United States Assessments of Undiscovered Oil and Gas Resources Active
Explore US Undiscovered Oil and Gas Assessment Provinces
Assessment results, publications, data and more are available
USGS Energy Resources Program provides periodic assessments of the oil and natural gas endowment of the United States and the World. This website provides access to new, prioritized, assessment results and supporting data for the United States, as part of the Energy Policy and Conservation Act (EPCA).
Assessment Overview
The USGS assesses potential for undiscovered oil and gas resources in priority geologic provinces in the United States. This website highlights conventional and unconventional (continuous) oil and gas assessments.
Recent Assessments
Below are the latest US Assessments:
National Oil and Gas Assessment Methodology
The U.S. Geological Survey Energy Resources Program assesses the potential for undiscovered oil and gas resources in priority geologic provinces in the United States and around the world (click here for information about World Oil and Gas Assessments). Two methodologies are used by the USGS; one for assessing conventional oil and gas resources and one for assessing unconventional (continuous) oil and gas resources (such as shale gas and coalbed gas). USGS publications detailing and explaining the conventional and continuous assessment methodologies are provided below. These methodologies have been subjected to rigorous peer reviews by non federal panels, and the two panel reports are provided on this page.
Conventional Resources
USGS Reports
U.S. Geological Survey Assessment Concepts for Conventional Petroleum Accumulations
By James W. Schmoker and T.R. Klett
U.S. Geological Survey Input-Data Form and Operational Procedure for the Assessment of Conventional Petroleum Accumulations
By T.R. Klett, James W. Schmoker, and Ronald R. Charpentier
A Monte Carlo Simulation Method for the Assessment of Undiscovered, Conventional Oil and Gas
By Ronald R. Charpentier and T.R. Klett
Continuous Resources
USGS Reports
U.S. Geological Survey Assessment Concepts for Continuous Petroleum Accumulations
By James W. Schmoker
U.S. Geological Survey Input-Data Form and Operational Procedure for the Assessment Of Continuous Petroleum Accumulations, 2002
By T.R. Klett and James W. Schmoker
Analytic Resource Assessment Method for Continuous Petroleum Accumulations—The ACCESS Assessment Method
By Robert A. Crovelli
FORSPAN Model Users Guide
By T.R. Klett, and Ronald R. Charpentier
Methodology Revisions
Improved USGS methodology for assessing continuous petroleum resources.
Charpentier, R.R., and Cook, T.A.
Applying Probabilistic Well-Performance Parameters to Assessments of Shale-Gas Resources
By Ronald R. Charpentier and Troy Cook
Assembling Probabilistic Performance Parameters of Shale-Gas Wells
By Cook, Troy, and Charpentier, R.R.
USGS Methodology for Assessing Continuous Petroleum Resources
By Ronald R. Charpentier and Troy Cook
New U.S. Geological Survey Method for the Assessment of Reserve Growth
By Timothy R. Klett, Emil D. Attanasi, Ronald R. Charpentier, Troy A. Cook, Philip A. Freeman, Donald L. Gautier, Phuong A. Le, Robert T. Ryder, Christopher J. Schenk, Marilyn E. Tennyson, and Mahendra K. Verma (Reserve Growth Assessment Team)
Variability of Distributions of Well-Scale Estimated Ultimate Recovery for Continuous (Unconventional) Oil and Gas Resources in the United States
By U.S. Geological Survey Oil and Gas Assessment Team
Peer Review
Reserve Growth Methodology
USGS Reports
New U.S. Geological Survey Method for the Assessment of Reserve Growth
By Reserve Growth Assessment Team
Reserve Growth of Oil and Gas Fields - Investigations and Applications
By Troy Cook
Peer Review
Below are a list of recent assessment areas. You can also use the National Oil and Gas Assessment Map to browse these assessments.
Uinta-Piceance Basin Oil and Gas Assessments
Eastern Great Basin Oil and Gas Assessments
San Joaquin Basin Oil and Gas Assessments
Sacramento Basin Oil and Gas Assessments
Eastern Oregon-Washington Oil and Gas Assessments
Western Oregon-Washington Oil and Gas Assessments
Williston Basin Oil and Gas Assessments
Permian Basin Oil and Gas Assessments
Alaska Petroleum Systems
Gulf Coast Geologic Energy Assessments
Appalachian Basin Oil and Gas Assessments
Below are datasets related to the National Oil and Gas Assessments.
Below are publications associated with this project.
