DOCSLIB.ORG

L'.3350 Deposmon and DISSOLUTION of the MIDDLE DEVONIAN PRAIRIE FORMATION, Williston BASIN, NORTH DAKOTA and MONTANA By

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

l'.3350 DEPOsmON AND DISSOLUTION OF THE MIDDLE DEVONIAN PRAIRIE FORMATION, WilLISTON BASIN, NORTH DAKOTA AND MONTANA by: Chris A. Oglesby T-3350 A thesis submined to the Faculty and the Board of Trustees of the Colorado School of Mines in partial fulfillment of the requirements for the degree of Master of Science (Geology). Golden, Colorado Date f:" /2 7 /C''i::-- i ; Signed: Approved: Lee C. Gerhard Thesis Advisor Golden, Colorado - 7 Date' .' Samuel S. Adams, Head Department of Geology and Geological Engineering II T-3350 ABSTRACf Within the Williston basin, thickness variations of the Prairie Formation are common and are interpreted to originate by two processes, differential accumulation of salt during deposition, and differential removal of salt by dissolution. Unambiguous evidence for each process is rare because the Prairie/Winnipegosis interval is seldom cored within the U.S. portion of the basin. Therefore indirect methods, utilizing well logs, provide the principal method for identifying characteristics of the two processes. The results of this study indicate that the two processes can be distinguished using correlations within the Prairie Formation. Several regionally correlative upward-brining, and probably shoaling-upward sequences occur within the Prairie Formation .. Near the basin center, the lowermost sequence is transitional with the underlying Winnipegosis Formation. This transition is characterized by thinly laminated carbonates that become increasingly interbedded with anhydrites of the basin-centered Ratner Member, the remainder of the sequence progresses up through halite and culminates in the halite-dominated Esterhazy potash beds. Two overlying sequences also brine upwards, however, these sequences lack the basal anhydrite and instead begin with halite and culminate in the Belle Plaine and Mountrail potash Members, respectively. A fourth sequence is indicated by several feet of halite capping the Mountrail Member in some parts of the basin. Subsequent erosion or dissolution prior to burial may have removed the upper portion of this sequence. Cross-sections show that the Lower Prairie gradually decreases in thickness from the basin to its margins. This thickness variation is most simply explained by decreasing accommodation potential due to decreased basin topography away from the basin ill T-3350 depocenter and by depositional onlap of the Prairie toward the basin margins. A depositional onlap pattern is characteristic of the basin's southern margin. In this case, there is a progressive increase in areal extent of the formation from the base to the top. By correlating the four sequences within the Prairie, some local thickness variations are shown to originate by depositional onlap onto Winnipegosis reefs. Other thickness variations occur in response to minor vertical movements across basement faults. Inparticular the Brockton-Froid fault zone and the Nesson anticline have affected deposition of the Prairie and Winnipegosis Formations. In other areas, such as along the western and eastern basin margins, the basal parts of the