Date of Award
M.S. in Engineering Science
Geology and Geological Engineering
Louis G. Zachos
The Tuscaloosa Marine Shale in southwest Mississippi and Southeast Louisiana's Florida Parishes has become an unconventional target for the exploration and production of oil. Spurred by early estimates of over 7 billion barrels of oil in place, the target region for this production is the basal portion of the shale where a continuous increase in resistivity greater than 5 Ohmm can be observed. This increase was originally attributed solely to the generation of hydrocarbons from the organic matter contained within the shale, with the presence of the oil and gas impeding the flow of electrons through what would normally be a low resistivity lithology. Though this basal region of the shale has proven capable of producing economic quantities of oil, analysis of the mineralogy, pore fluids, and physical properties of the shale calibrated with the resistivity readings from wireline logs give evidence that the increase in resistivity is not due entirely to the generation of oil, but instead caused by the relationship of pore fluids, porosity, and mineralogy. The strongest influence is the amount of carbonate content within the groundmass. Though carbonates do not show directly the strongest influence on resistivity, they do exert major influence on the amount of porosity, pore fluids and pore fluid wettability, and the percentage of clays and siliciclastics. All of these characteristics combined produce the resistivity signature that can be seen in the oil producing basal portion of the Tuscaloosa Marine Shale throughout the proposed play area.
Story, Thomas Hetherington, "Fluctuations in resistivity in the Tuscaloosa Marine Shale, southwest Mississippi and southeast Louisiana" (2014). Electronic Theses and Dissertations. 1318.