Pervasively dolomitized, anhydritic carbonates of the upper San Andres Formation in the Emma field of West Texas constitute an upward-shallowing sequence of lithofacies representing four major depositional environments. Open Platform fusulinid packstone/wackestone and burrowed wackestone form the base of the sequence.
The State-owned submerged lands of Texas encompass almost 6,000 mi2 (15,540 km2). They lie below waters of the bay-estuary-lagoon system and the Gulf of Mexico and extend 10.3 mi (16.6 km) seaward from the Gulf shoreline (fig. 1).
Geologic map that depicts the surface geology of Hardeman, Wilbarger, Wichita, Clay, Knox, Baylor, Archer, Haskell, Throckmorton, Young, and Foard Counties and part of Jack County, Texas. The 20-page booklet indicates geologic formations, abbreviations, and ages.
San Andres and Grayburg reservoirs have yielded about 42 percent (9.8 billion barrels) of the total cumulative production of oil from the Permian Basin of West Texas. However, recovery efficiencies have been low, and significant quantities of mobile oil remain after primary and conventional secondary recovery.
