Permeability and Mineral Composition Evolution of Primary Seal and Reservoir Rocks in Geologic Carbon Storage Conditions

An experimental study to probe the geochemical interactions of CO2/brine/rock system under geologic CO2 storage conditions was performed in a static reaction system. Marine shale (primary sealing formation) and Lower Tuscaloosa sandstone (CO2 storage formation) core samples taken from the Plant Daniel CO2 storage test site ( Jackson County, Mississippi) were exposed to CO2-saturated brine in a batch reactor at relevant geologic storage conditions for six months. X-ray diffraction, scanning electron microscopy, computed tomography, and brine chemistry analyses were performed before and after the exposure. Permeability measurements from the marine shale and sandstone core samples before and after CO2/brine exposure indicated a considerable effective permeability change. Sealing marine shale permeability increased after exposure while the permeability of the sandstone from the storage formation decreased. These results have implications for the integrity of the primary seal in a CO2 storage setting.

Duke Scholars

Author Laura Elizabeth Dalton Civil and Environmental Engineering