formation are more extensive and completely preserved, but upper parts are progressively diminished in areal extent from the top down. This pattern is explained by progressive dissolution of Prairie evaporites from the top downward, suggesting that the aquifers contributing to the dissolution overlie the Prairie Formation. Although no distinct linear pattern emerged, the coincidence between tectonic features such as the Brockton- Froid fault system, the Nesson anticline and the Superior/Churchill contact and major dissolution areas suggests that dissolution is controlled primarily by tectonic fracturing. Dissolution was also recognized over several Winnipegosis pinnacle reefs. This dissolution preferentially removed the overlying potash horizons and resulted in partial dissolution of the Prairie. These observations suggest that dissolution resulted from an upward-directed flow of waters localized by the reeffacies. IV T-3350 TABLE OF CONTENTS lli!@ ABSTRACT iii TABLE OF CONTENTS v LIST OF FIGURES vii LIST OF PLATES x ACKNOWLEDGEMENTS xi IN1RODUCTION I STRUCTURAL SETTING 4 DEPOSITIONAL SETTING 7 rv1E1HOOOLOGY 22 Genetic Stratigraphy 22 Deposition of thick evaporite sequences 27 CAUSES OF PRAIRIE FORMATION THINNING 29 Depositional thinning by onlap 29 Temporal Relationship between the Prairie Formation and Winnipegosis Formation Pinnacle Reefs 36 RECOGNmON OF SALT DISSOLUTION 39 Presence of collapse breccias 39 Isopach and isochron patterns 39 Geophysical methods 43 DISSOLUTION MODELS 46 Dissolution thinning by groundwater flow 46 Compaction and dewatering model 46 v T-3350 Surface water model. 47 Depositional facies controls on dissolution 49 Tectonic controls on dissolution 51 DIFFERENTIATING BETWEEN DEPOSmONAL AND DISSOLUTION THINNING 57 INTERPRETATION OF ISOPACH MAPS 59 PETROLEUM GEOLOGy 62 CONCLUSIONS 69 FUTURE WORK 71 REFERENCES CITED 73 APPENDIX 79 Winnipegosis Pinnacle Reef wells 79 Vl T-3350 LIST OF FIGURES Figure 1. Stratigraphic column of the Devonian in the Williston basin. 2 2. Map of the study area showing major structural features and the Prairie Formation subcrop within the Williston Basin. 3 3. Map of the major lineaments within the U.S.A. portion of the Williston Basin and location of the contact between the Churchill and Superior Precambrian provinces. 6 4. Map of the Elk Point Basin (Middle Devonian) showing facies within the Prairie Formation. 9 5. Type well log (gamma ray - sonic) for the Prairie Formation. 10 6. Colored photograph of core showing laminated carbonate facies of the Winnipegosis Formation. (Sunray-Gagnum #1, sw/nw, 13-169n-89w, Burke Co., N.D., Depth=8,322). 11 7. Colored photograph of core showing laminated carbonate and anhydrite transitional facies .(Sunray-Gagnum #1, sw/nw, 13-169n-89w, Burke Co., N.D., Depth=8,302) 12 8. Colored photograph of core showing enterolithic anhydrite facies (Ratner member) (Sunray-Gagnum#l, sw/nw, 13-169n-89w, Burke Co., N.D., Depth=8,300.4). 13 9. Colored photograph of core showing, nearly pure, bedded (laminated) anhydrite facies (Ratner member) (Sunray-Gagnum #1, sw/nw, 13-169n- 89w, Burke Co., N.D., Depth=8,286). 14 10. Colored photograph of core showing transition of anhydrite facies into halite facies (lower Prairie Formation) (Sunray-Gagnum #1, sw/nw, 13- 169n-89w, Burke Co., N.D., Depth=8,282). 