id, 0.11-mm film thickness) was programmed from conventional reserves in the basin. Angeles Basin, California. AAPG Memoir 52, 35-134. 150 to 325oC at 2oC/min. Mass spectrometry was in SIM mode In summary, geochemistry and stratigraphy of the oil families for m/z 177, 191, 205, 217, 218, 221, 231, and 259. Response suggest the following source rocks: factors were determined by comparing m/z 221 for a deuterated standard (d4-C29 20R sterane; Chiron Laboratories, Norway) with Suboxic Upper Miocene (Delmontian) shale with significant terpane (m/z 191) and sterane (m/z 217) standards. angiosperm input generated tribes 1-2 in the Central Trough east of NIFZ.

130 131 OG24 The software package Statistica 8 (Statsoft Inc.) was used in the considered less thermally evolved. Figure 1. PCA score plot (A) and loadings (B) with (1, solid line) = statistical calculations. A X(11x15) matrix for saturated and aromatic biodegradation saturated parameter, (2, dashed line) = maturation aromatic Less routinely used saturated biomarker maturity ratios, however, parameters. Application of Comprehensive Two- biomarker ratios was created and a Principal component analysis (PCA) was carried out based on the covariance matrix. All variables lead to somewhat conflicting results. According to the C29 Dimensional Gas Chromatography - Time were mean centered and scaled by the sample standard deviation. trisnorhopane/C29 hopane (H29Ts/H29) ratio, which increases Conclusions of Flight Mass Spectrometry to evaluate Results and Discussion with increasing maturation, S05, S07 and S09 should be the most GC×GC–TOFMS analysis was used to determine maturity ratios in maturation of Brazilian crude oils The geochemical parameters were calculated for biomarkers in mature oil samples. On the other hand, according to the moretane/ B/C and aromatic fractions for 11 Brazilian crude oil samples. PCA B/C and in aromatic fractions. The main focus of this study was hopane (M30/H30) ratio, which decreases with increasing allowed the integration of maturity parameters, pointing S05, S06 Jaakko Laakia1, Alessandro Casilli1, Félix T. Gonçalves1, Elaine the characterization of thermal maturity using biomarkers (Table maturation, oils S05 and S07 are the most mature while the oils and S07 samples as the most mature oils and recognizing S02 as Marotta1, Cleverson J. F. Oliveira2, Alexandre A. Ferreira2, Maria 1). Since the origin and the degree of biodegration can affect S02 and S09 are the less mature. Finally, Ts/(Ts+Tm) ratios indicate the most biodegraded oil. Regina B. Loureiro1,Débora A. Azevedo1, Francisco R. Aquino the abundance of most of the biomarkers used in the maturation that S01, S02 and S09 oil samples has the lowest degree of thermal Neto1 parameters, these aspects are briefly discussed for the analyzed maturity whereas S05 and S07 are the most mature samples. Acknowledgements samples. The authors thank CNPq, ANP, Petrobras, and FAPERJ. 1 Universidade Federal do Rio de Janeiro, Instituto de Química, Aromatic biomarker maturity ratios were also analized. Methyl- LAGOA-LADETEC, Ilha do Fundão, 21941-909, Rio de Janeiro, Table 1. Selected biomarker ratios in B/C fractions of the crude oils and dimethyl-dibenzothiophenes (MDBDT and DMBDT) ratios, References RJ, Brazil. measured using GC×GC-TOFMS. which can be used for highly mature oils, show the highest values Casilli, A., Silva, R.C., Laakia, J., Oliveira, C.J.F., Ferreira, A.A., Loureiro, 2 Division of Geochemistry, PETROBRAS Research and in the S06 and S07 oil samples. The percentage of mono- and M.R.B., Azevedo, D.A., Aquino Neto, F.R., 2014. High resolution molecular Development Center (CENPES), PETROBRAS, Rua Horácio triaromatic steroid ratio of MA C21 / (MA C21 + C28)% and TA organic geochemistry assessment of Brazilian lacustrine crude oils. Organic Macedo, 950, Ilha do Fundão, Rio de Janeiro, RJ 21941-915, C20/(TA C20 + C27)%, which increase with increasing maturation Geochemistry 68, 61-70. Brazil show the highest values in the S05 oil sample. Peters, K.E., Walters, C.C., Moldowan, J.M., 2005. The Biomarker Guide, [email protected] Principle component analysis Biomarkers and Isotopes in Petroleum Exploration and Earth History, Vol 2. With the aim of integrating the results from the diverse parameters, Cambridge University Press, Cambridge, UK. a PCA analysis was carried out with all ratios presented in Table 1. Copyright 2014, ALAGO. The analysis allowed the separation of distinct groups of oils (Fig. This paper was selected for presentation by an ALAGO Scientific Committee following 1A). PC1 analysis clearly separated oils S05, S06 and S07 from review of information contained in an abstract submitted by the author(s). the others, being the aromatic maturation parameters the principal

components (Fig. 1B). PC2 separated S02 and S09, being the Introduction 3 -methylhopane index one driving force to this. In addition, Gas chromatography (GC) has been an essential technique for β sample S02 is also influenced by biodegradation processes (25NH/ the analysis of non-polar biomarkers, initially only connected to H30). Thus, maturation parameters separated samples S05, S06 flame ionization detectors (FID), later to also mass spectrometry and S07 as the most mature within this set of samples, and S02 as (MS) and nowadays, with a variety of manufacturers offering a the most biodegraded. range of distinct setups. One of the setups that have proved to be particularly powerful is the Comprehensive Two-Dimensional Gas

Chromatography - Time of Flight Mass Spectrometry (GC×GC– TOFMS). Regarding the origin, some selected source-dependent parameters In this study, 11 Brazilian crude oils from different origins and (Table 1) St27-St29/H29-H33, Tr26/Tr25, 3β-MH31/H30 % depositional conditions (5 lacustrine, 5 marine and 1 mixture), with indicates a lacustrine source for oils S01, S02, S08 and S09, a variable biodegradation and maturity levels, were analyzed. The aim marine source for oils S10, S04, S05, S6, S07 and S11, and a was to evaluate the degree of maturation of the oil samples with mixture of sources for oil S03 (Peters et al., 2005). conventional and non-conventional biomarker ratios measured by GC×GC-TOFMS. The biodegradation process was monitored with the 25-norhopane Experimental to C30 hopane (25NH/H30) ratio (Table 1). According to this Analyses were performed on a Pegasus 4D (Leco, St. Joseph, MI, parameter, only samples S02 and S07 are significantly altered. USA) GC×GC-TOFMS composed of an Agilent 6890 GC equipped Biodegradation can affect other parameters. The hopanes, for with a secondary oven, a non-moving quad-jet dual-stage example, are preferentially removed compared to the tricyclic modulator and a Pegasus III time of flight mass spectrometer. A terpanes. Tr19-Tr30 (S+R) /H28-H34 (S+R) ratio (Table 1), DB-5 column (30 m, 0.25 mm i.d., 0.25 mm df) was used as the corroborates that oils S02 and S07 are biodegraded. Interestingly, first-dimension column (1D). A BPX-50 (1.5 m, 0.1 mm i.d., 0.1 the oil S09 although could be considered biodegraded according mm df) was used as the second-dimension column (2D). The 2D to this ratio, but do not show nor-hopanes (25NH/H30 = 0.01). column was connected to the TOFMS by means of a 0.5 m x 0.25 mm i.d. uncoated deactivated fused silica capillary. Regarding maturity (Table 1), the routinely used steranes and The selected crude oils were pre-fractionated in saturated and terpanes ratios indicate that most of the oils have reached a aromatic fractions. The saturated hydrocarbon fractions were moderate to high degree of maturity (between the beginning of further processed to remove the n-alkanes via the formation of urea the oil window and the peak of oil generation). Practically all the adduct to obtain the branched and cyclic hydrocarbon fractions oils have reached the equilibrium for the 22S/(22S+22R) H32 ratio. (B/C). The B/C and aromatic fractions (total of 22 samples) were Oil samples S05 and S06 show the highest values for the [20S/ dissolved in dichloromethane before chromatographic analyses (20S+20R) St29] and[ββ(S+R)/ββ(S+R)+αα(S+R) St29] steranes (Casilli et al., 2014). ratios, being considered the most mature, whereas oils S02, S03 and S09 show lower values for these ratios and therefore are

132 133 PETROLEUM SYSTEMS AND and lithosphere flexure under differential loading (Garcia, 2012). models of deformation in numerical simulations of petroleum Thus, independent restorations were performed for different systems proved to be an effective tool to mitigate cases where BASIN MODELING sections looking for results with consistencybetween the timing is a major risk. deformation and the sedimentary record described by the basin stratigraphic chart. Acknowledgements PSBM01 The authors thank Petrobras forthe encouragement to publication Restored 1D geohistorieswere extracted from vertical projections of and the financial support. Evaluating source-rock maturation changes the calibration wells on the geological sections.A local thermal field, considering deformations of salt over time, was adequatelymodeled due to thermal contrast between salt and References from these restored geohistories. The movement of salt responding other overlying sediments using an integrated Araújo L.M.; Garcia S.F.M.; Queiroz C.L.; Cortez M.M.M.; Saito M., 2005. A to sedimentation changed the thermal field through the overburden, structural restoration approach 4-D Petroleum System Model in asouthern area in the Santos Basin, Brazil. sometimes making it relatively hotter above a thick diapir, ALAGO Workshop Basin Modeling, Buenos Aires (CDROM) 4, Abstracts, 3 p. sometimes less disturbing in areas withfault growing or minibasins Sávio F. M. Garciaaa*, Carlos Pinto Fracalossia, André Figure 1. development (Mello et al., 1995). Garcia, S. F. M., 2008. Fenômenos térmicos associados aos evaporitos. Danderferb, Dominique F. De Lamottec Maturity levels calculated for restored (left) and unrestored (right) 2D models In: W.U. Mohriak, P. Szatmari, S. Anjos(Org.) Sal geologia e tectônica: showing maturation differences in the sediments underlying the salt layer in Vitrinite reflectance and temperature data from a few wells in the exemplos nas bacias brasileiras. Beca Edições Ltda., p.: 91-163. a Petrobras, E&P-EXP/GEO/MSP, 20000-000, Rio de Janeiro, the past, mainly because there was no overburden over the saltdiapir in the Brazil studied area were used to calibrate a regional heat flow history unrestored model at that time. Garcia, S. F. M., 2012.Restauração estrutural da halotectônica na porção obtained fromthermal models of lithospheric stretching. b Universidade Federal de Ouro Preto, Departamento de central da Bacia de Santos e implicações para os sistemas petrolíferos. Geologia, 34500-000, Ouro Preto, Brazil Positions adjacent to salt bodies were more sensitive to the geometry PhD ThesisUniversidade Federal de Ouro Preto (Contribuições às Ciências c Université de Cergy-Pontoise, LaboratoireGéosciences et Thus, extrapolating the restored 1D thermal geohistoriestoa 2D and size of the salt structures. The thermal effects on maturity in da Terra. Série D) 235, 206pp. EnvironnementCergy, 95031,Cergy-PontoiseCedex, France petroleum systems model, different thermal maturity levels were some relatively narrow minibasins surrounded by largesalt bodies simulated. were lower than those affecting broader depocenters, which Mello, U. T.; Karner, G. D.; Anderson, R. A., 1995.Role of salt in restraining *[email protected] are less influencedby the higher salt thermal conductivity. These the maturation of subsalt source rocks. Marine and Petroleum Geology, situations did not show large differences betweenrestored and In order to be used in a results comparison, another 2D non-restored models. v.12, p 697-716. Introduction petroleum system modelling was performed without the restored Structural restoration of halokinetic deformation in sedimentary backstripping or 2D restored sections, using only conventional 1D basins is often simplified or even neglected in numerical Thermal simulations showed relatively less mature source and 2D approaches. simulations that evaluate the maturation of organic matter, rocks underlying saltbodies of great volume and thickness. Nevertheless,the effects on the maturity of sediments in the expulsion and migration of petroleum. Such procedure is usual restored structures were conditioned by the timingof those but unsophisticateddue to limitations of the software meshes, Results and Discussion sediments beingsubjected to higher temperatures. Another factor in spite of the notoriously high contrast of thermal conductivities As expected, source rock maturity was differentially affected in all affecting maturity of underlyingsediments was the lateral translation between salt and other sedimentary lithologies,as wellaspossible directions close to salt structures (Garcia, 2008). This does not (sliding) of salt structures, which changed the temperature flow. changesthat a salt diapirmay cause on the thermal maturity in its mean that large differences occur between one structurally restored vicinity. model and an unrestored one. The comparison of simulation results Halokinetic deformations, as well as thermal evolution of for both restored and unrestored models, albeit in a simplified sediments,were strongly influenced by sedimentation rates and, In order to measure effects of the structural deformation in a real approach, showed the role of halokinesison sediments heating and as consequence, by the sedimentary burial in different areas of halokinesis case, the present paper workson a well-known area on the thermal evolution of theunderlying source rock. Santos Basin (Araújo et al., 2005). Thus, the timing of greatest in the Santos Basin,previously studied by several authors,where salt deformation was not necessarilysynchronous with the optimal significant lateral movement along the Cabo Frio Fault could be Although the thermal field becomes relatively warmer at positions period for maturation of the underlying source rocksacross restored through time. This area has an entire record of the Santos just above the salt bodies, organic matter remains immature for the studied area. According to the simulation results, such synchronicityoccurred only locally.These differences of maturity Basin sedimentation coveringbothextensionaland compressional petroleum generation due to the small burial magnitude in these scenarios can produce consequences for migration and timing for structural domains which also provides different timings of the situations. Simulation results above the salt structures were almost petroleumentrapment processes. petroleum system activities. the samebetweenrestored and unrestored models.However,where the burial geometry was recomposed in the restoration model, Conclusions The goal is to use structural restoration and petroleum systems local heat escape was hamperedby a relative insulation of the In the continental platform, closer to the shore, the earlier and modeling tools in an integrated and synergistic way in order to less thermal conductive lithology, and the sediment maturation more expressive marine sedimentshastened the petroleum system assess the impact of salt tectonics on the maturity of underlying differences weregreaterbetween both scenarios (Figure 1). maturation. source rocks. Along the region where the Cabo Frio Fault has causedmajor lateral Experimental development, the salt restoration role is to determine the formation Geological sections were interpreted on seismic data in order of welds (salt windows) that would allow petroleum migration to characterize the geometry of salt bodies and the affected pathways to the overlying post-salt section. sedimentary vicinity, as well as the rift sequence below salt In the deepwater region, there is a lack of synchronism betweenthe wherethe source rocks were deposited. petroleum system constraints and the salt deformation which fortunately minimizes errors of the simulations when these are Structural restoration of these sections provided incremental performedin unrestored sections. shapes and relative positions of the layersduring salt deformation. Furthermore, the structural restoration followed procedures to We can conclude by stating that the application of kinematic include theeffects of compaction, isostasy, bathymetric changes

134 135 PSBM02 source rock, due to the fact that this parameter is the most sensitive in PSBM03 simulate the burial history of sediments including compaction, the Guo et al. (2011)and the Shuichang et al.(2013) equations. pressure, temperature and maturation of organic matter, petroleum generation, migration and accumulation through time. The model Possible controls of Andes-associated An example of quantitative estimation of In nature, the estimated values of pore saturation by residual oil was constructed using PetroMod software and covers the overpressure caused by oil generation in in source rocksgenerally are over 50% (Shuichang et al., 2013). volcanic activity on Hydrocarbon generation continental Austral Basin, Austral Marina, the Rio Chico High and Campos Basin, Brazil. In tests made in Santos, Campos and Ceará basins,these values and leakage in the on/offshore northern Austral the western Malvinas Basin. would need to be between64 and 80% to reach the measured Basin, southern Argentina, South America. Carlos Pinto Fracalossia*. Hyalla Queiroz Valente da Silvaa. Laury overpressure values in the order of 15 to 30MPa. According to

a a the calculations made in this study for a well in Campos Basin, Medeiros de Araujo , Henrique Luiz de Barros Penteado Victoria F. Sachsea,c*, Zahie Ankaa, Rolando di Primioa, Ralf for a source with an average original TOC and HI of 4.2% and Littkec, Jorge F. Rodriguezb, Marcelo Cagnolattib, a Petrobras, E&P-EXP/GEO/MSP, 20000-000, Rio de Janeiro, Brazil 700 mg HC/g TOC respectively, and a transformation ratio of 50%, a residual oil saturation of 64%in the source rock is required for a Helmholtz Centre Potsdam, GFZ German Research Centre *[email protected] overpressure to attain the value of 32 MPameasured in the well. for Geosciences, Section 4.3., Telegrafenberg, 14473 Potsdam, For a better prediction of the magnitude of overpressure,it is Germany Introduction important to obtain data whichwould allow estimating the residual b Petrobras Argentina S.A., Buenos Aires, Argentina In oil exploration, it has been quite usual to find abnormal high oil saturation in source rock, as well as porosity, permeability, c Institute for Geology and Geochemistry of Petroleum and Coal, pore pressures, which may be caused by one or more geological capillary pressure and residual TOC. EMR Group; RWTH Aachen University, Germany processes. Repeatedly, mechanical problems during the drilling phase have been reported wheninvestigating deep plays, especially A sensitivity analysis with parameters similar to those considered in *[email protected] those that require drilling through source rocks. our simulation indicates that organic-leaner source rocks intervals would require a higher transformation ratio and/or lighter petroleum The conversion of solid kerogen into liquid oil and gas during the to achieve a residual oil saturation that leads to the same kind of Copyright 2014, ALAGO. Figure 1.Overview of the study area and provided seismic data (grey lines process of petroleum generation results in fluid volume expansion overpressure values. Conversely, richer source rock intervals This paper was selected for presentation by an ALAGO Scientific Committee following within the red polygon). The outline of the 3D basin model is shown in red. and pore pressure increase. This occurs due to the fact that the could achieve similar overpressures at lower transformation ratios, review of information contained in an abstract submitted by the author(s) original kerogen dispersed in the rock matrix is denser than the oil because comparable residual oil saturation would be reached due Results and Discussion and gas generated that moves into the pore space (Luo & Vasseur, to the higher petroleum potential. Introduction In the model source rock qualities were assigned to the Lower 1996; Swarbrick et al., 1998; Xie et al., 2001; Guo et al., 2011; Numerous oil and gas fields have been developed on- and offshore Cretaceous Springhill Formation (up to 6 %TOC), Lower Inoceramus Shuichang et al., 2013). Acknowledgements Austral Basin, southern Argentina.Whereas source rocks and and Margas Verdes Formation (>2 %TOC). Reservoirs and seals The authors thank Petrobras forthe authorization to publish this work. reservoirs are well known,the processes of hydrocarbon generation occur from Jurassic up to the Eocene, but the main reservoir is and accumulation in time and space, including migration and In exploratory terms, pore pressure prediction is crucial in present in the Early Cretaceous Springhill Formation. An initial leakage dynamics remain not completely understood. In order to engineering drilling projects, since the abnormal high pressure References constant heat flow of 60mW/m² was assigned, adjusted during the better understand how the regional tectonic setting, i.e. the Andes zones require special equipment and some modifications in the well Guo, X., He S., Liu, K., Zheng, L. 2011. Quantitative estimation of calibration process for the model. A recent burial depth of up to 8 evolutionand associatedvolcanism may have influenced the HC casingwhich, if not previously diagnosed, can make the drilling of overpressure caused by oil generation in petroliferous basins. Organic km in the southernmost northern Austral Basin shallowing up to system history, we carry out an integrated basin analysis including a prospectimpracticable. With the increasing demand for reducing Geochemistry 42, 1343-1350. 2.5 km on the western flank of the Rio Chico High were deduced long-distance onshore-offshore correlations.Based on geophysical the risks and costs of drilling, and to avoid ecological disasters, for the base of the Early Cretaceous. Modelled vitrinite reflectance and geochemical data3D modeling of basin subsidence as well Luo, X., Vasseur, G. 1996. Geopressuring mechanism of organic matter values indicate gas window or even over-mature ranges for organic the accuracy of this type of prediction has become a strategic as hydrocarbon generation, migration and accumulation through prerequisite for the planning of exploration activities. cracking: numerical modeling. AAPG, 80, p. 856-874. matter samples from the south-western basin where highest geologic time was performed. thicknesses and deepest burial took place.A general decrease of Shuichang, Z., Bin, Z., Jin, S., Xiaomei, W. 2013. A conceptual model of oil maturity is obvious to the north and east of the Austral Basin.Lower In petroleum systemmodeling, pore pressure has a criticalimportance The Austral and Malvinas Basins are part of the South American expulsion efficiency driven by hydrocarbon generation. 26th IMOG. Organic vitrinite reflectance values were modelled for the eastern part, because it has a great influence in the porosity decay, in the thermal plate and surrounded by the Nazca plate to the west, the Antarctic where maturity ranges between immature and the oil window. This field and in regional pressure regimes. The pore pressure field is Geochemistry: trends for the 21st Century. 2, 579-580. plate to the southwest and south, the Scotian plate to the south maturation trend is depending on the geometry of the basin, with responsible for the petroleum migration pattern and for controlling and the African plate to the east (Figure 1) and thus situated in shallower areas to the north and to the east. Of course, also the the capacity of hydrocarbon retention. Swarbrick, R.E., Osborne, M.J. 1998. Mechanisms that generate abnormal a zone of high tectonic activity.1D well backstripping across the decreasing sediment thickness of the potential source rocks will pressures: an overview. AAPG memoir 70, p. 13-34. study area confirms three main tectonic stages (Diraison et al., Experimental 2000), containing (1) the break-up phase forming basement graben play a role leading to the low petroleum generation rates observed This study was based on the equations proposed by Guo et al. Xie, X., Bethke, C.M., Li, S., Liu, X., Zheng, H. 2001. Overpressure and systems and the evolution of the ancient backarc Rocas Verdes in the northernmost area. (2011) and Shuichang et al. (2013) which calculate overpressure petroleum generation and accumulation in the Dongying Depression of the Basin (RVB), (2) the inversion of the RVB and the development of caused by petroleum generation as a function of hydrogen index Bohaiwan Basin, China. Geofluids, p. 257-271. the Austral Basin, and (3) the recent foreland Austral Basin. (HI), transformation ratio, kerogen mass, residual oil coefficient, hydrostatic pressure, oil compressibility, water compressibility, Methods kerogen compressibility, pore water volume at hydrostatic pressure, In order to better understand the impact of tectonic events on basin kerogen density and oil density. formation to its present-day structure we analyzed 2D seismic reflection data covering about 95.000 km² on- and 115.000 km² offshore (Austral “Marina” and Malvinas Basin). A total of 10 The source rock parameters applied to calculate pore overpressure seismic horizons, representing 9 syn- and post- rift sequences, caused by petroleum generation come from one analyzed well in were mapped and tied to well data to analyze the evolution of Campos Basin (Brazil), which has a residual total organic carbon sedimentary supply and depocenter migration through time.In (TOC) of 2.7% and HI values around 390 mgHC/gTOC. An original HI additionto the seismo-stratigraphic analysis, 1D backstrippingwas of 700 mgHC/gTOC, an original TOC of 4.2% and a transformation carried out in order to calculate the tectonic subsidence and ratio around 50%were estimated based on regional data. sediment accumulation rate.Based on the resulting maps of the seismic interpretation, additional information about source Results and conclusions rocks (TOC, HI), potential reservoirs. and sealswere used for a Figure 2.3D BasinModel including the Austral Basin, the Rio Chico The main challenge for the pore pressure prediction caused by 3D petroleum system/ basin model. This model was created to High and the western Malvinas Basin. petroleumgeneration is to estimate the residual oil saturation inside the

136 137 Conclusions PSBM04 Differences in maturity distribution can be explained by the Objectives and Methodologies The goal of this work is to establish a method to integrate differential burial depth between the west and east. However, this The Link Between Stratigraphic and preliminary run of the petroleum system model does not comply stratigraphic and petroleum systems modeling using PETROBRAS entirely with present-day accumulations known in the basin. Thus, Petroleum System Models: proprietary softwares in order to apply such workflow to exploratory either the temperatures during burial were not high enough or the Insights for Hydrocarbon Exploration frontier areas. Two synthetic petroleum systems models based on common real situations were constructed with different stratigraphic reservoir facies needs refinement. Increased past-temperatures can Luiz Felipe C. COUTINHOa*, José Eduardo FACCIONa, José resolutions. The regional permeability structures based on low- be explained by volcanic activity during different times during the Alberto ARAUJOa, Pedro A. M. N. MIRANDAa, Marco Antônio S. and high-resolution sequences obtained by previous stratigraphic Cenozoic. Identified seismic features which have been interpreted MORAESa, Stefane R. X. LOPESb, Alexandre Antônio O. LOPESc, simulations were compared in order to better understand the as magmatic intrusions (sills and dikes) within the sediments, and Wagner N. RIBEIROd formation of the carrier beds. The more detailed sequence and also at the surface, support this idea of increased heat flow field lithological representation at the third-order scale allowed a better in the past. However, they do not have a primary influence on the a - Petrobras Research and Development Center (CENPES), Rua definition of carrier beds and regional seals, which significantly hydrocarbon system. The 3D model indicates the occurrence of Horácio Macedo, 950, Ilha do Fundão, Rio de Janeiro, RJ 21941- changed the patterns of petroleum secondary migration, favoring two phases of major petroleum generation in the Austral Basin. 915, Brazil the identification of plays not currently represented in lower The primary generation phase is related to deep burial due to basin b - Fundação Gorceix, Rua Carlos Walter Marinho Campos,57, resolution models. subsidence in the Early and Late Cretaceous, as a consequence of Vila Itacolomy, Ouro Preto, MG 35400-000, Brazil basin inversion and the sediment supply from the growing Andes in c - Petrosoft, Rua Mário Agostinelli, 55, Barra da Tijuca, Rio de Results and Discussion Figure 2.Basin modeling – migration results the west. A second generation phase is also related to deep burial Janeiro, RJ 22775-046, Brazil A) Stratigraphical Model in the Miocene, but it could be clearly shown, that the Miocene d – INJ Tecnologia, Rua Sagrados Corações, 95, Caiçaras, Belo Three depositional sequences (sense of Vail et al., 1977 and The HC generation was modeled based on a kinetic model volcanic episode plays a major role for the secondary petroleum Horizonte, MG 30770-220, Brazil Posamentier et al., 1988) were simulated (Fig. 1). From the oldest presented in Behar et. al. (2008), considering a closed system and generation phase in the Austral Basin. Secondary cracking due to to the youngest, they can be described as follows: Sequence n° type II kerogen, with a petroleum potential of 30 mg/g. volcanic activities cannot be excluded. *[email protected] 1 - a transgressive succession of three retrogradational 3rd order The models were simulated using an in-house software applying depositional sequences corresponding to the beginning of basin fill the finite volume method to solve the governing equations (thermal Acknowledgements Copyright 2014, ALAGO. with a total time-span of 10 Ma; the main objective was to simulate and migration) and tetrahedral meshes. The authors thank Petrobras Argentina S.A. for providing data This paper was selected for presentation by an ALAGO Scientific Committee following a classic source-rock depositional environment; Sequence The high resolution model has 147186 tetrahedral elements and and for permission to publish this work. This project is part of the review of information contained in an abstract submitted by the author(s). n° 2 - a set of stratigraphic high-frequency of progradational the low resolution ones has 103896 elements, both models has German Research Foundation (DFG) - SAMPLE “South Atlantic depositional sequences, typically representing the deposition an approximate length of 36 km and a width of 34 km, with a total Margin Processes and Links with onshore Evolution”. Introduction of potential reservoirs and seals; Sequence n° 3 - a 3rd order thickness of 5 km. The three-dimensional numerical simulation of sedimentary sequence integrated by a progradational basal unit followed by two processes based on sequence stratigraphy concepts (i.e. retrogradational episodes and a final progradational higher order Conclusions References stratigraphic modeling) has been used in sedimentary basin sequence. Coupling stratigraphic and petroleum systems modeling leads to Diraison, M.; Cobbold, P.R.; Gapais, D.; Rossello, E.A.; Le Corre, C., 2000. analysis to understand and represent the interplay between space a better representation of the lithological distribution and hence Cenozoic crustal thickening, wrenching and rifting in the foothills of the accommodation generation and filling, along with the action of B) Basin Modeling Approach of the spatial relationships among source rocks, carrier beds, southernmost Andes. Tectonophysics316, 91-119. sedimentary processes that control facies distribution. In order to input the modeled facies into the petroleum systems reservoirs and seals. 3D cells, it was necessary to define each Folk’s component as a Two of the main products of stratigraphic modeling are (1) the mixed lithotype (Fig. 2). The mixing rule used for each petrophysical Concerning the studied case, the results obtained integrating such breaking of the basin-filling packages into stratigraphic sequences or thermal property is geometric, except for specific mass and technologies permitted: of different orders and (2) the detailed representation of lithofacies specific heat which is arithmetic. distribution within each sequence. 1 – a better understanding of the thermal evolution of the petroleum A relative permeability evolution was applied with absolute system and, as a consequence, a best fit of source rock maturation Petroleum systems modeling, on the other hand, allows the permeability, as a result of the porous space variation, based on and hydrocarbon generation; geological history reproduction of sedimentary basins including the experimental and theoretical rules proposed by Okui et al. (1998). 2 – a more consistent representation of petroleum migration, processes of compaction, heat and fluid flow, along with generation, combining the vertical and lateral components, the latter specially migration and accumulation of petroleum. The technique involves improved where the carrier beds are confined within the source the dynamic calculation of essential parameters such as porosity, rocks (Fig. 2); pore pressure, temperature and maturation of source rocks. The 3 – a significant improvement in the comprehension of petroleum method is based on the mass conservation of components, and system’s elements and processes, resulting in more realistic solves numerically the governing equations for mass balance, and predictions of generation, accumulation, losses, migration paths also the equations for energy and momentum conservation. and efficiency (Fig. 2).

Even though the petroleum systems models are highly sophisticated, The results obtained herein suggest that the improved their representation of the stratigraphic framework and lithofacies representation of lithological distribution is not just a matter of distribution is commonly poor. As a consequence, although the resolution refinement. It comes from the construction of more independent application of these techniques by the oil industry realistic geologic frameworks, where tools such as stratigraphic and the scientific community is quite widespread, their integration forward modeling can be helpful. remains not fully explored. This includes the assessing the Figure 1.Stratigraphic inverted model potential impact of incorporating detailed stratigraphic framework Constant surface temperature (ST) and basal heat flow References and lithofacies distribution into the modeling of petroleum migration (HF) values were applied to the whole model for each Okui, A., Siebert, R. M., Matsubayashi, H., 1998, Simulation of oil expulsion by and accumulation. time interval, ST = 15.5 ºC e HF = 50 mW/m2. 1-D and 2-D basin modelling – saturation threshold and relative permeabilities of source rocks. Geological Society of London Special Publications, 141, 45-72

138 139 Vail, P.R., R.M. Mitchum, Jr., and S. Thompson, III, 1977, Seismic stratigraphy PSBM05 and global changes of sea level; Part 3, Relative changes of Relative changes PSBM06 ofsea level from coastal onlap: AAPG Memoir 26, p. 63-81. Possible Causes and Consequences Basin Modeling: A Key Tool For Assessing Posamentier, H.W., Jervey, M.T., Vail, P.R., 1988, Eustatic controls on of Anomalous Geothermal Regimes in Unconventional Play clastic deposition. I. Conceptual framework. In: Wilgus, C.K., Hastings, Carbonate Platforms B.S., Kendall, C.G.St.C., Posamentier, H.W., Ross, C.A., Van Wagoner, J.C. F. Schneidera, J.m. Laiglea, L. Kuhfuss Monvala, P. Lemouzya, P. a b (Eds.), Sea Level Changes––An Integrated Approach, vol. 42. SEPM Special Roger BAUDINO , Khalid EL JAFAARI and Antonio MARTIN Jermannauda c Publication, pp.110– 124. MONGE a Repsol Exploration, Direction of Geology, Méndez Alvaro 44, a Beicipfranlab, 232, Av. Napoleon Bonaparte, 92502 Rueil- 28045, Madrid, Spain Malmaison, France b Repsol Exploration, Direction of Operations, Méndez Alvaro 44, 28045, Madrid, Spain [email protected]; [email protected] c Repsol Exploration, Exploration Africa, Méndez Alvaro 44, 28045, Madrid, Spain Copyright 2014, ALAGO. This paper was selected for presentation by an ALAGO Scientific Committee following [email protected] review of information contained in an abstract submitted by the author(s). Figure 1. Illustration of the different porosity that can store gas Retention Copyright 2014, ALAGO. Summary Model This paper was selected for presentation by an ALAGO Scientific Committee following review of information contained in an abstract submitted by the author(s). The objective is to demonstrate how a basin modeling study can help 1) evaluating of the initial organic matter distribution, type and An important volume of hydrocarbons, mainly gas,is trapped, through adsorption, inside the source rocks. The adsorption The geothermal regime is a key factor for the generation of quality inside a formation, and 2) assessing the present day total hydrocarbons and their preservation in sedimentary basins. organic content (TOC) and maturity level of the formation. These capacity of the rock is modeled as a function of TOC, pressure and parameters have a first order control on the volume of hydrocarbons temperature through Langmuir isotherms. A correct estimation at both present and in the past is hence generated and still retained in the formation. mandatory to perform reliable predictive petroleum system models. Workflow The latter are thermically based on the one hand on user defined We present an improved expulsion model accounting for the To assess the potential for shale gas/oil in a formation, it is boundary conditions, surface temperature and basal heat influx retention capacity as a function of maturity. necessary to evaluate: (through heat flow, temperature gradient or crustal architecture), and on the other hand on thermal properties of the sedimentary Introduction • initial TOC, organic matter distribution, type and quality; infill (including thermal conductivity and heat production). The Hydrocarbons are generated from kerogen during the source rock • source rock present day maturity; existence of calibration data allows tuning these parameters. But burial thanks to temperature elevation. It can be either of biogenic • storage capacity in the non-organic porosity, organic porosity they are not always available, and in such cases one have to rely origin, or of thermogenic origin. and adsorption; on general trends adapted to his regional geology knowledge (for • generated HC quantity and quality, in order to quantify how much example the so called “normal” temperature gradient of 0.03ºC/m). Hydrocarbons composition and volumes generated and retained is retained in the source rock, in the porosity or by adsorption. Unexpected temperature anomalies can however be encountered depend on the initial organic matter properties and maturity.In In order to achieve these tasks, numerical basin modelof the study when drilling, invalidating the predicted present day geothermal the past, expulsion modelswere designed in order to quantify the area is built and calibrated in temperature, maturity and pressure. It regime. In addition, they arise a great uncertainty on any maturity expelled amounts. These models have to be revisited and improved is used to compute an evaluation of the shale gas potential of the and generation/expulsion timing forecast since they could have in order to better quantify the retained gas/oil. formation. been affecting the prospected area during geological times. The retention capacity is tightly linked to the TOC content, the Initial TOC and kerogenHI are computed from present day values. Through several examples we will try to illustrate the occurrence of organic matter type and the maturity. Hydrocarbons can be stored The present day TOC is deduced from logs using an improved geothermal regime anomalies in carbonate platforms. in source rocks by adsorption and as free hydrocarbons inside the Carbolog® methodology, which combines sonic and resistivity porosity. logs. Forward stratigraphic model can also help in assessing One of the possible causes can be related to shallow phenomena, source rock extent, thickness and internal architecture. such as fluid circulation, in intervals where the drilling program There are two types of porosity in mature source rockthat represent rarely include sample and temperature data collection, as well The geochemical studyenables to define the kerogen type, quality as their adequate correction and interpretation. The existence a storage place for hydrocarbons: of temperature anomalies has consequences on the reliability of and relevant kinetic scheme. The calibrated basin modelallows petroleum system model predictions, the maturity of source rocks 1/ Effective porosity inside non-organic rock fraction. The evolution estimating the kerogentransformation ratio, used to calculate the if it is long-lived, diagenetic processes and reservoir quality, and on of this porosity vs. depth is controlled by burial and possible initial TOC. the preservation of hydrocarbon accumulations. diagenetic phenomena Accurate compositional kinetic parameters for kerogen thermal It is then clear that geothermal regime anomalies can greatly affect 2/ Porosity inside the organic matter itself. This porosity is decomposition are key elements in this kind of study to predict the the relative value of an exploration project or area, and they are created consequently to the loss of kerogen mass resulting of the hydrocarbons fluids quality and type as a function of maturity. IFP not always easy to detect. Their causes and consequences have transformation of organic matter into hydrocarbons. kinetics schemes have proven to provide accurate and describe consequently to be considered in detail through an adequate data reactions scheme, that able to predict early or late gas. A solution collection and interpretation process. for modeling biogenic gas has also been proposed.

