Update of Oil and Gas Reservoir Data Base, Permian and Fort Worth Basins, Texas

This study updates previous work on oil and gas production in the Permian and Fort Worth Basins by Galloway and others (1983), Kosters and others (1989), and Holtz and others (1993). The original delineation of oil plays in Texas was published by Galloway and others (1983) in the Atlas of Major Texas Oil Reservoirs, which classified into plays all oil fields that had produced more than 10 MMbbl of oil through 1981. Gas reservoirs that had produced more than 10 Bcf of gas through 1986 were grouped into gas plays in the Atlas of Major Texas Gas Reservoirs (Masters and others, 1989). In 1993, Holtz and others updated and expanded the database from the two atlases. The Update of Atlas of Major Texas Oil Reservoirs Database and Atlas of Major Texas Gas Reservoirs Database (Holtz and others, 1993) updated cumulative production data through December 31, 1992, for reservoirs already in the database and added smaller but significant-sized reservoirs (cumulative production > 1 MMbbl of oil equivalent [boe]) to the database. The addition of new reservoirs to the database resulted in the modification of existing plays and the determination of several new oil plays. Play boundaries were also modified to accommodate the additional reservoirs. The goals of this project were (1) to update cumulative production data through December 31, 1998, for all oil and gas reservoirs in the Permian and Fort Worth Basins, Texas, that were included in the database of Holtz and others (1993) and (2) to add additional reservoirs now having cumulative production greater than 1 MMboe to the database. (Reservoirs having production > 1 MMboe are referred to as "significant" reservoirs in this report). Following the U.S. Geological Survey (1995), this report uses a value of 6,000 cf of gas to equal 1 boe; 6 Bcf is therefore the equivalent of 1 MMbbl of oil. The new reservoirs were assigned to plays, and play boundaries from Holtz and others (1993) were modified to include the additional reservoirs. Because one oil reservoir and one gas reservoir did not fall into existing plays, new plays were established for these reservoirs: the Mississippian Platform Carbonate (oil) play in the Permian Basin and Barnett Shale (gas) play in the Fort Worth Basin. Information about the two new plays is provided in this report.