William C. Parcell¹
(1) University of Alabama, Tuscaloosa, AL

Abstract: Distribution and Controls on Carbonate Reservoir Quality in the Mississippian Mission Canyon Formation, Carter Creek Field, Uinta County, Wyoming

A predictive geologic model relating depositional and diagenetic controls on carbonate reservoir quality in the Mission Canyon Formation has produced recommendations for the placement of development wells in Carter Creek Field, southwestern Wyoming. To date, prediction of reservoir quality in the field has proven difficult because porosity distribution does not necessarily follow structural trends. Carbonate reservoir quality is primarily controlled by original depositional texture and degrees of dolomitization and dissolution.

Carter Creek Field and neighboring Whitney Canyon Field have produced over 1.4 TCF of sour gas since the late 1970s. An estimated 500 BCF remain in Carter Creek and 200 BCF remain in Whitney Canyon. Both fields are combination structural-stratigraphic traps. The primary reservoir is the Mission Canyon Formation, which is composed of interbedded dolomite, limestone and anhydrite. The reservoir runs along the crest of an anticlinal closure, but in Carter Creek Field reservoir quality distribution does not necessarily follow structural trends.

In order to predict reservoir quality, a geologic model was constructed from core and well log data that relates dolomite and porosity types to depositional and early diagenetic processes. Original depositional textures and degrees of dolomitization and dissolution were found to control carbonate reservoir quality. Through mapping, it was determined that local paleotopography strongly controlled the distribution of depositional and early diagenetic processes. Thus, paleotopographic reconstructions provide a tool for predicting reservoir quality distribution. This study suggests that the best quality reservoirs are associated with shallow marine, shoal and restricted lagoonal facies preferentially located along the flanks of paleohighs.

AAPG Search and Discovery Article #90914©2000 AAPG Annual Convention, New Orleans, Louisiana