Acknowledgements The modeling of hydrocarbons generation allows estimating the The authors thank Repsol Exploration for allowing the presentation mass loss in the kerogen and the organic porosity consequently of this work.

140 141 created as a function of maturity. identification. Large research effort is still required to understand PSBM07 and to quantify the physical processes that occur in shaly organic Gas adsorption potential on organic material is calculated using matter (retention, adsorption, diffusion). Modeling oil composition in reservoirs a Langmuir model implemented within the simulator which takes submitted to biodegradation in offshore into account spatial distribution of pressure, temperature, and References remaining TOC. oilfields in the Brazilian southeastern margin. Behar, F.,Jarvie, D., 2011. Compositional modeling of gas generation from two shale gas resource systems: Mississippian Barnett Shale (USA) and The effective porosity in the shale matrix is estimated from log Gustavo Garciaa¬*, Sávio F. M. Garciaa, Henrique L. B. Penteadoa, Lower Jurassic Posidonia Shale (Germany), Hedberg Research Conference. analysis, using a methodology that allows correction from the effect Luciene S. Jesuínob,Joelma P. Lopesb, Erica T. Moraisb, Rosane Béhar F., F. Lorant, and L. Mazeas, 2008, Elaboration of a new compositional of organic matter. A. Fontesb. kinetic scheme for oil cracking: Organic Geochemistry, v. 39, p. 764-782. The integration of these tasks allows estimating the retention the Carpentier, B., A. Huc, and G. Bessereau, 1991, Wireline 550 logging and a Petrobras, Explorationteam, 20000-000, Rio de Janeiro, Brazil formation, accounting for shale effective and organic porosity and source rocks.Estimation of organic carbon by the CARBOLOG method, b Petrobras, Research center, 21941-915, Rio de Janeiro, Brazil adsorption capacity (dependingmainlyon TOC distribution and The Log Analyst, 1991, p. 279–297. Figure 1- Fractional distillation from pre-and post-salt oils with variable decreases with maturity. *[email protected] extents of biodegradation from an oilfield in the Brazilian southeastern Romero-Sarmiento M.F., M. Ducros, B. Carpentier, F. Lorant, S. Rohais, margin. The Gas Initially in Place (GIIP) can then be directly deduced from I. Moretti, and A.Y. Huc, 2012, Predicting TOC, Organic Porosity and Discussion the basin modeling simulation results, as a function of this retention Gas Retention Distribution in a Shale-Gas System Using Petroleum Basin Furthermore, petroleum systems modeling using PetroMod Volumetric and compositional petroleum prediction constitutes a (Schlumberger) was applied to simulate petroleum generation, capacity. The numerical model computes a GIIP value at play scale Modeling: Search and Discovery Article #40973 and gives also access to spatial variations of gas distribution. crucial requirement to the exploratory process in areas subjected migration and accumulation, as well as the compositional to biodegradation. It is well known that biodegradation causes evolution of biodegraded oils. The quantitative approach to Schneider, F. J. S., J. A. Noya, and C. Magnier, 2010, Model of low-maturity Using experimental design and response surface-based a preferential loss of the light ends of oil, a relative enrichment biodegradationisbased on the assumption that different compound generation of hydrocarbons applied to the Carupano Basin, Offshore methodology, the calculated GIIP may be risked as a function of the in resins and asphaltenes, a reduction in API gravity, and an classes in oil are biodegraded at different rates at the oil-water Venezuela, in K. Peters, D. Curry, and M. Kacewicz, eds., Basin and uncertainty associated to the values of some key input parameters. increase in acidity and viscosity. As a consequence, petroleum contact, and that the rates are a function of compound susceptibility GIIP percentiles are then computed (P10, P50 and P90). Petroleum System biodegradation entails a substantial decrease of the volume of oil in to biodegradation and temperature (Krooss, B. M. and Di Primio, place, lower recovery factors, as well as a reduction in oil quality and R., 2007). Examples price. Therefore, there is a great need for modeling tools capable The methodology has been successfully applied in various of before-drilling prediction of the effects of biodegradation on A biodegradation rate as a function of temperature and a worldwide formations, in Algeria, Sudan, Argentina, or even United petroleum accumulations in order to avoid prospects with greater “biodegradable” fraction arethus assigned to each compound States. risk of containing heavy oils. class. The amount of methane generated by anaerobic degradation of hydrocarbons was taken from the work of Zengler et al. (1999). This work was based on a detailed study of oil and gas samples Reservoir temperature history and filling by petroleum were subjected to variable extents of biodegradation from offshore calculated using the petroleum systems simulator. oilfields in the Brazilian southeastern margin, and on numerical simulations to quantify the alterations in geochemical and physical As a first step in biodegradation modeling, the volumes and the properties in the petroleum accumulations due to biodegradation. original properties of non-biodegraded accumulations in Aptian The main objectives of this study were: 1) to quantify compositional pre-salt reservoirs were reproduced accurately by using a PVT- changes in the oil and gas caused by progressive biodegradation; based compositional kinetic scheme. and 2) to propose a set of parameters to simulate and reproduce the volumes and compositions of petroleum affected by Then, taking samples of non-biodegraded pre-salt oils as reference biodegradation. for the original oils in biodegraded intervals and using mainly the formation factor (Bo) and densities, volumes and masses of Petroleum accumulations with non-biodegraded oil in the pre-salt biodegraded oil in Maastrichtian reservoirs were corrected for their Figure 2.Workflow used to assess shale gas potential (Aptian) reservoirs were compared with oils subjected to various losses caused by biodegradation (equation 1). intensities of biodegradation in Maastrichtian reservoirs. Among Conclusions the laboratory procedures, gas chromatography was utilized to Equation (1): The methodology presented allows estimating the hydrocarbons subdivide the oils in compositional classes (C6-C15, C15-C25, up to C55+), PVT analyses to quantify the fluid properties (API gravity, retention capacity of the formation and the composition of Surface oil Volume(biodegraded) = VOIP(biodeg.) / Bo(biodeg.), where density, GOR, and others) and fractional distillation to estimate the hydrocarbons still retained. these properties can vary significantly VOIP(biodeg.)= in place biodegraded oil volume; oil mass losses with the advancement of biodegradation.A method Bo = formation oil (biodegraded) factor. laterally and vertically, and that the shale gas potential of a formation (biodeg.) was devised by Petrobras whereby cumulative distillation curves can then not be simply deduced from a local evaluation that would are used. For a range of oils from the study area encompassing Surface oil mass (biodegraded) = surface oil volume(biodeg) * oil be extrapolated throughout the basin. Shale development presents non-biodegraded ones and others with variable extents of density on the surface (biodeg.) huge opportunity and faces large geological uncertainty. Innovative biodegradation, mass losses can be calculated considering the tools and methods are key to diminish the geological risk from total cumulative yield and the residues at a high temperature. The Surface oil mass (non-biodegraded) = (surface oil mass (biodeg) * resource evaluation to optimal well development. integration of these techniques allowed to estimate around 35% of 100%) / percent of mass loss. mass losses in a degraded oil with 18° API, which is the average

Basin modeling play a key role in the shale evaluation process value found for biodegraded oils in the Maastrichtian level (Fig. 1). Surface oil volume (non-biodegraded) = surface oil mass (non- as it allows integrating all knowledge into a consistent and biodeg.) / density (non-biodeg.). comprehensive model, from early stages of exploration to pilot zone

142 143 resulting in a single petroleum accumulation in the deepest reservoir, with leakage of the gas cap through the seal. However, the VOIP (non-biodegraded)= surface oil volume (non-biodeg.) * Bo (non- PSBM08 reservoir layer of the model. In scenarios 2, 4 and 6, all the seal additional late C1 causes more dry gas to move upwards, leading biodeg.) Understanding geochemical properties by layers behave similarly, with capillary pressures equivalent to those to phase separation in almost all the accumulations, gas washing Biodegradation rates and degradable fractions were adjusted compositional simulation of petroleum vertical of a shale, thus allowing the simulation of a stack of petroleum of the lighter oil fraction and enhanced vertical migration, with a accumulations. The data on simulated petroleum accumulations total of seven accumulations formed (Fig. 2). The injection of more for each compound class until a good match was achieved migration and evaporative fractionation – volumes, filling and leakage histories, as well as changes in methane in the system increased the overall API gravity (between between measured and calculated compositions. The simulated petroleum compositions – have been analyzed through time and 27º and 55º) and gas-to-oil ratios (between 130 and 2900 m3/m3) biodegraded accumulations reproduced the mass losses, API Luís Maurício S.A. Corrêa, Henrique L. de B. Penteado, Laury M. space in all tested scenarios. of the upper accumulations. This suggests that late methane is Araújo, Carlos P. Fracalossi & Hyalla Q.v. Da Silvaaa* gravities and compositions of oils consistent with those assessedby responsible for carrying the lighter fractions of petroleum towards the integration of laboratory techniques (Fig. 2). Regarding the kinetics of primary cracking assigned to the basal the top. Therefore, the results of scenario 4 demonstrate that the a Petrobras, Petroleum Systems Modeling Team source rock, the compositional scheme from Penteado& Araujo process of evaporative fractionation by forced depletion can be [email protected], [email protected], carlos. (2009) was used. This scheme is characterized by ten classes of adequately modeled. [email protected], [email protected], compounds for primary cracking, including the gaseous (C1, C2 and C3-C5) and liquid (C6-C60+) fractions. The compositional Copyright 2014, ALAGO. scheme also includes the kinetics of late C1 generation from This paper was selected for presentation by an ALAGO Scientific Committee following refractory kerogen, in addition to the parameters for secondary review of information contained in an abstract submitted by the author(s). cracking. Scenarios 1 and 2 were simulated using only the kinetics Introduction for primary cracking. For scenarios 3 and 4, the kinetic scheme for primary cracking was coupled with late methane generation. Petroleum systems modeling allows the dynamic simulation of a Finally, scenarios 5 and 6 were simulated through the use of the series of processes during the geological history of a basin. Among full kinetic scheme, including secondary cracking of compound these processes, physical and chemical changes in petroleum classes both within and outside the source rock. associated with vertical migration are of utmost importance for the assessment of petroleum volumes and composition in an exploratory context. Figure 1.Synthetic geological model showing the stacking of reservoir (sandstone) and seal (shale) layers. At the base of the model, the source rock layer in green. Scenarios 5 and 6 are the only ones that take into account Evaporative fractionation is one of the processes related secondary cracking. In scenario 5, after all oil and gas generated Figure 2 - Graph ofMaastrichtian reservoir filling history without petroleum to petroleum migration which may cause alterations in the by primary cracking and late-gas cracking are accumulated in biodegradation, graphof APIgravity and temperature through time composition of an accumulation. Thompson (1987, 2010) defined Results and Conclusions In scenario 1 (Fig. 2), the single oil accumulation in the deepest the lowermost reservoir, GOR and API gravities increase in the and results table comparing properties of the reconstituted oil(without evaporative fractionation as a product of either gas injection or reservoir remains a monophasic black oil with a constant liquid phase until it is completely cracked (Fig. 2). In scenario 6, the biodegradation), oil in place and modeledbiodegraded oil. reservoir decompression in an oil accumulation, followed by phase composition (27° API gravity and gas-to-oil ratio – GOR – of 100 phases and compositions in all the accumulations are a result of destabilization/separation and gas escape, which carries upwards m3/m3) throughout the model history because the mass fractions a complex interaction of evolving fluids with migration processes. Conclusions the light fractions derived from the oil in solution. of the compound classes are the same for all activation energies in The end result of scenario 6 is a stratified pattern of accumulations: These new achievements enable, using the set of biodegradation the kinetics for primary cracking. the lowermost reservoirs contain essentially gas; intermediary Several studies have confirmed, by the analyses of reservoirs parameters and reservoir filling history, to assess the biodegradation reservoirs are filled by volatile oils; and the shallower reservoirs fluid data and laboratory scale experiments, the occurrence of risk, as well as the volume and oil composition in new prospects In scenario 2 the lower capillary pressures in the seals favor contain only gas condensates. evaporative fractionation in basins. In order to investigate the effects located in areas subject to biodegradation.Further developments petroleum vertical migration (Fig. 2). of evaporative fractionation during petroleum vertical migration in this model will be made as these parameters are tested and The results of the six modeled scenarios have shown that petroleum using a basin simulator, tests were performed using a synthetic validated in other geological areas. vertical migration is a highly complex process as a function of: 1) geological model built in the PetroMod software (Schlumberger). capillary seal breach induced by underlying accumulations; 2) The method usedfor migration combines multiphase Darcy flow phase separations during vertical migration; 3) leakage of gas caps Acknowledgements and ray tracing, with petroleum composition based on a kinetic through seals and losses to the surface; 4) gas washing caused The authors thank Petrobras forthe authorization to publish this scheme with eleven compound classes, which is representative of by upward migration of late methane sweeping light compounds study. the PVT properties of lacustrine oils from Brazil. PVT calculations upwards, and 5) progressive cracking of heavier compound (phase separation, physical and chemical properties of each classes as accumulations are buried deeper. Thus, the numerical phase) were undertaken for each accumulation during the whole experiments have shown that evaporative fractionation both References: model history. by decompression (self-depletion) and by gas washing (forced Krooss, B. M. and Di Primio, R., 2007: Personal communication (apud Synthetic Geological Model depletion) can be adequately reproduced in the scale of petroleum T.; Hantschel, T.; Kauerauf. 2009, Fundamentals of Basin and Petroleum systems modeling, and be used to assess its effects on fluid To build the synthetic model for the flow simulation and numerical Systems Modeling, Springer, 2009). Four other accumulations are formed farther above because of the composition in exploration prospects. tests, the PetroMod (v.2011) software was used. The model has breach of the capillary barrier of the first seal layer, with slightly an area of 32 x32 km, a maximum depth of 7 km and a total of Lopes, J.P. e Penteado, H.L.B., 2009: Field-scale quantitative assessment greater API gravities and lower GOR values (between 35 and Figure 2.Petroleum accumulations resulting from the different modeling conditions 23,808 grid cells. The model is characterized by stacked pairs of petroleum mass losses due to biodegradation under reservoir conditions, 100 m3/m3). As petroleum moves upwards, phase separation of scenarios 1 to 6.Liquid accumulations shown in green, and gas in red. of a sandstone layer with petrophysical properties of a reservoir Proceedings of the24th International Meeting on Organic Geochemistry, takes place in some of these shallower reservoirs, and the gas- rock overlain by a shale layer with properties of a seal rock (Fig. 1). References condensate (API = 56º and GOR> 24000 m3/m3) cap is partly lost Bremen, Germany, pp. 480. For the basal layer of the model, a shale source rock was defined. Penteado, H.B. & Araujo, L.M., 2009.Compositional kinetics with a PVT to higher reservoirs and to the surface. Later, further burial andthe The various layers comprise a domic structure with its apex at description applied to the prediction of petroleum quality in Brazilian basins. associated increase in seal capillary pressure prevent further losses. Penteado, H.L.B. e Lopes, J.P., 2007: Application of distillation data the center of the model. Sedimentation, compaction, heat flow, In: AAPG International Conference and Exhibition, Rio de Janeiro (abstract). The model was thus able to simulate the occurrence of evaporative for the estimation of mass losses in biodegraded oils: A new approach, petroleum generation and migration were computed during a total fractionation by decompression, phase separation and loss of the Thompson, K.F.M., 1987. Fractionated aromatic petroleums and the Proceedings of the 23rdInternational Meeting on Organic Geochemistry, model history of 125 Ma. lighter fractions through the disrupted seal layers (self-depletion). generation of gas-condensates. Organic Geochemistry 11, 573-590. Torquay, England, pp. 847-848. Simulated Scenarios Scenario 3 differs from scenario 1 by the inclusion of late methane Thompson, K.F.M., 2010. Aspects of petroleum basin evolution due to gas Six scenarios were performed to test variations in the capillary Zengler, K.; Richnow, H.H.; Rosselló-Mora, R.; Michaelis, W.and Widdel, generation, which causes an increase in GOR values until a phase advection and evaporative fractionation. Organic Geochemistry 41, 370-385. pressure of the deepest seal layer and in the kinetics of petroleum F. (1999). Methane formation from long-chain alkanes by anaerobic separation occurs in the lowermost reservoir layer (Fig. 2). In generation and cracking. In scenarios 1, 3 and 5, the capillary microorganisms.Nature, 401:266-269. scenario 4, accumulations are initially formed above the deepest pressure of a salt layer was assigned to the deepest seal layer,

144 145 PSBM09 In order to obtain an accurate kinetics estimate, sealed-gold tube PSBM10 Geochemical Basin Models for pyrolysis with well-controlled Temperature and Pressure conditions Unconventional Shale Plays is conducted (closed system) at two different heating rates, 20oC/ Prediction of Biogenic Gas Accumulations: hr and 2oC/hr from T = 250 ~ 550oC; and all solid, liquid and Application to the Eastern Mediterranean YongchunTanga,*, Li Gaoa, QishengMaa, James Chena gaseous components were measured to derive their kinetics as illustrated in Figure 1. F. Schneider, M. Dubille, L. Montadert, P.Y. Chenet and R. Traby Beicip-Franlab, 232 Avenue Napoléon Bonaparte, 92500 Rueil- a GeoIsoChem Corporation, Covina, CA, USA Malmaison, França

[email protected] Figure 3: Comparison of SARA distributions of the expelled oils from the [email protected] upper Bakken (left) with the field-observed SARA distribution in the middle Copyright 2014, ALAGO. Bakken. Copyright 2014, ALAGO. This paper was selected for presentation by an ALAGO Scientific Committee following This paper was selected for presentation by an ALAGO Scientific Committee following review of information contained in an abstract submitted by the author(s). It is well recognized that the Bakken shale oil is very light, with an review of information contained in an abstract submitted by the author(s). oil API gravity above 40 degree. Our basin model also provides Introduction the quantitative model to predict the oil viscosity. Because of the Accurate assessment of the Original Oil-in-place (OOIP) or Original distinguishable expulsion efficiencies for oil and SARA compounds, Gas-in-place (OGIP) is one of the most essential tasks in petroleum Introduction the majority of viscous oil compounds such as asphaltene and Biogenic gas is becoming increasingly important as an exploration exploration and production. Geochemical basin models have a resins will be retained in source rocks as a deposit of solid contents. target in the petroleum industry because it occurs in geologically focus on understanding effects of generation and compositions of Only the saturates/aromatics compounds that dissolved in the predictable circumstances and in large quantities at shallow depths hydrocarbonson OOIP/OGIP predictions. Within the geochemical Figure 1: A comprehensive kinetic network for the hydrocarbon liquid phase will be readily expelled and become easily producible. as free gas or gas hydrates. As accumulations of biogenic gas framework, OOIP/OGIP is calculated from a product of the total generation and secondary cracking from kerogen sources. Each result in a subtle synchronization between early generation and generated hydrocarbons (HC), the expulsion ratio R1 that is related dashed line represents a type of chemical reaction that follows the H2S risk is another important issue in both conventional and early trapping, we integrated a macroscopic model of microbial to hydrocarbons expelled from source rocks (primary migration), Arrenhius’s Equation (2). unconventional petroleum exploration and production. Our basin gas generation within a 3D basin and petroleum system forward and the migration/diffusion efficiency R2 for hydrocarbons travelling model also provides a quantitative model to determine the amount simulator. from sources to the trap (secondary migration). The mass balance and volumetric analyses wereusedto determine the hydrocarbon expulsion from source rocks. At the early of H2S presented in the petroleum system. Our model also offers the potential to distinguish the sources of H2S either fromkerogen Based on microscopical considerations we developed the OOIP/OGIP = HC * R1 * R2 (1) generation stage, due to the volume expansion, the excessive liquid compounds will be expelled according to their partitions decomposition or from oil secondary cracking. macroscopical model of low maturity / biogenic gas generation in which hydrocarbons are generated through first order kinetic In the unconventional shale plays, the majority of shale oil/gas in solid/liquid phases, which can be calculated using the Peng- Conclusions reactions at low maturity. is stored locally inside the organic porous space or in the vicinal Robinson Equation of State (EoS). Geochemical basin models combining hydrocarbon generation and natural fractures, and thus the primary migration (expulsion) is 2 2 expulsion processes can provide a systematic petroleum system the predominant effect on the shale oil/gas composition and P = RT/(V-b) – a(T)/(V +2bV-b ) (3) Microscopic model assessment for both conventional and unconventional reservoirs. distributions. In this work, we present an integrated geochemical Our comprehensive kinetic network including individual generation/ basin model combiningthe hydrocarbon generation, expulsion Where P and V are the pressure and volume of system, and a(T) expulsion/cracking of the oil SARA compounds is essential in order and secondary cracking processes.Theoretically predicted oil and b are the EoS parameters. The retained oils will undergo to obtain a reliable geochemical model to better predict the oil/gas properties, e.g., ratios of Saturates, Aromatics, Resin-NSO, and secondary cracking to give rise of more gaseous components. properties. Asphaltene (SARA) and the API gravity of shale oil are compared and calibratedwith the geological field observation from the Bakken Results and Discussion Acknowledgements Shale oil formation. Our models not only can provide important The Bakken shale oil reserve consists of three layers, upper This research was supported by the Joint Industrial Program shale oil properties, but also offer more accurate information of Bakken, middle Bakken and lower Bakken. While the lower and for the GeoIsoChem Corporation, Power Environmental Energy gaseous components, especially the non-hydrocarbon gases such upper Bakken are primary shale sources, the middle dolomite Research Institute and industrial sponsors, PetroChina fund as H2S and CO2 generations. layer behaves as the oil bank to preserve shale oils for production. (13HT10500000038) and International Science & Technology Such a geological system offers excellent field data to calibrateour Cooperation Program of China (ISTCP) (2010DFB64070). Methodology geochemical basin models. For example, the shale oil composition Kinetics of hydrocarbon generations from kerogen and the (SARA) in retained shale layers can be calculated and compared References secondary cracking are determined through a series of parallel with the field data (Figure 2). SARA distributions in expelled oils Behar, F.; Vandenbroucke, M.; Tang, Y.; Marquis, F.; and Espitalie, J.; 1997. chemical reactions, with each following the Arrenhius’ Equation: from the upper/lower Bakken layers match the field-observed Thermal Cracking of Kerogen in Open and Closed Systems: Determination SARA ratios in the middle Bakken layer (Figure 3). of Kinetic Parameters and Stoichiometric Coefficients for Oil and Gas Figure 1: Reaction scheme used in the 1D microscopic model k =Afexp (-Ea/RT) (2) Generation. Org. Geochem. 26, 321-339. whereAf is the frequency factor, Ea is the activation energy, R is the The microscopic model consists in a 1D sedimentary column that Sandvik, E. I.; Young, W. A.; and Curry, D. J.; 1991. Expulsion from thermal constant and T is the absolute temperature. Hydrocarbons accounts for sedimentation, compaction, Darcy flow and Diffusion Hydrocarbon Sources: the Role of Organic Absorption. Adv. in Org. generated from kerogen decompositions can be grouped into: flow. The organic carbon is the only non-soluble element considered Geochem.19, 77-87. o Heavy oils (C15+) that include Saturates (S), Aromatics (A), Resin- in this version of the model. The dissolved elements are O2, SO4--, NSO (N), and Asphaltene (Asph); CO2, H2, CH4COOH, and CH4. Methane is dissolved in water or Pepper, A. S.; and Corvi, P. J.; 1995. Simple Kinetic Models of Petroleum present as a free phase if its concentration exceeds its solubility at Formation. Part 1: Oil and Gas Generation from Kerogen. Marine and • Light oils (C6-C14) that include Saturates (S6) and given pressure and temperature. The reactions accounted for in Petrol. Geo. 12, 291-319. Aromatics (A6); this version of the model are given in Figure 1. • Condensates (C3-C5); Figure 2: Comparison of SARA distributions of retained oils in the upper • Ethane (C2); Bakken shale oil formation, (left) theoretical prediction from the integrated The transformation of substrate into biomass is described through • Methane (C1); basin model and (right) observed field data. a set of logistic equations coupled with the transport equations • Carbon Dioxide (CO2); (advection and diffusion). • Hydrogen Sulfide (H2S); and • Nitrogen (N2).

146 147 The first results of the model (see Figure 2) are consistent with the methodology has been developed for identifying which layers could PSBM11 observations in terms of nutrients and microbes concentrations develop a biogenic gas generation potential. Figure 1. Transformation ratio of carbonates in layer Lower Serdj(Late Quantitative Prediction of CO2 and H2S in the Triassic) The computed HC composition indicated: (1) the gas, mostly Gulf of Gabes, Offshore Tunisia biogenic, completely dominates the shallow plays from the Pliocene Under subsurface conditions, both gases are highly soluble in to the Oligocene; In particular, the Miocene play below the salt is Aimee Browna, Michael D. Linesb, Jonathan McQuilkenb,C. water and a mutual solubility model, based on work of Duan et al., easily filled by biogenic gas (2) the oil/condensate content would Ian Warburtonb,Taina Coutoc,e,Thomas Hantscheld, Armin I. 2006 and Duan et al., 2007, has been implemented into petroleum increase in the Eocene, and overall in the Cretaceous-Jurassic; (3) d,*, c Kaueraufd, Adrian Kleinec, Peter Schlicht , systems modeling. Excess inert gas amounts dissolve in liquid or then the gas (mostly thermogenic) content increases, up to 100% vapor phases of the petroleum. in the Triassic play. a BG Brasil, Av.Republica do Chile, 330, 25 Andar, Torre Oeste, Rio de Janeiro, 20031-170, Brazil Migration of the inert gases, which are dissolved in water, was Recent works seem to demonstrate that the same deep biosphere b BG Group, Thames Valley Park, Reading, RG6 1PT, UK modeled with a diffusion equation based on Fick’s law with diffusion is responsible for early gas generation and biodegradation of c Schlumberger Brazil Research and Geoengineering Center, Rua thermogenic hydrocarbons. Furthermore, the exploration for Paulo Emídio Barbosa, 485, Quadra 7B, Parque Tecnológico, coefficients determined according to an Eyring type equation unconventional gas demonstrated that late biogenic gas can Cidade Universitária, Rio de Janeiro, Brazil Deff=Dφδ/τ, D=D0exp(-Ea ⁄RT) be generated from old source rocks. Further efforts will be done d Aachen Technology Center, Schlumberger, Ritterstr. 23, Aachen, toward a better modeling of the effects of the deep biosphere on Germany with D0 the pure component diffusion coefficient, Deff the effective the petroleum systems. e SIS Brazil, Schlumberger,Rua Paulo Emídio Barbosa, 485, diffusion coefficient,φ porosity,δ constrictivity, τ tortuosity, Ea Quadra 7B, Parque Tecnológico, Cidade Universitária, Rio de the activation energy, R the universal gas constant and T the Figure 2: Species and microbes concentrations calculated by the 1D model. References Janeiro, Brazil temperature. It has been observed, that, according to these Clayton, C., 1992, Source volumetrics of biogenic gas generation, in R. equations, high temperatures allow for a significant migration due Macroscopic Model Vially, ed., Bacterial Gas: Paris, Editions Technip, p. 191–204. *[email protected] to diffusion inside the water phase. Especially, CO2 originating from Based on the previous microscopic considerations we developed deeply buried carbonates might pass quite long distances. in TemisFlow a macroscopic model of low maturity / biogenic gas Dubille M., L. Montadert, J.M. Laigle and F. Schneider, 2013, Offshore Introduction generation in which hydrocarbons are generated through first order Lebanon: biogenic and/or thermogenic plays? An answer from 3D Within the Gulf of Gabes, offshore Tunisia, the inert gases CO2 The migration of CO2 and H2S dissolved in liquid or vapor kinetic reactions at low maturity. basin modeling, AAPG European Regional Conference: Exploring the and H2S are an important exploration risk. A quantitative prediction Mediterranean: New Concepts in an Ancient Seaway, 8-10 April, Barcelona, of occurrence of these gases at locations of interest is difficult. petroleum phases was performed with separate phase flow such The sensitivity analysis carried out with the microscopic model Spain, abstract. We present new developments in basin and petroleum systems as Darcy flow or Invasion Percolation (Hantschel and Kauerauf indicates that free methane generation is conditioned by the initial modeling to improve the understanding on the behavior of such 2009). Herein, the gases aredissolved within migrating petroleum TOC, the sedimentation rate and the thermal gradient. A modified Schneider, F. J. S., J. A. Noya, and C. Magnier, 2012, Model of low-maturity inert gases. A number of CO2 and H2S specific processes have phases. The equilibrium between dissolution into water and the Clayton chart (Clayton, 1992) has then been derived in which the generation of hydrocarbons applied to the Carupano Basin, Offshore newly been integrated in a coupled modeling approach, which petroleum phases was continuously updated in the entire model at lower boundary is now a function of the initial TOC. It should be Venezuela, in K. E. Peters, D. J. Curry, and M. Kacewicz, eds., Basin accounts for the interactions of those with geological processes. all locations and geological times. noticed that the upper boundary of the Clayton chart is not justified Modeling: New Horizons in Research and Applications: AAPG Hedberg Finally, this method was applied to an already existing modelof by the microscopic model. Furthermore, methane generation Series, no. 4, p. 51– 69. the area (Grimmer et al., 2011)to better analyze and quantitatively Finally, a modeling method with a full coupling of all relevant occurs at low temperature (< 80°C) and low maturity (Ro < 0.6 %). predict generation and migration amounts of inert gases. processes, namely generation of CO2 and petroleum, destruction In order get a macroscopic model usable in a basin model, the Schneider F., Dubille M., and M. Ducros, 2013, Prediction of Low-Maturity of petroleum with subsequent generation of H2S, mutual dissolution set of logistic reactions is up scaled into a set of first order kinetics / Biogenic Gas Accumulations: Application to the Offshore Lebanon. AAPG Method of inert gases into water and petroleum phases, and migration via assuming that the biomass is a catalyst. It should be noticed that Geosciences Technology Workshop: Challenges of New Frontier Off-Shore The key mechanism for the generation of H2S in the basin is the kinetic parameters calibrated from lab experiments are not able Deep Water Hydrocarbon Basins, 27-29 May, Beirut, Lebanon, abstract. Thermochemical Sulfate Reduction (TSR) which occurs mainly in diffusion and separate phase flow has been used. to reproduce the nature of the fluids generated at low maturity. the carbonate reservoir intervals. A reaction scheme developed Indeed, the kinetic parameters are mainly calibrated with kerogen by Tang (Tang et al., 2009) has been used for modeling of this Results and Discussion samples for which Ro is taken to be approximately 0.6%. geological process (Kauerauf et al., 2012). Thismethod has been applied to a basin model inthe Gulf of Gabes, offshore Tunisia (Grimmer et al., 2011). It already contained C_n H_m+〖SO_4〗^(2-)+H^+→H_2 S+CO_2+H_2 O In our simulations, most of the gas is generated at a very low an overall thermal analysis with generation and migration of maturity: Ro less than 0.6 %. In this domain, it has been stated Helium isotope analysis indicates that generation of CO2 is mainly hydrocarbons, performed with established methods of petroleum that the thermal C-C–bound breakage is unlikely to be significant from the thermal destruction of deeply buried carbonates (Grimmer systems modeling. It has been found that large amounts of CO2 without catalysis. Because microbial enzymes are the most efficient et al., 2011). The corresponding reaction dissolve in the water, Table 1, and diffuse into reservoir layers which low-temperature catalysts known, we could describe our kinetic are of interest for exploration. model as a microbial enhanced thermal model. CaCO3→CaO + CO2

Applications is modelled by a kinetic equation based on Arrhenius law which The previous model has been applied successfully on different yields huge amounts of CO2, cmp. Fig. 1. basins such as the Carupano Basin from the offshore Venezuela (Schneider et al, 2012), Magdalena Delta (offshore Colombia) and the offshore Vietnam where direct observations of low-maturity gas were available. Furthermore, it has been applied in the offshore Lebanon in order to check the viability of a biogenic gas system (Dubille et al, 2013; Schneider et al., 2013). Table 1.Mass Balance of CO2 and H2S. An integrated interpretation of regional 2D seismic surveys offshore Lebanon provided structural maps and an improvement Due to a limited capacity of water to dissolve both inert gases, of the geological knowledge. These data allowed the building of a dissolved CO2 inhibits dissolution of H2S.Significant amounts of geological model in 3 dimensions at the scale of the whole offshore

Lebanon. The thermogenic source rocks observed in surrounding H2S are thus not dissolved into water and kept in the petroleum basins were implemented and tested in the model. An advanced 0% 5% 10% phases. In total, measured concentrations of both inert gases could be reproduced, see Table 2.