Geologic assessment of undiscovered conventional oil and gas resources in the Lower Paleogene Midway and Wilcox Groups, and the Carrizo Sand of the Claiborne Group, of the Northern Gulf coast region
Characterization and origin of brines from the Bakken-Three Forks petroleum system in the Williston Basin, USA
Assessment of water and proppant quantities associated with petroleum production from the Bakken and Three Forks Formations, Williston Basin Province, Montana and North Dakota, 2016
Assessment of undiscovered continuous oil and gas resources in the Heath Formation, central Montana and western North Dakota, 2016
Assessment of undiscovered oil and gas resources in the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas, 2017
Assessment of undiscovered oil and gas resources in the Bossier Formation, U.S. Gulf Coast, 2016
Assessment of undiscovered oil and gas resources in the Haynesville Formation, U.S. Gulf Coast, 2016
Assessment of continuous oil resources in the Wolfcamp shale of the Midland Basin, Permian Basin Province, Texas, 2016
Geological, geochemical, and reservoir characterization of the Uteland Butte member of the Green River Formation, Uinta Basin, Utah
Overpressure development through time using 4D pressure-volume-temperature modeling in the deep Anadarko Basin, Colorado, Kansas, Oklahoma, and Texas
Petroleum system model of the Upper Devonian-Lower Mississippian Bakken Formation in the northern Williston Basin, Saskatchewan, southwestern Manitoba, and southeastern Alberta, Canada
Evolution of the Lower Tertiary Elko Lake Basin, a potential hydrocarbon source rock in Northeast Nevada
Below are datasets related to the National Oil and Gas Assessments.
Below are news stories associated with this project.
Below are FAQ associated with this project.
Below are partners associated with this project.
- Overview
USGS Energy Resources Program provides periodic assessments of the oil and natural gas endowment of the United States and the World. This website provides access to new, prioritized, assessment results and supporting data for the United States, as part of the Energy Policy and Conservation Act (EPCA).
Assessment OverviewThe USGS assesses potential for undiscovered oil and gas resources in priority geologic provinces in the United States. This website highlights conventional and unconventional (continuous) oil and gas assessments.
Recent AssessmentsBelow are the latest US Assessments:
National Oil and Gas Assessment Methodology
The U.S. Geological Survey Energy Resources Program assesses the potential for undiscovered oil and gas resources in priority geologic provinces in the United States and around the world (click here for information about World Oil and Gas Assessments). Two methodologies are used by the USGS; one for assessing conventional oil and gas resources and one for assessing unconventional (continuous) oil and gas resources (such as shale gas and coalbed gas). USGS publications detailing and explaining the conventional and continuous assessment methodologies are provided below. These methodologies have been subjected to rigorous peer reviews by non federal panels, and the two panel reports are provided on this page.
Conventional Resources
USGS Reports
U.S. Geological Survey Assessment Concepts for Conventional Petroleum Accumulations
By James W. Schmoker and T.R. KlettU.S. Geological Survey Input-Data Form and Operational Procedure for the Assessment of Conventional Petroleum Accumulations
By T.R. Klett, James W. Schmoker, and Ronald R. CharpentierA Monte Carlo Simulation Method for the Assessment of Undiscovered, Conventional Oil and Gas
By Ronald R. Charpentier and T.R. KlettContinuous Resources
USGS Reports
U.S. Geological Survey Assessment Concepts for Continuous Petroleum Accumulations
By James W. SchmokerU.S. Geological Survey Input-Data Form and Operational Procedure for the Assessment Of Continuous Petroleum Accumulations, 2002
By T.R. Klett and James W. SchmokerAnalytic Resource Assessment Method for Continuous Petroleum Accumulations—The ACCESS Assessment Method
By Robert A. CrovelliFORSPAN Model Users Guide
By T.R. Klett, and Ronald R. Charpentier
Methodology Revisions
Improved USGS methodology for assessing continuous petroleum resources.
Charpentier, R.R., and Cook, T.A.Applying Probabilistic Well-Performance Parameters to Assessments of Shale-Gas Resources
By Ronald R. Charpentier and Troy CookAssembling Probabilistic Performance Parameters of Shale-Gas Wells
By Cook, Troy, and Charpentier, R.R.USGS Methodology for Assessing Continuous Petroleum Resources
By Ronald R. Charpentier and Troy CookNew U.S. Geological Survey Method for the Assessment of Reserve Growth
By Timothy R. Klett, Emil D. Attanasi, Ronald R. Charpentier, Troy A. Cook, Philip A. Freeman, Donald L. Gautier, Phuong A. Le, Robert T. Ryder, Christopher J. Schenk, Marilyn E. Tennyson, and Mahendra K. Verma (Reserve Growth Assessment Team)Variability of Distributions of Well-Scale Estimated Ultimate Recovery for Continuous (Unconventional) Oil and Gas Resources in the United States
By U.S. Geological Survey Oil and Gas Assessment TeamPeer Review
Reserve Growth Methodology
USGS Reports
New U.S. Geological Survey Method for the Assessment of Reserve Growth
By Reserve Growth Assessment TeamReserve Growth of Oil and Gas Fields - Investigations and Applications
By Troy CookPeer Review
- Science
Below are a list of recent assessment areas. You can also use the National Oil and Gas Assessment Map to browse these assessments.
