ABSTRACT: Regional Extent and Hydrocarbon Potential of the Tuscaloosa Marine Shale

JOHN, CHACKO J., BOBBY L. JONES, BRIAN J. HARDER, and JAMES E. MONCRIEF*

The Gulf Coast region of the United States is considered a mature producing province. In order to maintain and/or increase future hydrocarbon production, future trends must include the research and evaluation of untested ideas about non-conventional hydrocarbon occurrences. Many studies have been conducted on hydrocarbon production associated with shale formations e.g. the Bakken shale, Williston Basin; Antrim shale, Michigan basin; etc. However, no published information is available relative to the lithological characteristics or existence of hydrocarbons in the Tuscaloosa Marine Shale.

The marine shale section lies between sands of the upper and lower Tuscaloosa sections and varies in thickness from 500 ft in southwestern Mississippi to more than 800 ft in the southern part of the Florida Parishes, southeastern Louisiana. The primary zone of interest, a high log resistivity (10+/- ohms) zone at the base of the above referenced shale section, varies in thickness from 100 ft to 180+ ft over the area and is found at the shallowest depth of approximately 11,500 ft. Two wells have produced from the marine shale in southeastern Louisiana with one having produced over 20,000 barrels of oil in the last eighteen years. Since the wells do not appear to be on a structural high, fracturing is thought to be the cause of porosity and permeability. Preliminary evaluations indicate that the Tuscaloosa Marine Shale may be a sizeable hydrocarbon resource. Horizontal drilling, if feasible, could maximize production and minimize environmental impacts.

AAPG Search and Discovery Article #90941©1997 GCAGS 47th Annual Meeting, New Orleans, Louisiana