148 149 PSBM12 Results and discussion Sixteen single-ramp experiments on aliquots of the Bellagio Road Figure 2. Range of kinetic parameters derived for two samples using Petroleum Generation Kinetics: Single- vs. sample gave an average Ea of 53.54 ±0.28 kcal/mol. At a geological multiple heating ramps shows that the differences in mean A and Ea are real and not a measurement artifact. Multiple-Heating heating rate of 3ºC/Ma, the predicted range in temperature at 10, 50, and 90% transformation ratio (TR) is 9.90 ± 2.35, 2.69 ± Ramp Open-System Pyrolysis The 52 studied samples show a range of calculated A of about four 2.03, and 7.63 ± 2.85oC, respectively. This is the minimum error orders of magnitude (~1012 to1016 sec-1). These A values are for geological extrapolation of single-ramp experiments using our K.E. Petersa,b* and A.K. Burnhamc real because they are reproducible within experimental precision. Pyromat II. Replicate measurements by Burnham (1994) on a set Furthermore, Burnham (1994) saw a similar range in A for his Table 2. CO2 and H2S concentrations at some specific locations. aSchlumberger Information Solutions, Mill Valley, CA 94941; of samples where A was optimized give a standard deviation of ~1 samples. Based on his 1-2-3 rule, he calculated that using a fixed [email protected] kcal/mol with a compensating two-fold change in A, resulting in a A of 1 x 1014 sec-1 could result in error for geologic extrapolations Conclusions bDepartment of Geological & Environmental Sciences, Stanford standard deviation of 3oC (1-2-3 rule) for geologic extrapolations, up to 20oC. Thus, our data show that one-ramp kinetic analysis

Measured concentrations of both inert gases, H2S and CO2, University, Palo Alto, CA 94305 similar to our results and also well within the range of geologic introduces the potential for significant error that can be avoided by using high-quality kinetic measurements and multiple-ramp could be approximately reproduced by modeling. Mutual water cAmerican Shale Oil Corporation, LLC, Livermore, CA 94550 uncertainties. dissolution of inert gases and diffusion in deeply buried layers experiments. are important processes, which are necessary for a quantitative *[email protected] Figure 1 shows deviation from average Ea for two samples from prediction of these gases. As such the overall workflow of basin the dataset versus the heating rate ratio. Open symbols are results Conclusions Single-ramp pyrolysis using a fixed A to determine petroleum and petroleum systems modeling with incorporation of inert gas for combinations of two to six different heating rates where A was Copyright 2014, ALAGO generation kinetics is fast and inexpensive. However, our data processes has given a better understanding of the distribution of optimized by Kinetics05. When only one heating rate is used (filled This paper was selected for presentation by an ALAGO Scientific Committee following show that single-ramp experiments yield kinetic results that can H2S and CO2 in the Gulf of Gabes. symbols), the variability of Ea and the corresponding A is very review of information contained in a abstract submitted by the authors. be inconsistent with multiple ramp experiments based on discrete large. The variability of Ea becomes relatively small for heating rate Ea distribution modeling. It is unwise to assume a universal value Acknowledgements Introduction ratios >16. The dashed lines are the expected variation in Ea as for A. This work shows that for a worldwide 52-sample dataset, A The authors thank the BG Group for allowance to publish this study. Some publications promote open-system pyrolysis using a single a function of heating rate ratio calculated from the Bellagio Road varies over four orders of magnitude (~1012 to1016 sec-1) and is heating ramp and fixed frequency factor (A) to determine the standard deviation. reproducible within experimental precision. References petroleum generation kinetics of source rock because the method 56 The data show that discrete Ea distribution modeling based on Duan, Z., Sun, R., Zhu, C., Chou, I-M., 2006. An improved model for the is faster and less expensive than multiple-ramp experiments (e.g., three pyrolysis temperature ramps closely approximates the results calculation of CO2 solubility in aqueous solutions containing Na+, K+, Waples et al., 2002; Waples and Nowaczewski, 2014). According Kimmeridge (all heating rates) from additional ramps, provided that the ramps span an appropriate Ca2+, Mg2+, Cl-, and SO42-, Marine Chemistry 98, 131-139. to Waples, the key to single-ramp kinetics is to use a fixed A (1 54 Duan, Z., Sun, R., Lui, R., Zhu, C., 2007. An accurate thermodynamic range. We recommend three or more ramps that span at least a or 2 x 1014 sec-1). Our paper compares the reliability of various twenty-fold variation of rates, such as 1, 5, and 25oC/min, or 1, 3, model for the calculation of H2S solubility in pure water and brines, Energy combinations of open-system pyrolysis heating rates to determine 52 9, 27oC/min. Caution is needed for ramps of 30 and 50oC/min, & Fuels 21, 2056-2065. Kimmeridge Clay the kinetics of petroleum generation. Three questions must be Monterey Monterey Shale which can cause temperature errors due to impaired heat transfer. (all heating rates) addressed to evaluate the single-ramp method: 50 The product of heating rate and sample size should not exceed Grimmer, J., Brahim, A.B., Hamdi, A., Nadin, P., McQuilken, J., 2011 ~100 mgoC/min. Compound volatility may inhibit pyrolyzate yield Activation Energy, kcal/mol Energy, Activation Tunisia: Gulf of Gabes - 3D Modelling of Hydrocarbon and CO2 Generation Are there real differences in A for different kerogens? at the lowest heating rates depending on the effectiveness of the and Migration, AAPG Milano. 48 1 x 1012 1 x 1013 1 x 1014 1 x 1015 gas sweep. For some kerogens having narrow activation energy Are the differences large enough to have a significant impact on Frequency Factor, sec-1 distributions, both single- and multiple-ramp discrete models are Hantschel, T., Kauerauf, A.I., 2009. Fundamentals of Basin and Petroleum extrapolation to geological time? insufficient and nucleation-growth models are necessary. Systems Modeling, Springer. Acknowledgements What experimental conditions are required to answer questions 1 and 2? Figure 1. Deviation from average activation energy (Ea) vs. heating Kauerauf, A.I., Hantschel, T., Tang, Y, Xia, D., Warburton, I., 2012. rate range (ratio of fastest to slowest heating rate) for samples from the We thank Clifford C. Walters (ExxonMobil) for discussions, technical Integration of Thermochemical Sulfate Reduction into Petroleum Systems Kimmeridge Clay and Monterey Shale (type II and IIS kerogen, respectively). assistance, and review of the draft. Methods References Modelling, AAPG Hedberg. To test precision of kinetic results, a source rock sample from Burnham, A.K., 1994. Comments on “The effects of the mineral The kinetic parameters for these two samples are statistically Bellagio Road containing type II kerogen was run 16 times by matrix on the determination of kinetic parameters using modified Tang, Y., Ellis, G.S., Zhang, T., MA, Q., Armani, A., 2009. Experimental different (Figure 2). The points are for heating rateratios of 16 or Pyromat II® micropyrolysis at 30ºC/min. Fifty-two well characterized Rock-Eval pyrolysis” by H. Dembicki Jr., and the resulting comment and Theoretical Determination of the Kinetics of Thermochemical Sulfate source rock samples (Peters et al., 2006) were analyzed to more. Using all heating rates yields parameters in the middle of the by R. Pelet. Organic Geochemistry 21, 985-986. Reduction, Goldschmidt Conf., Davos, Switzerland. compare results based on (1) one ramp (30oC/min) with a fixed range. The frequency factors differ by tenfold for the two samples. A (1 x 1014 sec-1), and (2) combinations of ramps (1, 3, 5, 10, The most precise temperature predictions are obtained using a Burnham, A.K.; and Braun, R.L., 1999. Global kinetic analysis of 30, and 50oC/min) where A was optimized by the software. These wide range ofheating rate ratios (Figure 1), but fast ramps such as complex materials. Energy & Fuels 13, 1-22. worldwide samples include kerogen types I, II, IIS, II/III, and III that 50oC/min should be used with caution. Peters, K.E.; Walters, C.C.; Mankiewicz, P.J., 2006. Evaluation of are immature to slightly mature with respect to oil generation. Rock 10 kinetic uncertainty innumerical models of petroleum generation. samples were ground to a fine powder (~150 mesh) in an agate Kimmeridge Clay AAPG Bulletin 90, 1-19. mortar and pestle. Two- to 10-mg aliquotsof the rock powder 6 Monterey Shale were pyrolyzed using Pyromat II at one or more of the six heating Waples, D.W.; and Nowaczewski, V.S., 2014. Source-rock kinetics, rates. Temperatures were measured by a calibrated thermocouple 2 in Encyclopedia of Petroleum Geoscience, New York, Springer.

in contact with the sample. Products were transferred to a flame , kcal/mol a 3σ ionization detector by helium flow at 50 ml/min. Pyrolyzate peaks E -2 Waples, D.W.; Vera, A.; Pacheco, J., 2002. A new method for

were processed using Kinetics05® software (Burnham and Braun, from Deviation kinetic analysis of source rocks: development and application as 1999). We used discrete Ea distribution modeling with 1 kcal/mol Average a thermal and organic facies indicator in the Tithonian of the Gulf -6 energy spacing for most samples. Some samples with very narrow of Campeche, Mexico: Abstracts, 8th Latin American Congress on Ea distributions required nucleation-growth modeling. Organic Geochemistry, Cartagena, p. 296-298. -10 0 10 20 30 40 50 60 Heating Rate Ratio

150 151 depth of generation of biogenic gas generation is not the only issue PSBM13 that needs to be understood. Migration and trap/seal mechanisms PSBM14 of biogenic gas fields also need to be considered, especially as Controlling factors in mixed biogenic / ‘conventional’ seals are not expected to have adequate sealing Occurrence, Distribution and Character of thermogenic petroleum systems – a case properties at the shallow depths at which biogenic gas is assumed to be generated. Both generation and seal quality evolution need to Hydrocarbon Source Kitchens in the Southern study from the Levantine Basin be considered as closely coupled processes in these plays. Foredeep of the Llanos Basin, Colombia

1 1 2 Bjorn Wygrala , Martin Neumaier , Chris Clayton , Thomas The Levantine Basin offers a particularly interesting ‘laboratory’ Y. Blancoa*, V. Blancob¬, N. Sánchezb¬, E. Cardozoa, W. Espitiaa, Hantschel1, Adrian Kleine1, Abdulaziz Al-Balushi3, Alistair Fraser3 b to test the variables that control the evolution of biogenic gas J. Lunab, M. Naranjo . fields. It is a sub-salt play with regionally extensive salt coverage Figure 2. Conceptual model of the event sequence during the Messinian 1 Schlumberger SIS, Aachen, Germany; of Messinian age, however the gas is not trapped and sealed Salinity Crisis, and the resulting effects on the boundary conditions and a Gerencia de Exploración Regional Llanos. Vicepresidencia de 2 Geochemistry Consultant, UK; directly below the salt but within Oligocene-Miocene silty/sandy subsurface pressure and temperatures in the Levantine Basin. Exploración-Ecopetrol S.A. Bogotá. Colombia 3 Dept. of Earth Science and Engineering,Imperial College, turbidite sequences which are assumed to be both the gas source b Instituto Colombiano del Petróleo-Ecopetrol S.A. Km7 vía London, UK and reservoir. The most unusual feature is that the area was The regional type-section is used to show the data and Piedecuesta. Colombia subjected to a geologically extreme event during the Messinian interpretations related to the construction and calibration of the [email protected] Salinity Crisis (MSC) between 5.96 and 5.33 Mabp when the sea model, as well as the underlying assumptions that were used to *[email protected] level in the entire Mediterranean Sea dropped by approximately constrain the properties and boundary conditions of the model. Copyright 2014, ALAGO. 2000m followed by salt deposition of locally up to 2000m in a The properties andprocesses related to the formation of the Copyright 2014, ALAGO. This paper was selected for presentation by an ALAGO Scientific Committee following very short time span of less than 50,000 years. This caused rapid currently known biogenic system are then investigated within This paper was selected for presentation by an ALAGO Technical Committee following review of information contained in an abstract submitted by the author(s). changes in the depositional environments and sediment surface these constraints. Only limited thermal calibration data is currently review of information contained in an abstract submitted by the author(s). conditions, as well as in the pore pressures and temperatures in publicly available, but uncertainties related to this will be shown Introduction the subsurface. As the timing and the conditions induced by the where applicable. Special emphasis will be placed on the topic of Introduction The petroleum systems in the Levantine Basin in the Eastern event are reasonably well defined, it offers a unique opportunity to biogenic gas generation, and various generation concepts will be A foreland basin system like the Llanos Basin is an elongated Mediterranean have an interesting combination of geological test and possibly constrain some of the controlling factors in both presented, from simple thermally controlled biogenic gas generation depozone formed as a consequence of geodynamic processes features and processes, each of which are highly relevant to many shallow and deep gas plays to more complex approaches which, for example, enable deep linked to subduction and the adjacent fold-thrust belt which other exploration areas. These include biogenic gas generation, biogenic gas generation to be explained. This will then enable according to DeCelles & Giles (1996), encompasses four distinctive successful entrapment of biogenic gas at shallow burial depths, Study an assessment of gas migration and accumulation timing and depocenters defined as wedge-top, foredeep, forebulge, and back the potential for mixed biogenic and thermogenic systems, as well A 240 km long regional 2D type section which connects the three additional controlling factors such as gas migration volumes and bulge. This work focuses on the evaluation of hydrocarbon source as the effect of rapid changes in PT conditions on oil and gas in major discoveries was interpreted and reconstructed (Fig.1), and rates, the impact of the pressure reduction on hydrocarbon volume kitchens within the southern foredeep depozone of the Llanos petroleum systems. Petroleum systems modeling in the Levantine used for petroleum systems modeling to investigate the sequence changes (density, gas exsolution from oil and water, desorption), as foreland system and the relevant implications for exploration risk therefore offers interesting opportunities to test hypotheses and of events in the study area and their possible effects on the proven well as seal quality evolution and potential entrapment processes assessments in the region. The configuration of the study area constraints concerning the relative importance of these factors and biogenic and assumed thermogenic petroleum systems. through geologic time. is the unavoidable consequence of thrusting and as stated by the resulting exploration risks. Hoffman, 1987, it contains a transitional stratigraphic record, in In the final part, we then assess the assumed deeper thermogenic time and space from shelf or cratonic conditions to orogeny. Background petroleum systems which are at the moment speculative in the The Levantine has become an attractive area for oil and gas study area, and show which range of conditions could lead to the The vertical stratigraphic successions present within the study area exploration due to the discovery of a series of major gas fields co-existence of biogenic and thermogenic petroleum occurrences reveal a lateral range of depositional conditions, which evolved in the pre-salt sequences since 2009. More than 40 tcf of gas and the possible contributions from the different potential through geologic time to ultimately develop the various critical have now been confirmed in several fields since the original thermogenic source units. Due to the extremely rapid changes in features (e.g. quality, thickness and lateral continuity) for major discovery was made. Information on whether the gas in these the PT conditions in the subsurface during the Messinian Salinity components of a given petroleum system such as: source, reservoirs, new discoveries is of thermogenic or biogenic origin was at first Crisis, there are considerable additional risks for the preservation of and seals at a local scale. The Llanos foredeep depozone has been restricted, as the strategic implications are clear: if the discovered oil and gas accumulations which were formed prior to and during filled throughout geological time with thick sediment packages, gas is thermogenic, then the potential for deeper thermogenic oil the event, and these are also investigated. which have been mainly sourced from the Eastern Cordillera as it could be lower or even excluded. However, if the gas is biogenic, was uplifted and deposited within non-marine to shallow marine an opportunity could exist for deeper thermogenic systems which Conclusions environments. Furthermore, rapid sedimentation rates since the could include oil. It is now known that the gas is predominantly of The petroleum systems modeling study proved to be an extremely Pliocene, coupled with the presence of multiple organic-rich beds biogenic origin in Tamar, Leviathan and Aphrodite, with possible useful exercise to create awareness of which factors in the of Cretaceous and Paleogene age have complemented suitable minor thermogenic contributions. As a result, exploration for Figure 1. Regional type section in the Levantine Basin with a) original geological history of the basin play a controlling role in the evolution conditions for hydrocarbon generation from areas where such deeper thermogenic systems and especially for oil is now planned uninterpreted seismic data, b) interpreted seismic used for this study with of the proven biogenic gas fields and the potential thermogenic oil source facies have achieved adequate thermal maturity. in the Levantine. This shows the importance of understanding the well control from Eratosthenes seamount and Levant margin, and c) 2D and gas prospects. Inspite of the limitations of the publicly available processes which resulted in the formation of the newly discovered seismic based petroleum systems model used for the study with lithology data, the model already enables the interrelated processes, On this basis, the present work aimed at establishing the spatio- gas fields. overlay. Section length is 240 km. constraints and risks to be assessed. Companies which are directly temporal distribution of source rock properties such as: organic involved in exploration in the area, and have access to additional matter content, hydrocarbon-generating potential, thermal maturity Gas fields of biogenic origin have been producing from depths of data which can be used to improve the calibration of the model, and stratigraphic thicknesses, for Cretaceous and Paleogene up to 4500m for more than 30 years in Northern Italy, and many will be able to further reduce the uncertainties and considerably potential source-rocks which may have reached the hydrocarbon commercially important deeper biogenic gas discoveries have been improve the predictive capabilities of the modeling and increase window during the last 5 ma. The outcomes of a comprehensive added in the last few years, in many cases opening completely new their understanding of the potential risks. organic geochemical characterization enhanced with field plays. However, biogenic gas discoveries at very shallow depths observations, well sample descriptions and biostratigraphic control have also been made, such as the Peon field in Norway (at 160m were integrated and then utilized to conduct a multi-1D petroleum below the sediment surface!), and these show that the timing and system modeling which allowed us to assess the timing of

152 153 generation, expulsion, migration and entrapment of hydrocarbons simulation of the petroleum system in the southern foredeep of been provided regarding an enhanced petroleum potential of the SOURCE ROCK within the reservoir rocks. A plausible scenario of the volumetrics the Llanos was conducted using the PetroMod® software, which Cretaceous source formations compared to those of younger ages, and petroleum charge has been estimated in order to build an allowed illustrating the hydrocarbon potential on the bases of the this geochemical characterization demands further investigation, CHARACTERIZATION AND integrated approach with direct application on industry exploration information gathered and the definition of thermal models. focusing on the Carbonera and Los Cuervos formations. The operations in the study area. preexisting information for these two formations is still limited and ORGANIC PETROGRAPHY Results and discussion critical characteristics to better understand their real petroleum Methods and Materials The present integrated approach reveals that, for both the potential such as kinetics parameters and oil – source-rock Total organic carbon analysis (TOC) was the first step in order to Cretaceous and Paleogene deposits, the key geochemical correlations need to be addressed in detail. SR01 assess the source-rock generative potential of the various potential properties required to develop hydrocarbon source kitchens source formations (i.e. Une, Chipaque, Los Cuervos, Carbonera converge in specific locations. Lateral variations in both lithofacies Acknowledgements Biological marker analysis of coal and Mirador). A total of 1250 well-cutting samples were analyzed in and organic facies are the main conditions controlling the The authors thank the Vice- Presidency of Exploration, Ecopetrol a LECO C-230 carbon determinator. The majority of these samples behavior of the petroleum potential in the sediments investigated. S.A. (VEX) and the Colombian Petroleum Institute for the technical, samples from Chico Lomã, Brazil are from black-to-medium-grey mudstone beds in the selected With respect to the Paleogene source beds, the member of the administrative and financial support to conduct the present study. wells (Fig.1). Of the analyzed samples, 400 samples were discarded Carbonera Formation that has been addressed in this work, Janaina B. da Costaa*, Maria do Carmo R. Peralbaa, Tânia M. for subsequent evaluation due to their negligible TOC values (i.e. exhibits a variable potential which ranges from fair to good (%TOC References Pizzolatoa¬, Wolfgang Kalkreuthb lower than 0.5%) and therefore poor petroleum potential. Rock- ranging from 0.5 to 2.5 and HI from 17 to 341mg HC/g TOC), Hoffman P. (1987). Early Proterozoic Foredeeps, Foredeep Eval pyrolysis analyses were carried out on 850 samples by utilizing with the most promising features for oil generation in the central Magmatism and Superior-Type Iron-Formations of the Canadian a Universidade Federal do Rio Grande do Sul, Instituto de Química, a Rock-Eval 6 Turbo apparatus. In each case, a 60mg-aliquot of and north (nearby transect 4 in Figure1) parts of the study area. Shield. American Geophysical Union. 91501-970, Porto Alegre, RS, Brazil powdered sample was initially heated at 300ºC for 3 minutes under Middle Eocene to Lower Eocene sediments corresponding to the b Universidade Federal do Rio Grande do Sul, Instituto de N2 atmosphere. Adsorbed and thermogenic hydrocarbons evolved top of Mirador Formation show mainly gas prone facies (average DeCelles P., and Giles K. (1996). Foreland Basin Systems. Basin Geociências, 91501-970, Porto Alegre, RS, Brazil from kerogen were recorded as the S1 and S2 peaks respectively HI of 250) with a relative improvement in oil potential in the centre Research., Vol8, Issue2, P. 105-123. DOI: 10.1046/j.1365- and the temperature of maximum yield during the production of of the basin, the area between transects 4 and 1. Good properties 2117.1996.01491.x. *[email protected] S2 defined the Tmax parameter. S1 and S2 are expressed as mg appear to be maintained further to the north of the study area. HC/g rock, while Tmax is expressed in oC. The S3 peak is defined The Los Cuervos Formation (Paleocene) has its best features for Copyright 2014, ALAGO. by the oxygen produced during the kerogen cracking phase (CO2), hydrocarbon generation toward the north (HI values between 50 This paper was selected for presentation by an ALAGO Scientific Committee following which is measured in an infrared cell and then reported as (mg and 598). Therefore, the petroleum potential of this unit is restricted review of information contained in an abstract submitted by the author(s). CO2/g TOC). HI (S2 x100/TOC) and OI (S3 x100/TOC) represent to the surrounding areas of transect 4. Regarding the Cretaceous the amounts of hydrogen and oxygen in the kerogen respectively units, The Chipaque and Une Formations (Turonian to Santonian Introduction and were useful to classify the various kerogen types. and Aptian to Cenomanian respectively) display potential Coal is and will continue to be one of the world main energy sources. This statement is justified not only by more than a thousand year Vitrinite reflectance profiles and corresponding visual kerogen for both liquid and gaseous hydrocarbons throughout the entire history of coal use but also by the scarcity of environmentally analyses carried out for 13 wells were microscopically determined area (HI values ranging from 50 to 551, and from 45 to 260 friendly natural energy sources. utilizing a Leitz MPV SP system by means of 546nm reflected respectively) especially by the locations neighboring transect 4 and light in both white and fluorescent light modes using oil immersion the region between transects 1 and 2. Biomarkers are molecular compounds which can be extracted objectives. from crude oils, coals, and other of sedimentary rocks. They can The 1-D modelling study was useful to depict the maturity history be detected by gas chromatography and mass spectrometry of the depozone, the gas and oil generation temperatures and the techniques in the hydrocarbon fractions obtained from extracts of burial history. From such outcomes we obtained the timing for recent and ancient sediments. These biomarkers allow recognizing generation as well as the depth at which the various source facies the main input of organic matter, estimating the paleodepositional entered the hydrocarbon window. Finally, the vitrinite reflectance environment on which they were deposited determining the thermal model was superimposed onto the burial history to describe the maturity of the sedimentary rocks. thermal maturation path of the evaluated source-rocks. Experimental Distributions of TOC (%), HI (mg Hc/g TOC) and thickness (ft) for both Cretaceous and Paleogene source rocks varies from poor to Four coal samples collected from borehole excellent, with the lowest concentrations attributed to significant CBM 001-CL-RS located in Chico Lomã, in the northeastern siliciclastic dilution taking place mostly toward the south, whereas, state of Rio Grande do Sul, Brazil, were characterized by organic these properties along with thermal maturity levels for hydrocarbon geochemical methods. The coal samples were crushed (< generation indicated by Rock Eval Tmax (°C) and vitrinite reflectance 0.25 mm) and extracted with CH2Cl2 (93:7 v/v) using a Soxtec (%) suggest the occurrence of local generation pods in the central system. Medium pressure liquid chromatography (MPLC) of the and north portions of the study area. maltene fraction enable isolation of saturate, aromatic and polar compounds. The saturated hydrocarbons from all 4 samples were Conclusions analyzed by gas chromatography-mass spectrometry (GC-MS- Figure1. Location map of wells selected for sampling in the study area. In the light of the new geochemical results, we have found that MS). Instrument: Agilent 6890 N gas chromatograph connected the hydrocarbon generating potential of the various organic- to a Waters Quattro Micro GC tandem quadrupole mass The new data set has been processed and incorporated into rich beds from different Cretaceous and Paleogene time-spans spectrometer. GC-column: Agilent HP-5, 30 m x 0.25 mm i.d., a multidisciplinary framework (stratigraphy, sedimentology, reveal a generalized increase to the northwest and a rapid film thickness 0.10 µm. Injection temperature: 70°C (2 min hold.) biostratigraphy, and geochemistry) to enable mapping of the depletion toward the east, where dilution of the organic material Temperature programme: 30°C/min from 70 to 100°C and 40°C/ distribution of the various source-rocks properties in geological and by siliciclastic sediments played a major role in the preservation of min from 100 to 308°C (held 8 min). Method used: Selected Ion geographic terms within the study area. The multi 1-dimensional the source-rock properties laterally. Although, solid evidence has Monitoring (SIM):m/z71.10 and 191.18 (n-alkanes and hopanes).

154 155 Results and Discussion also present, and the value of the Ts/(Ts + Tm) ratio ranges between SR02 The m/z 71 fragmentogram in the 12-045 sample coal from Chico 0.03 and 0.42. All ratios obtained for hopanes, are consistent with Lomã revealed that saturated hydrocarbons in the coal extracts are mature organic material. Biogeochemistry features of sediments dominated by a series of n-alkanes ranging from C14 to C30with a unimodal profile. Gas chromatographic analyses of saturated from Cabo Frio upwelling system hydrocarbons for the others samples show a similar n-alkane Mendonça Filho, J.G.a, Carvalhal-Gomes, S.B.V.a, Silva, F.S.a, distribution in all coal samples (Figure 1). Fontana, L.F.a, Innecco, B.R.a,Crapez, M.A.C.b, Laut, V.M.a, Capilla, R.c

a Universidade Federal do Rio de Janeiro, Laboratório de Palinofácies e Fácies Orgânica, IGEO, Ilha do Fundão, 21941-909, Rio de Janeiro, RJ, Brazil. b Universidade Federal Fluminense, Laboratório de Microbiologia Marinha, Departamento de Biologia Marinha, Cx Postal: 100.644,

24.001-970, Niterói, RJ, Brazil. Figure 1.Map of the study area showing the box core and Kullenbergs core c GEO/CENPES/PETROBRAS Figure 2.Mass fragmentogramof m/z191 (hopanes) from sample 12-023. sampling sites.

[email protected] Conclusions Results and Discussion Figure 1.Representative gas chromatogram of saturated fractions from The results of organic geochemical investigationsuggest that the Box Cores samples showed contents of TOC ranging from 0.63 to Copyright 2014, ALAGO. sample 12-045. coals from Chico Lomã were formed in a sub-oxic deposition 1.47wt% and sulfur (S) from 0.06 to 0.40%, and TOC:S ratio varied This paper was selected for presentation by an ALAGO Scientific Committee following environment. from 4.6 to 12.12. The Bacterial respiratory activity predominantly review of information contained in an abstract submitted by the author(s). The carbon preference index (CPI) of n-alkanes in all samples Biomarker data from saturated fraction indicate that these coals detected was aerobic, fermentation and denitrification. TOC:S is ~1 (Table 1), indicating high rank of the coals. The pristane/ present characteristics of thermal maturity. The equilibrium value ratio associated with the bacterial metabolism showed a clear Introduction phytane ratio is a commonly applied geochemical parameter used of the C32 22S/22S + 22R homohopane epimerization is inside preference of aerobic metabolism, which can classify the Coastal upwelling is a phenomenon characterized by uplift of for assessment of depositional environment oxicity. It is based 0.57–0.62. The profile of hopanes showed the absence of ββ- environment as sub-oxic to oxic. The quantification of biopolymers cold deep nutrient-rich waters into the ocean euphotic surface upon a different type of reaction during phytoldefunctionalisation, hopane and the dominance of 17α(H),21β(H)-hopanes with the established averages of carbohydrates of 27.9 (± 8.86) mg.g-1, layer in response of winds forces creating favorable conditions depending on the amount of oxygen available in the depositional 22S epimer superior to 22R epimer; proteins 9.9 (± 2.24) mg.g-1, and finally the lipid with an average for high primary productivity. The most important upwelling zones environment. In the studied coals, the Pr/Ph ratio varies between of 21.77 (± 3.61) mg.g-1 and showed the following relationship: are located off the west coast of South America, Africa and North 2.72 and 8.30 (Table 1).Therefore, this parameter suggests suboxic carbohydrate>lipid>protein. This relationship is considered normal America. In Brazil, the coastal region of Cabo Frio is characterized conditions for all studied samples. Acknowledgements for marine environment. The biopolymers also showed different by the occurrence of unusual eastern upwelling system. The Cabo distribution at the Cabo Frio shelf. High values of proteins and Frio Upwelling System (CFUS) is located in an area where there is a Table 1- Geochemical parameters for Chico Lomã coals. The authors acknowledge the financial support of ConselhoNacional lipids were found on the nearshore samples and on the middle conspicuous change in the shoreline orientation, a predominance de DesenvolvimentoCientífico e Tecnológico (CNPq). Dr Hans part of the shelf. On the other hand, high values of carbohydrates of northeastern trade winds, mainly during austral summer–spring, P. Nytoft and Dr Jorgen A. Bojesen-Koefoed from Geologycal were found predominantly on the offshore samples. The electron and synergetic oceanographic mechanisms favors the upflit of Survey of Denmark and Greenland (GEUS) are deeply thanked for transport system (ASTE) showed high concentrations and was South Atlantic Central Water (SACW) resulting in different upwelling providing the facilities for the GC-MS-MS analyses. detectable on all sampling station, while the esterase enzymes areas on the shelf (Belem et al., 2013).The production of organic (EST) presented high values only offshore. Thebacterialpopulation matter in these systems is directly influenced by upwelling favoring References density observedwas high, but no majorchangesin their biomass the production and accumulation of organic-rich sediments. Bielowicz, B., 2012. A new technological classification of low-rank coal on (≈108-1010cells.g-1). The main goal of this study is characterize the biochemistry and the basis of Polish deposits. Fuel, 96, 497–510. geochemistry of organic matter associated with bacterial activity in The samples of Kullenberg cores showed high mean values of TOC sediments cores (Box-cores and Kullenbergs cores). Fabianska, M.J., Cmiel, S.R., Misz-Kennan, M., 2013. Biomarkers and and S at the CF10-04C and CF10-09C (middle part of shelf). In aromatic hydrocarbons in bituminous coals of Upper Silesian Coal Basin: contrast, low values were found at the CF10-01C and CF10-15C Experimental Example from 405 coal seam of the Zaleskie Beds (Poland). International cores. The amount of biopolymers showed a peculiar distribution Twelve Box Core (BC) samples and four Kullenbergs cores (CF10- Journal of Coal Geology, 107, 96-111. at the shelf with major values of carbohydrates for CF10-01C 01C, CF10-04C, CF10-09C and CF10-15C) (Figure 1) were taken core, lipids for CF10-15C and proteins for CF10-04C and CF10- from continental Cabo Frio. shelf. Total Organic Carbon (TOC) Killops, S.D., Killops, V.J., 2005.Introduction to Organic Geochemistry, 09C cores (Table 1). The relationship between biopolymers can and Sulfur (S) content analyses were performed on a LECO SC second ed. Blackwell Publishing, Oxford, UK. 393pp. be expressed by carbohydrate>lipid>protein for CF10-01C and 144 device. The adopted methods were ASTM D 4239 (ASTM, The coals from Chico Lomã are characterized by the occurrence of CF10-15C cores and protein>carbohydrate>lipid for CF10-04C 2008). Protein analyses were carried out according to Hartree 17α(H),21β(H)-hopanes (22S and 22R epimers) from C27 to C35. Romero-Sarmiento, M-F., Riboulleau, A., Vercoli, M., Laggoun-Defarge, and CF10-09C cores. The formation of particulate organic carbon (1972) a Rice (1982). Carbohydrates content were obtained One representative example of the m/z 191 mass fragmentogramof F., Versteegh, G.J.M., 2011. Aliphatic and aromatic biomarkers from as a result of primary production plays a vital role in organic carbon according to Gerchacov and Hatcher (1972). Lipids were analyzed the analyzed samples is show in Figure 2. The hopane parameters Carboniferous coal deposits at Dunbar (East Lothian, Scotland): accumulation at different rates in specific deposits along continental according to Marsh and Wenstein (1966). Esterase enzyme for all analyzed samples are listed in Table 1. Palaeobotanical and palaeoenvironmental significance. Palaeogeography, shelves (Sanders et al., 2014).The pattern of distribution of activity was performed according to Stubberfield and Shaw Palaeoclimatogogy, Palaeoecology, 309, 309-326. biopolymers indicates different origins of organic matter on CFUS. (1990). Determination of the electron transport system was made The dominant hopane in all samples is C3017α(H),21β(H)- according to Trevors (1984) and Houri-Davignon (1989). Bacterial hopane. The extended hopanes decrease uniformly from 31 αβ respiratory activity was analyzed using methodology described by to 35 αβ and the 22S/[22S+22R] ratio for all samples were 0.58, Alef and Nannipieri (1995).Bacterial count was obtained according a value situaded within the equilibrium range (0.57 to 0.62). The to Kepner &Pratt (1994). C2717α(H)-trisnorhopane (Tm) and 18α(H)-trisnorhopane (Ts) are

