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
![Image shows a map of the assessment units of the 2018 Delaware Basin oil and gas assessment](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/info_block/public/thumbnails/image/Map%202.jpg?itok=Hqf7Zpca)
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.
Sioux Arch Oil and Gas Assessments
Southwest Montana Oil and Gas Assessments
Park Basin Oil and Gas Assessments
South-Central New Mexico Oil and Gas Assessments
Southern Arizona-Southwestern New Mexico Oil and Gas Assessments
Pedernal Uplift Oil and Gas Assessments
Western Great Basin Oil and Gas Assessments
Northern Arizona Oil and Gas Assessments
Albuquerque-Santa Fe Rift Oil and Gas Assessments
Idaho-Snake River Downwarp Oil and Gas Assessments
Northern Coastal Oil and Gas Assessments
Sonoma-Livermore Basin Oil and Gas Assessments
Below are datasets related to the National Oil and Gas Assessments.
USGS National and Global Oil and Gas Assessment Project - Wind River Basin, Mowry Shale Formation Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project-Gulf Coast Mesozoic Province, Upper Cretaceous Austin Chalk Group and Tokio and Eutaw Formations Assessment Units and Input Data Forms
USGS National and Global Oil and Gas Assessment Project - San Juan Basin Province, Fruitland Total Petroleum System Assessment Units and Input Data Forms
USGS National and Global Oil and Gas Assessment Project - San Juan Basin Province, Lewis Shale Total Petroleum System Assessment Units and Input Data Forms
USGS National and Global Oil and Gas Assessment Project - San Juan Basin Province, Mancos-Menefee Composite Total Petroleum System and underlying Todilto Total Petroleum System Assessment Units and Input Data Forms
USGS National and Global Assessment Project-Sacramento Basin, Conventional and Continuous Assessment Unit Boundaries and Assessment Input Forms
USGS National and Global Oil and Gas Assessment Project - Appalachian Basin Province, Middle Devonian Marcellus Shale Assessment Units and Input Data Forms
USGS National and Global Oil and Gas Assessment Project - Appalachian Basin Province, Point Pleasant Formation and Utica Shale Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project-Michigan Basin Province, Collingwood-Utica Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project-Eastern Great Basin Province, Delle Phosphatic Member Shale Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project-Southwestern Wyoming Province, Phosphoria Shale Gas Assessment Unit Boundaries and Assessment Input Data Forms
LAS digital data files for the U.S.Geological Survey Alcova AR-1-13 core hole, Natrona County, Wyoming
Below are publications associated with this project.
Assessment of continuous oil and gas resources in the Mississippian Delle Phosphatic Member of the Woodman Formation in the Eastern Great Basin Province of Nevada, Utah, and Idaho, 2019
Assessment of continuous gas resources in the Permian Phosphoria Formation of the Southwestern Wyoming Province, Wyoming, 2019
Assessment of undiscovered continuous oil and gas resources in the Upper Ordovician Point Pleasant Formation and Utica Shale of the Appalachian Basin Province, 2019
Assessment of undiscovered gas resources in the Middle Devonian Marcellus Shale of the Appalachian Basin Province, 2019
Assessment of continuous oil resources in the Eastern Great Basin Province of Nevada, Utah, and Idaho, 2018
Assessment of undiscovered continuous tight-gas resources in the Mesaverde Group and Wasatch Formation, Uinta-Piceance Province, Utah and Colorado, 2018
Assessment of undiscovered oil and gas resources in the South Florida basin, 2016
Lithologic descriptions, geophysical logs, and source-rock geochemistry of the U.S. Geological Survey Alcova Reservoir AR–1–13 Core Hole, Natrona County, Wyoming
Assessment of continuous oil and gas resources in the Niobrara interval of the Cody Shale, Wind River Basin Province, Wyoming, 2018
Assessment of undiscovered continuous oil and gas resources in the Wolfcamp Shale and Bone Spring Formation of the Delaware Basin, Permian Basin Province, New Mexico and Texas, 2018
U.S. Geological Survey input-data forms for the assessment of the Upper Jurassic Bossier Formation, U.S. Gulf Coast, 2016
U.S. Geological Survey input-data forms for the assessment of the Upper Jurassic Haynesville Formation, U.S. Gulf Coast, 2016
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
![Image shows a map of the assessment units of the 2018 Delaware Basin oil and gas assessment](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/info_block/public/thumbnails/image/Map%202.jpg?itok=Hqf7Zpca)
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.
