Controlling Factors on Productivity in the Love Area, Natural Buttes Field, Uinta Basin, Utah

Ragas, Aisha, Logan MacMillan, Steve Stancel, and Jerry Cuzella
Anadarko Petroleum Company, Denver, CO

     The Greater Natural Buttes Field (GNB) of the Uinta Basin, northeastern Utah, currently produces over 200 MMCFG per day, primarily from the late Cretaceous Mesaverde Group and early Tertiary Wasatch Formation. Productive units are comprised of stacked, highly lenticular, tight, fluvial sandstones, interbedded with non-marine, organic-rich siltstones and shales, and occasional thin coal seams. GNB was discovered in 1955 and has an aerial extent of approximately 400 square miles.
     A WNW trending fairway, deemed the “sweet spot” in GNB, is located through T9S R21-22E and T10S R23E. This area contributes significantly to the overall production of the field. As part of efforts to fully exploit GNB, thirty-six wells were drilled in a fringe area to the south, the “Love Area” (T11S R21E). These wells were drilled sporadically since 1960, but most (22) were drilled in 2006. Production results for these wells are marginally economic, with a few exceptions.
     In the Love Area, the number of sandstone bodies of the Wasatch and Mesaverde, especially those that are gas-charged, decrease to the south. The low net-to-gross sandstone ratio may provide a type of large-scale regional stratigraphic trap. Also, regional vitrinite reflectance indicates a decrease in thermal maturity north to south across GNB into the Love Area. These factors and the influence of structural elements on gas migration and trapping in GNB may explain productivity in the Love Area and help define the economic limit of the Greater Natural Buttes Field.

AAPG Search and Discovery Article #90071 © 2007 AAPG Rocky Mountain Meeting, Snowbird, Utah