United States Assessments of Undiscovered Oil and Gas Resources

Assessment Overview

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.

Summary of Continuous Asessments

Summary of Continuous Asessments

This applications shows maps and tables of all continuous assessments in the United States.

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Science Center Objects

USGS Energy Resources Program provides periodic assessments of the oil and natural gas endowment of the United States and the World (click here for information about World Oil and Gas Assessments).  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).

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. 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

American Association of Petroleum Geologists Committee on Resource Evaluation (CORE) Subcommittee to review the United States Onshore Continuous (Unconventional) Gas Assessment Methodology Used by the USGS

 

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

American Association of Petroleum Geologists Committee on Resource Evaluation (CORE) Subcommittee to review the Growth-to-Known Reserves