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.
Below are datasets related to the National Oil and Gas Assessments.
Below are publications associated with this project.
Assessment of undiscovered oil and gas resources in sandstone reservoirs of the Cotton Valley Group, U.S. Gulf Coast, 2015
Assessment of unconvential (tight) gas resources in Upper Cook Inlet Basin, South-central Alaska
Geologic assessment of undiscovered oil and gas resources of the U.S. portion of the Michigan Basin
Map of assessed continuous (unconventional) oil resources in the United States, 2014
Petroleum systems and assessment of undiscovered oil and gas in the Anadarko Basin Province, Colorado, Kansas, Oklahoma, and Texas: USGS Province 58
Map of assessed coalbed-gas resources in the United States, 2014
Map of assessed tight-gas resources in the United States
U.S. Geological Survey 2013 assessment of undiscovered resources in the Bakken and Three Forks Formations of the U.S. Williston Basin Province
Assessment of continuous oil and gas reservoirs, Paradox Basin, Utah, Colorado, New Mexico, and Arizona
Lower Cody Shale (Niobrara equivalent) in the Bighorn Basin, Wyoming and Montana: thickness, distribution, and source rock potential
National Assessment of Oil and Gas Project: geologic assessment of undiscovered gas hydrate resources on the North Slope, Alaska
Upper Devonian–Mississippian stratigraphic framework of the Arkoma Basin and distribution of potential source-rock facies in the Woodford–Chattanooga and Fayetteville–Caney shale-gas systems
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: 59 - 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: 97Assessment of undiscovered oil and gas resources in sandstone reservoirs of the Cotton Valley Group, U.S. Gulf Coast, 2015
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered mean volumes of 14 million barrels of conventional oil, 430 billion cubic feet of conventional gas, 34,028 billion cubic feet of continuous gas, and a mean total of 391 million barrels of natural gas liquids in sandstone reservoirs of the Upper Jurassic–Lower Cretaceous Cotton Valley Group in onshore laAuthorsJennifer D. Eoff, Laura R.H. Biewick, Michael E. Brownfield, Lauri Burke, Ronald R. Charpentier, Russell F. Dubiel, Stephanie B. Gaswirth, Nicholas J. Gianoutsos, Scott A. Kinney, Timothy R. Klett, Heidi M. Leathers, Tracey J. Mercier, Stanley T. Paxton, Ofori N. Pearson, Janet K. Pitman, Christopher J. Schenk, Marilyn E. Tennyson, Katherine J. WhiddenAssessment of unconvential (tight) gas resources in Upper Cook Inlet Basin, South-central Alaska
A geologic model was developed for the assessment of potential Mesozoic tight-gas resources in the deep, central part of upper Cook Inlet Basin, south-central Alaska. The basic premise of the geologic model is that organic-bearing marine shales of the Middle Jurassic Tuxedni Group achieved adequate thermal maturity for oil and gas generation in the central part of the basin largely due to severalAuthorsChristopher J. Schenk, Philip H. Nelson, Timothy R. Klett, Phuong A. Le, Christopher P. AndersonGeologic assessment of undiscovered oil and gas resources of the U.S. portion of the Michigan Basin
In 2004, the U.S. Geological Survey (USGS) completed an assessment of the undiscovered oil and gas potential of the U.S. portion of the Michigan Basin. For this assessment, the Michigan Basin includes most of the State of Michigan, as well as parts of Illinois, Indiana, Minnesota, Ohio, and Wisconsin. The assessment was based on the geologic elements of each of the six total petroleum systems defiAuthorsChristopher S. Swezey, Joseph R. Hatch, Daniel O. Hayba, John E. Repetski, Ronald R. Charpentier, Troy A. Cook, Timothy R. Klett, Richard M. Pollastro, Christopher P. Anderson, Christopher J. Schenk, Joseph A. East, Phuong A. LeMap of assessed continuous (unconventional) oil resources in the United States, 2014
The U.S. Geological Survey (USGS) conducts quantitative assessments of potential oil and gas resources of the onshore United States and associated coastal State waters. Since 2000, the USGS has completed assessments of continuous (unconventional) resources in the United States based on geologic studies and analysis of well-production data and has compiled digital maps of the assessment units classAuthorsPetroleum systems and assessment of undiscovered oil and gas in the Anadarko Basin Province, Colorado, Kansas, Oklahoma, and Texas: USGS Province 58