Sioux Arch Oil and Gas Assessments
Southwest Montana Oil and Gas Assessments
Park Basin Oil and Gas Assessments
South-Central New Mexico Oil and Gas Assessments
Southern Arizona-Southwestern New Mexico Oil and Gas Assessments
Pedernal Uplift Oil and Gas Assessments
Western Great Basin Oil and Gas Assessments
Northern Arizona Oil and Gas Assessments
Albuquerque-Santa Fe Rift Oil and Gas Assessments
Idaho-Snake River Downwarp Oil and Gas Assessments
Northern Coastal Oil and Gas Assessments
Sonoma-Livermore Basin Oil and Gas Assessments
Below are datasets related to the National Oil and Gas Assessments.
USGS National and Global Oil and Gas Assessment Project - Wind River Basin, Mowry Shale Formation Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project-Gulf Coast Mesozoic Province, Upper Cretaceous Austin Chalk Group and Tokio and Eutaw Formations Assessment Units and Input Data Forms
USGS National and Global Oil and Gas Assessment Project - San Juan Basin Province, Fruitland Total Petroleum System Assessment Units and Input Data Forms
USGS National and Global Oil and Gas Assessment Project - San Juan Basin Province, Lewis Shale Total Petroleum System Assessment Units and Input Data Forms
USGS National and Global Oil and Gas Assessment Project - San Juan Basin Province, Mancos-Menefee Composite Total Petroleum System and underlying Todilto Total Petroleum System Assessment Units and Input Data Forms
USGS National and Global Assessment Project-Sacramento Basin, Conventional and Continuous Assessment Unit Boundaries and Assessment Input Forms
USGS National and Global Oil and Gas Assessment Project - Appalachian Basin Province, Middle Devonian Marcellus Shale Assessment Units and Input Data Forms
USGS National and Global Oil and Gas Assessment Project - Appalachian Basin Province, Point Pleasant Formation and Utica Shale Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project-Michigan Basin Province, Collingwood-Utica Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project-Eastern Great Basin Province, Delle Phosphatic Member Shale Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project-Southwestern Wyoming Province, Phosphoria Shale Gas Assessment Unit Boundaries and Assessment Input Data Forms
LAS digital data files for the U.S.Geological Survey Alcova AR-1-13 core hole, Natrona County, Wyoming
Below are publications associated with this project.
Assessment of continuous oil and gas resources in the Mississippian Delle Phosphatic Member of the Woodman Formation in the Eastern Great Basin Province of Nevada, Utah, and Idaho, 2019
Assessment of continuous gas resources in the Permian Phosphoria Formation of the Southwestern Wyoming Province, Wyoming, 2019
Assessment of undiscovered continuous oil and gas resources in the Upper Ordovician Point Pleasant Formation and Utica Shale of the Appalachian Basin Province, 2019
Assessment of undiscovered gas resources in the Middle Devonian Marcellus Shale of the Appalachian Basin Province, 2019
Assessment of continuous oil resources in the Eastern Great Basin Province of Nevada, Utah, and Idaho, 2018
Assessment of undiscovered continuous tight-gas resources in the Mesaverde Group and Wasatch Formation, Uinta-Piceance Province, Utah and Colorado, 2018
Assessment of undiscovered oil and gas resources in the South Florida basin, 2016
Lithologic descriptions, geophysical logs, and source-rock geochemistry of the U.S. Geological Survey Alcova Reservoir AR–1–13 Core Hole, Natrona County, Wyoming
Assessment of continuous oil and gas resources in the Niobrara interval of the Cody Shale, Wind River Basin Province, Wyoming, 2018
Assessment of undiscovered continuous oil and gas resources in the Wolfcamp Shale and Bone Spring Formation of the Delaware Basin, Permian Basin Province, New Mexico and Texas, 2018
U.S. Geological Survey input-data forms for the assessment of the Upper Jurassic Bossier Formation, U.S. Gulf Coast, 2016
U.S. Geological Survey input-data forms for the assessment of the Upper Jurassic Haynesville Formation, U.S. Gulf Coast, 2016
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.