Utah coalbed gas exploration poised for growth

G. Alan PetzetExploration Editor

Eastern Utah Coalbed Methane Scene [74689 bytes]

Coalbed methane production in eastern Utah is growing despite a relaxed pace of exploratory drilling.

Coalbed methane made up less than 4% of the Utah's total gas production last year. However, 1995's output was 12.2 bcf, two and one half times 1994 production, calculates David Tabet of the Utah Geological Survey.

Three companies operated 119 producing wells at yearend 1995 in the Ferron and Blackhawk coal trends of the Uinta basin. Some 90% of the action is in the Ferron trend.

UGS previously suggested that a 12 by 80 sq mile fairway could contain 4-9 tcf of coalbed methane and support as many as 3,000-4,000 wells in full development.

Coalbed methane accounted for 5% of U.S. natural gas production and 6% of proved reserves as of yearend 1994 (OGJ, Jan. 1, 1996, p. 56).

Trying to ignite

Leasing has been active the past 2 years, but a delay in issuance of a federal environmental impact statement could retard drilling.

Anadarko Petroleum Corp., Houston, Chandler & Associates Inc., Denver, and Texaco Exploration & Production Inc. acquired a combined 20,483.7 acres at federal lease sales in 1995, and Texaco acquired 12,079 acres at a February 1996 federal lease sale.

Klabzuba Oil & Gas, Fort Worth, acquired about 5,000 acres and Contex Energy, Denver, about 3,500 acres in 1994, UGS noted.

Only 19 new wells began producing coalbed gas during 1995, but gas production increased from existing wells as dewatering progressed.

The U.S. Bureau of Land Management will allow limited exploration but no field development on federal lands until the EIS is completed, possibly as early as this month. BLM's Moab office handles the EIS.

Wells, production

The Ferron trend produces from the Ferron sandstone member of the Cretaceous Mancos shale, while the Blackhawk trend is associated with the Blackhawk formation of the Cretaceous Mesaverde Group. UGS notes that Ferron is stratigraphically lower than Blackhawk.

River Gas of Utah Inc., an affiliate of River Gas Corp., Northport, Ala., completed 16 gas wells in 1995, bringing the total in Drunkards Wash field to 89. The 89 wells produced 11 bcf of gas and 5.7 million bbl of water last year. Dewatering raised production to 428 Mcfd in December 1995 from 310 Mcfd in January 1995.

Drilling has been confined to state and private lands. The company has proposed to drill as many as 1,000 coalbed gas wells to 1,200-3,800 ft in 11-16s, 8-10e in the Ferron trend if the federal EIS is favorable (OGJ, Sept. 12, 1994, p. 99).

Anadarko produced 782 MMcf of coalbed gas from 25 wells in Castlegate field and 337 MMcf of gas from five wells in an unnamed field 5 miles north of Price during 1995.

Texaco has not placed any wells on production, UGS said, although it drilled 11 coalbed wells through 1995. The wells are in northwestern Emery County.

Chandler operates Buzzard Bench, a six well field discovered in the mid-1980s that has produced gas from Ferron sandstones.

Joint Association Survey show that 30 coalbed methane gas producing wells drilled in Utah in 1994, the latest data available, cost an average of $98.88/ft to drill and equip at an average TD of 2,492 ft (OGJ, Mar. 11, 1996, p. 102).