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.
Eastern Basins Oil and Gas Assessments
Cincinnati Arch Oil and Gas Assessments
Arkoma Basin Oil and Gas Assessments
Southern Oklahoma Oil and Gas Assessments
Ozark Uplift Oil and Gas Assessments
Iowa Shelf Oil and Gas Assessments
Cambridge Arch-Central Kansas Uplift Oil and Gas Assessment
Nemaha Uplift Province Oil and Gas Assessment
Forest City Basin Oil and Gas Assessments
Sedgwick Basin Oil and Gas Assessments
Marathon Thrust Belt Oil and Gas Asessments
Superior Oil and Gas Assessments
Below are datasets related to the National Oil and Gas Assessments.
Data release for the 3D petroleum systems model of the Williston Basin, USA
New source rock data for the Mowry and Thermopolis Shales in the Wind River Basin, Wyoming
Total organic carbon and pyrolysis analysis data for the Rock Well Petroleum core #8, southern Casper arch, Natrona County, Wyoming
USGS National and Global Oil and Gas Assessment Project-U.S. Gulf Coast, Deep Tuscaloosa Conventional Gas: Assessment Unit Boundary, Assessment Input Data, and Fact Sheet Data Tables
Aggregated Oil and Natural Gas Drilling and Production History of the United States (ver. 1.1, April 2023)
USGS National and Global Oil and Gas Assessment Project-Montana Thrust Belt Province: Assessment Unit Boundaries, Assessment Input Data, and Fact Sheet Data Tables
USGS National and Global Oil and Gas Assessment Project - Resource Allocations for the BLM Carlsbad Planning Area
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Bakken and Three Forks Formations Continuous Assessment Unit Boundaries and Assessment Input Data Forms
Total organic carbon and pyrolysis analysis data for the U.S. Geological Survey Alcova AR-1-13 core hole, Natrona County, Wyoming
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Lower Paleozoic Conventional Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Tyler Formation Assessment Unit Boundaries and Assessment Input Data Forms
USGS National and Global Oil and Gas Assessment Project - Williston Basin, Upper Paleozoic Conventional Assessment Unit Boundaries and Assessment Input Data Forms
Below are publications associated with this project.
Assessment of undiscovered conventional gas resources in the Deep Tuscaloosa Group Sandstones of the Western Gulf Basin Province, U.S. Gulf Coast region, 2021
Assessment of undiscovered conventional oil and gas resources of the Montana Thrust Belt Province, 2021
Assessment of undiscovered continuous oil resources in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana, 2021
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 undiscovered gas resources in the Williston Basin Province, 2020
Assessment of undiscovered conventional oil and gas resources of upper Paleozoic strata in the Williston Basin Province, 2020
Assessment of undiscovered oil and gas resources in the Pennsylvanian Tyler Formation of the Williston Basin Province, 2020
Assessment of undiscovered conventional oil and gas resources in the lower Paleozoic of the Williston Basin Province, 2020
Assessment of undiscovered gas resources in Upper Devonian to Lower Cretaceous strata of the western North Slope, Alaska, 2021
Assessment of continuous gas resources in the Horn River Basin, Cordova Embayment, and Liard Basin, Canada, 2019
Assessment of continuous oil and gas resources in the Mowry Shale, Wind River Basin Province, Wyoming, 2020
Geologic assessment of undiscovered oil and gas resources in the Cherokee Platform area of Kansas, Oklahoma, and Missouri
Below are datasets related to the National Oil and Gas Assessments.
Aggregated Oil and Natural Gas Drilling History of the United States Web Application
This application provides an overview of oil and gas well history of the United States, from 1880 to September 1, 2022. Well history data is aggregated into 10-mile squares indicating the total number of wells and counts of wells classified as oil, gas, dry, injection, hydraulically fractured, and/or horizontal wells.
Explore US Oil and Gas Assessments
This map shows the provinces assessed by the USGS for undiscovered oil and gas resources.
USGS Domestic Continuous (Unconventional) Oil & Gas Assessments, 2000-Present
Interactively explore assessment summary information for continuous (unconventional) assessments conducted at the USGS from 2000-2018. The assessment results data used to generate this visualization can be downloaded here in Excel Format. These data represent all assessment results for Continuous Assessments only from 2000-2018.
