Structural Geometry of Thief Creek Field Discovery, Uinta County, Wyoming

Dolly, Edward D. ¹, Paul R. Lamerson² (1) The Houston Exploration Company, Denver, CO (2) Consultant, Lakewood, CO

Thief Creek Field, which was placed on production in 2002, represents the latest Nugget Sandstone production found in the Absaroka Thrust hanging wall in the Fossil Basin of southwestern Wyoming. Thief Creek Field is located in T13N, R121W, immediately northeast of the east lobe of Anschutz Ranch East Field. Statistical Curvature Analysis Techniques (SCAT) played a significant role in the discovery of these additional reserves. SCAT analysis of the Anschutz Exploration #26-08 (SE NE 26, T13N, R121W) indicated 10 degrees of southwest plunge in this marginal Nugget producer and 3 degrees of northeast plunge in the Amoco Production #1 Black (NW NE NW 24, T13N, R121W), a well with 30 degrees northwest dip and excellent oil shows in the Nugget Sandstone. Other SCAT data in the area complimented the long axis of the Thief Creek anticline. The discovery well, the Anschutz Exploration #13-24, was directionally drilled out of a window in the #26-08 casing northeast into Section 24 and parallel to the anticline’s long axis into the Nugget Sandstone, which yielded gas and condensate on test. SCAT analysis indicated 10 degrees of southwest plunge and 12 degrees northwest dip. The confirmation well, the Anschutz Exploration #10-24 (SW SE 24, T13N, R121W) was directionally drilled to the northwest, encountering Nugget Sandstone near the center of Section 24 and reaching total depth in the Nugget in the SE SE NW Section 24 where it was completed as a gas and condensate producer. SCAT analysis indicated 5 degrees of northeast plunge and 60-80 degrees of southeast dip. Long axis determinations were essentially the same in all wells. In the Fossil Basin area other structural targets are available using these exploratory techniques.

AAPG Search and Discovery Article #90055©2006 AAPG Rocky Mountain Section Meeting, Billings, Montana