Hoskins Mound Salt Dome Brazoria County, Texas

Abstract

Hoskins Mound is a typical Gulf Coast salt dome situated in southeastern Brazoria County, Texas. It has a low topographic mound, roughly circular in outline and characteristic of the intrusion of a salt plug into the overlying Tertiary and later formations found in this region. The salt is capped by anhydrite and limestone, with commercial deposits of sulphur occurring in the limestone on the flanks of the dome. Drilling has well outlined the cap rock which underlies between 400 and 500 acres of the dome area. The sulphur is secondary and later than the anhydrite and limestone. Since 1923, sulphur mining has been carried on by the method known as the Frasch process, in which superheated water is pumped into the formations and melts the sulphur. The sulphur collects at the bottom of the well and is brought to the surface by means of an air lift. To date, more than 4,000,000 long tons of sulphur have been produced from Hoskins Mound. Between 1905 and 1915, approximately 500,000 barrels of oil were produced from sands and sandstones immediately above the cap. Only a few off-dome tests have been drilled, and consequently very little information is available in regard to the oil possibilities of the lateral beds abutting the dome.