This publication provides research results and related data in support of the U.S. Geological Survey assessment of the undiscovered oil and gas resource potential of the Anadarko Basin Province of western Oklahoma and Kansas, northern Texas, and southeastern Colorado. This province area includes the Las Animas arch of southeastern Colorado, part of the Palo Duro Basin of Texas, and the Anadarko BaAuthorsDebra K. HigleyMap of assessed coalbed-gas resources in the United States, 2014
This report presents a digital map of coalbed-gas resource assessments in the United States as part of the U.S. Geological Survey’s (USGS) National Assessment of Oil and Gas Project. Using a geology-based assessment methodology, the USGS quantitatively estimated potential volumes of undiscovered, technically recoverable natural gas resources within coalbed-gas assessment units (AUs). This is the tAuthorsLaura R. H. BiewickMap of assessed tight-gas resources in the United States
This report presents a digital map of tight-gas resource assessments in the United States as part of the U.S. Geological Survey’s (USGS) National Assessment of Oil and Gas Project. Using a geology-based assessment methodology, the USGS quantitatively estimated potential volumes of undiscovered, technically recoverable natural gas resources within tight-gas assessment units (AUs). This is the seconAuthorsLaura R. H. BiewickU.S. Geological Survey 2013 assessment of undiscovered resources in the Bakken and Three Forks Formations of the U.S. Williston Basin Province
The Upper Devonian Three Forks and Upper Devonian to Lower Mississippian Bakken Formations comprise a major United States continuous oil resource. Current exploitation of oil is from horizontal drilling and hydraulic fracturing of the Middle Member of the Bakken and upper Three Forks, with ongoing exploration of the lower Three Forks, and the Upper, Lower, and Pronghorn Members of the Bakken FormaAuthorsStephanie B. Gaswirth, Kristen R. MarraAssessment of continuous oil and gas reservoirs, Paradox Basin, Utah, Colorado, New Mexico, and Arizona
No abstract availableAuthorsLawrence O. Anna, Katherine J. Whidden, Krystal M. PearsonLower Cody Shale (Niobrara equivalent) in the Bighorn Basin, Wyoming and Montana: thickness, distribution, and source rock potential
The lower shaly member of the Cody Shale in the Bighorn Basin, Wyoming and Montana is Coniacian to Santonian in age and is equivalent to the upper part of the Carlile Shale and basal part of the Niobrara Formation in the Powder River Basin to the east. The lower Cody ranges in thickness from 700 to 1,200 feet and underlies much of the central part of the basin. It is composed of gray to black shalAuthorsThomas M. FinnNational Assessment of Oil and Gas Project: geologic assessment of undiscovered gas hydrate resources on the North Slope, Alaska
Scientists with the U.S. Geological Survey have completed the first assessment of the undiscovered, technically recoverable gas hydrate resources beneath the North Slope of Alaska. This assessment indicates the existence of technically recoverable gas hydrate resources—that is, resources that can be discovered, developed, and produced using current technology. The approach used in this assessmentAuthorsTimothy S. USGS AK Gas Hydrate Assessment Team: Collett, Warren F. Agena, Myung Woong Lee, Kristen A. Lewis, Margarita V. Zyrianova, Kenneth J. Bird, Ronald R. Charpentier, Troy A. Cook, David W. Houseknecht, Timothy R. Klett, Richard M. PollastroUpper Devonian–Mississippian stratigraphic framework of the Arkoma Basin and distribution of potential source-rock facies in the Woodford–Chattanooga and Fayetteville–Caney shale-gas systems
Wireline logs were used to document the stratigraphic framework of Upper Devonian–Mississippian strata in the Arkoma Basin, and maps of high-gamma ray (HGR) log response were used to analyze the spatial distribution of potential source rocks in the Woodford–Chattanooga and Fayetteville–Caney shale-gas systems. The Woodford–Chattanooga shale is a transgressive deposit that accumulated on an arid coAuthorsDavid W. Houseknecht, William A. Rouse, Stanley T. Paxton, John C. Mars, Bryant R. Fulk - 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.