16 11. Colored photograph of core showing milky halite facies (chevron crystals) (Sunray-Gagnum #1, sw/nw, 13-169n-89w, Burke Co., N.D., Depth=8,261). 17 12. Colored photograph of core showing clear halite facies (hopper crystals) (Sunray-Gagnum #1, sw/nw, 13-169n-89w, Burke Co., N.D., Depth=8,152). 18 va T-3350 13. Colored photograph of core showing thin anhydrite beds in Lower Prairie Formation, "jahresringe", (Sunray-Gagnum #1, sw/nw, 13-169n-89w, Burke Co., N.D., Depth=8,233). 20 14. Colored photograph of core showing potash (sylvite and carnallite) facies, (Sunray-Gagnum #1, sw/nw, 13-169n-89w, Burke Co., N.D., Depth=7,971). 21 15. Stratigraphic and time stratigraphic sections showing correlation of genetic ~~. ~ 16. Idealized evaporite sequences from deep basin to basin margin. 25 17. Sequences within the Prairie Formation. 27 18. Paleogeography of the Elk Point Basin during Winnipegosis time. 29 19. Aggradational evaporite deposition within basin displaying onlap geometry. 30 20. Log cross-section showing onlap of Prairie Formation onto the Winnipegosis Formation shelf (depositional thinning). 32 21. Wheeler diagram of Prairie Formation through time. 33 22. Log cross-section showing onlap of the Prairie Formation onto Winnipegosis Formation pinnacle reefs. 34 23. Seismic section showing the Prairie Formation onlapping a Winnipegosis reef. 36 24. Depositional model of Prairie and Winnipegosis Formations, indicating two separate of carbonate and two stages of salt deposition. 38 25. Colored photograph of core near contact of Winnipegosis with overlying collapse breccia showing large clasts which occur near the base of the breccia, (California Company, 1 Blanche Thompson, 31-160n-81w, Depth=6,351). 40 26. Colored photograph of core near the middle of the collapse breccia showing less deformation and a decrease in fragment sizes, (California Company, 1 Blanche Thompson, 31-160n-81w, Depth=6,299). 41 27. Colored photograph of core near the top of the collapse breccia showing vertical fractures filled with anhydrite, (California Company, 1 Blanche Thompson, 31-160n-81 w, Depth=6,266). 42 VUI T-3350 28. Model of Winnipegosis mound showing groundwater flow and slumping due to dissolution and collapse. 44 29. Hypothetical model for groundwater flow in the presence of reefs (Leduc and Ireton Formations. 46 30. Model of vertical fractures and lineaments developed over basement fault blocks. 48 31. Model (two-dimensional) showing various flow paths in a fractured media. 53 32. Model (three-dimensional) showing various flow paths in a fractured media. 55 33. Log cross-section across the Roosevelt Co., Montana salt void showing top down nature of dissolution thinning. 56 34. Schematic diagram illustrating development of two-stage salt dissolution and the subsequent formation of a "turtle structure". 58 35. Distribution of oil fields related to two-stage salt dissolution, Roosevelt County, Montana. 64 36. Map showing location of Wiley field, Bottineau County, N.D. and its relationship to the underlying Prairie subcrop. 68 IX T-3350 LIST OF PLATES 1. Isopach map of Winnipegosis Formation, eastern Montana, scale 1:20000
Recommended publications
  • Modern Shale Gas Development in the United States: a Primer

