GLOYN, ROBERT W., ROGER L. BON,* and STEVEN N. SOMMER, Utah Geological Survey, Salt Lake City, UT

ABSTRACT: Coal-bed Methane Exploration and Development in Utah

Utah has joined the ranks of coal-bed-methane producing states and has active coal-bed methane exploration. The targets are coals in the Cretaceous Blackhawk Formation and the slightly older Ferron Sandstone Member of the Mancos Shale.

In 1990, Cockrell Oil Corporation completed five test wells in the Book Cliffs coal field north of the town of Price. These wells produce between 51 and 196 thousand cu ft/day per well from Castlegate coals in the middle part of the Blackhawk Formation at depths of 4200 to 4400 ft. The wells have been producing for over a year and through July 1992 had cumulatively produced 201 million cu ft of gas and 1.11 million bbl of water. The daily production of gas has been increasing and the daily production of water decreasing.

Due to the success of these initial wells, a large, aggressive drilling program covering 21,450 ac is planned to develop the new gas field. Pacific Gas and Electric, which acquired the property, plans to drill over 120 wells to depths from 3000 to 7600 ft on 160-ac spacing to test multiple coal seams in the Blackhawk Formation. Projected average production per well is estimated at 300 to 320 thousand cu ft/day during the first 5 yr of production, with total field production estimated to reach 62 million cu ft/day by 1997.

Several other areas are being explored for coal-bed methane including (1) additional Blackhawk tests east and west of the producing area and (2) Ferron tests in the northern Emery and northern Wasatch Plateau coal fields. These are all smaller programs of 3 to 10 wells.

Recent calculations by the Utah Geological Survey show 8.3 to 10.6 tcf of coal-bed methane for four Uinta basin coal fields. This value is two to three times larger than previously estimated, but is still considered conservative. The Book Cliffs and the Emery coal fields have the best methane potential.

AAPG Search and Discovery Article #90993©1993 AAPG Rocky Mountain Section Meeting, Salt Lake City, Utah, September 12-15, 1993.