In 1983, the Bureau of Economic Geology published the Atlas of Major Texas Oil Reservoirs, a precedent-setting synthesis of key geological and engineering data on 450 major oil reservoirs grouped into 48 regional plays.

The search for oil, its development, production, and marketing have, for the better part of a century, been a fundamental part of the Texas economy. The history of Texas oil finders, from the self-educated wildcatter to the highly trained explorationist, is a part of Texas lore.

The Atlas of Major Central and Eastern Gulf Coast Gas Reservoirs is the second in a series compiling geologic and engineering data on natural gas reservoirs in the major gas-producing regions of the United States.

A preliminary study of the Frio sand distribution and formation temperatures and pressures was undertaken in order to define prospective areas in which a more detailed reservoir analysis is necessary prior to the selection of a site for a geothermal well.

Knowledge of the regional sand distribution and its relationship to formation temperature and pressure is a preliminary step in evaluating the geothermal resources of the Frio Formation.

The objective of this study is to identify major sand trends, which, along with subsurface temperatures and pressures, aid in evaluating the potential of producing geothermal energy from the Frio Formation, Upper Texas Gulf Coast.

The Bureau of Economic Geology has been conducting regional studies of the Frio Formation along the Texas Gulf Coast to evaluate potential geothermal energy from deep, geopressured sandstone reservoirs (Bebout, Dorfman, and Agagu, 1975; Bebout, Agagu, and Dorfman, 1975).

Reservoir quality of lower Teritary sandstone reservoirs along the Texas Gulf Coast is controlled by sandstone depositional environment, mineralogical composition, and consolidation history (compaction, cementation, and leaching).