Geologic characterization of the hydrocarbon resource potential of the Upper Cretaceous Tuscaloosa marine shale in Mississippi and Louisiana, U.S.A.

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Abstract

Recent oil production from the Upper Cretaceous Tuscaloosa marine shale (TMS) has elevated the formation, previously assessed by the USGS in 2011 as part of the Eagle Ford Group, to its own distinct assessment unit for an upcoming assessment. Geologic characterization in preparation for the 2017 assessment has included the analysis of rock samples and produced oils, and the interpretation of well logs and biostratigraphic data. Results include new mapped extents of the reservoir, which reaches a maximum thickness of almost 500 feet in southern Mississippi and central Louisiana, and geochemical interpretations which support a self-sourced origin for high gravity (36-48 API) low sulfur oil. Programmed pyrolysis and petrography indicate the TMS contains dominantly Type III gas-prone kerogen with some Type II oil-prone kerogen present in the most organic-rich samples. TMS samples contain an average of 47 weight percent total clays, had organic carbon content which ranged from 0.14 to 4.0 weight percent, and had a thermal maturity of 0.57 to 0.99 percent vitrinite reflectance in the productive area. These characteristics were the same for the TMS within an area defined as a “high resistivity zone” and outside of it. These results will be integral to the planned USGS assessment of the TMS.

Additional publication details

Publication type Conference Paper
Title Geologic characterization of the hydrocarbon resource potential of the Upper Cretaceous Tuscaloosa marine shale in Mississippi and Louisiana, U.S.A.
Volume 67
Year Published 2017
Language English
Publisher Gulf Coast Association of Geological Societies
Contributing office(s) Eastern Energy Resources Science Center
Description 15 p.
Larger Work Type Conference Paper
Larger Work Subtype Conference Paper
Larger Work Title Gulf Coast Association of Geological Societies Transactions
First page 95
Last page 109
Conference Title 67th annual GCAGS convention and 64th annual GCSSEPM meeting
Conference Location San Antonio, TX
Conference Date November 1-3, 2017
Other Geospatial Tuscaloosa Marine Shale