Results of the National Assessment of Potential Additions to Oil and Gas Reserves of the United States

Donald L. Gautier, Gordon L. Dolton, Richard F. Mast, James W. Schmoker, John D. Grace

The U.S. Geological Survey, in cooperation with the Minerals Management Service, has completed a 3-year analysis of potential additions to the oil and gas reserves of the United States. The USGS is responsible for evaluation of state waters and all onshore areas. The MMS has legal authority and responsibility for assessment of the Federal offshore.

Three categories of resources were assessed: 1. Undiscovered, conventional accumulations of oil and gas; 2. Potential additions to reserves from development of unconventional, continuous-type accumulations such as gas in tight sandstones, coalbed gas, and oil or gas in fractured shales; 3. Additions to reserves in accumulations already discovered as of December 1992. Undiscovered conventionally recoverable accumulations were assessed by means of geological play analysis and discovery-process modeling. Unconventional, continuous-type accumulations were assessed by means of a new, cell-based methodology utilizing probability distributions of estimated ultimate recoveries of wells yet to be drilled. Reserve growth was evaluated by means of statistical extrapolation of growth fiends of fi lds during the last 13 years.

Results are reported by national commodity total, by resource category, by play, by province (basin), by region, by state, by depth, by accumulation size, and by anticipated well performance. Documentation for the assessment is published on CD-ROM and is available through the internet.

AAPG Search and Discovery Article #91020©1995 AAPG Annual Convention, Houston, Texas, May 5-8, 1995