United States Assessments of Undiscovered Oil and Gas Resources
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.
Bighorn Basin Oil and Gas Assessments
North-Central Montana Oil and Gas Assessments
Hanna, Laramie, Shirley Basins Oil and Gas Assessments
San Juan Basin Oil and Gas Assessments
Paradox 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
Gulf Coast Geologic Energy 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 the Ventura Basin Province, California, 2016
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
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
Geological, geochemical, and reservoir characterization of the Uteland Butte member of the Green River Formation, Uinta Basin, Utah
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.
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.
Bighorn Basin Oil and Gas Assessments
North-Central Montana Oil and Gas Assessments
Hanna, Laramie, Shirley Basins Oil and Gas Assessments
San Juan Basin Oil and Gas Assessments
Paradox 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
Gulf Coast Geologic Energy 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 the Ventura Basin Province, California, 2016
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
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
Geological, geochemical, and reservoir characterization of the Uteland Butte member of the Green River Formation, Uinta Basin, Utah
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.