Reexploration of old fields in mature hydrocarbon provinces, such as the Permian Basin of West Texas and New Mexico, may significantly increase known oil and gas reserves.

Lower Permian Wolfcamp and Wichita carbonates and anhydrites in the Palo Duro Basin, Texas Panhandle, record a change from normal-marine to marine evaporite depositional environment.

To recover gas remaining in solution, large volumes of brine must be produced from watered-out gas reservoirs in the Gulf Coast.

The Hueco Basin of Trans-Pecos Texas and Chihuahua, Mexico, formed in response to Basin and Range extensional tectonism that began about 24 Ma ago and continues to the present.