PGC estimated the yearend 1998 gas resource at 1,038 tcf, excluding proved reserves but including 896 tcf attributable to traditional reservoirs and 141 tcf in coalbed methane reservoirs.
It said that, compared with yearend 1996, traditional resources decreased 2.7%, and the coalbed methane resource declined by 3.4%.
However, according to PGC estimates, future U.S. gas supplies in- creased during the 1990s. The total gas resource base increased 2.8% from 1,172 tcf in 1990 to 1,205 tcf estimated through 1998, although more than 150 tcf of gas has been produced from the resource base during that time period.
Changes in PGC's estimates from 1996 to 1998 were primarily the result of the transfer of gas resources associated with existing fields to proved reserves in the North Central, Gulf Coast, Midcontinent, and Rocky Moun- tain areas.
Also, changes were made due to analysis of new seismic, drilling, and production data in each of those four areas.
Compared with 1996:
- The North Central region dropped 25.5% from 29.8 to 22.2 tcf.
- The Gulf Coast sector increased 0.2% from 264.9 to 265.5 tcf.
- The Midcontinent region fell 4.9% from 128.4 to 122.1 tcf.
- The Rocky Mountain sector declined 6.9% from 161.2 to 150 tcf.
- The Pacific region slipped 1.6% from 37.8 to 37.2 tcf.
- The Atlantic sector was un- changed at 103.9 tcf.
- Alaska remained unchanged at 193.8 tcf.
- Coalbed methane declined 3.4% from 146.3 to 141.4 tcf.
Abundant resourceJohn Curtis, Potential Gas Agency (PGA) director, said, "The 1998 assessment reaffirms the committee's evaluation of an abundant U.S. natural gas resource potential."
He said the estimates do not assume any time schedule for the discovery and production of future gas supply.
"Estimates of the PGC are baseline estimates in that they attempt to provide a reasonable appraisal of the total natural gas resource potential of the U.S."
PGC consists of 165 volunteers from the gas industry, government agencies, and academic institutions. The committee functions independently, but with guidance and technical assistance from PGA, based at the Colorado School of Mines, Golden, Colo.
PGA receives financial support primarily from the American Gas Asso- ciation and the Gas Research Institute, but also from individuals, companies, and government agencies.
Chris McGill, AGA's gas supply and transportation director, said, "If you look back over time, you'll see that the committee has historically reported remarkably similar estimates for the future resource base.
"Despite a 35% increase in natural gas consumption since the mid-1980s, advances in new exploration technologies have helped to open new resources to development."
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