    Modern Shale Gas Development in the United States: a Primer

    U.S. Department of Energy • Office of Fossil Energy National Energy Technology Laboratory April 2009 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe upon privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. Modern Shale Gas Development in the United States: A Primer Work Performed Under DE-FG26-04NT15455 Prepared for U.S. Department of Energy Office of Fossil Energy and National Energy Technology Laboratory Prepared by Ground Water Protection Council Oklahoma City, OK 73142 405-516-4972 www.gwpc.org and ALL Consulting Tulsa, OK 74119 918-382-7581 www.all-llc.com April 2009 MODERN SHALE GAS DEVELOPMENT IN THE UNITED STATES: A PRIMER ACKNOWLEDGMENTS This material is based upon work supported by the U.S. Department of Energy, Office of Fossil Energy, National Energy Technology Laboratory (NETL) under Award Number DE‐FG26‐ 04NT15455. Mr. Robert Vagnetti and Ms. Sandra McSurdy, NETL Project Managers, provided oversight and technical guidance.
  • Bakken – the Biggest Oil Resource in the United States?

    Bakken – the Biggest Oil Resource in the United States?

    Winter 2011 Oil & Natural Gas Program Newsletter Bakken – The Biggest Oil Resource in the United States? The announcement of the acquisition of large acreage positions in the Bakken play has become a fairly regular event. Leasing activity in the Bakken has exploded over the last five years and bonus payments per acre CONTENTS have jumped. Total lease bonus payments exceeded $100 million in 2009 (Figure 1). Bakken – The Biggest Oil Resource in the United States? ...1 The heightened acquisition activity is driven by the Bakken’s immense potential. In 2008, the United States Geological Survey (USGS) estimated Commentary ...................................2 that the U.S. portion of the Bakken formation contains between 3 and 4.3 Successful Oil Production in billion barrels (a mean of 3.63 billion barrels) of undiscovered, recoverable the Bakken Formation .................6 oil, ranking it among the very largest U.S. oil plays. The Bakken—An Unconventional Petroleum The number of producing wells and Reservoir System ................9 and volume of oil production has Crude Souring in the Bakken ....11 grown with the growth in leasing and drilling (Figure 2). Production Geomechanical Study has reached nearly 8 million barrels of the Bakken .................................13 per month from roughly 4500 Bakken Requires Outlet for producing wells. Increased Production ................. 16 E&P Snapshots ............................ 18 The Bakken Formation Upcoming Meetings and The Bakken petroleum system is Presentations ............................... 20 part of a larger depositional system CONTACTS laid down in the Williston Basin during the Phanerozoic period with Roy Long Figure 1: Lease payments in North Dakota’s portion sediments up to 16,000 feet thick.
  • Evolution of Oil Production in the Bakken Formation

    Evolution of Oil Production in the Bakken Formation

    EvolutionEvolution ofof OilOil ProductionProduction inin thethe BakkenBakken FormationFormation JulieJulie A.A. LeFeverLeFever NorthNorth DakotaDakota GeologicalGeological SurveySurvey PlaysPlays ofof thethe BakkenBakken FormationFormation ¾¾ ConventionalConventional BakkenBakken (pre(pre--1987)1987) ¾¾ CycleCycle 11 –– AntelopeAntelope StructureStructure (1950s(1950s –– 60s)60s) ¾¾ CycleCycle 22 –– DepositionalDepositional EdgeEdge (1970s(1970s –– 80s)80s) ¾¾ HorizontalHorizontal DrillingDrilling ofof thethe BakkenBakken ShaleShale (post(post--1987)1987) ¾¾ HorizontalHorizontal DrillingDrilling ofof thethe BakkenBakken MiddleMiddle MemberMember (2001(2001 toto present)present) ConventionalConventional BakkenBakken CycleCycle 11 –– AntelopeAntelope FieldField ¾¾DiscoveryDiscovery WellWell ¾¾ StanolindStanolind -- #1#1 WoodrowWoodrow StarrStarr ¾¾ InitialInitial PotentialPotential (536(536 BO;BO; 0.10.1 BW)BW) ¾¾ AntelopeAntelope FieldField ¾¾ 5252 wells;wells; 12.512.5 millionmillion BO;BO; 1010 BCFBCF GasGas ¾¾ ““SanishSanish SandSand”” ¾¾ CompletionCompletion MethodMethod Conventional Bakken Exploration between Cycles ¾¾ElkhornElkhorn RanchRanch ¾¾ ShellShell OilOil Co.Co. -- #41X#41X--55--11 GovernmentGovernment ¾¾NessonNesson AnticlineAnticline ¾¾ #1#1 B.E.B.E. HoveHove ¾¾ IPIP -- 756756 BOPD,BOPD, 33 BWPDBWPD ¾¾ CompletionCompletion MethodMethod ConventionalConventional BakkenBakken CycleCycle 22 –– DepositionalDepositional LimitLimit ¾¾StratigraphyStratigraphy && StructureStructure ¾¾ ThinThin BakkenBakken ¾¾ MultipleMultiple PaysPays
  • Chapter 2 Paleozoic Stratigraphy of the Grand Canyon

