CASE HISTORY—DESERT SPRINGS GAS FIELD SWEETWATER COUNTY, WYOMING

Abstract

Desert Springs Area is located in central Sweetwater County, Wyoming, on the west flank of the Red Desert Basin, with the Rock Springs uplift to the west and the Wamsutter arch to the south. The producing reservoirs are in the Upper Cretaceous Lewis and Almond formations, with the Almond being the uppermost formation of the Mesaverde Group in the area. Petty Geophysical Engineering Company was contracted to conduct a seismic survey over the area. Work was initiated on April 3, 1956 and completed July 24, 1956. Fault evidence was noted in the area, based on discontinuity of seismic events and change of reflection characteristics. On the basis of this fault evidence, El Paso Natural Gas Company drilled the Desert Springs No. 1 well which potentialed for 7.7 million cubic feet of gas per day. This led to additional drilling; and, as of January 1959, eight wells have found production at an average depth of 6,100 ft, having potentials from 7.7 million cubic ft of gas per day with some distillate. A detailed study of stratigraphy, lithology, and sedimentation, along with a detailed review of the seismic data utilizing the velocity survey in Desert Springs No. 1 well, was undertaken. The final analysis revealed that the phenomena originally mapped as a fault is in reality a series of facies changes. Three main stratigraphic type traps: offshore bar, lateral facies change, and wedge‐out below an unconformity; are believed to be present in this area, thus making an integrated and coordinated exploration program between the geologists and the geophysicist necessary if we expect to find additional oil and gas reservoirs of this nature.