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.
Los Angeles Basin Oil and Gas Assessments
Ventura Basin Oil and Gas Assessments
Santa Maria Basin Oil and Gas Assessments
Central Coastal Oil and Gas Assessments
Black Warrior Basin Oil and Gas Assessments
Illinois Basin Oil and Gas Assessments
Michigan Basin Oil and Gas Assessments
Cherokee Platform Oil and Gas Assessments
Denver Basin Oil and Gas Assessments
Bend Arch-Fort Worth Basin Oil and Gas Assessments
Wyoming Thrust Belt Oil and Gas Assessments
Bighorn 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 - Permian Basin Province, Midland Basin, Wolfcamp Shale Assessment Unit Boundaries and Assessment Input Data Forms, Version 2.0
USGS National and Global Oil and Gas Assessment Project-Permian Basin Province, Delaware Basin, Wolfcamp Shale and Bone Spring Assessment Units and Input Data
USGS Gulf Coast Petroleum Systems, and National and Global Oil and Gas Assessment Projects - USGS Province 50 Assessment Unit Boundaries and Assessment Input Forms
The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the higher-level Total Petroleum System. The Assessment Unit is shown herein as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the province and incorporates a set o
USGS National and Global Oil and Gas Assessment Project-Appalachian Basin Province, Upper Devonian Shales Assessment Unit Boundaries and Assessment Input Forms
USGS National and Global Oil and Gas Assessment Project - Sunbury and Chattanooga Shales Assessment Unit Boundaries and Assessment Input Forms
USGS National and Global Oil and Gas Assessment Project-Permian Basin Province, Midland Basin, Spraberry Formation Assessment Units
USGS Alaska Petroleum Systems Project: Northern Alaska Province, Nanushuk and Torok Formations Assessment Units and Assessment Input Forms
USGS National and Global Oil and Gas Assessment Project-Gulf Coast Mesozoic Province, Bossier Formation Assessment Units
USGS National and Global Oil and Gas Assessment Project-Permian Basin Province, Val Verde Basin, Canyon Sandstones Assessment Units
USGS National and Global Oil and Gas Assessment Project-Permian Basin Province, Midland Basin, Wolfcamp Shale Assessment Units
Below are publications associated with this project.
Assessment of undiscovered continuous oil and gas resources in the Upper Cretaceous Tuscaloosa marine shale of the U.S. Gulf Coast, 2018
Assessment of undiscovered oil and gas resources in the Eagle Ford Group and associated Cenomanian–Turonian Strata, U.S. Gulf Coast, Texas, 2018
Multiple stacked plays to drive continued Permian development
Assessment of undiscovered conventional oil and gas resources in the downdip Paleogene formations, U.S. Gulf Coast, 2017
Assessment of undiscovered oil and gas resources of the Susitna Basin, southern Alaska, 2017
Assessment of undiscovered continuous gas resources in Upper Devonian Shales of the Appalachian Basin Province, 2017
Assessment of continuous gas resources in the Phosphoria Formation of the Wyoming Thrust Belt Province, Wyoming, Idaho, and Utah, 2017
Assessment of undiscovered conventional oil and gas resources in the Wyoming Thrust Belt Province, Wyoming, Idaho, and Utah, 2017
Assessment of undiscovered oil and gas resources in the North-Central Montana Province, 2017
Assessment of undiscovered oil and gas resources in the Cretaceous Nanushuk and Torok Formations, Alaska North Slope, and summary of resource potential of the National Petroleum Reserve in Alaska, 2017
Procedure for calculating estimated ultimate recoveries of wells in the Mississippian Barnett Shale, Bend Arch–Fort Worth Basin Province of north-central Texas
U.S. Geological Survey input-data forms for the assessment of the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas, 2017
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.
Los Angeles Basin Oil and Gas Assessments
Ventura Basin Oil and Gas Assessments
Santa Maria Basin Oil and Gas Assessments
Central Coastal Oil and Gas Assessments
Black Warrior Basin Oil and Gas Assessments
Illinois Basin Oil and Gas Assessments
Michigan Basin Oil and Gas Assessments
Cherokee Platform Oil and Gas Assessments
Denver Basin Oil and Gas Assessments
Bend Arch-Fort Worth Basin Oil and Gas Assessments
Wyoming Thrust Belt Oil and Gas Assessments
Bighorn 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 - Permian Basin Province, Midland Basin, Wolfcamp Shale Assessment Unit Boundaries and Assessment Input Data Forms, Version 2.0
USGS National and Global Oil and Gas Assessment Project-Permian Basin Province, Delaware Basin, Wolfcamp Shale and Bone Spring Assessment Units and Input Data
USGS Gulf Coast Petroleum Systems, and National and Global Oil and Gas Assessment Projects - USGS Province 50 Assessment Unit Boundaries and Assessment Input Forms
The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The Assessment Unit is defined within the context of the higher-level Total Petroleum System. The Assessment Unit is shown herein as a geographic boundary interpreted, defined, and mapped by the geologist responsible for the province and incorporates a set o
USGS National and Global Oil and Gas Assessment Project-Appalachian Basin Province, Upper Devonian Shales Assessment Unit Boundaries and Assessment Input Forms
USGS National and Global Oil and Gas Assessment Project - Sunbury and Chattanooga Shales Assessment Unit Boundaries and Assessment Input Forms
USGS National and Global Oil and Gas Assessment Project-Permian Basin Province, Midland Basin, Spraberry Formation Assessment Units
USGS Alaska Petroleum Systems Project: Northern Alaska Province, Nanushuk and Torok Formations Assessment Units and Assessment Input Forms
USGS National and Global Oil and Gas Assessment Project-Gulf Coast Mesozoic Province, Bossier Formation Assessment Units
USGS National and Global Oil and Gas Assessment Project-Permian Basin Province, Val Verde Basin, Canyon Sandstones Assessment Units
USGS National and Global Oil and Gas Assessment Project-Permian Basin Province, Midland Basin, Wolfcamp Shale Assessment Units
Below are publications associated with this project.
Assessment of undiscovered continuous oil and gas resources in the Upper Cretaceous Tuscaloosa marine shale of the U.S. Gulf Coast, 2018
Assessment of undiscovered oil and gas resources in the Eagle Ford Group and associated Cenomanian–Turonian Strata, U.S. Gulf Coast, Texas, 2018
Multiple stacked plays to drive continued Permian development
Assessment of undiscovered conventional oil and gas resources in the downdip Paleogene formations, U.S. Gulf Coast, 2017
Assessment of undiscovered oil and gas resources of the Susitna Basin, southern Alaska, 2017
Assessment of undiscovered continuous gas resources in Upper Devonian Shales of the Appalachian Basin Province, 2017
Assessment of continuous gas resources in the Phosphoria Formation of the Wyoming Thrust Belt Province, Wyoming, Idaho, and Utah, 2017
Assessment of undiscovered conventional oil and gas resources in the Wyoming Thrust Belt Province, Wyoming, Idaho, and Utah, 2017
Assessment of undiscovered oil and gas resources in the North-Central Montana Province, 2017
Assessment of undiscovered oil and gas resources in the Cretaceous Nanushuk and Torok Formations, Alaska North Slope, and summary of resource potential of the National Petroleum Reserve in Alaska, 2017
Procedure for calculating estimated ultimate recoveries of wells in the Mississippian Barnett Shale, Bend Arch–Fort Worth Basin Province of north-central Texas
U.S. Geological Survey input-data forms for the assessment of the Spraberry Formation of the Midland Basin, Permian Basin Province, Texas, 2017
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.