OLSON, MARK, RANDI MARTINSEN, DIANE BURNS*, and RON STEEL
University of Wyoming, Laramie, Wyoming

Abstract: Improving Reservoir Characterization Techniques with Behind Outcrop Coring and Logging Studies: Preliminary Results of the Rock Springs Drilling Project, Southwestern Wyoming

The Rock Springs Drilling Project (RSDP) is a joint endeavor by the University of Wyoming, Norsk Hydro, Union Pacific Resources and Schlumberger. The objectives of the project are to: 1) core and log each of the formations of the Mesaverde Group (Blair, Rock Springs, Ericson, and Almond) in the area of the Rock Springs Uplift, 2) improve geologic calibration of geophysical logs, especially Formation Micro-Imaging logs, through direct comparison with cores and outcrops, and 3) develop improved depositional and reservoir models for each of the reservoir classes represented. Five wells have been drilled and logged to date and 2600 feet of core has been obtained.

Preliminary results from the Almond include: 1) the construction of outcrop gamma-ray profiles that show good correlation to the core well gamma-ray log thus, enabling a better visualization of facies based on geophysical log response; 2) smallscale fracture orientations from the FMI log not observed in outcrop; 3) the documentation of facies architecture and the identification of at least one lowstand surface of erosion; 4) analysis of porosity and permeability data from potential reservoir facies in core and; 5) documentation of internal heterogeneities in core that was then applied to the outcrop to determine their lateral extent. These results led to an improved reservoir model that, when applied to the subsurface, can lead to enhanced development of pre-existing producing trends in the Almond or the discovery of new, previously unidentified reservoirs.

AAPG Search and Discovery Article #90919©1999 AAPG Rocky Mountain Section Meeting, Bozeman, Montana