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 of the Mississippian Sunbury shale and Devonian–Mississippian Chattanooga shale in the Appalachian Basin Province, 2016
Input-form data for the U.S. Geological Survey assessment of the Mississippian Barnett Shale of the Bend Arch-Fort Worth Basin Province, 2015
Assessment of tight-gas resources in Canyon sandstones of the Val Verde Basin, Texas, 2016
Assessment of undiscovered continuous oil and gas resources in the Monterey Formation, Los Angeles Basin Province, California, 2015
Assessment of continuous (unconventional) oil and gas resources in the Late Cretaceous Mancos Shale of the Piceance Basin, Uinta-Piceance Province, Colorado and Utah, 2016
Revisions to the original extent of the Devonian Shale-Middle and Upper Paleozoic Total Petroleum System
Geologic assessment of undiscovered oil and gas resources in the Albian Clastic and Updip Albian Clastic Assessment Units, U.S. Gulf Coast Region
Assessment of undiscovered shale gas and shale oil resources in the Mississippian Barnett Shale, Bend Arch–Fort Worth Basin Province, North-Central Texas
U.S. Geological Survey assessments of continuous (unconventional) oil and gas resources, 2000 to 2011
Assessment of undiscovered continuous oil and gas resources in the Monterey Formation, San Joaquin Basin Province, California, 2015
Assessment of undiscovered oil and gas resources in the Uteland Butte Member of the Eocene Green River Formation, Uinta Basin, Utah
Assessment of undiscovered oil and gas resources in the Cherokee Platform Province area of Kansas, Oklahoma, and Missouri, 2015
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 of the Mississippian Sunbury shale and Devonian–Mississippian Chattanooga shale in the Appalachian Basin Province, 2016
Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered, technically recoverable continuous resources that total 464 million barrels of oil and 4.08 trillion cubic feet of gas in the Lower Mississippian Sunbury Shale and Middle Devonian–Lower Mississippian Chattanooga Shale of the Appalachian Basin Province.AuthorsDebra K. Higley, William A. Rouse, Catherine B. Enomoto, Michael H. Trippi, Timothy R. Klett, Tracey J. Mercier, Michael E. Brownfield, Marilyn E. Tennyson, Ronald M. Drake, Thomas M. Finn, Nicholas J. Gianoutsos, Ofori N. Pearson, Colin A. Doolan, Phuong A. Le, Christopher J. SchenkInput-form data for the U.S. Geological Survey assessment of the Mississippian Barnett Shale of the Bend Arch-Fort Worth Basin Province, 2015
In 2015, the U.S. Geological Survey (USGS) released an updated assessment of undiscovered, technically recoverable shale gas and shale oil resources of the Mississippian Barnett Shale in north-central Texas (Marra and others, 2015). The Barnett Shale was assessed using the standard continuous (unconventional) methodology established by the USGS for two assessment units (AUs): (1) Barnett ContinuouAuthorsKristen R. Marra, Ronald R. Charpentier, Christopher J. Schenk, Michael D. Lewan, Heidi M. Leathers-Miller, Timothy R. Klett, Stephanie B. Gaswirth, Phuong A. Le, Tracey J. Mercier, Janet K. Pitman, Marilyn E. TennysonAssessment of tight-gas resources in Canyon sandstones of the Val Verde Basin, Texas, 2016
Using a geology-based assessment methodology, the U.S. Geological Survey assessed mean resources of 5 trillion cubic feet of gas and 187 million barrels of natural gas liquids in tight-gas assessment units in the Canyon sandstones of the Val Verde Basin, Texas.AuthorsChristopher J. Schenk, Marilyn E. Tennyson, Timothy R. Klett, Tracey J. Mercier, Michael E. Brownfield, Stephanie B. Gaswirth, Sarah J. Hawkins, Heidi M. Leathers-Miller, Kristen R. Marra, Thomas M. Finn, Janet K. PitmanAssessment of undiscovered continuous oil and gas resources in the Monterey Formation, Los Angeles Basin Province, California, 2015
Using a geology-based assessment methodology, the U.S. Geological Survey assessed technically recoverable mean resources of 13 million barrels of oil, 22 billion cubic feet of gas, and 1 million barrels of natural gas liquids in the Monterey Formation of the Los Angeles Basin Province, California.AuthorsMarilyn E. Tennyson, Ronald R. Charpentier, Timothy R. Klett, Michael E. Brownfield, Janet K. Pitman, Stephanie B. Gaswirth, Sarah J. Hawkins, Phuong A. Le, Paul G. Lillis, Kristen R. Marra, Tracey J. Mercier, Heidi M. Leathers-Miller, Christopher J. SchenkAssessment of continuous (unconventional) oil and gas resources in the Late Cretaceous Mancos Shale of the Piceance Basin, Uinta-Piceance Province, Colorado and Utah, 2016
