Basin Analysis of Upper Cretaceous Strata of the Washakie and Red Desert Basins, Southwestern Wyoming, Employing Computer-Generated Maps and Cross Sections

KOHLES, KEVIN M., and JOSEPH POTTS, Geological Data Services, Dallas, TX, and FRED S. REID, Consultant, Denver, CO

The Washakie and Red Desert basins comprise the eastern portion of the Greater Green River basin of southwestern Wyoming. Stratigraphically the basins are dominated by a thick package of Cretaceous clastic sediments, as much as 16,000 ft thick, which resulted from several major transgressive-regressive cycles. Upper Cretaceous strata deposited during the latest cycle contain extensive deposits of commercial hydrocarbons, particularly gas. Much of the present structural configuration of the area is the result of the Laramide Orogeny in Late Cretaceous time.

To facilitate a comprehensive geological analysis of the area a computerized subsurface data base was constructed from available well logs for approximately 3000 wells in the Washakie and Red Desert basins. This data base contains correlated tops for most of the major Upper Cretaceous stratigraphic units, including selected subdivisions and net sand thickness values. Consistent correlations were achieved through the use of a tight, loop-tied cross section and key well network containing over 400 correlated well-logs. A complete suite of structure contour maps on all correlated horizons was generated from the data base with commercially available software. These maps, along with selected computer-generated structural cross sections, reveal a detailed subsurface picture of the Washakie nd Red Desert basins. Isopachous maps of selected intervals were also produced to illustrate the Late Cretaceous depositional history of the area.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)