Filter Total Items: 59Uinta-Piceance Basin Oil and Gas Assessments
The U.S. Geological Survey (USGS) has conducted a number of geology-based assessments of undiscovered oil and gas resources in the Uinta-Piceance Basin (USGS Province 5020) of western Colorado and Eastern Utah. Recent assessments include.Eastern Great Basin Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas potential of the Eastern Great Basin Province of eastern Nevada, western Utah, southeastern Idaho, and northwestern Arizona 5019.San Joaquin Basin Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered continuous oil and gas resources of the Monterey Formation, San Joaquin Basin Province 5010.Sacramento Basin Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered natural gas resources of the Sacramento Basin Province of California 5008.Eastern Oregon-Washington Oil and Gas Assessments
In 2006, the U.S. Geological Survey (USGS) completed the following assessments of undiscovered gas resources of the Eastern Oregon and Washington Province 5005.Western Oregon-Washington Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas resources of the Western Oregon and Washington Province 5004.Williston Basin Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of conventional and continuous oil and gas resources of the Devonian Three Forks Formation and Devonian and Mississippian Bakken Formation in the Williston Basin Province 5031 of North Dakota, Montana, and South Dakota.Permian Basin Oil and Gas Assessments
The USGS has conducted several assessments of undiscovered oil and gas in formations in the Permian Basin of western Texas. This inlcudes the following.Alaska Petroleum Systems
The Alaska Petroleum Systems project has three main objectives: (A) conduct research that increases our understanding of Alaska petroleum systems, (B) conduct assessments of undiscovered oil and gas resources, and (C) deliver energy-resource information to land and resource managers, policy makers, and the public.Gulf Coast Geologic Energy Assessments
One of the main goals of the Gulf Coast Geologic Energy Assessments and Research (GEAR) project is to conduct assessments of undiscovered, technically recoverable petroleum resources of the U.S. Gulf Coast region. This goal is in accordance with the Energy Policy and Conservation Act (EPCA) and is performed in collaboration with the USGS National Oil and Gas Assessment project. These high-quality...Appalachian Basin Oil and Gas Assessments
The USGS has conducted numerous assessments of undiscovered oil and gas in the Appalachian Basin, including studies of the Marcellus Shale. The region extends from Alabama to Maine. The following is an overview of the assessments. - Data
Below are datasets related to the National Oil and Gas Assessments.
Filter Total Items: 44No Result Found - Publications
Below are publications associated with this project.
Filter Total Items: 97Geologic assessment of undiscovered conventional oil and gas resources in the Lower Paleogene Midway and Wilcox Groups, and the Carrizo Sand of the Claiborne Group, of the Northern Gulf coast region
The U.S. Geological Survey (USGS) recently conducted an assessment of the undiscovered, technically recoverable oil and gas potential of Tertiary strata underlying the onshore areas and State waters of the northern Gulf of Mexico coastal region. The assessment was based on a number of geologic elements including an evaluation of hydrocarbon source rocks, suitable reservoir rocks, and hydrocarbon tAuthorsPeter D. WarwickCharacterization and origin of brines from the Bakken-Three Forks petroleum system in the Williston Basin, USA
Brine (also referred to as ‘produced water’) samples were collected from 28 wells producing oil from the Late Devonian-Early Mississippian Bakken and Three Forks Formations in the Williston Basin of eastern Montana and western North Dakota. The samples were analyzed for major ions, trace metals, stable isotopes, and strontium isotopes. The brines in these formations are highly saline with total diAuthorsZell E. Peterman, Joanna N. Thamke, Kiyoto Futa, Thomas A. OliverAssessment of water and proppant quantities associated with petroleum production from the Bakken and Three Forks Formations, Williston Basin Province, Montana and North Dakota, 2016