156 157 Marsh, J.B. & Wenstein D.B. 1966. A simple charring method for SR03 determination of lipids. Journal of Lipid Research, 7:574–576. Rice D.L. 1982. The detritus nitrogen problem: new observations and Alkane Biomarker Stratigraphy perspectives from organic geochemistry. Marine Ecology Progress Series 9: 153–162. of Irati Formation in the southern portion of Paraná Basin Sanders C.J.; Caldeira, P.P.; Smoak, J.M.; Ketterer, M.E.; Belem, A.; . Table 1: Average values of geochemical and biochemical analyses on the Mendoza, U.M.N.; Cordeiro, L.G.M.S., Silva-Filho E.V., Patchineelam, S.R., Darlly E. S. dos Reis¹*, René Rodrigues¹. cores of CFUS. Albuquerque, A.L.S. 2014. Recent organic carbon accumulation (100years) along the Cabo Frio, Brazil upwelling region. Continental Shelf Research a Universidade do Estado do Rio de Janeiro, Faculdade de Geologia, Conclusions 75(2014)68–75. Rio de Janeiro. Departamento de Estratigrafia e Paleontologia- Figure 1 - Chemostratigraphic units from Irati Formation (Units A to I). Based on these results, TOC and S values determined on CFUS Instituto Nacional de Óleo e Gás (INOG) ANP/UERJ/PRH 17 samples are low when compared with other upwelling systems, Stubberfield, L.C.F. & Shaw, P.J.A. 1990. A comparison of tetrazolium The siliciclastic Taquaral Member (Units A, B and C) is characterized but it is in agreement with previous studies developed at the reduction and FDA hydrolysis with other measures of microbial activity. J of * [email protected] by the predominance of normal alkanes in the GC trace, while the same area. The presence of aerobic metabolism at the Box Cores Microbiology Methods, 12:151-162. limestones interbedded with shales, marls and two bituminous samples may be related to availability of O2 brought by upwelling. Copyright 2014, ALAGO. shales of Assistência Member (Units D and E) record the dominance It was also found that the bacteria present in sediments in the Trevors, J. 1984. Effect of substrate concentration, inorganic nitrogen, O2 This paper was selected for presentation by an ALAGO Scientific Committee following of iso alkanes, with the exception of its siliciclastic low TOC unit F, region are metabolically active in the environment, with low energy concentration, temperature and pH on dehydrogenase activity in soil. Water review of information contained in an abstract submitted by the author(s). where a higher proportion of normal alkanes was observed over iso expenditure breakdown of organic matter (OM), showing that OM alkanes (Figure 2). is in abundance and ideal size for consumption (<600Da). The Introduction peculiar distribution of TOC, S, biopolymers and relationships The black bituminous shale of Irati Formation is considered to be among the biopolymers can indicate both different depositional the source rock of almost all oil shows of Paraná Basin. For this systems and organic matter sources. reason, it has been studied in different geochemical aspects, but still remains as a gap in the organic geochemistry data of the southern Acknowledgements portion of the Paraná Basin. The new data presented here provides The authors are grateful to CNPq (National Council for Scientific elements which may help understand the organic geochemical and Technological Development) and ANP (National Agency variations due to a change in depositional environment conditions of Petroleum Natural Gas and Biofuels) for scholarships; and to during Early Permian time in the whole Paraná Basin. PETROBRAS-Brazil for the financial support through the project entitled “Produtividade na ressurgência costeira de Cabo Frio e The Irati Formation encompasses two Members: the shaly Lower seu potencial de acúmulo de matéria orgânica: Interação Biosfera – Taquaral Member deposited in a normal marine environmentand Geosfera”. the Upper Assistência Member deposited in a more restricted depositional environment, characterized by limestones interbedded References with shales and marls, and two bituminous shale intervals. Alef, K.; Nannipieri, P. Enrichment, isolation and counting of soil microorganisms. In: Methods in: applied soil microbiology and biochemistry Experimental Figure 2 – Mass-Chromatogram m/z 85, C, D, E and F chemostratigraphic Units. Academic Press,123-186. 1995. The Bulk geochemical analyses were carried out in 169 samplesof an approximately 50m thick Irati Formation derived from the well The high proportion of high molecular weight n-alkanes, C27(Tm) American Society for Testing and Materials (ASTM), 2008. Standard test SC-20-RS drilled by CPRM in the less well known southern portion terpane and moretanes, observed in units A, C and F point to methods for Sulfur in the analysis sample of coal and coke using high- of Paraná Basin. Based on the bulk geochemical data, 29 samples the dominance of terrestrial organic matter input (Figure 3) (Henz temperature tube furnace combustion methods ASTM D 4239. were chosen for organic extraction, liquid chromatography and (1986); Henz et al., (1989); Araújo (1990) and Rodrigues (1995)). biomarker analysis. Belem, A.L.,Castelao,R.M.,Albuquerque,A.L. 2013.Controls of subsurface temperature variability in a western boundary upwelling system.Geophysics All geochemical analyses were performed in the Chemical Research Letters 40,1362–1366. Stratigraphy and Organic Geochemistry Laboratory of the State University of Rio de Janeiro using the following equipment: LECO Gerchacov S.M. & Hatcher P.G. 1972. Improved technique for analysis of SC 444 for TOC and S analysis, Rock-Eval 6 for pyrolysis analysis carbohydrates in sediment. Limnology and Oceanography. 17: 938–943. and an Agilent system 6890 GC coupled to a 5977 Mass Detector and 7000 GC-MS triple quad for biomarker analysis. Hartree E.F. 1972. Determination of proteins: a modification of the Lowry method that gives a linear photometric response. Analles of Biochemistry. Results and discussion 48: 422–427. Based on TOC, sulfur and pyrolysis data it was possible to recognize nine chemostratigraphic units named from A to I. From these units, Houri-Davignon, C. & Relexans, J-C. 1989. Measurement of actual electron A to C belongs to the siliciclastic Lower Taquaral Member and D transport system (ETS). Activity in marine sediments by incubation with INT. to I are limestones, marls and interbedded shales from the Upper Environmental Technology Letters, 10:91-100. Assistência Member (Figure1). Kepner JR, R. & Pratt, J.R. 1994. Use of fluorchromes for direct enumeration of total bacteria in environmental samples: past and present. Microbiological Reviews, 58:603-615. Figure 3 – Mass-Chromatogram m/z 191.Moretanes= 17β, 29M, 30M, and 31M.

158 159 On the other hand, the higher TOC content and hydrogen index geoquímica dos carvões da jazida do FUERJ axinal, Município Arroio dos SR04 described considering the basin development main stages. Pre-rift values, and the corresponding decreasing of the above mentioned Ratos, Rio Grande do Sul. Geochimica Brasiliensis, 1(2): 161-175. deposits (Jurassic) of the onshore part of the Kwanza Basin contain biomarkers in Unit B, record a maximum flooding interval, indicating Overview on Kwanza Basin a terrigenous detrital sequence (basal red beds/red basal series) a better organic matter preservation and dominance of marine REIS, D.E.S. 2012. A Geoquímica Orgânica Aplicada à Formação Irati- which was deposited in continental-deltaic environments. Syn-rift organisms in the organic matter composition (Tissot & Welte, 1984). Bacia do Paraná, poço SC-20-RS, área de Pinheiro Machado – RS: Potential Source Rocks sequence (Neocomian to Barremian) of the onshore is represented Identificação Ambiental, Origem da Matéria Orgânica e Potencial Gerador. by lacustrine deposits and consists of tuffaceous rocks, shales, Cristina F. Rodriguesa,b, Júlia Carvalhob, Manuel J. Lemos de The Assistência Member was deposited in a more restricted Dissertação Mestrado. UERJ. organic-rich shales (Infra Cuvo and Maculungo formations), and c environment, where the interbedded limestones, marls and shale Sousaa, conglomerate, red sandstone and claystone, and interbedded intervals (units D and G) represent the maximum of salinity attained RODRIGUES, R. 1995. A GEOQUÍMICA ORGÂNICA NA BACIA DO volcanic ash of continental origin (Lower Cuvo Formation). The a Universidade Fernando Pessoa,4249-004 Porto, Portugal for the depositional environment as also shown by its higher relative PARNAÍBA. TESE DOUTORADO. URGS offshore is characterized of sandstone, siltstone, shale, organic-rich proportion of gammacerane (Figure 3). The oil shale unit E, which b Halliburton, Base Sonils, Luanda, Angola shale, and minor limestone.Basal post-rift deposits (Lower Aptian) c Academia das Ciências de Lisboa, Lisboa 1249-122, Portugal occurs just above the unit D, records a transgressive system tract TISSOT, B.P.; WELTE, D.H. Petroleum Formation and occurrence. Berlin e in the onshore consist of sandstone, dolomite and limestone with [email protected] with salinity decreasing towards the top section, as also shown by New York: Springer-Verlag, 1984. minor thin coals (Upper Cuvo Formation). The offshore includes decreasing gammacerane (Figure 4). sandstone, siltstone, shale, and minor limestone of fluvial and Copyright 2014, ALAGO. lacustrine origin. Syn-rift argillaceous sandstones of the Lower This paper was selected for presentation by an ALAGO Scientific Committee following Cuvo Formation are separated from the better-sorted sandstones * review of information contained in an abstract submitted by the author(s). of the Upper Cuvo Formation by a breakup unconformity.The Aptian to Albian evaporite units in the onshore basin were deposited as Introduction a succession of evaporite cycles beginning with the Massive Salt, Angola is currently developing oil and gas resource assessment and the offshore is represented by massive halite and interbedded studies on the Kwanza Basin, in order to increase oil production, anhydrite. eventually to reach the 2 million barrels/day, as well as, to build a medium-long term sustainable oil sector.

Only recently, Kwanza Basin has been submitted to more accurate petroleum system evaluations, since the well-known Congo Basin has reached a mature production stage. Until now, Kwanza Basin studies were mainly supported by seismic data and well reports produced during the sixties. Additionally, the main contribution in Figure 4 – Change gammacerane proportion from the base to the top of understanding the Kwanza Basin petroleum systems was provided oil shale interval. by geological analog studies with Congo Basin.

The low TOC siliciclastic Unit F presents similar GC trace and Geological Background biomarker distribution as the siliciclastic Taquaral Member (Units The Kwanza Basin, located in the central part of the Angolan A and C) coast, belongs to the West-Central Coastal Province Geology of the Sub-Saharan Africa region, and is about 300 km long (north- Conclusions south) and 170 km wide (east-west).Was formed during the Early Based on bulk geochemical parameters, mostly TOC, sulfur, Rock- Cretaceous opening of the south Atlantic Ocean, when the Congo– Eval pyrolysis and alkane biomarkers, it was possible to split the Sao Francisco craton was rifted along the grain of the Proterozoic Irati Formation into eight chemostratigraphic units, named from A west Congolian–Braziliano orogen. In the Gabon–Angola region, to C in the Taquaral Member and from D to I in the Assistência syn-rift strata were deposited in two margin-parallel troughs Member. Each of these units represents a distinct input of land separated by a chain of basement horsts.The Kwanza Basin, as derived organic matter type and/or a response of the organisms the others Angolan Coastal sedimentary basins, presents features living in the water system to a change in salinity and anoxia during typical of the Atlantic-type marginal sag basins filled with Meso- sedimentation. Cenozoic deposits. The formation of these basins began during the breakup of the Palaeozoic Gondwana supercontinent, in Acknowledgements Figure 1. Structural Provinces in the Kwanza Basin(Hudec and Jackson the Late Jurassic to Early Cretaceous. The geological history of The authors thank CNPq (Brazilian research council), FAPERJ (Rio 2002). Angolan coastal sedimentary basins can be divided into three main de Janeiro Research Foundation), INOG (National Institute of Oil stages: Pre-rift stage (Late Proterozoic to Late Jurassic); Syn- and Gas Institute), ANP/ UERJ/PRH 17/. Two transitional carbonate-evaporite cycles (Quianga and rift stage (Late Jurassic to Early Cretaceous), and Post-rift stage Binga formations) overlaid the salt, followed by the Tuenza (Late Cretaceous to Holocene).The Kwanza Basin is separated References Formation, characterized by six depositional cycles. From Albian into inner (onshore) and outer (offshore) basins and these in ARAUJO, C.V. 1990. Estudo petrográfico e geoquímico de carvões da to Maastrichtian widespread organic-rich marine mudstones turn are split into small-basins by basement structural highs, jazida de Santa Terezinha, Rio Grande do Sul, Brasil. Tese de Mestrado, and marls (Quissonde to Teba formations) developed lateral to produced by the major transform faults (Figure 1). The onshore Univ. Fed. Rio Grande do Sul (UFRGS), Porto Alegre, 285 p. and above the carbonate units (Catumbela/Tuenza formations). is an interior salt basin enclosed by the basement highs, and it is A regional erosional event that began during the early Senonian dominated by salt movements and fold belts, formed by basement HENZ, G.I. 1986. Organo-petrografia e organo-geoquímica dos carvões and continued into the Paleogene formed a general unconformity. shortening and uplift. The offshore is an open continental margin da jazida do Faxinal, Município de Arroio dos Ratos, Rio Grande do Sul, Cenozoic was dominated by progradational marine sedimentation. basin that deformed by gravity spreading, resulting in updip Brasil. Tese de Mestrado, Univ. Fed. Rio Grande do Sul (UFRGS), 243 p., The Paleocene and Eocene (Rio Dande to Cunga formations) are extension which is compensated by downdip shortening.The Porto Alegre. represented by regressive sandstones and siltstones, turbidites, independent development of both basins resulted in the deposition and deep-marine shale units. The post-Miocene deposits consist HENZ, G.I.; RODRIGUES, R. & FORMOSO, M.L.L. 1987. Organo- of stratigraphically different but time-equivalent units, usually

160 161 of poorly sorted marine rocks with localized channel-fill sandstones SR05 Figure 1 – Location of the Jaibaras Graben (Modified from Oliveira & Gammacerane is present, which is an indicator of the depositional and turbidites. Mohriak, 2003) paleo-environment salinity. The S/R ratio Homohopanes (C31 to C35) shows a good level organic matter thermal maturity. The Investigating a Cambrian-Ordovician Overview on Kwanza Basin Source rocks Experimental relative abundance of the Tricyclic Terpanes over Pentacyclics The Kwanza Basin is known by the occurrence of multiple and source rock in the Parnaíba Basin, Brazil Six collected outcrop samples from Pacujá Formation were all Terpanes characterizes algalic organic matter from Cambrian- hybrid petroleum systems based on at least six source formations crushed and pulverized. To geochemistry analysis, they were Ordovician 5. In the mineralogical analysis was identified the (Infra-Cuvo, Upper Cuvo, Binga, Teba, Cunga and Quifangindo) Helio J. P. Severiano Ribeiroª*, Eliane S. de Souzaª, Victor H. submitted to extraction with a dichloromethane solvent using the garronite, a mineral of the zeolite group, which suggest a very low Santosª, Laércio L. Martinsª of Neocomian to Eocene age. Other formations (Rio Dande, Soxhlet system. Then, the extracts from the rock samples were grade of metamorphism. Cabo Ledo and Quissonde) are also good to very good potential fractioned into saturates, aromatics, and polar compounds by a Laboratory of Engineering and Petroleum Exploration, Darcy sources but are not deep enough to have been submitted to successive elution with hexane, hexane/dichloromethane (8:2, v/v), Conclusions Ribeiro North Fluminense State University – LENEP/UENF, POB and dichloromethane/Methanol (9:1, v/v) on silica gel columns, The samples of the Pacujá Formation collected around Santana sufficient maturation. The Kwanza Basin is characterized by three 119562, 27910-970 Macaé, RJ, Brazil; Petroleum Systems: Pre-salt Petroleum System, Post-salt Binga respectively. The saturate hydrocarbon fraction was analyzed by do Acaraú City are in a senile stage of maturity, because of the Petroleum System and Post-salt Tertiary Petroleum System.The *[email protected] Gas Chromatography/Mass Spectrometry (GC/MS). TOC analyses very low grade of metamorphism caused by coeval igneous Pre-salt Petroleum System is represented by two sub-systems: were made in the Geochemistry Lab of the Stratigraphy and rocks intrusions. But the good quality of the bitumen extract can the pre-salt/pre-salt and the pre-salt/post-salt sub-systems. The Copyright 2014, ALAGO. Paleontology Department of UERJ. Equipment: LECO SC – 444 put some good expectative about the possibility to have a good first sub-system comprises pre-salt source rocks (Infra-Cuvo and This paper was selected for presentation by an ALAGO Scientific Committee following Carbon Sulphur Analyzer. generation potential inside the grabens subjacent to the Silurian- Cuvo formations) and oil/gas accumulations exist within pre-salt review of information contained in an abstract submitted by the author(s). Devonian sedimentary package of the Parnaíba Basin. reservoirs (sandstones from Cuvo Formation). The second sub- For mineralogical analysis, the pulverized rock was reduced to Acknowledgements system is defined by pre-salt source rocks (Infra-Cuvo and Cuvo Introduction 0,53 mm (280 Tyler series). Then, was made a tablet with 2,5g of The hydrocarbon generation in the Parnaíba Basin, located at the formations) and post-salt reservoirs (Upper Cretaceous and Tertiary the sample and analyzed in a equipment D2 Phaser (Bruker) with The authors thank FAPERJ (Rio de Janeiro State Research northeastern of Brazil, is well known as an atypical petroleum system, sequences). The Post-salt Binga Petroleum System is represented configuration 2Theta (Couple Two Theta/Theta) WI=1,54060. Supporting Foundation) for financial support (APQ-1, Proc. nº which consists in the intrusion of basic igneous rocks inside the by Binga source rocks (Aptian and Albian) and several Cretaceous Results and Discussion E-26/111.897/2012). rich organic matter shale of the Pimenteiras Formation (Devonian), reservoirs (Binga, Tuenza and Catumbela formations). The Post-salt as like others Paleozoic sedimentary basins in Brazil, such as Tertiary Petroleum System comprises Tertiary source rocks (Cunga Amazonas, Solimões and Paraná basins. In the Parnaíba Basin it is The TOC values were very low, reaching the maximum value at References and Quifangondo formations) and Tertiary reservoirs (Quifangondo so long recognized 1 the presence of the pre-Silurian sedimentary 0,23%. This low value is attributed to the heat from basic igneous 1Góes, A.M.O., Souza, J.M.P. & Teixeira, L.B. 1990. Estágio exploratório e and Luanda sandstones). packages, which are inside in several graben structures aligned intrusive rocks of the Parapuí Suite inside Pacujá Formation or perspectivas petrolíferas da Bacia do Parnaíba. Boletim de Geociências da with the Transbrasilano Lineament (northeastern-southwestern). from de Meruoca granite. In the GC/MS analysis were identified Petrobras, Rio de Janeiro, 4(1): 55-64 Conclusions Those pre-Silurian sediments were already described and cored n-Alkanes (C17 to C33), revealing there was a thermal maturation The Kwanza Basin was not one of the main targets in the last in several oil wells drilled by PETROBRAS in Parnaíba Basin, they for liquid hydrocarbon generation and suggesting a good quality 2 Oliveira, D.C. & Mohriak, W.U. 2003. Jaibaras Trough: na importante decades; therefore, the first studies were developed by comparing were named as Riachão Formation (Cambrian to Ordovician) organic matter (Figure 2). element in the early tectonic evolution of the Parnaíba interior sag basin, geochemically West African and Brazilian pre-salt and post-salt and Mirador Formation (Late Proterozoic). In the basement at Northern Brazil. Marine and Petroleum Geology, 20, 351-383. deposits. This geochemical comparison has been pointed out northeastern portion of the Parnaíba Basin outcrops several Early Paleozoic grabens structures, being the most expressive the as an excellent way to identify the different petroleum systems 3Galvão, C.C. 2002. Mapeamento Geológico Estrutural da Região Jaibaras Graben. As like as the grabens under the Parnaíba Basin, in the Kwanza Basin, due to stratigraphic and depositional Nordeste de Santana do Acaraú-CE, com Ênfase na Deformação Frágil. those outcropping grabens are either aligned with Transbrasilano similarities between Campos and Kwanza basins. However, this Undergraduate Final Repport, UFRN, 60p. Lineament (Figure 1). is particularly true for pre-salt source rocks deposited during the Early Cretaceous (Neocomian/Barremian), a period of time when Those grabens are interpreted as an Early Paleozoic rift stage2, 4 Torquato, J.R. & Nogueira Neto, J.A. 1996. Historia-grafia da região de the South American and African continents were close to each preceding the intracratonic sedimentary depositional phase of the dobramentos do Médio Coreaú, Revista Brasileira de Geociências, 26, other. Nevertheless, it is more difficult to establish a correlation Parnaíba Basin. In the Jaibaras Graben, the Cambrian-Ordovician 303-314. between post-salt source rocks deposited after the two continents sedimentary package is named as Jaibaras Group, subdivided drifted apart, when the depositional regimes of both continental in three formations: Massapê, Pacujá and Aprazível. There are 5 Peters, K., Walters, C. & Maldowan, M. 2007. The Biomarker Guide: coasts were submitted to a higher degree of organic diversity and several citations in the bibliography about the occurrence of dark Biomarker and Isotopes in the Petroleum Exploration and Earth History. to different geodynamic regimes. In this context, it was already shale in the Pacujá Formation 3 4. In such way, in this research 2nd ed. Cambridge University Press, vol 2, 1155 p. defined six source rocks from Infra-Cuvo, Upper Cuvo, Binga, were collected some sample of the dark shale of Pacujá Formation Teba, Cunga and Quifangondo formations, which are organized near Santana do Acaraú City (northwestern of the Ceará State), to evaluate its generation potential. These samples were submitted to in three different petroleum systems: Pre-salt Petroleum System organic geochemistry and mineralogical analyzes. (pre-salt/pre-salt sub-system and pre-salt/post-salt sub-system), Post-salt Binga Petroleum System and Post-salt Tertiary Petroleum

System.

Acknowledgements We gratefully acknowledge the support of various people from Halliburton for their contribution to this paper.

References Hudec, M. R.; Jackson. M. P. A., 2002. Regional restoration acrossthe Kwanza Basin, Angola:Salt tectonics triggeredby repeated uplift of ametastable passive margin. AAPG Bulletin, v. 8, no. 7, 971-990. Figure 2 - Mass chromatograms (m/z 85 and 191) of saturated hydrocarbons in a outcrop sample from Pacujá Formation. nC17 to nC33 =n-Alkanes; Tri23 = C23 Tricyclic terpanes; C31-C35 = Homohopanes; G = Gammacerane.

162 163 SR06 The TOC varied from 0.19 to 5.53% IH ranged from 278 to very SR07 low values of 16 mg HC / g TOC, while the S2 peak ranged from The immature facies of Pimenteiras 0.18 to 7.74 mg HC / g rock. The maximum temperature reached Organic geochemical by Organic Matter (Tmax) was the maximum values of 433 °C, Formation (Devonian) of the Parnaíba characterization of 30F-1X core samples which allows us to infer that all samples are below the hydrocarbon basin, state of Tocantins, Brazil: generation window are therefore immature. from Maracaibo Basin, Venezuela. palynofacies and organic geochemistry. By evaluating the Van Krevlen diagram expressing the function Carlos Ramírez y Patricia Lugo* Consuelo. L. N de Andrade¹*; Tereza R. M. Cardoso²; Altair J. in the IO IH (Figure 1) can be classified in general the kerogen Machado¹; Karina S. Garcia¹. ofnsamples studied as primarily type II and III. Instituto de Ciencias de la Tierra. Facultad de Ciencias. Universidad Central de Venezuela ¹Universidade Federal da Bahia; ²Universidade do Estado do Rio In 90% of the of the samples the Amorphous Organic Matter de Janeiro (AOM) predominates getting to in some samples occupy above *[email protected] *[email protected] 90% of the total components. The palynomorphs are second in the overall percentage, among which there is a predominance of Copyright 2014, ALAGO. This paper was selected for presentation by an ALAGO Scientific Committee following Copyright 2014, ALAGO. group achritarcs. The phytoclasts smallest percentage are in most This paper was selected for presentation by an ALAGO Scientific Committee following samples. review of information contained in an abstract submitted by the author(s). Figure 2: Ternary diagram with the percentages of the basic components review of information contained in an abstract submitted by the author(s). of the organic matter in samples studied in Pimenteiras Formation, state of Figure 2 illustrates a ternary diagram containing the three basic Tocantins, Brazil. Introduction Introduction constituents of organic matter percentage in the samples. According The Parnaíba Basin is one of the largest Brazilian sedimentary There are several studies on source rock characteristics from to palynofacies defined by Tyson (1995), also for percentage basins, has over 600.000Km2, however is one of the least known The AOM presented florescence in almost all samples, being less Maracaibo Basin, Venezuela, which have helped in determining the values for the three principal groups of organic matter, most of intense in some (medium brown) and very intense in other (yellow- of the geological point of view. Parnaíba is characteristically petroleum system in this basin. However, a little information has the samples is situated in in palynofacies VII and VIII, indicating green). The Palynomorphs showed intense fluorescence almost Palaeozoic but also contains Mesozoic and Cenozoic deposits bit been obtained by analyzing core samples 30F-1X located in west that deposition environments distal platform anoxic disoxic and always varied from green to yellow. thick. of the basin. a distal platform disoxic-oxic, respectively. Only 4 samples would The Pimenterias Formation is the main generator of the basin, be classified as palinofácie V, corresponding to the platform oxic Conclusions In 1992, Gallango and Cassani studied extracts from the belongs to Devonian sequence (Group Canide) and is the largest environments, dominated by mud (distal platform) and 2 classified Considering the geochemical results can infer the presence of a Maracaibo’s Lake and only analyzed a sample of rock core 30F-1X. marine ingression known in the basin, as well as a significant as XIX (suboxic-anoxic distal basin). predominantly Kerogen Type II, III and type IV a few samples. As For this reason, a larger number of samples in this study represent fossiliferous content. Are found in Pimenteiras Formation excellent for the content of palynofacies can be said that overall the organic outcrops with radioactive shales rich in organic matter, including matter is well preserved; very rich, including the presence of many a contribution to the petroleum system of Maracaibo’s Lake basin. on the western edge of the Basin (state of Tocantins) which was organisms with well preserved structures, and fluorescence. The rarely studied so far. Thus, the present study aims to characterize intense fluorescence of algae and Tmax indicates immaturity of the Experimental palynofacies and dregree of thermal maturity of organic matter organic matter. Five samples of ALPUF 30F-1X core from west Maracaibo’s Lake found in outcrops on the west edge of Fm Pimenteiras, Parnaíba basin were used. Total carbon concentration (Ct) was determinate Acknowledgements Basin-TO. by LECO carbon analyzer C-144; carbonate-carbon (Cinorg) by The authors thank CAPES for the scholarship granted to the first Bernard calcimeter method and total organic carbon (TOC) by author; the UERJ, UENF, Universidad de Barcelona (Barcelona / Material and Methods difference. Another analysis includes Tmax values obtained from To achieve the proposed objective 30 samples were collected from Spain) Universities and the Instituto Nacional del Carbón (Oviedo / rock samples by Rock-Eval pyrolysis. outcrops of Fm Pimenteiras located in the state of Tocantins. For Spain) for their support and technical and scientific exchange. the analysis of the Palynofacies thin glass slides of the kerogen Bitumen was extracted from powdered rock by Soxhlet extraction were prepared, from the acid digestion of the inorganic fraction References with methylene chloride as solvent. Asphaltene was precipitated with 32% hydrochloric acid and 40% hydrofluoric acid. Tyson, R.V.,1995. Sedimentary Organic Matter. Londres: Chap. & Hall, 615 p. The slides were evaluated using optical microscopy with white light from bitumen by n-heptane addition. Then, the maltene fraction and UV light. In each sample was carried out a quantitative and was separated by adsorption chromatography on alumina column qualitative analysis of palynofacies components, by counting 300 as stationary phase, using hexane to separate the saturate fraction, particles and identification of individual componetes organic matter toluene to aromatic fraction and toluene/methanol in a relation (phytoclasts, palynomorphs and amorphous organic matter) and 70/30. their relative proportions. The fluorescence of the kerogen was used to characterize the level of preservation of the components. The biomarkers were determined for m/z 113 in the aliphatic The fluorescence of the kerogen was used to characterize the fraction and m/z 178 and 192 in the aromatic fraction, with a mass levels of preservation of amorphous organic components and selective detector (MS)-(GC/MS), Agilent technologies, models palynomorphs and to assist in interpreting the maturity of the 6890N (GC) coupled with 5975 mass spectrometer (MS). maturity of organic matter. Hydrogen indices (HI) and Oxygen (IO), the S2 and S3 peaks and Tmax were measured by Pyrolyzer Rock- Results and discussion Eval and total organic carbon (TOC) was determined by Elemental The ALPUF 30F-1X core samples contain organic carbon ranging Analyzer. from 4.2 to 8.9% and bitumen from 3196 to 15919 ppm. According Figure 1: Diagram of Van Krevelen for classifying the type of kerogen found to these values, core rocks are considered excellent hydrocarbon Results and Discussion in the samples studied in Pimenteiras Formation, state of Tocantins, Brazil. source rock (Hunt, 1995).

164 165 The Tmax values obtained from Rock-Eval pyrolysis range from Killops, S., Killops, V., 2005. Introduction to organic geochemistry. Blackwell SR08 made, and petrography evidence was found to correlate this type 431° to 438 °C indicate a mature stage. The ratio C29 (αββ /(ααα + Publishing. Second edition, p. 393. of organic matter. αββ)) range from 0.51 to 0.53 and C29 ααα (20S/(20S +20 R) range Organic facies distribution in the passive from 0.43 to 0.48. This suggests that the samples have reached Peters, K.E., Walters, C.C., Moldowan, J.M., 2005. The Biomarker Guide, Once organic facies maps were generated for each genetic margin of the Barinas Apure Basin: Coastal sequence of the passive margin; original HI from mature rocks maturity stages to liquid generation hydrocarbons. The maturity 2nd. ed. Cambridge University Press, Cambridge, UK limit movement application were determined by compositional model (Cooles et al., 1986) to parameter based on methyl phenanthrene index, MPI (Radke and improve HI contours in organic facies lateral distribution maps. Welte, 1983), yields calculated vitrinite reflectances (Rc %) ranging Radke, M., Welte, D.H., 1983. The methylphenanthrene index (MPI): a Landann C. Escorciaa, Linda Montillaa y Nubia Santiago from 0.7% to 0.8% corresponding to peak oil generation. maturity parameter based on aromatic hydrocarbons. In: Bjoroy, M. (Ed.), Finally, organic facies vertical distribution was studied to establish Advances in Organic Geochemistry 1981. Wiley, Chichester, pp. 504–512. a PDVSA Exploración, Puerto La Cruz, Anzoátegui, Venezuela an interaction within the coastal border movement. Marine The results of GC/FID show a unimodal distribution of lower and terrestrial organic facies limit could be different from the molecular mass n-alkanes which maximum in n-C16 and n-C18. *[email protected] transgression to the regression into the passive margin. Besides This distribution show n-alkanes characteristic distribution from that, coherence between this distribution and palobatymetric maps marine source (Killops and Killops, 2005, Peters et al., 2005), Copyright 2014, ALAGO. were studied. corresponding to sedimentary environment where the rock This paper was selected for presentati on by an ALAGO Sci entific Committee samples in this study was originated, La Luna Formation (González following review of information contained in an abstract submitted by the author(s). Results and Discussion et al., 1980; James, 2000). Three (3) organic facies were defined in Barinas-Apure Basin Introduction where distribution is related to orogen position and sediment Lateral and horizontal variations of a source rock in a petroleum direction during passive margin. Two organic facies present a The fragmentogram m/z=191 shows C in greater proportion 23-3 system can be established in a sedimentary basin by using organic high marine influence and are located in the northern part of the than C , with a C /(C +C ) ratio shows values from 24-4 23-3 24-4 23-3 facies analysis. Through this type of analysis, fluid-rock correlations basin, deposited under neritic conditions: ABMI with the highest 0.79 to 0.96 and C 22R/C greater than 0.25 for all samples. The 31 30 are more accurate. Furthermore, if the potential of the source rock HI, and ABMII with the lowest HI component. The other organic fragmentogram m/z=217 shows a distribution C27>C28>C29. This is is established, liquid and gas volumes of generation can be inferred. facies has a terrestrial predominance; it is located in the southern characteristic of marine derived organic matter (Peters et al., 2005). part and was deposited under transitional to continental paleo- Specifically, for the Barinas-Apure Basin, this study allows bathymetries: ABTI. Principal characteristics and areal distribution The cross plot of dibenzothiophene/ phenanthrene versus pristane/ understanding the distribution and variation of the source rock are described: phytane (P/F vs MDTF/MF) indicates that all samples are derived within the passive margin. Some inferences about the coastal line from marine environment with high sulfur concentration under movement were made; due to geochemical changes that occur ABTI: 254 mgTOC/grock is the typical hydrogen index of this reducing conditions (Hughes et al., 1995). in this transition, with a positive correlation with paleo-bathymetric organic facies. Petrographic studies, prove that it is composed maps. by amorphous (60 to 70%), herbaceous (5 to 10%), woody (10 Conclusion to 20%), and coally (5 to 10%), with a predominance of woody Experimental content and vitrinite. There are some samples of mycrite content in The 30F-1X core was sedimented under, reducing conditions with Organic facies (Haoet al., 1993) are determined by mapping initial terrestrial environment as an evidence of terrestrial organic input. marine organic matter input as main contribution and the organic potential of a possible source rock in a delimited stratigraphic TOC distribution goes from poor to medium with a same pattern matter is within the oil window. sequence. Tectonostratigraphic chart of Barinas Apure Basin made from HI distribution. by Santiago et al., 2014 were used to establish petroleum potential Acknowledgements in depositional units and stratigraphic sequences. From this first ABMI: in this organic facies, hydrogen index is 634 mgTOC/ The authors thank CDCH-UCV (Consejo de Desarrollo Científico y step, only two depositional units had some potential intervals of grock. Petrographic studies, it is composed by amorphous (70 to Humanístico de la Universidad Central de Venezuela) for financial support source rock: UDII and UDIII. UDII is a passive margin and UDIII is 90%), herbaceous (5 to 10%), woody (10 to 25%), and coally (5 (Proyect PI-03.00.5889-2008). the beginning of the active margin. However, this study will focus to 10%), with a high level of amorphous content, possibly related into the passive margin (UDII, Figure 1) to initial marine organic matter. Moreover, there are evidences of References dinoflagellates. This organic facies is located in the northern part Gallango, O y Cassini, F., 1992.Biological marker maturity parameters of of the basin. marine crude oils and rock extracts from the Maracaibo Basin, Venezuela. Organic Geochemistry 18, 215-224. ABMII: hidrogen index from this organic facies is 399 mgTOC/ grock. Petrographic analysis show: amorphous (60 to 90%), González De Juana, C., Piccard, X., Pimentel, N., 1980. Geología de herbaceous (5 to 30%), woody (10 to 30%), and coally (0 to 10%). Venezuela y de sus cuencas petrolíferas. Ediciones Foninves, p.1001. Besides that, there are evidences of dinoflagellates and amorphous Hughes, W.B., Holba, A.G., Dzou, L.I.P., 1995. The ratios of fluoresce as well; located restrictively into the basal sequences of the transgressive sequence in the south western. dibenzothiophene to phenanthrene and pristane to phytane as indicators Figure 1. Tectonostratigraphic chart of Barinas-Apure Basin(Santiago et al., of depositional environment and lithology of petroleum source rocks. 2014) Distributions of the organic facies developed during the passive Geochimica et Cosmochimica Acta 59, 3581–3598. margin are shown in Figure 2 (ABTI, ABMI y ABMII). The movement Lithostratigraphically the UDII is an Albian transgressive sequence of coastal line in the passive margin can be observed in Figure 2 Hunt, J.M., 1995. Petroleum Geochemistry and Geology, 2nd edition. W.H. of aggrading sandy facies; then, that turned progressively into a evolution of the distribution of the organic facies during passive Freeman, shaly facies until the maximum depth in Coniacian age at 88,8 m.a. margin phase. There is a progressive advance of the marine line San Francisco, p. 743. represented by MFS_4 surface (Figure 1). during transgression and an advance of terrestrial line during regression. More to the point that, ABMII organic facies is restricted James, K., 2000. The Venezuelan Hydrocarbon Habitat, Part 1: Tectonics, structure, Based on stratigraphic sequences for the passive margin described to basal sequences; its higher potential could be thought as paleo- palaeogeography and source rocks. Journal of Petroleum Geology 23, 5-53. before, initial Hydrogen index (HI) values were mapped for each depocenter from the rifting phase in the basin and/or as a result of M.F.S. in Figure 1. Then, relationships between the data were a climate control.

