Facies architecture of the Tensleep Sandstone, Bighorn Basin, Bighorn County, Wyoming

The Tensleep Sandstone is characterized in terms of a hierarchy of architectural elements and reservoir properties. The study sites are located in the Bighorn Basin of Bighorn County, Wyoming. Alkali Creek, Ziesman Dome and Cold Springs Road were chosen for outcrop studies, and Byron and Bonanza fields were chosen for subsurface study. A Tensleep reservoir model is developed, and recommendations for resource exploitation are made.; The hierarchy of architectural elements ranks the elements into five orders. In increasing order or scale, the first is eolian stratification, the second is eolian surface bounded-elements, the third is facies, the fourth is parasequence, and the fifth is system tracts.; Outcrop studies investigated the distribution of eolian bounding surfaces and established a new classification that is applicable to the Tensleep Sandstone. Trough cross strata intrasets, or 0.1-bounded elements are confined within 1.0-bounded element and cut across 2.0-bounded element. The 1.0-bounding surfaces rise from the 0.0-bounding surfaces at angles ranging from 0.9° to 2.7° in the general direction of foreset dip.; Tabular-planar cross strata dune sandstone facies and elements contained within combined with interdune sandstone facies have the greatest influence on the reservoir model. The combination of well-cemented eolian interdune facies above 1.0-bounding surface and juxtaposition of low permeability (z-axis) wind ripple strata against intermediate permeability (y-axis) grain fall strata across 1.0-bounding surface strongly suggest that the 1.0-bounding surface acts as a baffle or barrier to fluid flow in vertical fluid communication.