Below are news stories associated with this project.
Below are FAQ associated with this project.
What are the different columns on a USGS oil and gas resource assessment table?
Oil and gas estimates always involve some amounts of uncertainty. To account for this, the USGS presents its assessments of oil and gas potential in the form of a range based on how certain we are that this amount of oil and gas exist. The USGS uses a statistically based process (or model) to calculate the likely range of its estimates. The range of values extends from a 5% or greater likelihood...
What are "technically recoverable" oil and gas resources?
“Technically recoverable” means that the oil and/or gas can be produced using currently available technology and industry practices. This is regardless of any economic or accessibility considerations. For example, the technology required to produce oil from a location might exist, but it costs more than the oil is worth. The oil is still technically recoverable. Learn more: USGS Energy Assessments...
Why do the oil and gas resource numbers sometimes change when the USGS releases a new assessment of an oil and gas formation?
Assessments regularly change based on our understanding of geology, as well as advances in technology. As more is learned about the geology of a given formation, both from USGS research and from industry activity, a clearer picture of the potential recoverable oil and gas resources can be created. In some cases, industry activity can show that a rock formation that was previous thought to have...
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: 59Eastern Basins Oil and Gas Assessments
The USGS has conducted several assessments of undiscovered oil and gas in formations in the Blue Ridge Thrust Belt (5068), Piedmont Province (5069), Atlantic Coastal Plain Province (5070), and the New England Province (5072). These basins are generally east of the Appalachian Basin Province (5067).Cincinnati Arch Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas resources of the Cincinnati Arch Province (5066) :Arkoma Basin Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas resources of the Arkoma Basin Province 5062.Southern Oklahoma Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered continuous oil and gas resources of the Southern Oklahoma Province (5061).Ozark Uplift Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas potential of the Ozark Uplift Province (5057).Iowa Shelf Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas potential of the Iowa Shelf Province (5052).Cambridge Arch-Central Kansas Uplift Oil and Gas Assessment
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas potential of the Cambridge Arch/Central Kansas Uplift Province (5053).Nemaha Uplift Province Oil and Gas Assessment
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas potential of the Nemaha Uplift Province (5055).Forest City Basin Oil and Gas Assessments
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas potential of the Forest City Basin Province (5056).Sedgwick Basin Oil and Gas Assessments
Province Code: 5059 The Salina Basin Province (5059), covers an area of about 45,000 sq mi, consisting of the eastern half of Nebraska and the north-central portion of Kansas. The basin lies between the Cambridge Arch-Central Kansas Uplift Province (5053) on the west, the Nemaha Uplift Province (5055) to the east, the Sioux Arch Province (5032) to the north, and a poorly defined structural saddle...Marathon Thrust Belt Oil and Gas Asessments
The U.S. Geological Survey completed the following assessments of undiscovered oil and gas resources of the Marathon Thrust Belt province 5046 in southwestern Texas.Superior Oil and Gas Assessments
The U.S. Geological Survey completed the following assessment of undiscovered oil and gas potential of the Superior Province 5051. - Data
Below are datasets related to the National Oil and Gas Assessments.
