Beaver Creek Madison, Wyoming's Deepest Water Injection Project

The Madison limestone at 11,000 ft is the deepest of six productive horizons in the Beaver Creek field. Although many Madison reservoirs in the Rocky Mountain region have a very active natural water drive, early performance at Beaver Creek indicated that the natural water drive would be inadequate to maintain producing rates and that costly artificial-lift equipment would be required. Therefore, a supplemental water injection program was chosen as the most logical plan of depletion to maintain reservoir pressure and reduce lifting expense. The performance of the pool and the analysis which dictated the water injection program are discussed. Introduction The Beaver Creek field, located in Fremont County, Wyo., approximately 14 miles southeast of Riverton, was discovered in 1938 when Unit Well 1 found gas and condensate in the Cretaceous Frontier, Muddy and Lakota horizons at 8,000 ft. Subsequent development, after a gas market was obtained in 1944, resulted in the discovery of oil in the Cretaceous Mesaverde (3,900 ft) in 1951, the Pennsylvanian Tensleep (10,600 ft) in 1949 and the Mississippian Madison (11,200 ft) in 1953. The Beaver Creek structure is a dome with a plunging nose to the north. The structure dips quite sharply to the east and south, with gentler dips to the north and west. Some faulting is present along the east flank and has had a major influence upon the accumulation of oil in the deeper Tensleep and Madison reservoirs. Fig. 1 shows the structural features of the field. The Madison reservoir, discovered in Dec., 1953, is at an average depth of 11,200 ft and has a proved productive area of about 1,260 acres. The reservoir is approximately 2-miles long and 1 1/2-miles wide and has a maximum oil-productive closure of 790 ft. There are presently 13 Madison wells drilled on approximately 80-acre spacing. Three of the wells are flowing and the remainder are pumping. The current producing rate is 4,860 BOPD and 300 BWPD. Cumulative production to Jan. 1, 1959 was 5,998,000 bbl of oil And 582,000 bbl of water.