White River Dome Field, Piceance Basin: Basin-Center Gas Production from Coals and

Sandstones in the Cretaceous Williams Fork Formation

By

Terrilyn M. Olson, Harry Held, Bill Hobbs, Byron Gale, and Robert Brooks

Tom Brown Inc, Denver, CO

White River Dome Field is located in the northeastern part of the Piceance Basin. Gas is produced from coals and discontinuous sandstones of the Williams Fork Formation of the Mesaverde Group between 5000 and 7500 feet measured depth. Stratigraphic pinchouts and a structural nose locally control gas distribution within the basin-center gas accumulation in the sands. An active drilling program, improved completion procedures, and new processing facilities have contributed to significant increases in gas production over the last 2 years.

Within the sandstone reservoirs, matrix permeability is enhanced in places by natural fractures, as demonstrated by Formation Micro Image log data. Data on permeability distribution and variability comes from analyses of production data (using Agarwal-Gardner type curves), pressure build-up tests, and permeability estimated from well logs using neural networks. Production log data indicate the relative amounts of gas and water production from respective sand and coal zones.

AAPG Search and Discovery Article #90004©2002 AAPG Rocky Mountain Section, Laramie, Wyoming