Chapter 3 Petroleum Systems of the Uinta and Piceance Basins— Geochemical Characteristics of Oil Types Click here to return to Volume Title Page By Paul G. Lillis, Augusta Warden, and J. David King Chapter 3 of Petroleum Systems and Geologic Assessment of Oil and Gas in the Uinta-Piceance Province, Utah and Colorado By USGS Uinta-Piceance Assessment Team U.S. Geological Survey Digital Data Series DDS–69–B U.S. Department of the Interior U.S. Geological Survey U.S. Department of the Interior Gale A. Norton, Secretary U.S. Geological Survey Charles G. Groat, Director Version 1.0 2003 For sale by U.S. Geological Survey, Information Services Box 25286, Denver Federal Center Denver, CO 80225 Any use of trade, product, or firm names in this publication is for descriptive purposes only and does not imply endorsement by the U.S. Government Published in the Central Region, Denver, Colorado Manuscript approved for publication July 24, 2002 ISBN=0-607-99359-6 Contents Abstract.......................................................................................................................................................... 1 Introduction ................................................................................................................................................... 1 Methods ................................................................................................................................................ 1 Results and Discussion................................................................................................................................ 2 Paleozoic Oil Types.............................................................................................................................. 4 Minturn ......................................................................................................................................... 4 Grassy Trail Creek....................................................................................................................... 5 Phosphoria................................................................................................................................... 7 Cretaceous Oil Types........................................................................................................................... 7 Mancos......................................................................................................................................... 7 Mesaverde................................................................................................................................... 8 Tertiary Oil Types.................................................................................................................................. 8 Green River .................................................................................................................................. 8 Oil Types Adjacent to the Assessment Area................................................................................... 9 Conclusions ................................................................................................................................................. 10 Acknowledgments...................................................................................................................................... 10 References Cited ........................................................................................................................................ 10 Figures 1. Index map of the Uinta-Piceance Province ........................................................................................ 2 2. Generalized stratigraphic column of the Uinta-Piceance Province ............................................... 3 3. Graph showing stable carbon isotope values of oils, oil stains, and seeps from the Uinta-Piceance Province and adjacent areas.................................................................................... 4 4. Map showing Paleozoic oil sample localities of the Uinta-Piceance Province............................ 5 5. Sterane mass chromatograms of A, Minturn and B, Mancos oil types ......................................... 6 6. Map showing Cretaceous oil sample localities of the Uinta-Piceance Province ........................ 8 7. Map showing Tertiary oil sample localities of the Uinta-Piceance Province................................ 9 Table 1. Geochemistry of oils, oil stains, and seeps from Uinta-Piceance Province and adjacent area, Utah and Colorado ...................................................................................................................... 14 III Petroleum Systems of the Uinta and Piceance Basins—Geochemical Characteristics of Oil Types By Paul G. Lillis, Augusta Warden, and J. David King petroleum occurrences, the term “total petroleum system” Abstract was proposed to include genetically related undiscovered petroleum occurrences that may exist outside of the mapped As a part of the U.S. Geological Survey’s (USGS) petro- petroleum system (Magoon and Schmoker, 2000). The maxi- leum resource assessment of the Uinta-Piceance Province in mum geographic extent of the total petroleum system includes the year 2000, over 170 oils, oil stains, and oil seeps were the geographic extent of the petroleum system as well as areas geochemically characterized and divided into genetic types where geologic evidence indicates that undiscovered petro- using stable carbon isotopes, API gravity, sulfur content, and leum accumulations may exist (Magoon and Schmoker, 2000). biomarker composition. Several oil types were identified that, In the year 2000, the USGS conducted a petroleum in many cases, could be linked to previously proposed oil types resource assessment of the Uinta-Piceance Province (fig. 1), or source rocks. Recognized petroleum systems include the which approximately coincides with the Uinta and Piceance Minturn, Phosphoria, Mancos, Mesaverde, and Green River. Basins, and total petroleum system maps were used as a basis The most important sources of oil are the Lower Permian for defining assessment units. This report summarizes the Phosphoria Formation or stratigraphically equivalent rocks, crude oil characteristics of each petroleum system within the the Upper Cretaceous Mancos Group, and the Paleocene and assessment area based on previous studies as well as new oil Eocene Green River Formation. New data from the Cisco data and interpretation. Gas and source-rock analyses and area, Utah, show that the Phosphoria petroleum system extends the Ferron/Wasatch Plateau Total Petroleum System (Henry throughout much of the Uinta Basin. The proposed Minturn and Finn, Chapter 8, this CD-ROM) are not discussed in this petroleum system is hypothetical based on the geologic simi- report. larities to the Paradox petroleum system. Methods Introduction Over 170 oils, oil stains, and oil seeps from the Uinta- Piceance Province and surrounding areas were geochemically A petroleum system is a classification scheme identifying characterized (table 1). Oils were analyzed for bulk properties all the essential geologic elements and processes necessary including sulfur content, API gravity, and the C15+ concen- for the creation of a family of petroleum accumulations in a tration of saturated and aromatic hydrocarbons, resins, and sedimentary basin (Magoon, 1988). The essential elements asphaltenes. Hydrocarbon compound distributions (for exam- include source rock, reservoir rock, seal, and trap. The level ple, n-alkanes and acyclic isoprenoids) were determined by of certainty of the source rock identity in a petroleum system gas chromatography using a flame ionization detector. Stable is expressed as known, hypothetical, or speculative depending carbon isotopes of the saturated and aromatic hydrocarbon on the amount of available geochemical, geophysical, and fractions were determined by placing the products of sealed- geologic evidence. The first step in characterizing petroleum tube combustion into a dual inlet isotope ratio mass spectrom- systems is identifying and mapping the areal extent of oil and eter. For samples analyzed in the year 2000 (lab number gas genetic types. The second step is to identify and map beginning with 00, table 1), stable carbon isotopes were the extent of the effective source rock for each petroleum measured using an elemental analyzer interfaced with a con- type. The geographic extent of a petroleum system is defined tinuous flow isotope ratio mass spectrometer. The relative by the line that circumscribes the pod of active source rock concentrations of molecular fossils or biomarkers were deter- and the locations of all petroleum shows, seeps, and accumula- mined by combined gas chromatography/mass spectrometry tions that originated from that pod (Magoon and Dow, 1994). using selected-ion monitoring at mass-to-charge (m/z) ratios Because the petroleum system definition includes only known of 191.1800 (terpanes) and 217.1956 (steranes). Results were 1 2 Petroleum Systems and Geologic Assessment of Oil and Gas in the Uinta-Piceance Province 112˚ 106˚ 111˚ 108˚ 107˚ 41˚ 110˚ 109˚ Great Salt Daggett Larimer Lake Summit 80 Flaming Gorge SAND WASH Reservoir t BASIN Salt Lake City Uinta Mountain uplif Moffat Routt Jackson Vernal A 40 xi Craig al Ba si Duchesne n Provo up Lake h lif Grand Utah c t Granby 40 r Lake Wasatch a Uintah k r 40˚ 15 Utah PICEANCE BASI Rive e do UINTA BASIN e ra r Rio Blanco lo r C W o e h C iv s ite R la R EAGLE BASIN n iv e g e e r u r up 70 G o lift Nephi Carbon