166 167 SR09

Aromatic Steroids Biomarker applied to high resolution Stratigraphy: Irati Formation, Southern of Paraná Basin, Brazil

Lina L. Osorio1/ Rene Rodrigues1*

1 Universidade do Estado do Rio De Janeiro, Departamento de Estratigrafia e Paleontologia, DEPA –UERJ, Rio de Janeiro, RJ – Brazil.

Figure 2. Organic facies distribution in genetic sequences from the passive *[email protected] margin of Barinas-Apure Basin. From SG V to basal deposits (Figure 1). Copyright 2014, ALAGO. Conclusions This paper was selected for presentation by the ALAGO Scientific Committee, Organic facies methodology used in the Apure Barinas Basin’s following review of information contained in an abstract submitted by the author(s). source rock intervals refined the potential of the basin to generate hydrocarbons. Moreover, the study of marine and terrestrial Introduction Figure 1.Variation in distribution of methylated triaromatic steroid organic facies interaction into small stratigraphic levels, allowed The use of aromatic steroids in geochemical studies is almost absent hydrocarbons, as displayed by the m/z 245 fragmetogram of selected the evaluations of eustatics controls related with coastal limit in Brazilian sedimentary basins. For this reason, it is intended to test samples from the well well SC-20-RS. TOC: Total organic carbon; IR: movement within the passive margin. the application of these compounds in high-resolution stratigraphy Insoluble Residue (%);Cn= methylated triaromatic steroid. in the relatively well known Lower Permian Irati Formation. The On the other hand, the methylated triaromatic steroids has shown References Irati Formation is around 40 meters thick, thermally immature, the best possibilities to be applied as a source parameter in the Cooles, G.P., Mackanzie, A.S., Quigley, T.M., 1986, Calculation of petroleum and comprise two lithological distinct Members: siliciclastic Irati Formation (Figure 1). The predominance of C29 homologous masses generated and expelled from source rocks, in: Leythaeuser, D., lowerTaquaral and calcareous member and the siliciclastic upper in the low TOC siliciclastic intervals C and F; increasing of C27 and Rullkötter, J. (eds.), Advances in Organic Geochemistry, 10, 235–245. Assistência Member. Based on whole rock data, mostly TOC, sulfur, C28 homologous in the interbeds of shales, marls and limestones Rock-Evalpyrolysis and alkanes biomarkers, was possible to split (interval D); and predominance of C28 homologous in the oil shale Hao F, Chen J, Sun Y. y Liu Y.,1993, Application of organic facies studies the Irati Formation in eight chemostratigraphic units, named from interval E. to sedimentary basin analysis: a case study from the Yitong Graben, China. A to C in the TaquaralMember and from D to I in the Assistência Organic Geochemistry20-1, Enero, 27-42. Member. Each one of these units represents a distinct input of land Distribution patterns of monoaromatic steroids derived organic matter type and/or a response of the organisms Variations in the relative amount of different homologous are Santiago, N., Bellizzi, L., Escorcia, L., Hernández,M.,Hernández, Z.,Lara, living in the water system to change in salinity and anoxia during another geochemical parameter difficult to be considered because J.,Marcano, J.,Moya, M.,Oliveros, R.,Oropeza, Y.,Parra, K., Peña, Y., Rivas, sedimentation. of the co-elution of the different isomers and homologues. Y., 2014, Proyecto Evaluación del Sistema Petrolífero Apure-Portuguesa. Up to now, the best source rock parameter correspond to the Informe interno PDVSA. Methods and samples higher amounts of rearranged structures in the low TOC siliciclastic A total of 29 rock samples previously analyzed for bulk geochemical intervals C and F, compared to the others intervals where practically parameters were selected from the well SC-20-RS drilled by no rearranged structures were observed. CPRM, located 6 Km southernfrom the Pinheiro Machado city, Rio Grande do Sul State, Brazil. Acknowledgements The authors thank CNPq (Brazilian research council)for The powdered rock samples were extracted using dichloromethane fellowships:INOG(National Oil and Gas Institute)and UERJ for and fractionated in alkanes and aromatic hydrocarbons. The financial support. biomarker analyses were performed using a GC-MS (Agilent Technologies 6890 GCcoupled to an Agilent 5977 Mass Detector) References and Mass SpectrometryAgilent 7000 GC-MS-MS System with a MACKENZIE A. S.; HOTFMANN C. F.; MAXWELL J. R. 1981. Molecular triple quadripole analyzersystem. parameters of maturation in the Toarcianshales, Paris Basin, France. III. Changes in aromatic steroid hydrocarbons. Geochim. Cosmochim. Acta Results and discussions 45, 1345-1355. Distribution patterns of triaromatic steroids REIS, D. E. S.; RODRIGUES, R., 2013. Geoquímica orgânica The fingerprint of the demethylatedtriaromatic steroids, best aplicada à Formação Irati - Bacia do Paraná, poço SC-20-RS, área de studied by the m/z 231 (Riolo et al., 1986), normally shows much pinheiro machado – RS. In: 7 CongressoPDpetro. Aracaju. Brasil. less variation than their methylated counterpart does. However, compositional variations could be observed in the oil shale interval, RIOLO, J.; HUSSLER, G.; ALBRECHT, P.; CONNAN, J.; 1986. Distribution in which occurs a net increasing of C26 e C27 homologous ofaromatic steroids in geochemical samples: Their evaluation as compared to the composition of others chemostratigraphic units. geochemicalparameters. Organic Geochemistry, v. 10. pp. 981-990.

TISSOT B.; OUDIN J. A. AND PELET R. 1972. Critèresd’origineetd’evolution des pétroles. Application à l’étudegéochimique des bassinssédimentaires. In Advances in OrganicGeochemistry, pp. 113-134. Pergamon Press, Oxford.v

168 169 SR10 Rock analyses were performed on a Rock-Eval 6 device (IFPEN, Conclusions SR11 France), according to the Basic/Bulk Rock method described in The three-component sedimentation model of Ricken applied to Behar, et al. (2001). The Rock-Eval measurements provide Total Organic-Rich Sediments : this basin enables to discriminate the different sedimentation styles Late Cretaceous organic matter Organic Carbon (TOC %wt) and Mineral Carbon (MinC %wt) linked to the deposition of an exceptional source rock. This very Quick Assessment Of Depositional contents. Carbonate contents (CaCO3 %wt) are calculated from simple approach delivers information on redox conditions and rich sediments of onshore Morocco MinC. Typology and maturity of the organic matter are determined Environment Characterization. sedimentation controls, which can be readily obtained after Rock- (Tarfaya Basin) and their relation to from hydrogen and oxygen indexes, (respectively, HI and OI) and Eval data. Further application of the method will be developed Oceanic Anoxic Events Tmax values. Valérie Beaumonta* during the meeting. Victoria F. Sachsea*, RalfLittkea¬ Results and Discussion acIFP Energies Nouvelles, 1 et 4 avenue de Bois Préau, 92852 All OM samples display low thermal maturity indices (Tmax < a Institute of Geology and Geochemistry of Petroleum and Coal, Rueil-Malmaison, France 430°C), well below the oil window, therefore excluding a significant EMR Group, RWTH Aachen University alteration due to burial or thermal diagenesis. In these conditions, e-mail: [email protected] pristine TOC and CaCO3 contents were preserved. Hence, * [email protected] coupled organic carbon-carbonates changes reflect changing

Copyright 2014, ALAGO. flux of carbonates, siliciclastic and organic matter components as Copyright 2014, ALAGO. This paper was selected for presentation by an ALAGO Scientific Committee following proposed by Ricken (1993). This paper was selected for presentation by an ALAGO Scientific Committee following review of information contained in an abstract submitted by the author(s). review of information contained in an abstract submitted by the author(s). A general overview of TOC and CaCO3 contents for both sections

(Fig. 2) gives evidence that sedimentation is mainly controlled by Introduction Introduction variations of carbonate deposition during Rhaetian and very Early The depositional environment of organic-rich sediments is a matter Oceanic anoxic events (OAEs) have been widely discussed in Hettangian. Then, three successive events of increasing rate of OM of interest in exploration and production of both conventional and literature and have been considered as key mechanism for organic deposition occur during Hettangian. These events are related to unconventional source rocks. Organic matter (OM) accumulation carbon burial for specific time intervals (i.e.Locklair et al., 2011; dysaerobic to anaerobic conditions prevailing at the time of the Wagreich, 2012). The sediments are generally characterized by the results from enhance primary production and preservation. Blue Lias Formation deposition. During these events, deposition occurrence of organic matter-rich pelagic sediments, such as black Nutrients availability and reducing conditions promote the formation of a high quality OM with HI higher than 700 mgHC/gTOC is shales. Three factors were noted by Wagreich (2012) to qualify for of organic rich sediments, while increasing sedimentation rates paramount, and led to the formation of a source rock with an an OAE: (1) widespread organic- rich strata, (2) correlation in time dilutes the OM content of a sediment. The distribution of OM in exceptional potential. to qualify as a supra- regional single event and (3) accompanied the sediment is therefore controlled by three main factors: primary by a significant carbon isotope excursionIn contrast to the global productivity, redox conditions and sediments supply. Comparison of beds 1 to 6 at Doniford bay and Saint Audrie’s bay extents of the early Aptian OAE 1a and the Cenomanian-Turonian suggests that despite lateral variation of facies, the same factors OAE 2, Arthur and Schlanger (1979) describe the occurrence of The extent of a source rock depends on the interplay of these control the dysaerobic event, recorded for both sections, and the OAE 3 (Coniacian- Santonian) as regionally more restricted. The OM supply, which is constant and more or less diluted by the factors and notably on the local or global nature of the triggers Figure 2. TOC (%wt) vs CaCO3 (%wt) at Saint Audrie’s bay (SA, lower TarfayaBasin in Morocco (Fig. 1) was highly affected by different carbonate input. It suggests that a global trigger precludes at this prevailing at the sediment depositional conditions. Determining diagram) and Doniford bay (DN, upper diagram). Aerobic, dysaerobic and phases of OAE, as the influence of OAE 2 is clearly stated in previous dysaerobic event. these conditions is paramount in understanding distribution of OM anaerobic domains are displayed for sedimentation rates higher than 4m/ studies (i.e.Kuhnt et al., 2002,Sachse et al., 2012), but the possible influence of OAE3 on type, quality and quantity of organic matter at the basin scale. Ma. The diagrams illustrate two different sedimentation styles associated to is still poorly investigated. The main objective of the study was to different redox conditions. determine conditions of deposition and preservation of organic Sedimentological, geochemical and paleoecological data usually matter based on a geochemical study on newly drilled cores. provides key information in approaching the conditions of Acknowledgements Indicators describing the depositional environment are discussed depositional environment. Herein we propose a simple approach, Thanks to Annachiara Bartolini (MNHN Paris) and Guillaume Paris and a detailed overview on organic matter (OM) type, quantity, and using basic geochemical data, i.e. total organic carbon and (Caltech) for sharing data. quality is presented to improve the overall geochemical information carbonate contents together with Rock-Eval parameters. This available for the Tarfaya Basin. In addition, the relation to the OAE3 approach is based on a three-component sedimentation model References can help to improve the knowledge about the extent of this event, developed by Ricken (1993). For a given sedimentation rates, Behar, F., Beaumont, V., De B. Penteado, H.L., 2001. Rock-Eval 6 its duration and quality with respect to source rock deposition it provides information on redox conditions and sedimentation Technology: Performances and Developments. OGST, 56, 111–134. (Sachse et al., 2014). controls (carbonate, siliciclastic or organic matter driven). The approach is exemplify on a serie of oil shales of Triassic/Jurassic Paris, G., Beaumont, V., Bartolini, A., Clémence, M.-E., Gardin, S., Page, In addition, these organic geochemical parameters give indication for the petroleum potential of the investigated Late Cretaceous ages. K., 2010. Nitrogen isotope record of a perturbated paleoecosystem in sediments. theaftermath of the end-Triassic crisis, Doniford section, SW England. G3,

Geological setting and methods 11 (8). The west Somerset coastline, (southern England) offers well exposed marine strata of late Triassic to Early Jurassic age, where Ricken, W., 1993. Sedimentation as a Three-Component System, Springer, a high-resolution sampling of Rhaetian to Hettangian samples was Berlin; performed for two outcrops located at Doniford bay and Saint Audries bay. Outcrops are distant of few kilometers and lateral facies variations are observed. Rhaetian environmental conditions are essentially marine. A Maximum Flooding Surface is observed during the deposition of the Westbury formation. The overlying Lilstock formation marked by a sea level fall, corresponds, to an inner-shelf tidal environment. Then a rapid sea level rise marked the Early Hettangian and corresponding Blue Lias formation correspond to an outer-shelf marine environment. An alternation of laminated shale’s, marls and limestone constitutes the sedimentary pile (Fig 1) (Paris, et al. 2010). Figure 1.Stratigraphic log of Doniford and Saint Audrie’s bay sections.

170 171 Figure 1Location of the Tarfaya Basin in Morocco and the location of the Figure 2Late Cretaceous ages plotted versus (A) Corgcontents for all SR12 considered the MFS of this sequence. Samples were taken from two wells (small red box bottom right). available samples, (B) temperature evolution, and (C) the eustatic sea level transgressive systems tract (TST) and highstand systems tract curve (Haq et al., 1987). Geochemical Characterization of Silurian (HST). TOC contents are low, around 1%. The hydrocarbon Methods source rock potential (S2) is poor, lower than 5 mg HC/g rock. and Devonian Section, Southern Sector of Organic geochemical and petrologicalanalyses have been carried Conclusions Hydrogen and oxygen indices (HI and OI) point out type-II kerogen. out for the whole Late Cretaceous (Cenomanian, Turonian, the Amazonas Basin, Brazil. The palynofacies assemblage is mainly composed by acritarchs A comparison of the investigated samples (outcrops, Sondage Coniacian, Santonian and Early Campanian) sequence of the and prasinophytes (marine algae). Tyson (1995) and Souza (2007) No.1 and Sondage No. 2) shows clearly that not all OAEs record Tarfaya Basin, southern Morocco. Core samples of two wells Igor V. A. F. de Souzaa*, Carla V. Araujo¬a, Ygor dos S. Rocha¬a, interpreted this type of palynofacies as an indication of proximal oxic similar depositional conditions as shown here for the temperature (TarfayaSondage No. 1 and 2) and additional outcrop samples of Nilo S. Matsudab, Wilson R.Winterc. shelf. The geochemical composition of bitumen from Pitinga Fm. dependence of preservation.More regional controls (continental Cenomanian age were analyzed in order to obtain more information is characterized by light δ13C (lighter than -31‰) high hopanes/ about the depositional environment, the kind of organic matter and run off, salinity and water circulation) and models especially with a Division of Geochemistry, Research and Development Center steranes ratio, TPP (Tetracyclic polyprenoid ratio) and TET24/26TRI the hydrocarbon generation potential.To estimate the quantity, respect to organic matter productivity and preservationshould be (CENPES), PETROBRAS, 21941-915, Rio de janeiro, RJ, Brazil. (C24 Tetracyclic/C26 Tricyclic ratio) and predominance of C29 quality and maturity of organic matter, Corg measurements, Rock- considered. In any case Late Cretaceous hothouse conditions b Division of Stratigraphy and Sedimentology, E&P-EXP, steranes. This geochemical composition was interpreted to reflect Eval pyrolysis and vitrinite reflectance measurements were carried leading to low oxygen levels in deep water provided a situation PETROBRAS, Rio de janeiro, RJ, Brazil. continental input in a marine environment. Rodrigues (1995) studied out. A modified van Krevelen diagram (HI/OI) and a cross-plot favorable for organic matter preservation. c Division of Stratigraphy and Sedimentology, UO-BC, the Devonian section of the Parnaiba basin. This author observed between HI and Tmax were used for kerogenclassification.Thermal PETROBRAS, Macaé, RJ, Brazil. a good correlation between the high values of Hopanes/Steranes maturity of sedimentary organic matter was evaluated by means of Acknowledgements ratio with the increment of continental input in a marine setting. pyrolysis parameters (Tmax, PI), microscopic color of liptinites in We thank RWE Dea AG for financial support. ONHYM, W. Kuhnt, *[email protected] Devonian-Tournaisian Sequence: Two samples were collected from fluorescence light (qualitatively) and vitrinite reflectance. In a next and A. Holbourn (Christian-Albrecht University, Kiel) are gratefully step molecular organic geochemistry (GC, GC-MS) was performed Copyright 2014, ALAGO. Ererê outcrop wich is mainly composed by heterolic facies interpreted acknowledged for logistic support and sample supply. on selected samples to specify the depositional environment of the This paper was selected for presentation by an ALAGO Scientific Committee following as a deltaic environment. TOC content is moderate, lower than 2%. organic matter. In addition sulphur content was measured giving review of information contained in an abstract submitted by the author(s). The S2 values are good, ranging from 5.15 to 7.24 mg HC/g rock. References further insight into the depositional environment and intensity HI and OI suggest type-II kerogen. Palynofacies is characterized Arthur, M. A.; Schlanger, S. O., 1979. Cretaceous “oceanic anoxic events” of bacterial sulphate reduction. Corg vs TS ratios reflect the Introduction by predominance of palymorph group which is mainly composed importance of sulphide reduction in the decomposition of organic as causal factors in development of reef-reservoired giant oil fields. The The Amazonas Basin, located in north part of Brazil, cover an area of by acritarchs. It is worth to mention the relative raise of phytoclasts and spores, pointing out an increment of fluvial input. Souza (2007) matter, and thus give a qualitative indication of the redox status of American Association of Petroleum Geologists Bulletin 63, 870–885. approximately 500,000 km² is an intracratonic basin mainly filled by observed a similar behavior in the palynofacies assemblage in HST the environment of deposition. Paleozoic rocks. This basin is considered an important exploratory of the Pimenteiras Fm. Geochemical composition of bitumens from Beckmann, B.;Flögel, S.; Hofmann, P., 2005.Linking Coniacian- Santonian frontier as known worldwide Silurian and Devonian source rocks Ererê Fm. is characterized by heavier δ13C, when compared to Results and Discussion (OAE3) black- shale deposition to African climate variability: a reference sections respectively, Pitinga and Barreirinhas formations. Pitinga Pitinga Fm. (≈ -29.7‰), low values of Hopanes/Steranes and TPP Highest Corg contents (Fig. 2A) can be correlated with times of or Fm. belongs to Neo-Ordovician/Eo-Devoniano sequence and was section from eastern tropical Atlantic at orbital time scales (ODP site 959, ratios, as well as C29 steranes predominance. close after temperature maxima as for the Cenomanian/Turonian off Ivory Coast and Ghana). In: Harris, N.B. (Ed.) The deposition of organic- deposited during the Silurian maximum flooding surface (MFS). with a maximum at 93 Ma (Fig. 2B). Santonian and Campanian Barreirinhas Fm. is mainly comprised by black shales and was Carbon – Rich Sediments: Models, Mechanisms, and Consequences. Eight samples were collected from two outcrops of the Barreirinhas formed during the Frasnian/Famenian worldwide anoxic events. The (85- 75 Ma) also represent periods of high temperatures, though SEPM Special Publications82, 125-143. Fm. Both outcrops are mainly composed by black and gray shales objective of this study is to carry out geochemical characterization somewhat lower than during the Cenomanian and Turonian deposited in a distal marine environment. Four samples were (Fig. 2B). The variations of Corg can therefore be explained by of these sequences and to integrate these data into a sequence Haq, B.U.; Hardenbol, J.; Vail, P.R., 1987. Chronology of fluctuating sea taken from the outcrop “A” which represents the lower section a stronger degradation of the organic matter due to increased stratigraphy model in order to obtain information on source rock of Barreirinhas Fm. According to Winter (2010) this outcrop is levels since the Triassic. Science235,1156 -1167. oxygen availability and decreased temperatures. In addition, the potential, as well as prediction of organic facies variations. composed by TST and the base of HST. It is important to highlight higher amount of organic matter and its better preservation in the presence of concretions with 1m height which marks the more Locklair, R.E.;Sageman, B.B.;Lerman, A., 2011. Marine carbon burial flux samples except the Campanian ones, can be explained by the Material and Methods important MFS of the Amazonas Basin. This MFS is attributed to relative rise of the sea level (Haq et al., 1987, Fig. 2C) coupled with and the carbon isotope record of Late Cretaceous (Coniacian- Santonian) Thirteen samples were collected during the fieldtrip carried out in Frasnian world wide anoxic event. The TOC content is high, varying oxygen deficient conditions during the initial phase of deposition Oceanic Anoxic Event III. Sedimentary Geology235, 38-49. Tapajos river area in the south border of Amazonas Basin. Samples from 4.21% to 5.62%. S2 values are very good, reaching up to as a result from restricted water circulation.Thus our data supports were obtained from Pitinga, Ererê, Barreirinhas e Curiri formations. 24.73 mg HC/g rock. HI and OI suggest Type-II kerogen. The HI the assumption of various authors (i.e. Wagreich, 2012) that Wagreich, M., 2012.“OAE 3”- regional Atlantic organic carbon burial during Total organic carbon (TOC), Rock-Eval pyrolysis, palynofacies reaches up to 460 mg HC/g TOC. The palynofacies is characterized OAE3 is distributed over a long time span and not a short term the Coniacian- Santonian. Climate Past 8, 1447- 1455. and maturation analyses (spore coloration index and vitrinite by predominance of amorphous organic matter (AOM), suggesting event as OAE2. The negative feedback of organic carbon burial reflectance) were carried out. Geochemical characterization of an anoxic distal marine environment (Tyson, 1993; 1995). Samples bitumen composition were based on extraction with accelerated from lower part of Barreirinhas Fm. show low values of Hopanes/ and preservation in contrast to Cenomanian/Turonian is thus Kuhnt, W.;Holbourn, A.; Gale, A.;Chellai, E.A.; Kennedy, J., 2009. solvent extractor method (ASE), carbon isotopic composition Steranes, TPP and TET24/26TRI ratios associated to high values related to decrease of global hothouse conditions during the Late Cenomanian sequence stratigraphy and sea-level fluctuations in the Tarfaya Cretaceous and the better solubility of O2as relatively high sea (δ13C), liquid chromatography (MPLC), gas chromatography of Tricyclic/Hopanes. Some authors correlate high amount of Basin (SW Morocco). Geological Society America Bulletin 121, 1695-1710. water temperatures occurred during the Late Cretaceous (Fig. 2B). (GC) and gas chromatography coupled with mass spectrometry tricyclic terpanes with prasinophytes (Greenwood et al, 2000). The As a consequence, changes in continent/ocean configuration as (GC-MS) analyses. The GC-MS was used in order to investigate upper section of the Barreirinhas Fm. (Outcrop “B”) and Curiri Fm. Sachse, V.F.;Littke, R.;Jabour, H.; Schümann, T.; Kluth, O., 2012.Late were deposited under HST influence. Samples from this sections the opening of the Atlantic, climate, water circulation and sea level the molecular composition (terpanes and steranes biomarkers) Cretaceous (Late Turonian, Coniacian and Santonian) petroleum source present moderate TOC content, varying from 1.64% to 2.12%. The fluctuation (i.e. Beckmann et al., 2005, Fig. 2C) ultimately control the of the bitumen. Biomarkers data were used to define the origin S2 valuesare good, reaching up to 6.15 mg HC/g rock. However, production and deposition of organic matter in the Atlantic Ocean. rocks as part of an OAE, Tarfaya Basin, Morocco. Marine and Petroleum and thermal evolution of organic matter (Peters et al., 2005). Data Geology 29, 35-49. were inserted within stratigraphy sequence framework proposed these values are lower than values observed in the lower part of by Winter (2010 apud Matsuda et al., 2013) based on definitions Barreirinhas Fm. HI and OI indicate type II-kerogen. As well as S2 values, HI tends to be lower when compared to the lower section Sachse, V.F.; Heim, S.;Jabour, H.;Kluth, O.;Schümann, T.; Aquit, M.;Littke, summarized by Catuneanu et al. (2009). of the Barreirinhas Fm. The δ13C of bitumens from Barreirinhas R., 2014.Organic geochemical characterization of Santonian to Early Results and Discussions and Curiri formations are similar to the values observed in the Campanian organic matter-rich marls (sondage No. 1 cores) as related to Ererê Fm. Otherwise, biomarkers of the extracts from upper part Ordovician-Devonian Sequence: Two samples were collected in OAE3 from the Tarfaya Basin, Morocco. Marine and Petroleum Geology, of Barreirinhas Fm. and Curiri Fm. show significant increment in pelitic section of this sequence. Outcrop presents by 2 meters http://dx.doi.org/10.1016/j.marpetgeo.2014.02.004 Hopanes/Steranes and TPP ratios that can be attributed to the rise of siltstones and shales with one level of concretions which is

172 173 of continental contribution. Palynofacies assemblage from upper SR13 SR14 limestone of the basal Guia Formation (Figure 1). section of the Barreirinhas Fm. and Curiri Fm. is characterized Experimental by predominance of acritarchs. Sample from Curiri Fm. presents The samples were submitted to acid treatment (HCl and HF). The Making Movies of Oil Generation Analysis of Molecular Biomarkers the highest phytoclast abundance, suggesting the highly proximal remainder was extracted to Soxhlet extractor by 72 h using CHCl3. trend. of cap carbonate from Amazonian Craton, The organic extracts were fractioned using preparative TLC using Jeremy Dahl1, Marc Castagna2, Kimball Skinner2, Eric Goergen2 Neoproterozoic, Brazil hexane/ethyl acetate (95:5 v/v) and fractions were submitted Maturation: The vitrinite reflectance is lower than 0.6% and is and Hermann Lemmens2 to GC-MS e MRM GC-MS-MS analysis.The chromatographic associated to a spore coloration index around 4.5, pointing out a Gustavo R. de Sousa Jra, Renata L.L. Hidalgob, Bruno Q. Araújoa, separations were achieved using HP-5MS capillary column and Stanford University Helium as gas carrier at 1.0 mL/min flow. For GC-MS analysis low maturation stage, with the exception of the sample collected Afonso C.R. Nogueirab, Candido A.V. Mourab, Eugênio V. Santos FEI Corporation a GC 7890A/5975C VL MSD Agilent instrument was used. The from Curiri Fm which presents Ro of 0.69%. Nevertheless, these Netoc, Francisco de A. M. Reisa* results of the Curiri Fm. could be influenced by reworked vitrinites. temperature program was 70 °C (1 min.) up to 300 °C (20 min.) at The maturation indicators obtained from biomarkers, such as Ts/ Scanning Electron Microscopy (SEM) of organic-rich shales is a 4 °C/min. The injector was configured to split mode (1:1 split ratio) a Universityof Campinas, InstituteofChemistry, 13083-970, at 280 °C. For the full SCAN (50-600 Da) and SIM mode, the ions (Ts+Tm), αββ/(αββ+ααα) and 20S/(20S+20R), suggest low stage powerful tool for understanding the distribution of organic matter, Campinas, SP, Brazil; source was adjusted to EI (70 eV) at 210 °C. The transfer line was of thermal evolution and is in agreement with petrographic data mineral content, porosity and permeability . Focused Ion Beam b Faculdade de Geologia, Instituto de Geociências, maintainedat 310 °C.For the MRM GC-MS analysis was used a and Tmax results. Scanning Electron Microscopy (FIB-SEM) makes possible digitized Universidade Federal do Pará. Rua Augusto Corrêa 1, GC 7890A/7000 MS Triple Quad Agilent instrument with the same 3-d shale reconstructions in which thin layers can be sequentially Guamá, 66075-110 Belém, PA, Brazil; conditions for GC-MS analysis. The MRM transitions were chosen Conclusions stripped away or added on a computer-rendered 3- d image. c Petrobrás/Cenpes/PDGEO, Av. Horácio Macedo 950, based on literature (Peters et al., 2005). It was possible to observe the variation of the geochemical data These types of “movies” show the interconnections of pore Cidade Universitária-Ilha do Fundão, 21941-915, Rio de within the stratigraphic framework that allows a better sampling networks. These important methodologies are routinely utilized to Janeiro, RJ, Brazil Results and Discussion as well as prediction of the source rock potential quality. TOC better understand unconventional oil and gas plays. All samples exhibit a distribution ofn-alkanes from C14 to C36, and pyrolysis results of samples collected from outcrops in the monomethylalkanes, from C15 to C22, alkylcyclohexane and *[email protected] Tapajós River area in the south border of Amazon Basin point out Here we report another breakthrough methodology, namely making alkylcyclopentane from C15 to C30, and isoprenoides from C15 to poor source rock potential for Pitinga Fm. Samples from Ererê movies of oil generation, through the use of an Environmental C25.The Pr/(Pr+Ph) ratios ranged between 0.36 and 0.54. and Curiri formations present moderate source rock potential. On Copyright 2014, ALAGO. Scanning Electron Microscope (ESEM) with a heating stage. By the other hand, samples from Barreirinhas Fm. show the highest This paper was selected for presentation by an ALAGO Scientific Committee following heating a thermally immature, organic-rich shale while continuously The m/z 191 mass chromatogram of the samples from Mirassol source rock potential. All studied section is immature for petroleum review of information contained in an abstract submitted by the author(s). d’Oeste locality is dominated for a distribution of tricyclic terpanes recording the image beneath an ESEM, we were able to make a generation. It is worth to mention that the studied area represents from C19 to, at least, C39. The mass chromatogram shows yet movie showing the oil generation process. The heating program the sedimentation near from southern paleoborder. The quality Introduction absence of the hopanoids compounds, including 17α-22,29,30- used was the same as that used by Rock-Eval pyrolysis and water of source rocks tends to become better into the basin center. The Neoproterozoic Era was characterized by global glaciations trisnorhopane (Tm), which prevents the use of the Ts/(Ts+Tm) ratio, vapor was pumped into the chamber to enhance the image making Better paleoenvironmental conditions for source rock formation is events so extreme that ocean surface was completely frozen. This as a more accurate evaluation of the thermal evolution. The m/z the pyrolysis in effect a hydrous pyrolysis. associated to the MFS. theory is known as Snowball/slushball Earth (Hoffman et al., 1998). 191 mass chromatogram of Tangará da Serra samples exhibited These events of extreme climatic changes were responsible by not only tricyclic terpanes, but also a complete distribution of References The movie can be found at: significant stress in the ocean life and triggered the deposition of hopane-type compounds and gammacerane (Figure 2).The low Catuneanu, O., Abreu, V., Bhattacharya, J.P., Blum, M.D., Dalrymple, R.W., http://www.youtube.com/watch?v=lISNwF5tMXM organic matter after glaciation, mostly in the Neoproterozoic cap values for Pr/(Pr+Ph) ratio and the presence of gammacerane, in case of the Tangará da Serra samples, indicate anoxic conditions Eriksson, P.G., Fielding, C.R., Fisher, W.L., Galloway, W.E., Gibling, M.R., carbonate succession. Giles, K.A., Holbrook, J.M., Jordan, R., Kendall, C.G.St.C., Macurda, From this movie, it is possible to actually visualize many of the associatedwitha saline paleoenvironment(Peters et al., 2005). B., Martinsen, O.J., Miall, A.D., Neal, J.E., Nummedal, D., Pomar, L., processes that occur during oil generation. These include the Both suite of samples (Mirassol d’Oeste and Tangará da Serra) Posamentier, H.W., Pratt, B.R., Sarg, J.F., Shanley, K.W., Steel, R.J., creation of porosity and permeability by the conversion of solid showed a strong predominance of C27pseudohomologues in Strasser, A., Tucker, M.E., Winker, C., 2009. Towards the standardization of kerogen to liquid and gas and the subsequent migration of those theirm/z217 and m/z 218 mass chromatograms and M+→m/z sequence stratigraphy. Earth Sci. Rev. 92, 1–33. hydrocarbons. In the case of this experiment, migration is into 217 MRM chromatograms. The intensity of M+ 358→m/z217 the vacuum. In nature, migration is either within or out of the tight response reveals that the C26pseudohomologues are the second Greenwood, P.F.; Arouri, K.R.; George, S.C., 2000. Tricyclic terpenoid shale. Furthermore, pressure associated with kerogen and oil most abundant.None of observed peaks in M+ 386 →m/z 217 composition of Tasmanites kerogen as determined by pyrolysis GC-MS. to gas cracking can be observed in the movie by the creation of and M+ 400 → m/z 217 MRM chromatograms correspond to Geochimica et Cosmochimica Acta, Vol. 64, No. 7, pp. 1249–1263. fractures parallel to bedding. At high maturities, as the amount of elution positions expected for C28 and C29 components.Ring oil and gas being generated decreases, the fracture can be seen to A-methylated and A-dimethylated steranes, respectively, were Matsuda, N.S.; Zerfass, H.; Wanderley Filho, J.R.; Farias, L.C.N.; Monteiro, begin to close. Fracturing parallel to bedding, as seen in the film, observed in M+386→m/z 231 and M+ 400 → m/z 245 MRM E.F.B.; Winter, W.R., 2013. Roteiro Geológico do Paleozóico do Rio Tapajós would result in horizontal migration within the carrier bed. chromatogram, with stereoisomer distributions comparable to Borda Sul da Bacia do Amazonas, Pará. Field trip guide. Reserved Material. those of the steranes. Peters, K.E.; Walters, C.C.; Moldowan, J.M., 2005. The Biomarker Guide. The making of ESEM movies of oil and gas generation from organic-

