Abstract: Gas Reserves, Gas Resource Base, and Prospects for Future Gas Supplies

Edwin D. Goebel

Natural gas production increased at an average annual rate of about 7 percent to 1970; from 1970 to 1973 the growth curve flattened; gas production of about 21.2 Tcf in 1974 represents a decline of 5.8 percent from the 1973 peak-year production. Our nation's proved gas reserves are diminishing. The ratio of reserves to production is approximately 11:1. Additions to reserves since 1968 have averaged only 9.5 Tcf. Estimates of undiscovered recoverable natural gas recently have been revised downward.

These facts have led to serious doubts about the ability of the gas industry to supply gas from known proved gas reserves of the lower 48 states or from other untapped conventional gas resources, at the current or at an accelerated rate over the next 15 years. "Conventional gas resources" is a phrase referring to those relatively imprecisely known quantities of natural gas (proved, though undiscovered recoverable) judged to be ultimately recoverable under current economic and operating conditions. Nonconventional gas resources include currently noneconomic, imprecisely known quantities of natural gas contained in coal seams, impermeable formations, and geopressured zones.

For purposes of a responsive national natural-gas-supply policy, planners and policy makers need credible estimates of how much, what kind, and at what rate gas will be supplied to the domestic network from either conventional or nonconventional sources. Must we really manage in the future with less gas in absolute terms? Or will finding rates, which have displayed a general downward trend the last 10 years, ultimately be reversed through reserves added by an expanded exploratory effort?

APG Search and Discovery Article #90974©1975 AAPG Mid-Continent Section Meeting, Wichita, Kansas