MOBIL STARTS UP WEST TEXAS CO2 RECOVERY PROJECT

Mobil Exploration & Producing U.S. Inc. has begun injecting carbon dioxide at its Salt Creek field in Kent County, West Texas.

The enhanced oil recovery program began after completion of Mobil's 128 mile Este pipeline to transport the CO2 to Salt Creek from Denver City, Tex., the main Permian basin CO2 supply hub.

In Phase 1 of a three phase EOR project, as much as 150 MMcfd of CO2 will be injected into 50 wells in the 3,500 acre central portion of the field, which produces from the Pennsylvanian Canyon. Field production before the CO2 program began was 20,000 b/d. When the program is fully implemented in 1997, it is expected to provide incremental production of 13,000 b/d.

Start of Phases 2 and 3, which will include the northern and southern portions of the field, hinges on results of Phase 1.

Field construction for the project began in January 1993. Expansion of an existing gas plant to add 18,000 hp of compressors and pumps is under way to process the gas. The processing section of the plant will separate produced CO2 from produced natural gas so CO2 can be reinjected into the reservoir.

The plant is designed to process as much as 75 MMcfd of produced gas.

Other project facilities include a CO2 distribution system, produced gas gathering system, satellite production facilities, new injection wellheads, and revamped injection metering equipment.

Total cost of the project, excluding the pipeline, is about $90 million.

BACKGROUND

Salt Creek field, discovered in 1950, has been under waterflood since 1953.

The field has produced almost 300 million bbl, reaching a peak of 40,000 b/d in 1972. It also currently produces 12.6 MMcfd of gas and 3,700 b/d of natural gas liquids.

Mobil acquired General Crude Co., operator of Salt Creek, in 1979 and resumed field development by drilling additional wells on 40 acre spacing and expanding the waterflood.

In 1985, Mobil began an infill drilling program on 20 acre spacing, which is near completion. This program added more than 150 wells and converted many others to water injection.

The field now has 178 producing wells and 131 water injection wells. Injection wells inject more than 300,000 b/d of water into the Canyon formation, which averages 6,300 ft in depth and 170 ft in thickness.

Robert W. White, Mobil U.S. president and general manager, said the CO2 program will extend Salt Creek's life well into the 21st century.