A Geological and Developmental Run Down of the Tuscaloosa Marine Shale
Energy Strategy Partners
According to a report by the Basin Research Institute, Louisiana State University, preliminary evaluations estimate a potential reserve of about 7 billion barrels of oil in the Tuscaloosa Marine Shale. The TMS follows the Cretaceous shoreline of the gulf coast and represents the lowest formation of the Gulf Cretaceous series. The Tuscaloosa Group is made up of three units. The lowest member is transgressive deposition consisting of argillaceous sands (Stringer). The inundated marine shale comprises the middle unit and consists of black to gray, fissile shale. The regressive upper unit is comprised of sands and shales closely resembling the upper Eutaw (Eagle Ford). The entire Tuscaloosa Group is over 1,000 feet thick. The middle marine shale interval varies in thickness from about 500 feet in southwestern Mississippi to 800 feet in southeastern Louisiana, depending on the underlying structural features. The primary producing area lies at a depth of about 10,000 feet. Permeability ranges from less than 0.1 to 0.06 md. Porosity varies from 2.3% to 8.0%.