Filter Total Items: 36Data release for the 3D petroleum systems model of the Williston Basin, USA
This data release contains data associated with the journal article "Modeling the maturation history of the stacked petroleum systems of the Williston Basin, USA". Collectively, the data release includes 13 child items and metadata files that provide detailed descriptions of the attributes, processing steps, and original data sources. There is also a data table, "Williston_Basin_Data_Release_OvervNew source rock data for the Mowry and Thermopolis Shales in the Wind River Basin, Wyoming
In 2020, the U.S. Geological Survey (USGS) assessed the potential for undiscovered, technically recoverable continuous (unconventional) oil and gas resources in the Mowry Shale in the Wind River Basin Province (Finn and others, 2021). To better characterize the source rock potential of the Mowry Shale and associated strata, 129 samples were collected from 45 wells from the well cuttings collectionTotal organic carbon and pyrolysis analysis data for the Rock Well Petroleum core #8, southern Casper arch, Natrona County, Wyoming
In 2006, Rock Well Petroleum drilled and logged nearly 1,600 feet (ft) of continuous core on the southern part of the Casper arch in Natrona County, Wyoming (see fig1.png). The core hole, named the Poison Spider core #8 penetrated the interval extending from the Upper Cretaceous Frontier Formation to the Triassic Alcova Limestone. The core was subsequently donated to the U.S. Geological Survey CorUSGS National and Global Oil and Gas Assessment Project-U.S. Gulf Coast, Deep Tuscaloosa Conventional Gas: Assessment Unit Boundary, Assessment Input Data, and Fact Sheet Data Tables
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered Deep Tuscaloosa Group sandstones conventional gas resources in the U.S. Gulf Coast in Louisiana and Mississippi. 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 wiAggregated Oil and Natural Gas Drilling and Production History of the United States (ver. 1.1, April 2023)
This data release provides several datasets that provide an overview of oil and gas well history and production of the United States, from 1817 to September 1, 2022. Well history data is aggregated into 1- and 10-mile squares indicating the total number of wells and counts of wells classified as oil, gas, dry, injection, hydraulically fractured, and/or horizontal wells. Well history is also binnedUSGS National and Global Oil and Gas Assessment Project-Montana Thrust Belt Province: Assessment Unit Boundaries, Assessment Input Data, and Fact Sheet Data Tables
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered gas resources in the Montana Thrust Belt province in Montana. 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 PetroleuUSGS National and Global Oil and Gas Assessment Project - Resource Allocations for the BLM Carlsbad Planning Area
The U.S. Geological Survey Central Energy Science Center (CERSC) was asked to provide allocations of oil and gas resources and numbers of potential wells calculated from these allocated resources for the BLM Carlsbad Planning Area in New Mexico. The resource allocations were based on the most current USGS assessment of continuous (unconventional) oil and gas resources within eleven geologically deUSGS National and Global Oil and Gas Assessment Project - Williston Basin, Bakken and Three Forks Formations Continuous Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Bakken and Three Forks formations in the Williston Basin province in Montana, North Dakota and South Dakota. The Assessment Unit is the fundamental unit used in the National Assessment Project for the assessment of undiscovered oil and gas resources. The AsseTotal organic carbon and pyrolysis analysis data for the U.S. Geological Survey Alcova AR-1-13 core hole, Natrona County, Wyoming
In 2013 the U.S. Geological Survey (USGS) drilled a continuous core in the southeastern part of the Wind River Basin, Wyoming to evaluate the source rock potential of the Lower and lowermost Upper Cretaceous marine shales . The well, named the Alcova Reservoir AR-1-13, located on the northeast flank of the Alcova anticline was spud in the lower part of the Frontier Formation and ended in the upperUSGS National and Global Oil and Gas Assessment Project - Williston Basin, Lower Paleozoic Conventional Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Lower Paleozoic of the Williston Basin province in Montana, North Dakota and South Dakota. 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 defUSGS National and Global Oil and Gas Assessment Project - Williston Basin, Tyler Formation Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Tyler formation of the Williston Basin province in Montana, North Dakota and South Dakota. 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 defUSGS National and Global Oil and Gas Assessment Project - Williston Basin, Upper Paleozoic Conventional Assessment Unit Boundaries and Assessment Input Data Forms
This data release contains the boundaries of assessment units and input data for the assessment of undiscovered oil and gas resources in the Upper Paleozoic of the Williston Basin province in Montana, North Dakota and South Dakota. 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 def - Publications
Below are publications associated with this project.