    Chapter 2 Paleozoic Stratigraphy of the Grand Canyon

    CHAPTER 2 PALEOZOIC STRATIGRAPHY OF THE GRAND CANYON PAIGE KERCHER INTRODUCTION The Paleozoic Era of the Phanerozoic Eon is defined as the time between 542 and 251 million years before the present (ICS 2010). The Paleozoic Era began with the evolution of most major animal phyla present today, sparked by the novel adaptation of skeletal hard parts. Organisms continued to diversify throughout the Paleozoic into increasingly adaptive and complex life forms, including the first vertebrates, terrestrial plants and animals, forests and seed plants, reptiles, and flying insects. Vast coal swamps covered much of mid- to low-latitude continental environments in the late Paleozoic as the supercontinent Pangaea began to amalgamate. The hardiest taxa survived the multiple global glaciations and mass extinctions that have come to define major time boundaries of this era. Paleozoic North America existed primarily at mid to low latitudes and experienced multiple major orogenies and continental collisions. For much of the Paleozoic, North America’s southwestern margin ran through Nevada and Arizona – California did not yet exist (Appendix B). The flat-lying Paleozoic rocks of the Grand Canyon, though incomplete, form a record of a continental margin repeatedly inundated and vacated by shallow seas (Appendix A). IMPORTANT STRATIGRAPHIC PRINCIPLES AND CONCEPTS • Principle of Original Horizontality – In most cases, depositional processes produce flat-lying sedimentary layers. Notable exceptions include blanketing ash sheets, and cross-stratification developed on sloped surfaces. • Principle of Superposition – In an undisturbed sequence, older strata lie below younger strata; a package of sedimentary layers youngs upward. • Principle of Lateral Continuity – A layer of sediment extends laterally in all directions until it naturally pinches out or abuts the walls of its confining basin.
  • The Arabian Gulf

    The Arabian Gulf

    Chapter 1 The Arabian Gulf Grace O. Vaughan, Noura Al-Mansoori, John A. Burt New York University Abu Dhabi, Abu Dhabi, United Arab Emirates 1.1 THE REGION Bound by deserts and located between the north-eastern Arabian Peninsula and Iran, the Arabian Gulf (also known as the Persian Gulf, and hereafter known as “the Gulf”) is bordered by eight rapidly developing nations. The Gulf is located in the subtropics between 24°N and 30°N latitude and 48°E and 57°E longitude (Fig. 1.1), and is considered as a biogeographic subprovince of the northwestern Indian Ocean (Spalding et al., 2007). During summers, the Gulf is the hottest sea on the planet, particularly in the shallow southern basin where sea surface temperatures (SSTs) regu- larly exceed 35°C in August. Sea temperatures are also highly variable among seasons, ranging over 20°C between summer and winter. Geologically, the Gulf is relatively young with coastlines that formed only in the past 3000–6000 years when polar ice sheets receded (Riegl & Purkis, 2012a). Today, the Gulf is bordered to the northeast by the Zagros mountains in Iran and the Hajar mountains in the Musandam peninsula and in the southwest by the sedimentary Arabian coast (Purser & Seibold, 1973). Presently, it covers an area of 250,000 km2 (Riegl & Purkis, 2012a). Generally, terrestrial systems sur- rounding the Gulf are arid to hyperarid (Riegl & Purkis, 2012a), limiting the input of freshwater to this semienclosed sea. The main freshwater input enters at the northern Gulf at the Shatt Al Arab waterway through the Tigris, Euphrates, and the Karun rivers (Sheppard, Price, & Roberts, 1992), although recent damming efforts have resulted in substantial reductions in freshwater discharge from these rivers (Sheppard et al., 2010).
  • Mannville Group of Saskatchewan

