Assessment of Reservoir Quality and Potential Impact of Sequestered Carbon Dioxide in Reservoir Units of Diverse Lithologies in South-Central, Mississippi, USA

Degny, Assonman D.; Kirkland, Brenda L.; Schmitz, Darrel W.

The objective of this study is to determine the impact of carbon dioxide on mineralogy, porosity, permeability, and fractures in hydrocarbon reservoirs in southern Mississippi with emphasis on the Heidelberg Field, Jasper County. Eight samples, two from the Eutaw Formation, one from the Tuscaloosa Formation, one from the Rodessa Formation, three from the Smackover Formation, and one from the Salem Formation (selected as control based on mineralogical homogeneity), were studied in a laboratory setting. Samples were placed in a carbonic acid solution, sealed into steel chambers, and heated. Pre- and Post-carbon dioxide analyses include: standard petrography, X-ray diffraction, and scanning electron microscopy. Potentially reactive minerals include: feldspars, glauconite, siderite, kaolinite, and calcite. In the pre-carbon dioxide samples porosity types identified are interparticle, intraparticle, voggy, and microfracture, with percent porosity ranging from 0.0114% to 29.318%. The first post-carbon dioxide sample was held for three months at an average temperature of 30 to 35 degrees Celsius. This sample from the Salem Formation showed limited evidence of dissolution. The other post-carbon dioxide samples were held for six months at an average temperature of 80 to 90 degrees Celsius. The significance of this study is that it contributes to the understanding of the behavior of reservoir rocks undergoing enhanced oil recovery with carbon dioxide or serving as carbon sequestration sites.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013