CORE CORRELATION OF THE EAGLE FORD FORMATION, MAVERICK BASIN, TEXAS

Chittam Ranch cores provided by Big Shell O&G Inc. and housed in the Department of Physics and Geosciences will be used in this project to model sedimentary environments. The cores target the Eagle Ford Formation of South Texas, which is a significant source of hydrocarbons and contains varying lithologies such as argillaceous mud rock, calcareous mud rock, and limestone. Sand and silt-sized grains found in the marls and limestones are predominantly planktonic foraminifera with few amounts of inoceramid fragments as well as other carbonate grains. The Eagle Ford play extends from the Mexican border into East Texas which is around 50 miles wide and 400 miles long with an average thickness of 250 feet. It is significant due to its capability of producing natural gas and more oil than other traditional shale plays. The Eagle Ford is notorious for its high carbonate shale percentage which is upwards of 70% in South Texas and causes brittle conditions which increases the conduciveness to hydraulic fracturing. The Upper Eagle Ford contains less total organic carbon when compared to the Lower Eagle Ford which is indicative that the bottom water oxygen levels were higher during its deposition.

The main procedures of this project will include documenting rock cutting descriptions of textures, mineralogy, and fossils. A minimum of 3 cores will be used to construct a 3D model of depositional environments during Cretaceous times via core correlation.

The 3D models may help us understand the stratigraphic changes including facies distribution in the region to be able to modify development of hydrocarbon-rich basins.