    Mannville Group of Saskatchewan

    Saskatchewan Report 223 Industry and Resources Saskatchewan Geological Survey Jura-Cretaceous Success Formation and Lower Cretaceous Mannville Group of Saskatchewan J.E. Christopher 2003 19 48 Printed under the authority of the Minister of Industry and Resources Although the Department of Industry and Resources has exercised all reasonable care in the compilation, interpretation, and production of this report, it is not possible to ensure total accuracy, and all persons who rely on the information contained herein do so at their own risk. The Department of Industry and Resources and the Government of Saskatchewan do not accept liability for any errors, omissions or inaccuracies that may be included in, or derived from, this report. Cover: Clearwater River Valley at Contact Rapids (1.5 km south of latitude 56º45'; latitude 109º30'), Saskatchewan. View towards the north. Scarp of Middle Devonian Methy dolomite at right. Dolomite underlies the Lower Cretaceous McMurray Formation outcrops recessed in the valley walls. Photo by J.E. Christopher. Additional copies of this digital report may be obtained by contacting: Saskatchewan Industry and Resources Publications 2101 Scarth Street, 3rd floor Regina, SK S4P 3V7 (306) 787-2528 FAX: (306) 787-2527 E-mail: [email protected] Recommended Citation: Christopher, J.E. (2003): Jura-Cretaceous Success Formation and Lower Cretaceous Mannville Group of Saskatchewan; Sask. Industry and Resources, Report 223, CD-ROM. Editors: C.F. Gilboy C.T. Harper D.F. Paterson RnD Technical Production: E.H. Nickel M.E. Opseth Production Editor: C.L. Brown Saskatchewan Industry and Resources ii Report 223 Foreword This report, the first on CD to be released by the Petroleum Geology Branch, describes the geology of the Success Formation and the Mannville Group wherever these units are present in Saskatchewan.
  • Bakken Production Optimization Program Executive Summary Years

    Bakken Production Optimization Program Executive Summary Years

    Bakken Production Optimization Program EXECUTIVE SUMMARY A premier public–private partnership harnessing the best minds in North Dakota and in industry to maximize productivity of the Bakken oil play while simultaneously reducing its environmental footprint. 2 BAKKEN PRODUCTION OPTIMIZATION PROGRAM This summary of Bakken Production Optimization Program (BPOP) achievements at the end of calendar year 2015 was produced at the request of the North Dakota Industrial Commission (NDIC) and the associated Oil and Gas Research Program, which funded a portion of the work performed in this program. This summary is intended for public distribution and is intended to relay the ongoing successes of this premier public–private partnership in advancing North Dakota’s economic and environmental interests directly related to exploration and production of oil from the Bakken and Three Forks Formations. EXECUTIVE SUMMARY 1 4 PROGRAM INTRODUCTION 6 Anticipated Outcomes 8 Partnership and Members 10 OPTIMIZATION OF WELLSITE OPERATIONS 12 Flaring Reduction 14 Water Opportunities Assessment 16 TENORM Waste Disposal 18 Spills Remediation 20 THE HAWKINSON PROJECT 23 Need for the Project 24 Industry Firsts 26 Results 27 Conclusions 28 PROGRAM WORK CONTINUES 2 BAKKEN PRODUCTION OPTIMIZATION PROGRAM BAKKEN PRODUCTION OPTIMIZATION PROGRAM EXECUTIVE SUMMARY 3 In June 2013, a consortium comprising the Energy & Environmental BAKKEN Research Center (EERC), Continental Resources, Inc., and several of the largest oil producers in the state was awarded North Dakota Oil PRODUCTION
  • Williston Basin Project (Targeted Geoscience Initiative II): Summary Report on Paleozoic Stratigraphy, Mapping and Hydrocarbon A

    Williston Basin Project (Targeted Geoscience Initiative II): Summary Report on Paleozoic Stratigraphy, Mapping and Hydrocarbon A