Filter Total Items: 93Assessment of undiscovered conventional gas resources in the Deep Tuscaloosa Group Sandstones of the Western Gulf Basin Province, U.S. Gulf Coast region, 2021
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 14,785 billion cubic feet of gas resources in the Western Gulf Basin Province, U.S. Gulf Coast region.AuthorsMatthew D. Merrill, Catherine B. EnomotoAssessment of undiscovered conventional oil and gas resources of the Montana Thrust Belt Province, 2021
Using a geology-based assessment methodology, the U.S. Geological Survey estimated means of 783 million barrels of conventional oil and 17,606 billion (17.6 trillion) cubic feet of conventional gas in the Montana Thrust Belt Province.AuthorsChristopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Phuong A. Le, Andrea D. Cicero, Ronald M. Drake, Geoffrey S. Ellis, Thomas M. Finn, Michael H. Gardner, Sarah E. Gelman, Jane S. Hearon, Benjamin G. Johnson, Jenny H. Lagesse, Heidi M. Leathers-Miller, Kristen R. Marra, Kira K. Timm, Scott S. YoungAssessment of undiscovered continuous oil resources in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana, 2021
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 4.3 billion barrels of oil and 4.9 trillion cubic feet of gas (associated) in the Bakken and Three Forks Formations of the Williston Basin Province, North Dakota and Montana.AuthorsKristen R. Marra, Tracey J. Mercier, Sarah E. Gelman, Christopher J. Schenk, Cheryl A. Woodall, Andrea D. Cicero, Ronald M. Drake, Geoffrey S. Ellis, Thomas M. Finn, Michael H. Gardner, Jane S. Hearon, Benjamin G. Johnson, Jenny H. Lagesse, Phuong A. Le, Heidi M. Leathers-Miller, Kira K. Timm, Scott S. YoungLithologic descriptions, geophysical logs, and source-rock geochemistry of the U.S. Geological Survey Alcova Reservoir AR–1–13 Core Hole, Natrona County, Wyoming
In 2013, a continuous 624-foot core hole was drilled and logged by the U.S. Geological Survey in Natrona County, Wyoming, with the goal to better understand Cretaceous source rocks in the Wind River Basin. The core hole, named the Alcova Reservoir AR–1–13, penetrated the interval extending from the upper part of the Lower Cretaceous Cloverly Formation to the lower part of the Upper Cretaceous FronAuthorsMark A. Kirschbaum, Thomas M. Finn, Christopher J. Schenk, Sarah J. HawkinsAssessment of undiscovered gas resources in the Williston Basin Province, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 2,438 billion (2.4 trillion) cubic feet of gas resources in the Williston Basin Province, in North Dakota, Montana, and South Dakota.AuthorsChristopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Geoffrey S. Ellis, Thomas M. Finn, Phuong A. Le, Kristen R. Marra, Heidi M. Leathers-Miller, Ronald M. DrakeAssessment of undiscovered conventional oil and gas resources of upper Paleozoic strata in the Williston Basin Province, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean oil and gas resources of 134 million barrels of oil and 81 billion cubic feet of gas in upper Paleozoic strata of the Williston Basin Province in North Dakota, Montana, and South Dakota.AuthorsChristopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Geoffrey S. Ellis, Thomas M. Finn, Phuong A. Le, Kristen R. Marra, Heidi M. Leathers-Miller, Ronald M. DrakeAssessment of undiscovered oil and gas resources in the Pennsylvanian Tyler Formation of the Williston Basin Province, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 161 million barrels of oil and 93 billion cubic feet of gas in the Tyler Formation of the Williston Basin Province, North Dakota.AuthorsChristopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Thomas M. Finn, Phuong A. Le, Kristen R. Marra, Geoffrey S. Ellis, Heidi M. Leathers-Miller, Ronald M. DrakeAssessment of undiscovered conventional oil and gas resources in the lower Paleozoic of the Williston Basin Province, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 83 million barrels of oil and 351 billion cubic feet of gas in lower Paleozoic strata of the Williston Basin Province, North Dakota, Montana, and South Dakota.AuthorsChristopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Geoffrey S. Ellis, Thomas M. Finn, Phuong A. Le, Kristen R. Marra, Heidi M. Leathers-Miller, Ronald M. DrakeAssessment of undiscovered gas resources in Upper Devonian to Lower Cretaceous strata of the western North Slope, Alaska, 2021