2nd ed., 2v. Cambridge University Press, Cambridge. TT24 rich shales will lead to a better understanding of the process in Mirassol d'Oeste samples Rodrigues R., 1995. A Geoquímica Orgânica na bacia do Parnaíba. Ph.D TT23 both conventional and unconventional plays. TT20 Thesis, IG/UFRGS, Porto Alegre. TT21

Figure 1. Geological, location map and general stratigraphy of study area. TT29 TT25 TT26 TT28 TT30 TT31

Souza, I.V.A.F., 2007. Faciologia Orgânica de Seções Devonianas da TT34 TT33 TT35 TT36 TT19 TT22 TT38 Bacia do Parnaíba (Formação Pimenteira): Implicações para Geração de In Brazil, the record of post-glacial cap carbonate related to the last TT39 Petróleo. Master Dissertation, IGEO/UFRJ, Rio de Janeiro. event of Cryogenian was firstly reported by Nogueira et al. (2001, H30 2003, 2007)in outcrops nearby Mirassol d’Oeste city, State of Mato Tangará da Serra samples Tyson, R.V., 1993. Palynofacies analysis. In: Jenkins, D.G. (Ed.), Grosso, Center-western Brazil. Afterwards, Soares and Nogueira 30-NH29

TT23 AppliedMicropaleontology. Kluwer Academic Publishers, Dordrecht, The (2008)described a new occurrence of cap carbonate in Tangará HH31 TT24 G Tm Netherlands, pp. 153–191. HH32 28,30-BNH28 da Serra city, 135 km to the NE of Mirassol d’Oeste (Figure 1). The TT29 HH33

TT21 TT26 TT28

TT25 HH34

Ts HH35 TT20 cap carbonate represent the basal portion of the Araras Group, TT19 TT22 Tyson, R.V., 1995. Sedimentary Organic Matter: Organic Facies and that include the dolostones of Mirassol d’Oeste Formation and the 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62 64 Palynofacies. Chapman and Hall, London. 615 pp. Time (minutes)

174 175 Figure 2. m/z 191 Mass chromatogram for selected samples. Peters, K.E., Walters, C.C., Moldowan, J.M., 2005. The Biomarker Guide: Since C28 and C29 steranes have not been detected, the co- Biomarkers and Isotopes in the Petroleum Exploration and Earth History, SR15 elution problems are eliminated, allowing to use C27 20S/(20S 2nd ed. Cambridge University Press, Cambridge, UK. + 20R) and C27ββ/(ββ + αα) as maturity parameter. All samples Oil exploration in the Mediterranean Basin: the exhibited C27 20S/(20S + 20R) ration between 0.47 and 0.50 and Soares, J.L., Nogueira, A.C.R., 2008. Depósitos carbonáticos de Tangará pre-Messinian source rocks C27ββ/(ββ + αα) ratio between 0.59 and 0.64. da Serra (MT): uma nova ocorrência de capa carbonática neoproterozóica no sul do Cráton Amazônico. Revista Brasileira de Geociências 38, 715- Albert Permanyer, Robert Jorge, Lluís Gibert Although cyanobacteria is the only microorganism known to 729. biosynthesize monomethylalkanes, several origins have been Dept. de Geoquímica, Petrologia i Prospecció Geològica, Universitat suggested for these compounds, such as direct biological Summons, R.E., Walter, M.R., 1990. Molecular fossils and microfossils of de Barcelona. Martí i Franquès, s/n. 08028 Barcelona, Catalonia contributions of branched alkanes, or as diagenetic products prokaryotes and protists from Proterorozoic sediments. American Journal (Spain) of carboxylic acids. Furthermore, monomethylalkanes can be of Science 290-A, 212-244. generated by chemical process like equilibration of a limited range [email protected]; [email protected] of isomers, or produced by thermal cracking of alkenes (Summons and Walter, 1990).Since the Amazonian Craton sedimentary rocks Figure1. Fluorescence microscopy. Finely banded organo-mineral matrix, Copyright 2014, ALAGO. studied here showed an early mature thermal evolution level, amorphous, displaying intense greenish-yellow and red fluorescence. This paper was selected for presentation by an ALAGO Scientific Committee following catagenetic reactions as the origin for the monomethylalkanes is review of information contained in an abstract submitted by the author(s). less likely and a contribution of cyanobacteria to the OM is more feasible. Introduction The last hydrocarbon discoveries in the eastern Mediterranean Conclusions basin have generated a specific interest on organic rich sediments A full suite of n-alkanes C15-C36 in all samples indicatea that pre-date the extensive evaporitic deposits originated during well preserved organic matter.Both sets of samples have the Messinian Salinity Crisis (MSC). Southeastern Spain has a homologous series of alkylcyclopentanes, alkylcyclohexanes large number of Late Neogene basins with substantial evaporitic and methylalkanes. All these compounds indicate a contribution deposits that developed under an overall NNW-SSE compression of cyanobacteria to sediment and are considered characteristic regime because of the African-European plate collision. These biomarkers of Neoproterozoic organic matter.The RIC m/z 217 basins are in the Alpine Betic range, and can be considered as mass chromatogram exhibited the same sterane composition marginal Mediterranean basins that became gradually isolated with predominance of C27 normal steranes for both location, from the Mediterranean Sea due to tectonic uplift. but m/z 191 mass chromatogram revealed very low abundance (or absence) of hopanes and a large prevalence of tricyclic in The Messinian evaporitic deposition was related first to a restriction Mirassol d’Oeste samples.Tangará da Serra samples showed Figure 2. Scanning electron microscopy. Laminated organic matter with in the communication with the Atlantic Ocean during the period a more usual profile of m/z 191 mass chromatogram with the authigenic dolomite crystals (d), chert nodules (c), and diagenetic halite (h); ~6-5.5 Ma followed by an isolation of the Mediterranean Sea presence of tricyclic,hopane biomarkers and gammacerane.The titanium crystals aggregate (Ti) and planktonic foraminifer (f). between ~5.5-5.3 Ma. Different evaporitic units accumulated in observed geochemical differences were probably due to local these marginal basins before and during the restriction stage of palioenvironmental variations that affected production and/or The laminae denote an undisturbed sedimentary environment, in the MSC. Evaporitic conditions seems to follow periods of organic preservation of the primary organic matter. which some authigenic calcite, dolomite and quartz crystals as well matter accumulation. as micro nodules of chert and diagenetic halite grew (Fig. 1). The Acknowledgements occurrence of benthic and planktonic foraminifera is noticeable, Previous studies of the pre-evaporitic deposits from Lorca Basin The authors thank CNPq (Brazilian research council) for fellowship, suggesting a marine environment (Fig. 2). showed: a) high oil potential, b) marine origin of the organic matter Petrobras S/A andUnicamp for financial support. and c) low degree of maturity (Permanyer et al, 1994; 2013). In the References present work we show the results obtained from Late Tortonian Hoffman, P.F., Kaufman, A.J., Halverson, G.P., Schrag, D.P., 1998. A organic rich shales collected from boreholes, mines and outcrops Neoproterozoic Snowball Earth. Science 281, 1342-1346. in the marine Lorca Basin and other less open or isolated Betic basins: Minas de Hellín, Cenajo and Socovos.

Nogueira, A.C.R., Riccomini, C., Kerkis, A., Fairchild, T.R., Hidalgo, R.L., Methods 2001. Hydrocarbons in carbonate rocks of the Neoproterozoic Alto This work examines first the petrological features of the organic Paraguai basin, Mato Grosso, Brazil. Anais da Academia Brasileira de matter using fluorescence and scanning electron microscopy, Ciências pp. 464-464. and second the main geochemical features by using Rock Eval pyrolysis, Gas Chromatography and Gas Chromatography-Mass Nogueira, A.C.R., Riccomini, C., Sial, A.N., Moura, C.a.V., Fairchild, T.R., Spectrometry 2003. Soft-sediment deformation at the base of the Neoproterozoic Puga cap carbonate (southwestern Amazon craton, Brazil): Confirmation of rapid Results icehouse to greenhouse transition in snowball Earth. Geology 31, 613-616. Studied samples appear to be made up of thin laminae in which the organic matter is optically amorphous, displaying intense greenish- Nogueira, A.C.R., Riccomini, C., Sial, A.N., Moura, C.a.V., Trindade, R.I.F., yellowish and red fluorescence with inverse fading. Fairchild, T.R., 2007. Carbon and strontium isotope fluctuations and paleoceanographic changes in the late Neoproterozoic Araras carbonate platform, southern Amazon craton, Brazil. Chemical Geology 237, 168-190.

176 177 Figure 3. HI vs OI diagram. HI between 700 and 850, oil potential up to 150 References SR16 to 183, and high organic sulfur content (>8%), lead to classify this kerogen Permanyer, A.; Baranger, R.; Lugardon, B., 1994. Oil shale characterization as type I-S to II-S in Messinian pre-evaporitic sediments from the Lorca basin (south-east Geochemical evaluation of Outcrops Spain). Bull.Centres Rech. Explor.-Prod. Elf Aquitaine, 18, 135-149. The geochemistry results show an organic carbon content up to from Tapajós River Valley, Southern Edge 20%; Hydrogen Index values between 400 and 900 mg HC/g Permanyer, A.; Marín, P.; Gibert, L., 2013. Pre-evaporitic Messinian of The Amazonas Basin of TOC; and oil potential reaching 150 to 183 mg HC/g of rock. Sediments: a New Challenge for Oil Exploration in the Mediterranean b b Immaturity of organic matter is indicated by Tmax values varying Basin. AAPG Search and Discovery Article #90161©2013 AAPG European Marcus F. Tenórioa, , Silvana M. Barbantia, Luiz Landau from 380 to 420ºC (Fig. 3). Regional Conference, Barcelona, Spain, 8-10 April 2013. a Integrated Petroleum Expertise Company, 22280-030, Rio de Janeiro, RJ, Brazil b Universidade Federal do Rio de Janeiro, COPPE, 21941-909, Rio de Janeiro, RJ, Brazil

*[email protected] Figure 1.Totalorganic carbon content ofthe outcrop samples.

Copyright 2014, ALAGO. The saturated hydrocarbon fractions show distribution of short- This paper was selected for presentation by an ALAGO Scientific Committee following chain n-alkanes, indicatingmainly algalcontribution. n-Alkanes are review of information contained in an abstract submitted by the author(s). in the range of C12 to C36 with an odd-even predominance. These features are associated with marine environments and indicate a Introduction possible contribution of marine algae and phytoplankton to the Figure 4. Mass fragmentogram (ion 71) showing n-alkanes and isoprenoids. Amazonas basin has been the target ofgeological investigationssince original sedimentary environment (Mello et al., 1988). Note the odd members predominance between n-C23 and n-C33. the 1960s, aiming at thediscovery ofpetroleum systemsfor the exploitation ofliquid and gaseous hydrocarbons. The generation Overall, low values for hopanes/steranes ratio (< 4) indicate Euxinic environment is supported by the presence of sulfur ofhydrocarbonswas initiallydetectedby analysis ofwell testsand deposition of marine organic matter with higher contribution compounds and low values of Pr/Ph ratio. The predominance of laterby integratedgeochemical studieswhichattributedgreat of planktonic organisms, whereas high values (> 7) indicate odd n-alkanes between n-C23 and n-C33 could be related to a potential of hydrocarbon generation, unfortunately with sub- deposition of terrestrial and/or microbial reworked organic matter. bacterial origin of the organic matter, which is in agreement with commercial character. Aiming ata better understandingof the Therefore, the molecular parameters, such as hopanes/steranes, microscopical observations (Figs. 4 & 5). Amazonas basin, outcrop samples from the BarreirinhaFormation, ratio, relative abundance of steranes, and presence of C30- which is considered the main source rock within the basin, were steranes corroborate a marine origin for these samples (Moldowan collected and analyzed toassess the hydrocarbon generative et al., 1990). The samples reveal a predominance of C29-steranes potential and to determine origin and thermal maturity by using and concentration of C30-steranes in the range of 90 to 300 ppm screening analyses, such as total organic carbon and pyrolysis, as (Figure 2). well as biomarker analysis. The maturity parameters based on biomarkers, such as 20S/ Experimental (20S+20R) and αββ/(αββ+ααα) C29-steranes, Ts/(Ts+Tm), 22S/ Twenty outcrop samples from Amazonas basin were selected to (22S+22R) C32-hopanes, and concentration of biomarkers, determine their generative potential, origin and thermal maturity. To indicate these samples are at immature stage of thermal evolution. assess the generative potential total organic carbon and pyrolysis analyses were performed. The samples were extracted using Soxhlet apparatus and the organic extracts were fractionated by liquid chromatography into saturate and aromatic hydrocarbons, and polar Figure 5. Mass fragmentograms (ions 184, 198 and 212) of aromatic compounds. The percentage of hydrocarbon fractions can assist in fraction showing abundance of sulfur compounds. (BT: dibenzothiophenes; the interpretation of the thermal evolution and the type of organic MDBT: methyl-dibenzothiophenes). material of rock samples (Tissot & Welte, 1984). Thesaturated hydrocarbonfractionswere analyzed by gas chromatography usingAgilent7890AGCequipmentwith a flame ionization detector, Conclusions FID. The branched and cyclichydrocarbonfractionswereanalyzed The Tortonian and Messinian deposits from the marginal bygas chromatography coupled tomass spectrometry(GC-MS) Mediterranean basins show high oil potential but did not reach using anAgilent Technologies7890Ninstrumentcoupled with amass sufficient burial to produce oil. In an offshore situation, the presence selective detectorAgilent5975C, and some of those fractions were of similar deposits might be expected. There, these organic rich selected for a more detailed biomarker analysis by MRM-GC-MS shales might be covered by up to ~3,000-4,000 m of sediments, using a high resolution mass spectrometer, DFS-Thermo Scientific. Figure 2.Concentration (ppm)of steranes by MRM-GC-MS. formed by detrital deposits derived from the Messinian subaerial exposure, Messinian evaporites and Pliocene sediments. Results and Discussion Conclusions The possibility of finding source rock deposits below the sealing Total organic carbon content is in the range of 3.7 to 6.6 % indicating The study of outcrops is important because it allows direct Messinian Salt associated with conditions of high burial and the samples are organic carbon rich and have therequiredcontent observation of the sediment section, enabling sampling for heat flow provides an exploration challenge in the Western of carbon for pyrolysis analysis (Figure 1). Based onpyrolysis geochemical analyzes and thus allowing its chemical and data (hydrogen index, Tmax andproduction rate) the samples are geochemical characterization, in addition to dating and verifying Mediterranean offshore. considered thermallyimmature. the fossil content.

178 179 The outcrop samples from Barreirinha Formation analyzed in this SR17 GC and GC-MS trace characterized by a lower proportion of low Acknowledgements study show high organic carbon content, with values ranging from molecular weight n-alkanes (<20) and high hopanes/steranes ratio The authors thank Capes, CNPq, FAPERJ; ANP/UERJ/PRH-17 for (Table 01). Between the terpanes, a predominance of C19 and C20 financial support. 3.7 to 6.6 %. The organic matter was classified as type II reaching Biomarker Characterization hydrogen index (HI) with values between 326 to 444 mg HC/g tricyclic terpanes can be observed, as well as a series of C24, C25 TOC that corresponds predominantly to the biomass of marine Of Barreirinha And Curiri Formations, and C26 des-e tetracyclic terpanes and high C27(Tm)/C30 hopane References origin. The pyrolysis data indicate the outcrop samples exhibited Upper Devonian Of Amazonas Basin ratio, all pointing to a terrestrial organic matter input (Fig.01). AQUINO NETO, F. R., TRIGUIS, J., AZEVEDO, D. A., RODRIGUES, R., excellent generative potential but are in the immature stage of and SIMONEIT, B. R. T. (1989) Organic geochemistry of geographically thermal evolution. These characteristics are associated with marine Pedro H. V. Garcia*, René Rodrigues As can be in the Table 01, the Urariá Member of Barreirinha unrelated Tasmanites. 14th International Meeting on Organic Geochemistry, environments with contribution of phytoplankton and seaweed. Formation shows a better biomarker correlation to the Curiri Paris, September 18-22, 1989, Abstract No. 189 The distribution of n-alkanes, hopanes/steranes ratio, relative a Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, Formation, which suggests different lithostratigraphic position for it. abundance of C27, C28, C29 and C30-steranes infer that the Brasil CUNHA, P. R. C., MELO, J. H. G., SILVA, O. B. 2007. Bacia do Amazonas, organic matter present in Barreirinha Formation is predominantly As can be seen in Table 01, the Urariá Member of Barreirinha Boletim de Geociências da Petrobrás. Rio de Janeiro, Brasil, v. 15, n.2, p. marine. *[email protected] Formation shows a better biomarker correlation to the Curiri 227-251. Formation, which suggests a different lithostratigraphic position for it. Acknowledgements Copyright 2014, ALAGO. The authors thank Integrated Petroleum Expertise Company, This paper was selected for presentation by an ALAGO Scientific Committee following IPEXco, and Universidade Federal do Rio de Janeiro, COPPE. review of information contained in an abstract submitted by the author(s).

References Introduction Tenório, M.F., 2013.Avaliação do Potencial Gerador e Caracterização de The Amazon basin has been studied since the beginning of the Biomarcadores em Afloramentos Rochosos do Vale do Rio Tapajós, Borda last century. The organic geochemical investigations carried out Sul da Bacia do Amazonas. Master thesis, Universidade Federal do Rio de since 1970 haves shown that oil and gas generation occurred Janeiro, pp. 173. in the basin, but few papers have been published related to biomarker characterization of the Upper Devonian section, Mello, M.R., 1988, Geochemical and Molecular Studies of the Depositional where the main source rock interval is included. The new data Environments of Source Rocks and their Derived Oils from the Brazilian presented here provide elements which may help understand the Marginal Basins. Ph.D., University of Bristol, pp. 240. organic geochemical variations due to a change in depositional environment conditions during Upper Devonian time in the whole Moldowan, J.M.; Fago F.J.; Lee C.Y.; et al. (1990) Sedimentary Amazonas Basin. Table 01: T: tricyclic terpanes; Te: tetracyclic terpanes; H: hopanes; Tm: 24-n-propylcholestanes, molecular fossils diagnostic of marine algae. trisnorhopane; Hop/Est: hopane/sterane ratio; nC17/nC27: ratio of low Science 247, 309-312. The Barreirinha Formation encompasses three shaly members and higher molecular weight of n-alkanes. deposited in a normal marine environment: the radioactive shales Tissot, B.P. & Welte, D.H., 1984. Petroleum formation and occurrence, 2nd of Lower Abacaxis Member, the non-radioactive shales of the ed., Springer-Verlag, Berlin, pp. 699. Urubus Member and the non-radioactive and high resistivity shales of the Upper Urariá Member. On the other hand, the Curiri Formation is mostly composed of diamectite with sandstone and shales interbedded (Cunha et al. 2007).

Experimental The Bulk geochemical analyses were carried out in 64 samples of an approximately 230m thick Barreirinha and Curiri Formations derived from one well drilled by Petrobras. Based on the bulk geochemical data, 7 samples were chosen for organic extraction, liquid chromatography and biomarker analysis. All geochemical analyses were performed in the Chemical Stratigraphy and Organic Geochemistry

Laboratory of the State University of Rio de Janeiro using the following equipment: LECO SC 632 for TOC and S analysis, Rock-Eval 6 for pyrolysis analysis and an Agilent system 6890 GC coupled to a 5977 Mass Detector and 7000 GC-MS triple quad for biomarker analysis.

Results and Discussion The radioactive shales of Barreirinha Formation record a GC and GC-MS trace characterized by a higher relative proportion of low molecular weight n-alkanes (<20), low hopanes/steranes ratio and higher tricyclic/pentacyclic terpanes ratio suggesting a normal Figure 01. Mass chromatogram of Curiri Formation at the depth of 1189,4 marine environment and an algal input (probably Tasmanites, m, showing the series of tetracyclic terpanes from 24 to 26 of carbon Aquino Neto et al., 1989) to organic matter composition (Table 01). number. On the other hand, the diamectites of Curiri Formation display a

180 181 OS57 Experimental Mora, C., Cordoba F, Luna O., Sarmiento L.F., Rangel A., Giraldo B.N., OS58 The geochemical characterization of the samples was done by Bartels H., Reyes J.P. 1996, Petroleum Systems of the Middle Magdalena Valley, Colombia: AAPG Boletín, v.80/8, Association Round Table, p.1316. Evaluation of hydrocarbon generation Total Organic Carbon (TOC),Rock- Eval pyrolysis and organic Orbital Controls On Lower Jurassic petrography analyses. Based on the results of these analyzes, potential of the Cretaceous sequence in the samples were selected for accelerated extraction using an ASE- Peters, K.E., Moldowan, J.M., 1993. The biomarker guide: Interpreting Source Rock Deposition northern sector of the Middle Magdalena 350 equipment. The recovered extracts were fractionated into molecular fossils in petroleum and ancient sediments. New Jersey, Prentice Lorenz Schwark a,c Wolfgang Rübsama, Bernhard Mayerb Valley Basin, Colombia their saturated, aromatics, resins and asphaltenescomponents Hall. by open liquid chromatography technique, using activated silica a Organic Geochemistry Unit, IfG, Christian-Albrechts-University, Robert Márquez1*, Maria A. Martínez2 and Tatiana Juliao1 packed column as the stationary phase, and organic solvents as Ramón, J.,Dzou, L, Giraldo, B., 1997. Geochemical evaluation of the Middle Kiel, Germany mobile phase. Solvent free extracts were analyzed by whole oil gas Magdalena Basin, Colombia.CienciaTecnología y Futuro 1 (3), 47-66. b Department of Geoscience, University of Calgary, Calgary, 1. Ecopetrol S.A., ICP, Piedecuesta – Colombia chromatography. The saturated and aromatic fractions were then Canada 2. Ecopetrol S.A., VEX-GEE, Bogotá – Colombia analyzed by gas chromatography coupled to mass spectrometer Ramón, J., Dzou, L., 1999. Petroleum geochemistry of the Middle c WA-OIGC, Curtin University, Perth, Australia (GC-MS) with an electron impact ionizationsystem. Magdalena Valley, Colombia. Organic Geochemistry 30, 249-266. *[email protected] Rangel, A., Giraldo, B., Magoon, L., Sarmiento, L. F., Bartels, H., Results and Discussion Mora, C., Cordoba, F., Luna, O., Reyes, J.P., 1996, Oil potential of the e-mail:[email protected] This paper was selected for presentation by an ALAGO Scientific The highest organic contents are found in Tablazoand La Cretacicmegasequence and associated oil families in the Middle Magdalena Copyright 2014, ALAGO. Committee following review of information contained in an abstract Lunaformations, with TOC values between 2 and 5%, and 4 to Valley: V CongresoLatinoamericano de Geoquímica Orgánica, Cancún, 105 p. This paper was selected for presentation by an ALAGO Scientific Committee following submitted by the author(s) 8%, respectively. Umir Formationalso has a high organic content, with TOC values between 6 and 50%, due to the presence of coal Tissot, B.P., Welte, D.H., 1984. Petroleum formation and occurrence. 2 ed. review of information contained in an abstract submitted by the author(s). Introduction seams. TOC values forTablazoFm.are overestimated in some cases New York, Springer. Introduction The analysis of rock samples for organic geochemistry techniques by the presence of solid bitumen. Rock Eval pyrolysis and organic During the Early Toarcian enhanced organic carbon accumulation allows to describe the quantity, quality and thermal maturity petrography data suggests the predominance of type II kerogen of trans-regional extent led to deposition of prolific hydrocarbon of the rocks, and thus establish whether they reached the right (mainly in La Luna Fm.), with mixtures of type II and III kerogenin source rocks on the NW-shelf of the Tetyhs Ocean during the so- conditions (temperature, pressure, amount of organic matter, several intervals of Simití, Tablazo, Paja and Rosablancaformations. called Toarcian Oceanic Anoxic Event (T-OAE). Comparable source etc.) for the effective generation of hydrocarbons. Rock samples rocks have been deposited in other regions of the World, e.g. the (cuttings) from ten wells located in the northern sector of the Middle Conclusions Gordondale Fm. of the Western Canada, the Los Molles Fm. of Magdalena Valley Basin (MMVB) were selected in order to perform The best hydrocarbons source rock (TOC,kerogen type, and the Neuquen Basin Argentina, or the Tyumen Fm. of Northwestern a geochemical characterization of the Cretaceous sequence maturity) characteristics are found in La Luna (Galembo and Siberia. hydrocarbon generating potential (Fig. 1). SaladaMembers) and Tablazoformations. Other potential source rock intervals within the Cretaceous sequence would have limited conditions to generate hydrocarbons.The presence of abundant On the NW-shelf of the Tethys Ocean the Toarcian source rocks solid bitumen in TablazoFm. suggests that part of the hydrocarbon have been studied in substantial detail by sedimentology and generated could not be expelled and migrate, and subsequently sequence stratigraphy, accompanied by bulk, isotope and was transformed into gas and solid bitumen by thermal cracking. molecular geochemistry. Thus a framework of conditions governing Migrated and/or in situhydrocarbons are identified in rock samples sedimentation of organic matter exists. We have extended existing knowledge by investigating cyclicity in the depositional regime and ofLa Luna, Rosablanca, andPaja formations. La Luna and Tablazo formations are in the hydrocarbon generation windowin this part of hence in the amount and composition of organic matter in a source the basin, with varying levels of maturity.This explains the differences rock of the NW-Paris Basin. in some physical properties (API, viscosity, etc.) of the hydrocarbons produced in the basin. La Luna and Tablazoformations also After establishing the cyclicity, the temporal constraints determining present good conditions as potential hydrocarbon reservoir rocks cycle lengths and frequencies were calculated and environmental in situ and/or migrated (shale oil and shale gas naturally fractured factors driving the cyclicity identified. The sub-basin morphology and or combinations thereof). the supra-regional paleogeography (the Viking Corridor connecting the Tethys with the Boreal Ocean) were found to control the degree Acknowledgements of basin restriction, the exchange of polar, low salinity, nutrient- The authors thank Ecopetrol for support our participation in the XIV enriched surface waters with equatorial, high salinity nutrient- Latin American Congress on Organic Geochemistry. deprived bottom waters. Water column salinity stratification was extreme and thus stabilized bottom water anoxia/euxinia, hence References leading to excellent preservation of organic matter. Fluctuations Agencia Nacional de Hidrocarburos (ANH), 2007. Colombian Sedimentary in redox conditions in dependence of orbitally controlled sea- Basins: Nomenclature, Boundaries and Petroleum Geology, a New level have been determined by a wide array of different isotopic, Proposal. Informe interno Ecopetrol, Bogotá. elemental and molecular proxies.

Córdoba, F., Malagón, F., Valentín, D., 2001. Evaluación del potencial Experimental generador de hidrocarburos de las formaciones Rosablanca, Paja y Our paleofacies reconstruction attempt requires a high-resolution Tablazo, cuenca Valle Medio del Magdalena, Colombia. Informe interno approach realized using continuous scanning techniques (spectral Ecopetrol, Bogotá. XRF, colour and magnetic susceptibility) on a drill core with full core recovery over the entire study interval of almost 40 m. Continuous Figure 1. Generalized stratigraphic colum of the Middle Magdalena Valley Mora, A.R., Naranjo, J.F., Moreno, N.R., Gómez, P.D., Sierra, J.M. records were complemented by analysis of a large number (>600) Basin (ANH, 2007). (2009). Correlaciones y Mapas de Paleo-Ambientes en el Valle Medio of discrete samples for determination of molecular, isotopic and del Magdalena. ECOPETROL- ICP. Unidad de Investigación. Empresa elemental proxies. The isotope proxies included 13C and 13O contratista UT – EOS, DTH. 182 183 on carbonates, 13C 15N on organic matter, 34S on sulfides This indicates a drawdown of certain trace elements caused by UNCONVENTIONAL a temperature-controlled box, a process taking another 5 to 10 and 98Mo on sediment to determine water and organic matter diminished connectivity to the open ocean, where commonly Mo is minutes. sources, microbial processes and organic matter diagenesis. not a biolimited trace element. PETROLEUM SYSTEMS Organic matter quality and abundance was assessed by Rock The temperature in the box containing the canisters was Eval, and biomarker studies (n= 150). Conclusions corresponding tothe estimated reservoir temperature at the depth, The deposition of source rocks, commonly assumed to reflect UP01 where the coals and carbonaceousshales had been collected. This Results and Discussion monotonous sedimentary regimes and organic facies associations, temperature level was based on a geothermal gradientdetermined This work investigates 30 m of Upper Pliensbachian and Lower has been shown to be far more complex than anticipated. Review on the CBM potential of Permian Coals from the bottom hole temperature of a nearby petroleum exploration Toarcian organic rich strata (TOC up to 12 wt.%) from the Lorraine Discovery of rhythmic variations in organic matter qualityrequires from the Paraná Basin, Brazil Based on Results welland the average annual temperature of the area. Basin (NE-Paris Basin), covering the entire T-OAE. High-resolution ultra-high resolution (up to <1 cm sample spacing) analytical from exploration wells in Rio Grande do Sul bulk geochemistry (>650 samples) reveals strong evidences approaches, previously not applied in source rock characterization. The measurement of desorbed gas volumes started immediately And Santa Catarina for a significant cyclicityin organic matter enrichment. Rock Eval Interpretation of cyclic variations in organic matter quality shed after the canisterswere closed, following the procedure as outlined Pyrolysis confirms a primary marine origin for organic matter from light on the key factors controlling source rock quality: i) organic by Mavor and Nelson (1997). Themeasurement of desorbed gas is 1Lourenzi, P*., 1Levandowski, J., 1Oliveira, J., 1Simão, G., the serpentinum zone (Kerogen Type II), whereby organic matter productivity stimulated by nutrient supply via fresh surface waters a simple technique, by which the canisters areperiodically opened 1Kalkreuth, W., 2Holz, M., 3Prissang, R., 4Krooss, 4Weniger, P. from the tenuicostatumzone and from the Domerian is of mixed and ii) exceptional water column stratification stabilized by and the volume of gas liberated from the coal is determined via origin (Type II/III). Fluctuations in water masses led to massive hyposaline surface water enforcing the establishment of stable aconnection to a water-filled burette, from which the volume (cm³) 1 Instituto de Geociências, UFRGS, Porto Alegre, RS salinity changes in surface waters, expressed in carbonate 18O- bottom water anoxia/euxinia causing excellent organic matter replacedby the gas is read off a scale. Each time a measurement 2 Instituto de Geociências, UFBA values and in molecular salinity proxies based on distribution of preservation. Orbitally-induced changes in organic matter quality was taken, the ambientpressure and temperature were also 3 Institut fuer Geologische Wissenschaften, FU Berlin, Germany alkylated chromans. The triggering mechanism for southward occurred in the 20, 40 and 100 ka year frequency band. Given a recorded and used for calculation of the final valueof the desorbed 4 Institute of Geology and Geochemistry of Petroleum and Coal, progradation of hyposaline cold surface waters is seen in land- total sedimentation time of the Toarcian black shale of app. 1.5 Ma, gas volume. RWTH Aachen, Germany locked and sea-ice melting in Polar Regions controlled by obliquity. up to 15 Obliquity cycles may occur. Results and Discussion *[email protected] Overall restriction of the Lorraine sub-basin is evidenced by The first CBM exploration well in Brazil was drilled in the Santa exceptionally low TOC/Mo-ratios, typical for the NW-Tethys shelf. Terezinha Coalfield in 2007, and encountered 12 coal seams Copyright 2014, ALAGO. at a depth between 606.35 – 638.22 m, with a cumulative coal This paper was selected for presentation by an ALAGO Scientific Committee following thickness of 7.41 m (Table 1). Desorbed gas values were found review of information contained in an abstract submitted by the author(s). to range between 0.32 – 1.63 cm3/g. Results from geological 3D modeling suggest a total of > 5 Billion m3 gas associated with the Introduction coal seams of the Santa Terezinha coalfield (Kalkreuth et al, 2013). Economically important coal deposits occur in the southern part of the ParanáBasin (Fig. 1) in the provinces of Rio Grande do Sul (RS) and Santa Catarina (SC). Based on coal rank, coal distribution and depth of the coal seams the Santa Terezinha and Chico-Lomã coalfields (RS) and the Southern Santa Catarina Coalfield (SC) have been the target for CBM exploration since 2007 (Fig. 1).