The U.S. Geological Survey (USGS) completed a geology-based assessment of the continuous (unconventional) oil and gas resources in the Late Cretaceous Mancos Shale within the Piceance Basin of the Uinta-Piceance Province (fig. 1). The previous USGS assessment of the Mancos Shale in the Piceance Basin was completed in 2003 as part of a comprehensive assessment of the greater UintaPiceance ProvinceAuthorsSarah J. Hawkins, Ronald R. Charpentier, Christopher J. Schenk, Heidi M. Leathers-Miller, Timothy R. Klett, Michael E. Brownfield, Tom M. Finn, Stephanie B. Gaswirth, Kristen R. Marra, Phoung A. Le, Tracey J. Mercier, Janet K. Pitman, Marilyn E. TennysonRevisions to the original extent of the Devonian Shale-Middle and Upper Paleozoic Total Petroleum System
Technically recoverable undiscovered hydrocarbon resources in continuous accumulations are present in Upper Devonian and Lower Mississippian strata in the Appalachian Basin Petroleum Province. The province includes parts of New York, Pennsylvania, Ohio, Maryland, West Virginia, Virginia, Kentucky, Tennessee, Georgia, and Alabama. The Upper Devonian and Lower Mississippian strata are part of the prAuthorsCatherine B. Enomoto, William A. Rouse, Michael H. Trippi, Debra K. HigleyGeologic assessment of undiscovered oil and gas resources in the Albian Clastic and Updip Albian Clastic Assessment Units, U.S. Gulf Coast Region
U.S. Geological Survey National Oil and Gas Assessments (NOGA) of Albian aged clastic reservoirs in the U.S. Gulf Coast region indicate a relatively low prospectivity for undiscovered hydrocarbon resources due to high levels of past production and exploration. Evaluation of two assessment units (AUs), (1) the Albian Clastic AU 50490125, and (2) the Updip Albian Clastic AU 50490126, were based on aAuthorsMatthew D. MerrillAssessment of undiscovered shale gas and shale oil resources in the Mississippian Barnett Shale, Bend Arch–Fort Worth Basin Province, North-Central Texas
Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean volumes of 53 trillion cubic feet of shale gas, 172 million barrels of shale oil, and 176 million barrels of natural gas liquids in the Barnett Shale of the Bend Arch–Fort Worth Basin Province of Texas.AuthorsKristen R. Marra, Ronald R. Charpentier, Christopher J. Schenk, Michael D. Lewan, Heidi M. Leathers-Miller, Timothy R. Klett, Stephanie B. Gaswirth, Phuong A. Le, Tracey J. Mercier, Janet K. Pitman, Marilyn E. TennysonU.S. Geological Survey assessments of continuous (unconventional) oil and gas resources, 2000 to 2011
From 2000 to 2011, the U.S. Geological Survey conducted 139 quantitative assessments of continuous (unconventional) oil and gas accumulations within the United States. This report documents those assessments more fully than previously done by providing detailed documentation of both the assessment input and output. This report also compiles the data into spreadsheet tables that can be more readilyAuthorsAssessment of undiscovered continuous oil and gas resources in the Monterey Formation, San Joaquin Basin Province, California, 2015
Using a geology-based assessment methodology, the U.S. Geological Survey assessed mean volumes of 21 million barrels of oil (MMBO), 27 billion cubic feet of gas, and 1 million barrels of natural gas liquids in two assessment units (AUs) that may contain continuous oil resources. Mean volumes of oil for the individual assessment units are 14 MMBO in the Monterey Buttonwillow AU and 7 MMBO in the MoAuthorsMarilyn E. Tennyson, Ronald R. Charpentier, Timothy R. Klett, Michael E. Brownfield, Janet K. Pitman, Stephanie B. Gaswirth, Sarah J. Hawkins, Paul G. Lillis, Kristen R. Marra, Tracey J. Mercier, Heidi M. Leathers, Christopher J. Schenk, Katherine J. WhiddenAssessment of undiscovered oil and gas resources in the Uteland Butte Member of the Eocene Green River Formation, Uinta Basin, Utah
Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean undiscovered resources of 214 million barrels of oil, 329 billion cubic feet of associated/dissolved natural gas, and 14 million barrels of natural gas liquids in the informal Uteland Butte member of the Green River Formation, Uinta Basin, Utah.AuthorsRonald C. Johnson, Justin E. Birdwell, Tracey J. Mercier, Michael E. Brownfield, Ronald R. Charpentier, Timothy R. Klett, Heidi M. Leathers, Christopher J. Schenk, Marilyn E. TennysonAssessment of undiscovered oil and gas resources in the Cherokee Platform Province area of Kansas, Oklahoma, and Missouri, 2015
Using a geology-based assessment methodology, the U.S. Geological Survey estimated mean volumes of undiscovered, technically recoverable resources of 463 million barrels of oil, 11.2 trillion cubic feet of gas, and 35 million barrels of natural gas liquids in the Cherokee Platform Province area of Kansas, Oklahoma, and Missouri.AuthorsRonald M. Drake, Joseph R. Hatch, Christopher J. Schenk, Ronald R. Charpentier, Timothy R. Klett, Phuong A. Le, Heidi M. Leathers, Michael E. Brownfield, Stephanie B. Gaswirth, Kristen R. Marra, Janet K. Pitman, Christopher J. Potter, Marilyn E. Tennyson - 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.