    Williston Basin Project (Targeted Geoscience Initiative II): Summary report on Paleozoic stratigraphy, mapping and GP2008-2 hydrocarbon assessment, southwestern Manitoba By M.P.B. Nicolas and D. Barchyn GEOSCIENTIFIC PAPER Geoscientific Paper GP2008-2 Williston Basin Project (Targeted Geoscience Initiative II): Summary report on Paleozoic stratigraphy, mapping and hydrocarbon assessment, southwestern Manitoba by M.P.B. Nicolas and D. Barchyn Winnipeg, 2008, reprinted with minor revisions January, 2009 Science, Technology, Energy and Mines Mineral Resources Division Hon. Jim Rondeau John Fox Minister Assistant Deputy Minister John Clarkson Manitoba Geological Survey Deputy Minister E.C. Syme Director ©Queen’s Printer for Manitoba, 2008, reprinted with minor revisions, January 2009 Every possible effort is made to ensure the accuracy of the information contained in this report, but Manitoba Science, Technol- ogy, Energy and Mines does not assume any liability for errors that may occur. Source references are included in the report and users should verify critical information. Any digital data and software accompanying this publication are supplied on the understanding that they are for the sole use of the licensee, and will not be redistributed in any form, in whole or in part, to third parties. Any references to proprietary software in the documentation and/or any use of proprietary data formats in this release do not constitute endorsement by Manitoba Science, Technology, Energy and Mines of any manufacturer’s product. When using information from this publication in other publications or presentations, due acknowledgment should be given to the Manitoba Geological Survey. The following reference format is recommended: Nicolas, M.P.B, and Barchyn, D.
  • Infrastructure Constraints in the Bakken

    Infrastructure Constraints in the Bakken

    U.S. Department of Energy Washington, DC 20585 Date: August 8, 2014 To: Members of the Public From: Quadrennial Energy Review Task Force Secretariat and Energy Policy and Systems Analysis Staff, United States Department of Energy Re: QER Public Stakeholder Meeting: Infrastructure Constraints in the Bakken 1. Introduction On January 9, 2014, President Obama issued a Presidential Memorandum establishing a Quadrennial Energy Review (QER). The Secretary of Energy provides support to the QER Task Force, including coordination of activities related to the preparation of the QER report, policy analysis and modeling, and stakeholder engagement. On Friday, August 8, 2014, at 11:00 AM CDT at the Bismarck State College, National Energy Center of Excellence, Bavendick Stateroom (No. 415), located at 1200 Schafer Street, in Bismarck, North Dakota, the U.S. Department of Energy (DOE), acting as the Secretariat for the QER Task Force, will hold a public meeting to discuss and receive comments on issues surrounding the infrastructure constraints in further developing shale resources in the Bakken region. There will be an opportunity for public comment via an open microphone session following panel discussions. Written comments can be submitted to [email protected]. The session will also be webcast at www.energy.gov/live. 2. Background Over the past decade, the energy profile of the United States has undergone a dramatic transformation. A major component of this shift has been the ability to unlock fossil fuel resources from diverse shale formations around the country. America’s economy and infrastructure will continue to adapt to the abundance of accessible shale and natural gas resources and the decreased carbon emissions, lower imports, and enhanced industrial competitiveness.
  • The Stonewall Formation Timothy O

    The Stonewall Formation Timothy O

    The Stonewall Formation Timothy O. Nesheim Introduction Geology The Stonewall Formation is one of numerous sedimentary strata The Stonewall Formation consists of three carbonate-evaporitic that have commercially produced oil and gas from North Dakota’s cycles deposited during Late Ordovician through Early Silurian subsurface. The Stonewall Formation is also one of many time (fig. 2). The Stonewall Formation is conformably under- geological formations being overshadowed by the prolific Bakken- lain by the Stony Mountain Formation and overlain by the In- Three Forks play. Interestingly, the first successful production terlake Formation. Each Stonewall cycle consists of three gen- test that recovered hydrocarbons (oil and gas) from the eral lithofacies: 1) bioturbated to laminated carbonate mudstone Stonewall Formation took place in 1952, less than a year after the 2) thin greyish green dolomitic and/or shaley, silty to sandy discovery of oil in North Dakota. However, sustained commercial mudstone, and 3) nodular to laminated anhydrite that is some- production from the Stonewall Formation did not take place for times interlaminated to interbedded with dolomite (fig. 3). another 27 years until 1979. Since then, the Stonewall Formation Deposition is interpreted to have taken place within a shallow has produced approximately 10 million barrels of oil equivalent marine (carbonate facies) to hypersaline (anhydrite facies) set- (MBOE) from 65 vertical wells (fig. 1). ting. The shaly sandy mudstone intervals have previously been Figure 1. Map depicting the extent of the Stonewall Formation and Stonewall productive wells in North Dakota (Carlson and Eastwood, 1962). For regulatory reasons the Stonewall Formation has been pooled together with the lower Interlake Formation.
  • Origin of Intraformational Folds in the Jurassic Todilto Limestone, Ambrosia Lake Uranium Mining District, Mckinley and Valencia Counties, New Mexico by Morris W

