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It has been said in the White Mesa field, "Every well is a wildcat." The present study indicates the situation is, perhaps, not entirely uncertain.
Located on the southern flank of the Paradox basin, the field (with one exception) produces from the Desert Creek zone of Pennsylvanian (Cherokee) age. To December 1, 1958, there were 48 oil wells.
Structurally the area can be divided into two units. The southeastern part strikes N. 30° W. to N. 90° E. (averaging N. 30-70° E.), and dips gently west and north at 60-115 feet per mile. It appears probable that this part is the west and north flanks of an anticline located east and southeast of present wells. In the northwestern part of the field, a small area of closure is present. This part trends northwest-southeast, and is related to the Ratherford field northwest of White Mesa. It is separated from the southeastern part of White Mesa by a narrow syncline opening (?) northeast.
Production in the field is from vuggy, bioclastic limestone, secondary dolomite and oolitic limestone.
The Desert Creek zone ranges from 137 to 207 feet in thickness. It is characterized by three centers of thickening: one in the northwest, one in the northeast, and one in the south part of the field.
Stratigraphically the field is an area of rapid lateral and vertical lithologic change. The lithofacies pattern can be divided into three units: high carbonate (limestone-dolomite versus evaporite more than 79%) rocks on the northern margin, similar high carbonate-versus evaporite rocks trending north-south, subsidiary to the northern unit, and a restricted lithofacies (increased evaporite) bordering the northern margin and surrounding the north-south-trending carbonate lithofacies. Because of these variations oil has been environmentally trapped. The specific change most instrumental in entrapment, is the transition from deposits of a shallow, well oxygenated, agitated, marine environment to deposits of a deeper-water, relatively quiet, restricted, marine environment. The latter migh be called "lagoonal."
Many wells in White Mesa produce from rocks deposited in the restricted environment; eleven dry holes have found a slightly greater environmental restriction and were not productive due to negligible permeability.
In origin White Mesa and the related fields (Aneth, McElmo Creek, Ratherford) have been called a "reef complex." The writer believes the term biostromal complex to be more descriptive of Desert Creek zone stratigraphy in the area.
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