Table 1. Well identification, number of seams encountered, cumulative coal thickness, depth range, rank, vitrinite reflectance range and total desorbed gas volumes for the wells drilled in the Santa Terezinha, Chico-Lomã and South Santa Catarina coalfields.

In the Chico-Lomã Coalfield the CBM exploration well was drilled in 2013, and encountered 9 coal seams at a depth between 386.95 - 429,27 m, with a cumulative coal thickness of 11.46 m (Table 1). The coal-bearing sequence has been altered severely by a 10 m thick volcanic intrusion transforming coal seams near the contact zone into anthracite and semi-coke. Desorbed gas values were found to range between nil – 0.53 cm3/g. Results from geological 3D modeling suggest a total of > 1.3 Billion m3 gas associated with the coal seams of the Chico-Lomã coalfield (Levandowski, 2013). Figure 1. Map showing the distribution of coal deposits in RS and SC and the locations of the CBM wells drilled in the Santa Terezinha, Chico-Lomã In the South Santa Catarina Coalfield three coal exploration wells and South Santa Catarina coalfields were accompanied to determine the gas contents associated with the seams. The drilling was carried out from 2011 to 2013, and encountered 3 to 7 coal seams at a depth between 166.14 – Experimental 339.83 m, with a cumulative coal thickness ranging from 5.38 to Figure 1.Variation in Toarcian source rock quality as governed by surface water mixing and intensity of water column stratification [A*-values derived from The core samples of coal and carbonaceous shale were collected 6.35 m (Table 1). Desorbed gas values were found to be very low L*a*b-colour space, HHI= homohopene index]. Note high-frequency oscillations in all parameters determined. Short-lived oxygenation events, associated with in 2 or 3 mintervals using a wireline coring device. In this technique ranging between nil – 0.11 cm3/g. The low gas values associated break-down of water column stratification are highlighted in grey. These water column mixing events are initiated by a decline in boreal hyposaline water supply the core samples are broughtrapidly to surface, minimizing the loss with the coal seams are most likely related to the fact that most and sea level drop. Water mixing is enhanced, oxygen supply to deep waters increases to an extent where episodic bioturbationoccurs (e.g. by massive storm of gas during retrieval.At surface the core was cut into intervals of if not all of the generated gas has been lost due to the relatively events) and trace element (Fe/S; V/Cr) or biomarker (HHI) proxies indicate oxygenation events. TOC and HI values are significantly reduced in these intervals, 36 cm length, corresponding to the sizeof the canisters. The core shallow depth of the coal seams (Lourenzi, 2011, 2013). thus hydrocarbon generation potential of the entire source rock is significantly lowered by extent and frequency of these short-lived events. was then put into the canisters, which were closed and placedinto Acknowledgements

184 185 This study received financial support from ElPaso/Petrobras UP02 Experimental and Workflows play cut off parameters(%TOC, thickness, depth, type of kerogen and Pronex, CNPq/ Fapergs Project 10/0025-9. The authors In order to evaluate this source rock as a shale reservoir, 3400 rock and rock mineralogy). However, the maturity, as a key parameter, also like to thank Carbonífera Criciuma and Eng. Cláudio Zilli Pozo D-129 Formation, new shale play? A samples from 200 wells were analysed. Data gathered includeTotal did not reach the minimum value to be considered a shale reservoir. (SATC – Associação Beneficiente da Indústria Carbonífera de case study in an oil field on the fold belt of Organic Carbon (%TOC) by acidization and LECO, Programmed Due to this interpretation and the excellent productionresults Santa Catarina) for logistical support to collect coal samples for GolfoSan Jorge Basin, Argentina Pyrolysis by Rock Eval and different organic petrography techniques obtained from conventional wells, Pozo D-129 formation was gas desorption measurements. P. Lourenzi and J. Levandowski (vitrinite reflectance (%Ro), visual kerogen, thermal alteration index classified as a hybrid shale oil play. acknowledge financial support in form of student grants by CNPq Martin E. Fasolaa*, Yanina A. Basilea and maceralanalysis). during their M.Sc and Ph.D. program, respectively. As a follow-up of this research, one well was stimulated in a YPF S.A., MacachaGuemes 515, CABA Argentina.CP 1106 In order to predict the fluid type to be produced from the shales, unconventional way to evaluate thePozo D-129 formation as a References mud gas from some conventional wells were interpreted and hybrid shale oil reservoirand the results showed a very good match *[email protected] Kalkreuth,W.; Holz, M.; Levandowski, J.; Kern, M.; Casagrande, J.; Weniger, samples extracted from cores and cutting were analysedthrough between the geochemical studies and the type of production fluids. P and Krooss, B. 2013. The coalbed methane (CBM) potential and CO2 GC thermal extract, High Resolution Gas Chromatography, MPLC Copyright 2014, ALAGO. storage capacity of the Santa Terezinha Coalfield, Paraná Basin, Brazil – 3D This paper was selected for presentation by an ALAGO Scientific Committee following (for saturates, aromatic, resins and asphaltenes), Saturate and modelling, and coal and carbonaceous shale characteristics and related review of information contained in an abstract submitted by the author(s). Aromatic Biomarkers by GCMS and Stable Carbon Isotopes in desorption and adsorption capacities in samples from exploration Borehole Saturate and Aromatics Fraction. CBM001-ST-RS. Energy Exploration & Exploitation. Vol 31, number 4. Introduction 485-527. Hydrocarbons associated with unconventional reservoirs have a Also, oil productionsamples were collected from conventional continuous, regional-scale distribution and are independent from wells(oil sands reservoirinterbeddedwithin the organic shales) and Levandowski, J. 2013. Características Petrográficas e Geoquímicas das trap type.Shales are one of the Earth’s most common sedimentary studied following the same analytical program than the extracted camadas de carvão do poço CBM 001-CL-RS, Jazida Chico-Lomã, e sua rocks. It is a fine-grain rock composed mainly of clay flakes and samples from rocks. Additionally, gas production and mud gas relação com coalbed methane associado. Tese de doutorado. Instituto de tiny fragments of other minerals, especially quartz and calcite. samples were analysed by GC Compositional Analysis and Carbon Shale can be a gas/oil reservoir, but only formations with certain Geociências, Universidade Federal do Rio Grande do Sul. and Deuterium Isotope Analysis [13C/12C (δ13C) and 2H/1H characteristics (source rock, seal and reservoir) are viable for (δD)]on the gas components. development. Lourenzi, P. 2011. Avaliação do Potencial de coalbed methane (gás natural) das camadas de carvão da Formação Rio Bonito, Maracajá-SC, Bacia According to the US Energy Information Administration, Argentina Most of the analytical results were used to calibrate the basin do Paraná. Trabalho de conclusão de curso. Instituto de Geociências, holds the second largest recoverable shale gas reserves worldwide modelling in 1 & 3 dimensions and finally, different geochemical Universidade Federal do Rio Grande do Sul. and the fourth largest recoverable shale oil reserves worldwide maps were generated to determine sweet spots in shale (Figure 1). (Kuuskraa et al, 2013). In 2010, YPF started a complete evaluation Lourenzi, P. 2013. O Potencial de geração CBM (coalbed methane) and data acquisition from the different sources rock in Argentina, Results and Discussion na Jazida Sul Catarinense da Bacia do Paraná, Brasil: características among them the shales of the Golfo San Jorge Basin. In the study area, the upper section of Pozo D-129 formation has petrográficas e químicas das camadas Barro Branco, Irapuá e Bonito. a variable thickness from 100 to 250 meters and an average depth Figure 2.Geochemical log and geochemical graphs from oil and extracted Dissertação de Mestrado. Instituto de Geociências, Universidade Federal This rift to sag basin is located in southern Argentina between of 1800 meters. samples do Rio Grande do Sul. the Somoncuraand Deseadocratons in the north and south respectively.It trends roughly east-west between 45-47° south The organic richness ranged from 0.5 to 5.5% of actual TOC with Acknowledgements latitude (Fitzgerald et al, 1990). The study area is located in the Mavor M. and Nelson C.R., 1997. Coalbed reservoir gas-in-place analysis. averages close to 2.5-2.8%, representing a very good source The authors thank YPF S.Ato give permission to present this western part of the basin (Figure 1). The main source rock in the GRI-97/0263, Gas Research Institute, Chicago, Illinois, USA. pp. 183. rock (Figure 2). The S1 peak from pyrolysis showed the presence abstract; Ricardo Clavijo, Ignacio Brisson, SilvanaUtgé, Pedro basin is the Pozo D-129 Formation, responsible for most part of of free hydrocarbon(S1 values are higher than 1 mg HC/gr rock) Kressand Virginia Martinez Cal for their valuable comments. the oil production in the basin which to date has produced more than600 x 106 m3 (3800 x 106 barrels) of oil and 70.3 x 109 m3 and the S2 peaks reach values of 20-25 mg HC/gr rock, showing References (2.5tcf) of gas.It is a lower Cretaceous lacustrine unit with high excellent petroleum potential.The S1/TOC parameter also shows Basile y Utgé, 2011. “Caracterización de la Fm. Pozo D-129, sus pyroclastic participation and the maximum thickness reaches up the presence of producible hydrocarbons. to 1500 m in the central area of thebasin.Based on lithological and condiciones generadoras y su potencialidad como un reservorio no geochemical variations, three main sections have been recognized, Maturity fromvitrinite reflectance varies from top to base between convencional”. Informe Interno YPF. where the upper section shows the highest TOC and HI values with 0.56% and 0.74%, the Tmaxvalues from pyrolysis did not show a type I kerogen (Basile y Utgé, 2011). changes in the entire analyzed interval and the hydrogen indexes Fitzgerald, M., Mitchum, R., Uliana, M. and Biddle, K.,1990. Evolutionofthe (HI) decrease from top to baseand the high values measured on the San Jorge Basin, Argentina. The American AssociationofPetroleumGeologist The present work aims to introduce a complete geochemical topsamples (up to 800 mg HC/gr TOC) are related to the maturity Bulletin, V. 74, No. 6, p. 879-920. characterization and analysis of the upper section of PozoD-129 of the rock (immature to low mature). Formation as a shale playin anoil field on the San Bernardo fold Kuuskraa, V.L., Stevens, S.H., andMoodhe, K.: “TechnicallyRecoverable- beltof GolfoSan Jorge Basin. No match could be observed between the compositional fractions ShaleOilandShaleGasResources: AnAssessmentof 137 ShaleFormations in

and maturity parameter obtained from the extracted samples 41Countries Outsidethe United States”, U.S.A. Energy InformationAdmin- from rocks and production oil. Extracted samples correspond to istrationReport, 2013. medium and early mature oils, whereas the production samples show a very high saturated hydrocarbons phase and high maturity oils.Gas production samples showed a very rich gas composition and an equivalent maturity from isotopes around 1.2 %VRE for C1 and a 0.9% VRE for C2. These different isotope behaviors for C1 and C2 gases were associated to different sources rocks or the same source rock with different maturity degrees.

Figure1.Location map, wells and maturity trend. In conclusion, the Pozo D-129 Formationshowed adequate shale

186 187 UP03 OI) and biomarker identification, a specific workflow was built up changes, switching from the dominance of amorphous organic UP04 as follows: matter of aquatic origin to the dominance of phytoclasts (i.e. derived from higher plants). Paleoenvironmental control on primary fluids Geochemical Characterizationof Hydrocarbon profiles of total extracts were first obtained by gas- Unconventional Shale Oil and Gasin characteristics of lacustrine source rocks, the chromatography coupled to a mass spectrometer (GC-MS). These preliminary results tend to indicate that primary-fluid example of the Autun Basin (France) characteristics are controlled by paleoenvironmental variations, Mesozoic Sedimentary Section – Neuquén Kerogens were isolated by specific treatment (Durand and Nicaise, such as water table level changes, along with paleoclimatic Basin Argentina Sylvain Garela,b*,Françoise Beharb, Olivier Brouckeb, Matthieu 1980) and analyzed by Rock-Eval 6, their extracts by GC-MS, and modifications during the Autunian. The same approach will be Buissona, Johann Schnydera ,François Baudina submitted to elemental analyses to obtain kerogens characteristics applied to the Recôncavo Basin. TaíssaR. MENEZESa*, Regina BINOTTOa, Juliana A. IEMINIa, Jorge and biomarker profiles F. RODRIGUEZb, Jaques S. SCHIMDTa a UPMC Univ. Paris 06 et CNRS, UMR 7193 ISTeP, 4 place Jussieu, Acknowledgements 75005 Paris, France. Then, kerogens were heated in gold tubes reactor at 325°C during The authors thank IFPen (French Petroleum Institute) for kerogen a Petrobras Research & Development Center, Division of b Total – Exploration & Production – Exploration division, 2 place 72 h. This T/t conditions were selected to reach a significant preparation and Total for financial support. Geochemistry Jean Millier – La Défense 6, 92078 Paris La Défense Cedex, France. Transformation Ration (>50 %) with a limitation of secondary b Petrobras Argentina S.A. *[email protected] cracking reactions. The mass-balances were performed on References pyrolysis products in order to determine the proportion of the light Durand, B., Nicaise, G., 1980. Procedure for kerogen isolation. In Durand, *[email protected] Copyright 2014, ALAGO. fraction and the total hydrocarbon profile. B., (Ed.), Kerogen – Insoluble Organic Matter from Sedimentary Rocks. This paper was selected for presentation by an ALAGO Scientific Committee following Editions Technip, Paris, 35-53. Copyright 2014, ALAGO. review of information contained in an abstract submitted by the author(s). Finally, palynofacies observations along with GC-MS analyses were This paper was selected for presentation by an ALAGO Scientific Committee following systematically performed for paleoenvironmental reconstructions. Lebedel, V., 2009. Etude sédimentologique des variations du potentiel review of information contained in an abstract submitted by the author(s). Introduction pétroligène des schistes bitumineux de l’Autunien du bassin d’Autun. First experiences on unconventional shale-oils in USA focused Master thesis, Université Pierre et Marie Curie, Paris. Introduction mainly on Type II organic matter (OM) such as in the Eagle Ford The Neuquén Basin, located in west-central Argentina, is part of Formation. Key parameters to define a sweet spot are volume in Marteau, P., 1983. Le bassin permo-carbonifère d’Autun : stratigraphie, the system of Sub-Andean foreland basins that extends along the place and quality: typically, it requires total organic carbon (TOC) > sédimentologie et aspects structuraux. Ph. D. thesis, Université de Dijon. eastern portion of the Andean Cordillera from Venezuela to Tierra 2 %, S1 > 2mg/g together with °API > 30. The aim of this study Document du BRGM 64. del Fuego, in the southern regionof South America. It has a roughly is to prospect lacustrine petroleum systems as new challenges for triangular shape with a surface area of more than 160.000 km2 shale-oil exploration. Penteado, H.L.B., Behar, F., 2000. Geochemical characterization and that contains a Mesozoic-Cenozoic sedimentary succession at compositional evolution of the Gomo Member source rocks in the least 7 km thick (Verganiet al., 1995). Previous works demonstrated that various fluids properties Recôncavo Basin (Brazil). In Mello, M. R., and Katz, B. J., (Eds.), Petroleum were encountered within lacustrine systems despite similar bulk systems of South Atlantic margins. AAPG Memoir 73, 179-194. This history of tectonic evolution is reflected in a complex structural kinetics and initial hydrogen index (Fig. 1; Penteado and Behar, framework. Thelate Jurassic-earliest Cretaceous shaly section 2000). In order to understand what are the factors controlling Virolle, C., 2010. Mise au point technologique et procédure de pyrolyse of Vaca Muerta Formation is an unconventional shale play for source rocks primary fluid characteristics, it is necessary to unravel d’oil shales en présence d’eau. Master thesis, Université Pierre et Marie exploration. paleoenvironmental conditions that prevailed during source-rock Curie, Paris. deposition. Experimental This study was carried out with cutting samples from Vaca Muerta Formation, which is a prolific source rock interval. In order to provide geochemical characterization a set of 932cutting samples wasanalyzedfor Total Organic Carbon (TOC wt%) and pyrolysis Rock Eval determinations. Some composite cutting samples were used to determine geochemical characteristics including vitrinite reflectance (%Ro), Spore Coloration Index (SCI) and spectrum fluorescence and Organic Extract. Kerogen characterization was based on palynofacies analyses (Tyson, 1995, MendonçaFilhoet Figure 2.Lithological composite log of the Autunian in the Autun Basin al., 2012). It was collected an immature outcrop sample from Vaca (modified from Marteau, 1983; Lebedel, 2009) Muerta to obtain kinetic parameters.

Figure 1.Hydrocarbon distributions and activation energy spectra (A = Results and Discussion Results and Discussion 1014) of samples from the Recôncavo (a) and Autun (b) Basins (modified Samples displayed relatively high TOC ranging from 1 to 33 %. TOC values revealed a rich sequence reaching up to 8.5 wt.%.The from Penteado and Behar, 2000; Virolle, 2010) Tmax values indicate that half of the Igornay and Lally Fms samples insoluble residue shows values between 30 and 85% indicating are mature (Tmax > 440°C); and that samples from Surmoulin a predominance of marls deposition. The pyrolysis results (free In this study, we focus on the Autun Basin (Saône et Loire, France) and Millery Formations are generally immature. Most of immature hydrocarbon - S1 peak andsource potential - S2 peak), are very known for its Permian oil shales (Fig. 2; Marteau, 1983). A set of samples show HI and OI values indicative of lacustrine organic low in the western part of the basin.These indicate mature and samples has been collected from a borehole drilled in the center matter, the other having a higher plants signature. overmaturesections which are corroborated by Tmax (ºC). Values of the Basin. Primary fluids characteristics are determined through indicating early mature sections were measured in the eastern kerogen extracts analysis, whereas paleoenvironmental conditions First-obtained hydrocarbon profiles indicate low to moderate region. are deduced from palynofacies and biomarker analyses. paraffinic oils. On the other hand, activation energy spectra are relatively homogenous and typical of mono-energetic oils (Fig. 1). The palynofacies analysis revealed that the samplespresented oil Experimental Preliminary palynofacies results indicate strong abundance prone kerogen (predominance of amorphous organic matter - AOM). After standard source rocks characterization study (e.g. TOC, HI,

188 189 Beside this, a maturation index based on petrographic analysis Panagiotaras, D. (Ed.), Geochemistry – Eath’s System Processes. Intech, UP05 m/z 191, 231 and 253 , characteristic of tricyclic and pentacyclic terpanes indicates some areas that are suitable for shale gas and others for Croatia, p. 211-248 , steranes and monoaromatics of triaromatics steranes, respectively, for the shale oil research. Geochemical characterization of Asphaltic nine samples free maltenes and occluded. Peters, K. E., Walters, C.C., Mankiewicz, P. J. 2006. Evaluation of kinetic Sandstones Based on Theanalysis In general, Vaca Muerta organic extracts presented bitumen uncertainty in numerical models of petroleum generation. AAPG Bulletin, By analyzing the calculated values for geochemical reasons chromatographic profile due to n-paraffin irregular distribution and 90, 3, 387-403. Biomarkers freed from and occluded In given in Table 1 we note significant differences for samples of the presence of UCM (unresolved complex mixture). Theasphaltenic Structures free and occluded maltenes. Monitoring the rate H29/H30 once Tyson, R. V., 1995. Sedimentary Organic Matter.Organic Facies and again highlights the stability calculated for samples of maltenes The molecular parameters obtained by GC-MS analysis pointed to Palynofacies.Chapman & Hall.Londres.615 p. a* a Tatiany De A. F. Britto / Eliane S. De Souza / Georgiana F. Da occluded , which were around 1.50 values , indicating a higher a high maturity level (Ts/(Ts+Tm), 20S/(20S+20R) sterane, C29αββ/ Cruza relative abundance of C29 α,β-norhopane (H29) compared the (C29αββ+C29ααα) sterane in the western region. Vergani, G.D., Tankard, A.J., Belotti, H.J., Welsink, H.J.1995. Tectonic C30 α,β-hopane (H30) . An inverse behavior in the same ratio Evolution and Paleogeography of the Neuquen Basin, Argentina. AAPG a Department ofGeology/Geochemistry, Laboratory of Engineering could be noticed for the samples of free maltenes, in which the For evaluation of plays and prospects, it is useful to analyze Memoir, 62, 383-402. and Petroleum Exploration, UENF, Macaé – RJ, Brazilv immature samples to provide input data formodelling studies such calculated values were generally less than 1.0, indicating a higher as: stratigraphic reconstruction and petroleum system to improve e-mail: [email protected] concentration of (H30) compared to C29 α,β-norhopane (H29). the understanding of the sedimentary basin. Further interpretation or analysis may be required to resolve differences. Copyright 2014, ALAGO. The calculated values for the triaromatics ratio (RTA) were exactly This paper was selected for presentation by an ALAGO Scientific Committee following the same (0.20) for the nine samples maltenes occluded, confirming TheVaca Muerta immature sample presented a highpercentageof review of information contained in an abstract submitted by the author(s). the protective capacity of asphaltenic structures also for aromatic yellow/light-orangefluorescingAOM Group. The Phytoclast Group compounds occluded. The RMTA ratio also varied significantly and is dominated by non-opaqueand Palynomorph group is mainly Introduction knowing that RMTA it increments from 0 to 100 % with increasing represented by well-preserved sporomorph components andrare Considering theprotective capacityofasphaltenesstructurestothe thermal maturity 3.4 and that biodegradation processes acted dynocists (marine microplankton). This palynofacies represents processes ofsecondary alteration, as reportedin previousstudies decisively affected the interpretation of the parameters of thermal organic matter deposited in a distal dysoxic-anoxic ramp. (LIAO et al., 2006; BENNET et al., 2006) this work had the main maturity, calculated from the maltenes free, one may conclude by Additionally, low energy and reducing conditions in depositional objectivestudy the influence ofbiodegradationingeochemical pa- examining the values found for the maltenes occluded group oil setting supplied potential source rock sequence (Tyson, 1995). This rametersnormally used asindicatorsof thermalmaturityoilsnotbio- samples A and B are shown a bit more heat evolved from the group sedimentary sequence is normally typical of organic-rich shales degradedbycomparativeanalysis of thedistribution profilesof the deposited in stratified shelf/rampsea conditions. The biomarker saturatedand aromaticbiomarkerspresent in themaltenesfreedan- C, with higher percentages of asphaltenes. data also suggested a marinepaleoenvironment. It was possible to doccluded, releasedbymildchemical oxidationof asphaltenesob- identify differences in organic facies such as shallow water facies tainedfromnineoil samplesfromoutcropsofasphalticsandstones of- 18α (H)-22,29,30-trisnorhopane/(18α (H)-22,29,30- and increase of continental organic matter. PiramboiaFormation. trisnorhopane+17α(H)-22,29,30-trisnorhopane) in m/z 191; (b) gamacerane/17α,21β(H)-hopane in m/z 191; (c)terpanetetraciclic Experimental C24/17α,21β(H)-hopane in m m/z 191; (d) 18α(H)-22,29,30- The ninesamples ofasphalticsandswere subjectedto twoSoxhle- trisnorhopane/17α,21β(H)-hopane in m m/z 191; (e) 17α,21β(H)- textractionwith hexaneand chloroform/methanol toobtain thefreed- 30-norhopane/17α,21β(H)-hopane in m/z 191; (f) (pico16 + fractionofmaltenes(MALTfreed) andasphaltenes(ASF). To obtainthe pico17)/ ∑(pico16 + pico17 + ... + pico22) in m/z 231; (g) (pico20 fraction ofmaltenesoccluded(MALToccluded), the asphalteneswere + pico21)/∑(pico11 + pico12 + pico14 + pico15 + pico20 + subjectedto oxidativereaction.The freemaltenesandoccludedwere pico21) in m/z 231 e 253. Standard deviation calculatedfor each Figure 1.Predominance of Amorphours Organic Matter Group. subjected toliquidcolumn chromatography onsilica gel (230-400 parameterbased on the totalpopulation ofsamplesper group(n =3). PhotomicrographicA was taken usingtransmitted white light. mesh,Merck)for separating thefractionsof saturatedcompoundsan- ni: not identified. PhtomicrographicB: was taken using fluorescence mode. daromaticresins.The fraction ofsaturated and aromatichydrocar- bonswere analyzed by GC/MSAgilentgas chromatograph, Model- According to maturation studies, the outcrop sample selected for 6890with selectiveion monitoring(SIM) analysis ofionswithm/z191, Conclusions kinetic analysis had shown 0.58% Ro presenting a good correlation 231 and253forfractionofsaturated and aromatichydrocarbons. The technique ofmildchemical oxidationof asphaltenesis efficientfor with SCI index (Barnard et al., 1981) and biomarkers data. Results and Discussion the release ofsaturated and aromaticcompounds, importantfor lifting Conclusions thegeochemical characteristicsof oilbiomarkers, even in aseverelevel Vaca Muerta Formation has excellent geochemical characteristics as ofbiodegradation. Whereas, in the literaturethere areno reports on producing unconventional shale oil/gas reservoirs. Unconventional themonitoringand identification ofbiomarkersaromatic compounds, shale oil resources are present in the eastern region, and gradually released fromasfaltênicasstructuresthroughchemical oxidation, our passinto shale gas to the west. results bringa new approach tothe useof mono-andtriaromaticsst eranesindicativeof thermalmaturitysamplesseverelybiodegradedoil. Acknowledgements The resultsfor the parametersof thermalmaturity,calculated from To Petrobras and Petrobras Argentina S.A. for the authorization to present this paper. thesaturated and aromaticbiomarkersobtainedfreeofmaltenes, were not reliable forevaluation ofgeochemicalsamplesof References oilswithsevere levels ofbiodegradation. Barnard, P.C., Collins, A.G., Cooper, B.S. Generation of hydrocarbons – Time, temperature and source rock quality.1981. In: Brooks J. (Ed.) Organic Acknowledgements Maturation Studies and Fossil Fuel Exploration. Academic Press, London, Table 1 shows the comparison of results obtained for the geochemical ratios The authors thank CNPq (Brazilian research council) for fellowships 1981. pp. 337-342. calculated from peak areas identified in the mass chromatograms of ions and Estácio de Sá University from financial support.

Mendonça filho, J. G., Menezes, T. R., Mendonça, J.O. 2012. Organic 190 191 Facies: Palynofacies and Organic Geochemistry Approches. In: References Peters, K. E.; Walters, C. C.; Moldowan, J. M.; The Biomarker Guide: correspond to free and sorbed HCs in shale plays). Figure 1 Liao, Z., Geng, A., Graciaa, A., Creux, P., Chrostowska, A., Zhang, Y., Biomarkers and Isotopes in the Petroleum Exploration and Earth History, UP06 illustrates the thermovaporization and pyrolysis conditions defined 2006. Saturated hydrocarbons occluded inside asphaltene structures and 2nd ed., University Press: Cambridge, 2005, vol. 2. for this new IFPEN “Shale Play” method in comparison to the existing methods (i) Reservoir and (ii) Basic/Bulk-Rock. their geochemical significance, as exemplified by two Venezuelan oils. New Rock-Eval method for Organic Geochemistry, 37, p 291–303. Huang, H.; Larter, S. R.; Bowler, B. F. J.; Oldenburg, T. B. P., 2004.A characterization of shale plays dynamic biodegradation model suggested by petroleum compositional a* a Bennet, B.; Fustic, M.; Farrimond, P.; Huang, H.; Larter, S. R., gradients within reservoir columns from the Liaohe Basin, NE China. Maria-Fernanda Romero-Sarmiento , Daniel Pillot , Géremie a a a 2006.25-Norhopanes: Formation during biodegradation of petroleum in the Organic Geochemistry, 35, 299-316. Letort , Violaine Lamoureux-Var , Valérie Beaumont , Alain-Yves a subsurface. Organic Geochemistry 37, 787-797. Hucb, Bruno Garcia

a IFP Énergies nouvelles (IFPEN), Direction Géosciences, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison Cedex –France b UPMC -Université Pierre et Marie Curie. Institut des Sciences de la Terre Paris (UMR 7193 UPMC-CNRS)

*[email protected]

Figure 1.Rock-Eval temperature program for HCs characterization for the Copyright 2014, ALAGO. new IFPEN “Shale Play”method in comparison to the classical “Basic/Bulk- This paper was selected for presentation by an ALAGO Scientific Committee following Rock” and “Reservoir” methods. review of information contained in an abstract submitted by the author(s).

Introduction The specific analytical conditions for the IFPEN “Shale Play” method are described as follow: Unconventional resources such as tight, fractured and hybrid shale plays are considered self-contained source and reservoir systems. The pyrolysis step starts at T1=100°C. This temperature is chosen A better understanding of the thermal cracking of sedimentary as the most appropriate to initiate thermovaporization. organic matter,hydrocarbons (HCs)generation, expulsion and retention mechanismsconstitutes a keypoint, estimating the oil From T1, the temperature is increased at a rate of 25 °C/min, up and gas in-place for their exploration. Herein, we introduce a new to T2=200°C. T2 is maintained for 3 minutes. During this step, the “ready to use” method of analysis and interpretation for the Rock- most easily thermovaporizable HCs are retrieved. Eval devicefor better assessmentof free or sorbedHCs in shale

(a) 18α(H)-22,29,30-trisnorhopane/(18α(H)-22,29,30-trisnorhopane+17α(H)-22,29,30-trisnorhopane) in m/z 191; (b)gamacerane/17α,21β(H)-hopane in m/z 191; (c)ter- plays. This method wasdeveloped at IFPEN (France). panetetraciclic C24/17α,21β(H)-hopane in m m/z 191; (d) 18α(H)-22,29,30-trisnorhopane/17α,21β(H)-hopane in m m/z 191; (e) 17α,21β(H)-30-norhopane/17α,21β(H)-ho- From T2, the temperature is increased at a rate of 25 °C/min, up to pane in m/z 191; (f) (pico16 + pico17)/ ∑(pico16 + pico17 + ... + pico22) in m/z 231; (g) (pico20 + pico21)/∑(pico11 + pico12 + pico14 + pico15 + pico20 + pico21) in T3=350°C. This temperature is maintained for 3 minutes. Heavier m/z 231 e 253. Standard deviation calculatedfor each parameterbased on the totalpopulation ofsamplesper group(n =3).ni: not identified. The Rock-Eval pyrolysis has been widely used to identify the organic molecular weight HCs are thermovaporized. matter occurrence, type and thermal maturity levelover the last 30 Table 1.Geochemical parametersof maturity andbiodegradationforsaturated and aromaticbiomarkersmonitoredthrough theionm/z177, 191, years.This technique has been also used to quantify the total organic From T3, the temperature is raised again at a rate of 25 °C/min, up 231 and253for the ninesamplesof freeandoccludedmaltenes. carbon (TOC) content as well as the mineral carbon content of both to T4=650°C in order to pyrolysis remaining organic matter. reservoir and source rocks (e.g. Espitaliéet al., 1986; Lafargueet al., 1998; Behar et al., 2001). This pioneering device,thanks to the New acquired parameters from the IFPEN “Shale Play” Method built-in “Basic/Bulk-Rock” method, providesrelevant parametersto The IFPEN “Shale Play”method provides 3 key parameters: Sh0, characterize source rocks in a petroleum system perspective. Sh1 and Sh2. These parameters are derived from the surface Applied to exploration purposes, the S2 peak, representing the oil areas of the 3 recorded peaks (Figure 2). They correspond to the residual potential, is the main focus of this method.When the S1 quantities of HC compounds monitoredby aFID. These acquired peak is the main concern, i.e. reservoir units studies, an alternative parameters are expressed in milligrams of HC compounds per built-in method, the “Reservoir” method, is available. It is based gram of initial rock, as for all Rock-Eval methods. on a pyrolysis temperature program allowing an optimal recovery of “free” HC and a better deconvolution of the components. This The Sh0 peak corresponds to the lightest thermovaporized method was shown to provide an estimation of API degree from HCsreleased between T1 (100°C) and T2 (200°C).The Sh1 peak cuttings (Trabelsiet al. 1994). corresponds to heavier thermovaporizedHCs released between T2 (200°C) and T3 (350°C). Finally, the Sh2 peak corresponds to HC Meanwhile, the interest in shale play requires the development of issued from both the pyrolysis of sedimentary organic matter and a new method providing operational relevant parameters devoted the thermovaporization ofthe heaviestHCsdetected between T3 to exploration and production of these source/reservoir plays.A (350°C) and T4 (650°C). specific Rock-Eval method, including a new pyrolysis program and associatedparameters for evaluation of shale plays is described New calculated parameters from the IFPEN “Shale Play” Method hereafter. The total quantity ofthermovaporizedHCs (Sh0 and Sh1) provides The IFPEN “Shale Play” Method : Description an estimation of total available HCs for production, from which is The IFPEN “Shale Play” method, is first characterized by a specific defined theHCContent Index (HCcont) : temperature program which allows a more exhaustiverecovery and separation of the thermovaporizable HCs (which probably HCcont = Sh0 + Sh1[Unit : mg of HC/g of initial rock

192 193 Europe. Graham and Totman, London, pp. 71-86 UP07 The relative quantity of lighter molecular weight HC provides an Lafargue, E., Marquis, F., Pillot, D., 1998. Rock-Eval 6 applications in Experimental The samples used in this study were immature Types II and IIs estimate of the quality of reservoir. The HC Quality Index (HQI) is hydrocarbon exploration, production, and soil contamination studies. Oil & Impact of high (900 bar) water pressure calculated fromSh0 and Sh1 Gas Science and Technology - Rev. IFP 53, 421-437. source rocks (Kimmeridge Clay, Dorset UK, and Monterey shale, on oil generation and maturation in California USA respectively).The hydrous pyrolysis experiments HQI = Sh0 /(Sh0+Sh1) * 100 [Unit: wt. %] Trabelsi, K., Espitalié, J., Huc, A.-Y., 1994. Characterization of Extra Heavy Kimmeridge Clay and Monterey source rocks: were conducted on non-extracted rocks using a 25 ml Hastalloy Oils and Tar Deposits by modified Pyrolysis Methods. Proceedings of the « Implications for hydrocarbon retention and cylindrical pressure vessel at 350°C and 380°C between 6 and 24 A Production Index of Shale Plays (PIShale) provides the information Heavy Oil Technologies in a Wider Europe » Thermie EC Symposium, Berlin gas generation in shale gas systems h in the pressure range of 180-900 bar. in order to define the section of interest of a shale play. 1994, 30-40. Results and Discussion Clement N. Ugunaa, Will Mereditha*, Colin E. Snapea, Andrew D. PIShale = (Sh0+Sh1)/(Sh0+Sh1+Sh2) * 100 [Unit: wt. %] The gas and oil yields generated for the Kimmeridge Clay formation Carrb, Iain C. Scotchmanc, Andrew Murrayd (KCF) source rock are presented in Figures 1 and 2 respectively as a function of pressure.At 350°C for 6 h the KCF source rock a Faculty of Engineering, University of Nottingham, Innovation had not started generating oil, however the gas (for 6-24 h) and Park, Energy Technologies Building, Jubilee Campus, Nottingham, expelled oil (for 12 and 24 h) yields reached a maximum at 180 NG7 2TU, UK. bar and progressively decreased to 900 bar, with the 900 bar gas b Advance Geochemical Systems Ltd, 1 Towles Fields, Burton-on- and oil yields being about 50% less than the 180 bar yields at 24 the-Wolds, Leicestershire, LE12 5TD, UK. h (maximum oil generation). The reduction in oil yield observed at c Statoil UK Ltd., 1 Kingdom Street, London, W2 6BD, UK. high pressures at 350°C is due to pressure retarding oil generation d Woodside Energy Ltd., Woodside Plaza, 240 St Georges Terrace, and expulsion. This resulted to significant amount of extractable Perth, WA 6000, Australia. bitumen being retained in the rocks at high pressures, such that for 24 h the 900 bar bitumen yield (809 mg/g TOC) was 50% more e-mail: [email protected]. than the 180 bar yield (398 mg/g TOC).

