Application of reservoir characterization and advanced technology to improve recovery and economics in a lower quality Shallow Shelf Carbonate reservoir. Quarterly report, October 1, 1996--December 31, 1996

Abstract

West Welch Unit is one of four large waterflood units in the Welch field in the northwestern portion of Dawson County, Texas. The Welch Field was discovered in the early 1940`s and produces oil under a solution gas drive mechanism from the San Andres formation at approximately 4800 ft. The field has been under waterflood for 30 years and a significant portion has been infill-drilled on 20-ac density. A 1982-86 pilot CO{sub 2} injection project in the offsetting South Welch Unit yielded positive results. Recent installation of CO{sub 2} pipeline near the field allowed the phased development of a miscible CO{sub 2} injection project at the South Welch Unit. This Class 2 project concentrates on the efficient design of a miscible CO{sub 2} project based on detailed reservoir characterization from advanced petrophysics, 3-D seismic interpretations and cross wellbore tomography interpretations. During the quarter, simulation performance forecasts were made using the base geologic model. The surface seismic and wellbore data were combined to develop an improved geologic model for the simulator. Efforts to integrate the wellbore seismic results into the reservoir characterization continue. Problems with the wellbore seismic processing were traced to the processing software which is being corrected.