Paper: Preliminary Work On An Integrated Study Of The Grayburg And San Andres Reservoirs, Foster And South Cowden Fields, Ector County, Texas

A cooperative study of the Grayburg/San Andres reservoir is being conducted in response to the United States Department of Energy's Class II Oil Program. The purpose of this study is to preserve access to existing wellbores by identifying additional reserves. Production problems associated with shallow shelf carbonate reservoirs are being evaluated by a technical team integrating subsurface geological and engineering data with 3-D seismic data. Engineering analysis, subsurface control from wireline logs, and 3-D seismic data will be integrated using a network of state-of-the-art software on a high performance computer workstation. It is expected that this study will demonstrate a methodology for reservoir characterization and subsequent development of the Grayburg and San Andres reservoirs that is feasible for even small independent operators. The integrated multidisciplinary approach of reservoir evaluation is relevant to many shallow shelf carbonate reservoirs throughout the United States. This paper reports on some of the work performed to date which consists mainly of collecting and appraising large volumes of data. principally well logs. well completion records, and laboratory results of rock and fluid property measurements. Much early well data is missing: this being a field discovered nearly 60 years ago at a time when such extensive reservoir evaluations were not contemplated. This factor is inherent in many fields in the surrounding area that have been successfully waterflooded. With the aid of modern technology, combined with sophisticated geological and engineering analyses, the probability of determining the economic feasibility of waterflooding this acreage should be enhanced.