PETROLEUM PRODUCTION AND HYDROCARBON POTENTIAL OF ALABAMA'S COASTAL PLAIN AND TERRITORIAL WATERS

Abstract

ABSTRACT With the discovery of oil in 1944 at the Gilbertown Field in Choctaw County, Alabama became an oil producing state. Since that discovery, Alabama’s coastal plain and territorial waters have become increasingly important areas for the exploration of oil and gas. The primary exploration targets have been the Upper Jurassic Smackover and Norphlet formations. However, the most productive oil field in the state continues to be the Citronelle Field, which produces from reservoirs of early Cretaceous age. Upper Cretaceous rocks productive in southwestern Alabama include fractured Selma chalk and sands of the Eutaw Formation and Tuscaloosa Group. The 1979 discovery of gas in Tertiary sands has resulted in the establishment of several Miocene gas fields in the state. Alabama should remain an excellent region to explore for oil and gas in the years ahead. Much of Alabama's coastal plain and territorial waters remain untested. Petroleum exploration will probably continue to be concentrated on Upper Jurassic Smackover and Norphlet prospects; however, the Haynesville Formation and Cotton Valley Group have petroleum potential in southwestern Alabama. With renewed interest in the Upper Cretaceous in the onshore northern Gulf of Mexico area, the Cretaceous in Alabama should also see additional hydrocarbon exploration. The Miocene shallow gas discoveries in coastal Alabama have demonstrated that hydrocarbons are present in Tertiary strata in the state. Other prospective Tertiary units include upper Paleocene and lower Eocene sands and Oligocene carbonates. The keys to successful prospecting in the region for Upper Jurassic and Cretaceous objectives are the delineation of petroleum traps associated with salt movement and the recognition of favorable lithofacies. Identification of favorable stratigraphy is critical to defining prospective Miocene reservoirs.