Copyright 2014, ALAGO. This paper was selected for presentation by an ALAGO Scientific Committee following review of information contained in an abstract submitted by the author(s).

Introduction In conventional hydrocarbon systems, oil and gas generation, and source rock maturation occur under water pressure conditions, yet the geochemical models currently used to predict hydrocarbon generation and source rock maturation are determined by the Figure 2.Rock-Evalpyrogramscomparing the 3 Rock-Eval methods: Basic/ thermal history of the source rock, with pressure being considered Bulk-Rock, Reservoir and Shale Play. to have no effect. The absence of pressure from geochemical models arise from pyrolysis methods such as Rock Eval (open The section of interest,which indicatesthe target for production system pyrolysis), MSSVanhydrous (closed system pyrolysis with isidentifiedfora production index of shale plays (PIShale) greater the vessel containing sample and inert vapour) or hydrous pyrolysis than a reference value. This reference value depends on the type (closed system pyrolysis under water, sample and inert vapour Figure 1.Hydrocarbon gas yields for Kimmeridge Clay pyrolysis. of organic matter, and can be defined by default or by numerical mixtures conditions) with no pressure effect used to derive the modeling (Espitaliéet al., 1987). models. However, it has been observed that when experiments were At 380°C the expelled oil yield (Figure 2) also reduced with an conducted under high pressure hydrous pyrolysis conditionstypical increase in pressure, with the 900 bar oil yield been 48% less Section of interest =PIShale>λ of conditions in geological basins, hydrocarbon generation and than the 245 bar yield at 12 h (maximum oil generation). This source rock maturation were both retarded by pressure (Uguna et Conclusions also resulted to the bitumen yield obtained at 900 bar (233 mg/g al., 2012). The proposedmethod can be easily programedwithin any Rock- TOC) being 48% more than the 245 bar (120 mg/g TOC) yield Evalinstrument. It provides an efficient, fast and ready to use tool at 12 h.At 380°C the retardation effect of pressure was minor Unconventional shale gas resource systems are slightly to highly informing on the quantities of “free and sorbed” HCs in shale plays. for gas generation (Figure 1).This is due to a combination of high over-pressured (Jarvie, 2012), and the same geochemical methods Moreover, key parameters are proposed to define sections of temperature (which reduced the effect of pressure) and cracking as used for conventional hydrocarbon exploration have also been interest. of bitumen retained in the rock at high pressures directly to gas. widely applied for unconventional shale gas exploration. In addition, The cracking of bitumen retained in the rock at high pressures to the few published studies so far have again used Rock Eval, References gas observed here have also been reported as the source of gas in pyrolysis gas chromatography or MSSV closed system pyrolysis Behar, F., Beaumont, V., De B. Penteado, H. L., 2001. Rock-Eval 6 shale gas systems (Bernard et al., 2012). to investigate gas generation and retention in shale gas resource Technology: Performances and Developments. Oil&Gas Science and systems (e.g. Bernard et al., 2012).It is currently believe that shale Technology 56, 111-134. gas generation results from cracking of bitumen andor oil retained in low porosity shale source rocks at high maturity (Bernard et al., Espitalié, J., Deroo, G., Marquis, F., 1986. La pyrolyse Rock-Eval et ses 2012). This study investigates the impact of high pressure on gas applications. Revue de l’Institut Français du Pétrole 41, 73-89. and oil generation, and source rock maturation in conventional hydrocarbon systems, and also to provide an insight on the role of Espitalié, J., Marquis, F., Sage, L., 1987. Organic geochemistry of the Paris pressure on gas generation via bitumen and/or oil cracking in shale Basin. In: Brooks, J., Glennie, K. (Eds.), Petroleum Geology of North West gas reserves using high water pressure hydrous pyrolysis.

194 195 UP08 48 (8), 16-21.

Swami, V.;Settari, A., 2012.A Pore Scale Gas Flow Model for Shale Gas Porosity, permeability and methane Reservoir.Society of Petroleum Engineers (SPE), Americas Unconventional sorption capacity ofoil and gas shales at Resources Conference, Pittsburgh, Pennsylvania, USA. SPE Paper 155756. different stages of thermal maturation Tinni, A.; Fathi, E.;Agarwal, R.; Sondergeld, C.;Akkutlu, Y.; Rai, C., 2012. RalfLittkea*, Bernhard M.Kroossa, Alexandra Amann-Hildenbranda, Shale permeability measurements on plugs and crushed samples.Society AminGhanizadeha, MatusGasparika, BenjaminBrunsa Figure 1.Relationship between methane sorption and pressure for immature, mature of Petroleum Engineers (SPE), Canadian Unconventional Resources and over-mature Posidonia Shale samples. Mature samples had significantly lower Conference, Calgary, Alberta, Canada. SPE Paper 162235. a Institute of Geology and Geochemistry of Petroleum and Coal, porosity and permeability values than immature/over-mature samples. EMR Group, RWTH Aachen University, Germany Conclusions *[email protected] The methane sorption capacities (in dry shales) show a linear positive trend with TOC but significant deviations from this trend Copyright 2014, ALAGO. exist that are linked to the overprinting effect of thermal maturity Figure 2.Oil yield for Kimmeridge Clay pyrolysis. This paper was selected for presentation by an ALAGO Scientific Committee following (Fig. 1). No correlation was observed between the clay content and review of information contained in an abstract submitted by the author(s). sorption capacity to methane and we conclude that clay minerals The KCF VR were always higher at 350°C and 380°C at 180 only play a minor role in methane sorption (Gasparik et al., 2014). bar and 245 bar respectively between 6-24 h. At 350°C for 24 Introduction Results of sorption experiments were implemented into a petroleum h(maximum oil generation), the VR decreased by 0.25% Ro going Shale gas and shale oil reservoirs are unconventional hydrocarbon systems model(PetroMod®) in order to calculate methane sorption from 180 bar (0.85% Ro) to 900 bar (0.60% Ro). At 380 also for 24 plays composed of a variety of fine-grained sedimentary rocks capacities and gas contents in the Posidonia Shale in NW-Germany h the VR was 0.29% Ro lower at 900 bar (0.99% Ro) compared to including shales, mudstones, marlstones, siliceous shales, and the Netherlands on a basin-wide scale, based on a previously 245 bar (1.28% Ro). The Monterey shale gas, expelled oil and VR results obtained at 350 and 380°C show the same trends as for limestones and siltstones (Javadpour et al., 2009). Despite published 3D basin model (Bruns et al., 2013). the KCF source rock. considerable gas-in-place (GIP) estimations for shale gas plays, these complex, heterogeneous reservoirs require innovative References Conclusions exploration and completion strategies to produce natural gas or Amann-Hildenbrand, A.; Ghanizadeh, A.; Krooss, B. M., 2012. Transport The huge decrease in gas and oil yields, and VR observed for oil economically (Chalmers et al., 2012). Economic gas flow rates properties of unconventional gas systems. Marine and Petroleum Geology both source rocks with increase in water pressure indicates that in in these reservoirs, which commonly have permeability coefficients 31 (1), 90-99. high pressure basins gas generation, oil generation and expulsion, down to the nDarcy-range, are still technically difficult to achieve, together with source rock maturation will all be retarded for Type II partially due to the poor understanding of the fluid transport Bruns, B.; di Primio, R.; Berner, U.; Littke, R., 2013. Petroleum system source rocks. Pressure retardation of oil generation and expulsion processes in these lithotypes (Amann-Hildenbrand et al., 2012; evolution in the inverted Lower Saxony Basin, northwest Germany: a 3D was identified for the first time as a possible mechanism for bitumen Eseme et al., 2012; Swami and Settari, 2012). Very few studies basin modeling study. Geofluids 13, 246-271. or oil retention in rocks in unconventional shale gas systems in have experimentally investigated the fluid flow mechanisms in the addition to low porosity of shales as currently thought. matrix of organic-rich shales and the characteristics of fluid flow Chalmers, G.R.L.; Ross, D.J.K.;Bustin, R.M., 2012. Geological controls on The implications from this study are that in geological basins, processes within the fracture and matrix systems of these lithotypes matrix permeability of Devonian Gas Shales in the Horn River and Liard pressure, temperature and time will all exert significant control are still poorly understood due to the difficulty of measuring the basins, northeastern British Columbia, Canada. International Journal of on the extent of hydrocarbon (oil and gas) generation and source low and extremely-low permeability of shales (e.g. Chalmers and Coal Geology 103, 120-131. rock maturation. In particular, the increase in un-expelled oil and Bustin, 2012; Tinni et al., 2012). preserved bitumen being retained in the source rock as bitumen Chalmers, G.R.L.;Bustin, R.M., 2012.Geological evaluation of Halfway– observed in the high pressure experiments is likely to have Experimental Doig–Montney hybrid gas shale–tight gas reservoir, northeastern British important implications for the further generation potential of the Here, we report data on a sample setof black shales(Posidonia Columbia. Marine and Petroleum Geology 38 (1), 53-72. source rocks into the gas window. Indeed this may explain the Shale, Lower Jurassic, North German basin) which reached observation that Type II source rocks matured to the gas window maturity levels between 0.5 and 1.45 % vitrinite reflectance. Eseme, E.; Krooss, B. M.; Littke, R., 2012. Evolution of petrophysical conditions contain the most profile shale gas resources, such as Laboratory studies were conducted to investigate the porosity as properties of oil shales during high-temperature compaction tests: the Barnett, Woodford and Marcellus shales in the USA. well as storage and transport of gas. Permeability measurements Implications for petroleum expulsion. Marine and Petroleum Geology 31 were performed at effective stresses ranging between 6 and 37 References (1), 110-124. MPa and a temperature of 45°C. The effects of different controlling BernardS.,Horsfield, B.,Schulz, hans-M.,Wirth, R.,Schreiber, A., 2008. Geochemical evolution of organic-rich shales with increasing maturity: A factors including permeating fluid, maturity, anisotropy, moisture Gasparik, M.; Bertier, P.; Gensterblum, Y.; Ghanizadeh, A.; Krooss, B. M.; STXM and TEM study of the Posidonia shale (Lower Toarcian, northern content and effective stress on the fluid conductivity were analysed Littke, R., 2014. Geological controls on the methane storage capacity in Germany). Marine and Petroleum Geology.87, 70-89. and discussed. organic- rich shales. International Journal of Coal Geology 123, 34- 51.

Jarvie, D.M. 2012, Shale resource systems for oil and gas: Part 1- Shale- Results and Discussion Ghanizadeh, A.; Amann- Hildenbrand, A.; Gasparik, M.; Gensterblum, gas resource systems, in Breyer, J.A. (Ed.), shale resources for the 21st Permeability coefficients measured perpendicular and parallel to Y.; Krooss, B. M.; Littke, R., 2014. Experimental study of fluid transport century: AAPG Memoir. 97, 69-87. bedding (3•10 22 - 9.7•10 17 m2) were within the range previously processes in the matrix system of the European organic- rich shales: II. reported for other shales and mudstones. Among the sample suite Posidonia Shale (Lower Toarcian, northern Germany). International Journal Uguna, C.N., Carr, A.D., Snape, C.E., Meredith, W., Castro-Diaz, M., 2012. studied, the lowest porosity and permeability coefficients were of Coal Geology 123, 20-33. A laboratory pyrolysis study to investigate the effect of water pressure measured on samples of intermediate thermal maturity (0.88% VRr, on hydrocarbon generation and maturation of coals in geological basins. oil-window). Permeability coefficients (He, CH4) measured parallel to Organic Geochemistry. 52, 103-113. Javadpour, F., 2009.Nanopores and apparent permeability of gas flow in bedding were up to more than one order of magnitude higher than mudrocks (shales and siltstone). Journal of Canadian Petroleum Technology those measured perpendicular to bedding (Ghanizadeh et al., 2014).

196 197 UP09 UP10 Results from the general analyses permitted the selection of Figure 2. BALUARTE SABINAS Isotherm coal 10 samples (Table 1) for CH4 injection testing to determine the adsorption-desorption gas capacity and the hydrocarbon potential Conclusions Designing Tight-Shale Production STUDY OF GAS ADSORPTION-DESORPTION production in the basins studied. 1. – In both basis, higher kerogen maturation levels, imply higher Strategies by Mapping Oil Cracking PROPERTIES IN UNCONVENTIONAL level of adsorption capacity and desorption rate of CH4. RESERVOIRS OF MEXICO Jeremy Dahl1 and J.M. Moldowan2 2. - Sabinas Basin is the most important in terms of methane gas J. Josué Enciso C. a,c,e, L. Martínezb, M. J. Lemos de Sousac,h, L. production, as well as, storage capacity and gas expulsion. 1 Stanford University F. Camacho Ortegónd, C. F. Rodriguesc, M.A.P. Dinisc, F. De La O 2 Biomarker Technology International Burrolaf, S. Omodeo Salég 3. - Petrographic analysis and the study of adsorption-desorption provide information about the retention capacity and circulation of Abstract a UMR-7359, CNRS GeoRessources, Université de Lorraine, gases in a unconventional reservoirs, thus permiting to establish Understanding in-reservoir oil-cracking (the natural conversion of Boulevard des Aiguillettes, 54506 Vandœuvre-lès-Nancy, France. the true potential of gas production from a basin oil to gas at elevated temperatures) is fundamental to designing b UMR 7516 - IPGS/EOST, CNRS - Université de Strasbourg, 1 production strategies in tight shales. Regions where little or no rue Blessig, 67084 Strasbourg cedex, France. Acknowledgments cracking has occurred may be difficult and uneconomicto produce. c Universidade Fernando Pessoa, Praça 9 de Abril 349, 4249-004 Table 1. (Results petrography), Thanks are due to the Consejo Nacional de Ciencia y Tecnologia Alternatively, shalesin which very high amounts of cracking has Porto, Portugal. MO Type – Organic matter type; %OM - Organic matter percentage; %Ro- (CONACYT), to the Corporacion Mexicana de Investigacion en occurred may be producible, but will be devoid of liquids, which d ESI, Universidad Autónoma de Coahuila, Blvd Adolfo López Vitinite reflectance percentage; %Vitrinite – Vitrinite percentage; %Liptinite– Materiales SA. de CV. (COMIMSA) and to the Servicio Geologico Liptinite percentage; %Inertinite – Inertinite percentage. can be crucial to the economics of production. The ideal areas Mateos s/n, C.P 26800, Nueva Rosita, Coahuila. México. Mexicano (SGM) for funding and providing samples for the project. for production are those in which intermediate amounts of cracking e COMIMSA, Calle Ciencia y tecnología No. 790, Col. Saltillo 400, Furthermore we thank Universidade Fernando Pessoa, Universite Results and Discussion de Lorraine and Universidad Autonoma de Coahuila for their has lowered the API and viscosity of the liquids, decreased the C.P. 25290, Saltillo, Coahuila. México. The adsorption isotherms are the technique used to predict contributions to the implementation of the project. size of the average molecules in the liquids and generated gas f SGM-SE, Gobierno de México, Blvd. Felipe Ángeles km. 93.50- the storage capacity of gas in a specific reservoir, which means, which can serve as a carrier for the remaining liquids. In addition, 4, Col. Venta Prieta, C.P. 42080, Pachuca, Hidalgo. México. the maximum amount of gas that the sample can hold from low the conversion of liquid to gas generates pressures which can g IGEO-CSIC, Universidad Complutense de Madrid, Ciudad pressures above the atmospheric pressure to 65 bar. The high affinity References cause natural fracturing in the reservoir increasing the efficiency of Universitaria, 28040, Madrid España. of the organic matter to store the gas depends directly on its physical Rodrigues C. F., 2002: The application of isotherm studies to production. h Academia das Ciencias de Lisboa, 1249-122, Lisboa Portugal. structure (% Ro) and intermolecular forces between organic material evaluate the coal bed methane potential of the Waterberg Basin, and fluid (Rodrigues, 2002), as shown in figure 1 that represents South Africa. (PhD thesis, Universidade do Porto, Portugal) Because of the importance of oil cracking to designing production [email protected] the sample Sahle gas ING-1 with a Ro of 0.32%, and Figure 2 that strategies, many indirect means of determining oil cracking have represents the coal sample Baluarte with a Ro of 1.35%. been employed in the industry. These include vitrinite reflectivity, Copyright 2014, ALAGO. Rock-Eval pyrolysis, retorting and the determination of gas This paper was selected for presentation by an ALAGO Scientific Committee following isotopes and composition. However, because none of these review of information contained in an abstract submitted by the author(s). methods were designed to directly measure oil cracking, each has its drawbacks and uncertainties. To better define oil cracking, we Introduction developed a method to directly and quantitatively determine the The present project focus on the study of the adsorption-desorption amount of cracking using nanotechnology. Our method is based capacities of gases in Mexican unconventional reservoirs samples on measuring the abundance of nanodiamond (diamondoid) of coal and shale gas from the “Region Carbonifera” of Coahuila in tight shale extracts. Using this method it is possible map the and Chihuahua states, respectively, both located on the calcareous extent of cracking which has occurred for any tight both areally and platform of the northeast part of Mexico. vertically. Such maps will allow the user to define regions which will be difficult and un-economic to produce, regions which will yield Samples of the project were provided by the Servicio Geologico predominantly gas with very little liquid hydrocarbons and “sweet- Mexicano – SGM. Currently, the project has 52 samples of shale spots” from which both gas and liquids can be produced. Obviously, gas type from the Chihuahua Basin and 52 coal samples from the these maps will be of great help in designing production strategies, Sabinas basin. but theywill also delineate the economics of any particular region helping drive important business decisions such as which areas of a On the basis of general analyses, 10 samples were selected for Figure 1. ING CHIHUAHUA shale gas Isotherm particular shale would be best to acquire, and which would be best adsorption-desorption tests of CO2 and CH4, through Langmuir to divest.In addition, mapping oil cracking allows for the calculation isotherms, in the Laboratory of Reservoirs Simulation at the of pressures generated during the process, some of which are in Faculdade de Ciência e Tecnologia, Universidade Fernando excess of that need to naturally fracture the reservoir. And finally, Pessoa, Porto, Portugal. because oil properties such as API, viscosity and GOR are related to cracking, these maps will serve as guides for predicting these Experimental work properties for any region. General characterization was performed by: Elemental analysis for the determination of C, H, O, N, and S, petrographic analysis for characterization of organic matter, and image analysis to determine the percentage of maceral composition. These analyses were conducted at the laboratories of the Université de Lorraine, Nancy, France. Rock Eval Pyrolysis was carried out at the University of Lausanne, Switzerland, for determining the oil potential by artificial maturation.

198 199 UP11 UP12 The CO2 and N2 adsorption and Hg picnometry analysis allowed to know the distribution of porous volume, showing than macropores and mesopores increase greatly from 0.024 cm3/g and 0.09 Characterization of solid bitumen and Understanding the organic porosity cm3/g respectively in low maturity to 0.052 cm3/g and 0.020 its impact in possible unconventional evolution with thermal maturity in shales cm3/g respectively in higher maturity, Table 1 and Figure 1. In other reservoirsfrom Tablazo formation, hand the micropores (< 2nm) don’t increase so much. Tatiana Juliao Lemus*1, Robert Emilio Márquez1, Isabel Suárez Magdalena Middle Basin, Colombia. Ruiz2 and Begoña Ruiz2

Robert Márquez1*,Tatiana JuliaoandIsabe Suarez-Ruiz2 1. Ecopetrol S.A., ICP, Piedecuesta – Colombia Figure 1.Bitumen solid filling holes and oval circular morphology and 1. Ecopetrol S.A., ICP, Piedecuesta – Colombia dispersed in the mineral matrix. 2. INCAR CSIC, Oviedo – España 2. INCAR-CSIC. Instituto Nacional del Carbón, Oviedo– España The stratigraphic levels with the highest solid bitumen contents are *[email protected] *[email protected] Table 1.Geochemical Data and Solid Bitumen Reflectance measured in associated to areas with the higher organic content (TOC > 8%) two phases identified (homogeneous and dispersed).*free bitumen sample. and high total gas content (> 60 scf/ton). This association and the This paper was selected for presentation by an ALAGO Scientific Committee following This paper was selected for presentation by an ALAGO Scientific Committee following %Ro equiv = 0.0180xTmax – 7.16. review of information contained in an abstract submitted by the author(s) porous texture developed in those levels (with pores ranging from review of information contained in an abstract submitted by the author(s) 237 nm to 5 m in size ) suggest that the solid bitumen presence Optical microscopy and SEM allowed to recognize the solid can favour the accumulation of gaseous hydrocarbons. All this Introduction bitumen formation along to the studied maturity profile, however it Introduction confirms the good potential of the Tablazo Formation as shale gas The organic porosity plays an important role in the Unconventional The solid bitumen is a degraded, residual product rich in heavy reservoir. was observed that with increasing thermal maturity is most evident Reservoir – Shale Gas- Shale Oil together another parameters NSO compounds from the transformation of organic matter a porous texture in the solid bitumen, being possibly the bigger size as brittleness, Organic Content, and hydrocarbon types, thermal and / or oil. Its presence in source rock can be indicative that it pores in most advanced stage of thermal maturity, which can explain maturity. Now is known than the organic porosity enhance as generated petroleum and can play an important role in the storage the increase of macropores and mesopores volume, (Figure 2). the thermal maturity increase. In other hand it believed that gas and production of shale gas. In the Middle Magdalena Basin has and gas/light oil is stored in (smaller than 2 nm) micropores from been recognized good to excellent organic content in the marine, kerogen generated during the organic matter breakdown with lower-mid cretaceous Tablazo formation (TOC> 4%) which reached thermal maturity increase, in order to try understanding how is moderate-high thermal maturity (Ro between 1.1 and 1.6%), these the organic porosity evolution as increase the burial temperature, geochemical characteristics allow to propose good potential for we carried out an artificial maturation by means of hydropyrolysis unconventional resources for Tablazo formation. In recent studies experiments from an Upper Cretaceous organic-rich source rock in we have identified abundant presence of solid bitumen along La Luna Formation in the Magdalena Middle Basin. sequence rock according to that, we propose to characterize and to try understand its impact in possible rich-organic unconventional Experimental reservoirs from this formation. The artificial maturation was carried out inParr reactors using a methodology modified from Lewanet al 1979, Lewan 1993. The Experimental experiments were run on aliquots of same sample at temperatures The geochemical characterization of solid bitumen and source rock Figure 2.High bitumen solid associated with high TOC and high gas content between 290 and 365⁰C (300°C/72h, 320°C/72h, 330°C/72h, samples was done by Total Organic Carbon (TOC), Rock- Eval in 2 wells from TablazoFm. 45°C/72h, 355°C/72h y 365°C/72h). The geochemical analyses pyrolysis and organic petrography analyses. Based on the results (TOC, Pyrolysis Rock Eval and Organic Petrology) and porosity of these analyzes, samples were selected for accelerated extraction analysis were carried out previous and after hydrous-pyrolysis Conclusions Figure 1.Presence of solid bitumen along thermal maturity experiments. using an ASE-350 equipment. The recovered extracts were The presence of solid bitumen derived from high thermal maturity experiments. The samples were extracted in order to eliminate Red circles indicate pores. fractionated into their saturated, aromatics, resins and asphaltenes favors the accumulation of gas in the Tablazo formation, possibly bitumen or free hydrocarbon by means the solvent extraction. The components by open liquid chromatography technique Solvent related with porous texture/structure recognized in the bitumen- porosity was measured by means of different kind of techniques free extracts were analyzed by whole oil gas chromatography. rich levels identified by SEM and optical microscopy. as mercury intrusion using MicrometriticsAutopore IV 9500, helium The saturated and aromatic fractions were then analyzed by gas density in MicromeriticsAccuPyc1330Tequipment, N2 adsorption in The analysis showed that Tablazo formation have good potential chromatography coupled to mass spectrometer (GC-MS) with an a MicromeriticsAsap 2420 and CO2 adsorption in a Quantacrome as a Unconventional Shale Gas Reservoir which the gas was electron impact ionization system. Additionaly gas content was Instruments. measured from cores preserved in canister. Detailed analysis was generated possibly by secondary cracking of liquid hydrocarbons and stored in the organic porosity (kerogen and bitumen pores) carried using optical microcopy –OM, Scanning Electron Microscopy Results and Discussion and total porosity. – SEM, RAMAN spectroscopy and Thermogravimetric Analysis. The initial sample consist a laminated calcareous mudstone with Figure 2.Increasing volumes of macropores, mesopores and micropores high organic content of marine, kerogen Type II (TOC 5.5%, Acknowledgements with thermal maturity. Results and Discussion The authors thank Ecopetrol for support our participation in the XIV bitumen free) and relatively low thermal maturity (Tmax 438°C, Roe The detailed assessment allowed identify two phases of solid Latin American Congress on Organic Geochemistry. 0.7%). The initial total porosity (bitumen-free) measured by helium Conclusions bitumen: One phase filled holes, oval circular morphology and density is 11.9% weight. The artificial maturation results show than The experiments carried out allowed to confirm that the organic References fractures characterized by homogeneous, non-porous and the maturity increased from 0.7%Roe to 1.4%Roe in the highest porosity promote to the total porosity in organic-rich shales; Peters, K.E., Moldowan, J.M., 1993. The biomarker guide: Interpreting reflectance between 2.0 to 2.27% Rm. The other one appears temperature experiment (365°C/72h). The total porosity also additionally the porous texture of solid bitumen developed during dispersed in the mineral matrix is heterogeneous, porous and molecular fossils in petroleum and ancient sediments. New Jersey, Prentice increased from 11.9% in early oil window to 17.1% weight in gas Hall. increasing thermal maturity is a key factor in order to understanding reflectance between 1.2 to 1.69% Rm. This solid bitumen was window, having in account than the mineralogy is the same for the organic and total porosity evolution. The generation of small classified as impsonite type with high thermal maturity (RB: 1.2%, each of analyzed samples is possible to associate the increases Ramón, J.,Dzou, L, Giraldo, B., 1997. Geochemical evaluation of the porous (micropores< 2 nm) and its coalescence can explain the not fluorescent) and high density (dHe: 1.71g/cm3) that was in porosity owing to pores generated during breakdown of organic Middle Magdalena Basin, Colombia.CienciaTecnología y Futuro 1 (3), 47-66 increase in the porous volume for macropores (50 nm- 12x103 nm) generated during the oil cracking and then partially retained in the matter in petroleum. and mesopores (2 nm- 50 nm). rock porosity and fractures. .

200 201 Acknowledgements UP12 shales need to be integrated and combined with the lithology to The authors thank Ecopetrol for support our participation in the XIV determine the most prospective targets for horizontal drilling and hydrofracking. Latin American Congress on Organic Geochemistry and INCAR Utilization of Petroleum CSIC for their cooperation in this research. Geochemical concepts in Using the Woodford Shale as an example, a number of key References characterization of Shale oil prospects geochemical parameters will be discussed along with their BRUNAUER, S., en Surface Area Determination, Everett, D.H. y Ottewill, integration into the sequence stratigraphic models for the region. R.H. (Eds.), Butterworths, Londres, 70, 1970. R. Paul Philp The first parameter is the so-called residual hydrocarbon potential (RHP). This parameter is simply the S1+S2 from Rock Eval CARDOTT, B.J., Application of Organic Petrology to Shale Oil and Gas School of Geology and Geophysics, Uni. of Oklahoma, Norman, normalized to TOC. This parameter correlates very closely with sea Potential of the Woodford Shale, Oklahoma, USA. 2011. OK. 73019. level changes. This is not entirely surprising since with increasing sea level preservation of organic matter increases and hence S1 ELGMATI, M. et al., 2011. Submicron-Pore Characterization of Shale Gas [email protected] and S2 will increase. This in turn will provide supporting information Plays. Paper SPE 144050. for the sequence stratigraphy interpretationand assist in identifying Copyright 2014, ALAGO. those facies with the highest TOC and productivity. GREGG, S.J. Y SING, K.S.W., Adsorption, Surface Area and Porosity, This paper was selected for presentation by an ALAGO Scientific Committee following Academic Press Inc. 2ª edición, Orlando, Florida, USA, 1982. review of information contained in an abstract submitted by the author(s). A second parameter which has also been useful in the case of the Woodford Shale is based on the presence of arylisoprenoids. These

HOLDITCH, S., Unconventional Gas. Unconventional Gas Subgroup of the Introduction compounds exist as homologous series of several isomers ranging Technology Task Group of the NPC Committee on Global Oil and Gas. Over the past decade the US, in particular, has seen an exponential from C16 to C40. They are indicative of a source contribution Topic Paper No. 29. 2007. increase in exploration activities related to shale gas and shale from the green alga, Chlorobiacea, which in turn is indicative of oil prospects. Much of this activity has been driven both by the the presence of a euxinic depositional environment or photic zone KEEGAN, C., 2010. Understanding Porosity and Permeability Relationships successful development of horizontal drilling and hydraulic anoxia. In general we have observed that these events are also to Mineralogy and Organic Matter in Unconventional Gas Reservoirs fracturing techniques along with a comprehensive understanding associated with organolithofacies with greater source potential that Utilizing New Technologies. AAPG International Convention and Exhibition. of the targetedshales. Geochemistry has played a key role in facies where these conditions were not as prevelant. furthering our understanding of the shale characteristics. In the AAPG Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May case of shale gas plays the techniques were basically determination In addition to these very specific and diagnostic parameters, the 19-22, 2013. of TOC, various Rock Eval (RE) parameters and vitrinite reflectance. full suite of conventional geochemical parameters are also used However shale oil prospects have been characterized by the full extensively in characterizing oils and all of the organofacies within KUCHINSKIY, v., 2013. Organic Porosity Study: Porosity Development suite of geochemical techniques including RE, gas chromatography, the shale. This can also important in determining whether you are within Organic Matter of the Lower Silurian and Ordovician Source Rocks and gas chromatography-mass spectrometry. evaluating a conventional or unconventional resource. For example of the Poland Shale Gas Trend. a recent prospect being evaluated in Oklahoma was proposed to This talk will focus on recent work that has been undertaken primarily be an unconventional shale oil prospect. In other words the oil was Lewan , M. D., 1993. Laboratory Simulation of Petroleum Formation: on the Woodford Shale in Oklahoma. This shale is one of the major being generated in situ. However determination of the maturity Hydrous-Pyrolyisis in M.H Engel And S.A Macko, eds., Organic source rocks in Oklahoma and has been producing conventional parameters based on sterane and terpane isomers showed the oil Geochemistry:New York, Plenum Press, p. 419-442. oil for more than 100 years. Over that period more that 500,000 was significantly more mature than the shale in which the oil was wells have been drilled in the State of Oklahoma. However recently trapped. This in turn lead to the conclusion that in this particular Lewan, M. D.,, J. C. Winters and J. H. McDonalds, 1979, Generation of horizontal drilling has led to renewed and significant production case the oil had been generated in a deeper part of the basin and Oil-like Pyrolizates from Organic-rich shales: Science, V. 203, p. 897-899 in areas where production had declined significantly. For the first had migrated into the shale. The net result of this was that the time this year the number of horizontal wells was greater than the prospect had to be developed as a conventional reservoir rather number of vertical wells. than an unconventional reservoir.

One of the keys has been a better understanding of the heterogeneity Conclusions of the shales and the variability of the organic matter in what was For many years geochemistry played an important role in developing previously considered to be a homogeneous black shale shale. shale gas prospects, primarily using Rock Eval and maturity data. Utilizations of the geochemical parameters and integration into In more recent years in the US primarily as a result of the economic sequence stratigraphic models has permitted targeting of specific situation emphasis has shifted to shale oil prospect development. organolithofacies as drilling targets. This presentation will describe Geochemistry continues to play an important role in developing the geochemical characterization of the Woodford Shale and these prospects. It is even more important with shale oil prospects discuss the variability that has been observed and how these data to evaluate the heterogeneity of the shales and determine are integrated with the sequence stratigraphic models. the most productive organolithocies that can be identified as potential horizontal drilling targets. This requires integration of the Discussion geochemical parameters into the sequence stratigraphic models There are a number of very useful geochemical parameters that along with an understanding of the lithology, which will aid in provide significant information that can used to distinguish and determining the frackability of the facies. characterize organolithofacies within shale oil prospects. With the widespread use of horizontal drilling in developing these prospects In this talk results from a detailed study of the Woodford shale this can be very important in identifying specific drilling targets. will be discussed. Concepts developed in these studies will be The black shales are not homogeneous and there is a great deal applicable to other oil shale plays both in the US and overseas. of variability in productivity of different facies. Hence geochemical data along with sequence stratigraphic interpretations of the

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