Using a geology-based assessment methodology, the U.S. Geological Survey estimated a mean of 1,407 billion (1.4 trillion) cubic feet of gas in conventional accumulations in Upper Devonian to Lower Cretaceous strata of the western North Slope, Alaska.AuthorsDavid W. Houseknecht, Tracey J. Mercier, Christopher J. Schenk, Thomas E. Moore, William A. Rouse, Julie A. Dumoulin, William H. Craddock, Richard O. Lease, Palma J. Botterell, Margaret M. Sanders, Rebecca A. Smith, Christopher D. Connors, Christopher P. Garrity, Katherine J. Whidden, Jared T. Gooley, John W. Counts, Joshua H. Long, Christina A. DeVeraAssessment of continuous gas resources in the Horn River Basin, Cordova Embayment, and Liard Basin, Canada, 2019
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 135.4 trillion cubic feet of continuous gas in Devonian–Mississippian shales in the Horn River Basin, Cordova Embayment, and Liard Basin of Canada.AuthorsChristopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Thomas M. Finn, Phuong A. Le, Michael E. Brownfield, Kristen R. Marra, Stephanie B. Gaswirth, Heidi M. Leathers-Miller, Janet K. PitmanAssessment of continuous oil and gas resources in the Mowry Shale, Wind River Basin Province, Wyoming, 2020
Using a geology-based assessment methodology, the U.S. Geological Survey estimated undiscovered, technically recoverable mean resources of 288 million barrels of oil and 2.6 trillion cubic feet of gas in the Mowry Shale in the Wind River Basin Province, Wyoming.AuthorsThomas M. Finn, Christopher J. Schenk, Tracey J. Mercier, Cheryl A. Woodall, Marilyn E. Tennyson, Kristen R. Marra, Phuong A. Le, Heidi M. Leathers-Miller, Geoffrey S. EllisGeologic assessment of undiscovered oil and gas resources in the Cherokee Platform area of Kansas, Oklahoma, and Missouri
In 2015, the U.S. Geological Survey completed a geology-based assessment to estimate the volumes of undiscovered, technically recoverable petroleum resources in the Cherokee Platform Province area of southeastern Kansas, northeastern Oklahoma, and southwestern Missouri. The U.S. Geological Survey identified four stratigraphic intervals that contain petroleum source rocks: (1) thin shales in the MiAuthorsRonald M. Drake, Joseph R. Hatch - Web Tools
Below are datasets related to the National Oil and Gas Assessments.
Aggregated Oil and Natural Gas Drilling History of the United States Web Application
This application provides an overview of oil and gas well history of the United States, from 1880 to September 1, 2022. Well history data is aggregated into 10-mile squares indicating the total number of wells and counts of wells classified as oil, gas, dry, injection, hydraulically fractured, and/or horizontal wells.
Explore US Oil and Gas Assessments
This map shows the provinces assessed by the USGS for undiscovered oil and gas resources.
USGS Domestic Continuous (Unconventional) Oil & Gas Assessments, 2000-Present
Interactively explore assessment summary information for continuous (unconventional) assessments conducted at the USGS from 2000-2018. The assessment results data used to generate this visualization can be downloaded here in Excel Format. These data represent all assessment results for Continuous Assessments only from 2000-2018.
- News
Below are news stories associated with this project.
- FAQ
Below are FAQ associated with this project.
What are the different columns on a USGS oil and gas resource assessment table?
Oil and gas estimates always involve some amounts of uncertainty. To account for this, the USGS presents its assessments of oil and gas potential in the form of a range based on how certain we are that this amount of oil and gas exist. The USGS uses a statistically based process (or model) to calculate the likely range of its estimates. The range of values extends from a 5% or greater likelihood...
What are "technically recoverable" oil and gas resources?
“Technically recoverable” means that the oil and/or gas can be produced using currently available technology and industry practices. This is regardless of any economic or accessibility considerations. For example, the technology required to produce oil from a location might exist, but it costs more than the oil is worth. The oil is still technically recoverable. Learn more: USGS Energy Assessments...
Why do the oil and gas resource numbers sometimes change when the USGS releases a new assessment of an oil and gas formation?
Assessments regularly change based on our understanding of geology, as well as advances in technology. As more is learned about the geology of a given formation, both from USGS research and from industry activity, a clearer picture of the potential recoverable oil and gas resources can be created. In some cases, industry activity can show that a rock formation that was previous thought to have...
- Partners
Below are partners associated with this project.