    Origin of Intraformational Folds in the Jurassic Todilto Limestone, Ambrosia Lake Uranium Mining District, Mckinley and Valencia Counties, New Mexico by Morris W

    DEPARTMENT OF THE INTERIOR GEOLOGICAL SURVEY Origin of Intraformational Folds in the Jurassic Todilto Limestone, Ambrosia Lake Uranium Mining District, McKinley and Valencia Counties, New Mexico By Morris W. Green U.S. Geological Survey Open-file Report 82-69 1982 Contents Page Abstract................................................................ 1 Introducti on............................................................ 3 Stratigraphy and Environments of Deposition.............................3 The Formation of Intraformational Folds................................10 Todilto Uranium Deposits...............................................22 Exploration and Favorability...........................................24 References ci ted....................................................... 25 Illustrations Figure 1. Index map showing location of mineral belt, the Todilto study area, and adjacent areas.....................4 2. Index map of the Ambrosia Lake mining area...................5 3. Schematic diagram showing a segment of the Todilto depositional basin.........................................9 4. Remnants of a Summerville (Js) eolian dune overlying the Todilto Limestone (Jt)................................12 5. Schematic diagram showing the plastic and shear phases of Todilto load deformation...............................13 6. Large-scale, low amplitude intraformational fold within the Todilto Limestone.....................................14 7. Large-scale, high amplitude, intraformational fold within the Todilto Limestone..............................14
  • Coral Reefs Within a Siliciclastic Setting, 1997

    Coral Reefs Within a Siliciclastic Setting, 1997

    Proc 8th Int Coral Reef Sym 2:1737-1742.1997 CORAL REEFS AND CARBONATE PLATFORMS WITHIN A SILICICLASTIC SETTING. GENERAL ASPECTS AND EXAMPLES FROM THE LATE JURASSIC OF PORTUGAL. Reinhold Leinfelder Institute of Geology and Paleontology, University of Stuttgart, Herdweg 51, D-70174 Stuttgart, Germany. ABSTRACT in the water (op. cit.). Additionally, terrigeneous influx is mostly accompanied by an unfavourable increase Both in the Modern and Ancient examples coral reefs and in nutrient and sometimes even freshwater influx. carbonate platforms occur frequently very close to or even directly within areas of siliciclastic sediment- ation. Particularly fine grained, often suspended terri- geneous influx is mostly problematic for the reef fauna due to lowering of illumination and oxygenation, in- TableÊ1: Possible negative effects of terrigeneous creasing nutrient values or directly settling on the influx on reefs: organims. The modern examples show that reef growth in such settings is only possible by the existence of sheltering mechanisms such as arid climate, structural REEFS AND SILICS? WHAT'S BAD ABOUT IT? and sedimentary traps or longshore currents. If not completely effective, reefs may still prosper under 1 . Increase of nutrient concentration reduced but noticeable siliciclastic sedimentation, but 2 . Freshwater influx both composition and diversity of the reefs changes drastically. The Ancient examples show that temporal 3 . Reduction of oxygen concentration relations are important as well: Autocyclic switches in 4 . Impoverished illumination depositional systems and especially allocyclic events 5 . Loss of hard substrates such as tectonic activation/deactivation or sea level 6 . Pollution / suffocation of reef organisms change may open and close reef windows through time.