The U.S. Geological Survey (USGS) has completed an assessment of water and proppant requirements and water production associated with the possible future production of undiscovered oil and gas resources in the Three Forks and Bakken Formations (Late Devonian to Early Mississippian) of the Williston Basin Province in Montana and North Dakota. This water and proppant assessment is directly linked toAuthorsSeth S. Haines, Brian A. Varela, Sarah J. Hawkins, Nicholas J. Gianoutsos, Joanna N. Thamke, Mark A. Engle, Marilyn E. Tennyson, Christopher J. Schenk, Stephanie B. Gaswirth, Kristen R. Marra, Scott A. Kinney, Tracey J. Mercier, Cericia D. MartinezAssessment of undiscovered continuous oil and gas resources in the Heath Formation, central Montana and western North Dakota, 2016
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 884 million barrels of oil and 106 billion cubic feet of gas in the North-Central Montana and Williston Basin Provinces of central Montana and western North Dakota.AuthorsRonald M. Drake, Christopher J. Schenk, Timothy R. Klett, Phuong A. Le, Heidi M. Leathers, Michael E. Brownfield, Thomas M. Finn, Stephanie B. Gaswirth, Kristen R. Marra, Marilyn E. TennysonAssessment of undiscovered oil and gas resources in the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas, 2017
Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean resources of 4.2 billion barrels of oil and 3.1 trillion cubic feet of gas in the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas.AuthorsKristen R. Marra, Stephanie B. Gaswirth, Christopher J. Schenk, Heidi M. Leathers-Miller, Timothy R. Klett, Tracey J. Mercier, Phuong A. Le, Marilyn E. Tennyson, Thomas M. Finn, Sarah J. Hawkins, Michael E. BrownfieldAssessment of undiscovered oil and gas resources in the Bossier Formation, U.S. Gulf Coast, 2016
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 2.9 billion barrels of conventional oil and 108.6 trillion cubic feet of natural gas in the Upper Jurassic Bossier Formation in onshore lands and State waters of the U.S. Gulf Coast region.AuthorsStanley T. Paxton, Janet K. Pitman, Scott A. Kinney, Nicholas J. Gianoutsos, Ofori N. Pearson, Katherine J. Whidden, Russell F. Dubiel, Christopher J. Schenk, Lauri A. Burke, Timothy R. Klett, Heidi M. Leathers-Miller, Tracey J. Mercier, Seth S. Haines, Brian A. Varela, Phuong A. Le, Thomas M. Finn, Stephanie B. Gaswirth, Sarah J. Hawkins, Kristen R. Marra, Marilyn E. TennysonAssessment of undiscovered oil and gas resources in the Haynesville Formation, U.S. Gulf Coast, 2016
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 1.1 billion barrels of conventional oil and 195.8 trillion cubic feet of gas in the Upper Jurassic Haynesville Formation in onshore lands and State waters of the U.S. Gulf Coast region.AuthorsStanley T. Paxton, Janet K. Pitman, Scott A. Kinney, Nicholas J. Gianoutsos, Ofori N. Pearson, Katherine J. Whidden, Russell F. Dubiel, Christopher J. Schenk, Lauri A. Burke, Timothy R. Klett, Heidi M. Leathers-Miller, Tracey J. Mercier, Seth S. Haines, Brian A. Varela, Phuong A. Le, Thomas M. Finn, Stephanie B. Gaswirth, Sarah J. Hawkins, Kristen R. Marra, Marilyn E. TennysonAssessment of continuous oil resources in the Wolfcamp shale of the Midland Basin, Permian Basin Province, Texas, 2016
The U.S. Geological Survey completed a geology-based assessment of undiscovered, technically recoverable continuous petroleum resources in the Wolfcamp shale in the Midland Basin part of the Permian Basin Province of west Texas. This is the first U.S. Geological Survey evaluation of continuous resources in the Wolfcamp shale in the Midland Basin. Since the 1980s, the Wolfcamp shale in the MidlandAuthorsStephanie B. GaswirthGeological, geochemical, and reservoir characterization of the Uteland Butte member of the Green River Formation, Uinta Basin, Utah
No abstract available.AuthorsJustin E. Birdwell, Michael D. Vanden Berg, Ronald C. Johnson, Tracey J. Mercier, Adam Boehlke, Michael E. BrownfieldOverpressure development through time using 4D pressure-volume-temperature modeling in the deep Anadarko Basin, Colorado, Kansas, Oklahoma, and Texas
No abstract available.AuthorsDebra K. HigleyPetroleum system model of the Upper Devonian-Lower Mississippian Bakken Formation in the northern Williston Basin, Saskatchewan, southwestern Manitoba, and southeastern Alberta, Canada
No abstract available.AuthorsDebra K. Higley, Nicholas J. GianoutsosEvolution of the Lower Tertiary Elko Lake Basin, a potential hydrocarbon source rock in Northeast Nevada
No abstract available.AuthorsRonald C. Johnson, Justin E. Birdwell - Web Tools
Below are datasets related to the National Oil and Gas Assessments.
- News
Below are news stories associated with this project.
- FAQ
Below are FAQ associated with this project.
- Partners
Below are partners associated with this project.