The West Tepetate oil field, located in the Louisiana Gulf Coast area, was discovered by the Barnsdall Oil Company and Vincent and Welch in 1944. The presence of the structure was first suggested in 1930 by torsion-balance exploration conducted by Vincent and Welch and was subsequently disclosed by various seismograph surveys during 1941-1944. The producing section lies below the Heterostegina zone in the middle Miocene, and consists of twelve oil- and gas-bearing sands ranging from 7,600 to 9,900 feet in depth. The structure is a gentle, irregularly elongate dome, believed to have been produced by the deep-seated intrusion of salt, though none has been encountered to date. There is nearly 100 feet of effective closure at the producing levels. Only one fault has been enco ntered in drilling, though a major regional fault, downthrown on the south, is indicated by seismograph on the north side of the field, probably being a westward extension of the similarly bounding fault in the Tepetate field. The productive limits thus far established enclose 1,400 acres, offering a reserve of 30-40 million barrels of liquid hydrocarbons, and 60-70 billion cubic feet of gas.