GEOLOGICAL CHARACTERIZATION OF CRETACEOUS SANDSTONE ON THE EASTERN GULF OF MEXICO CONTINENT SHELF: CO2 SEQUESTRATION POTENTIAL OF CRETACEOUS FORMATIONS

The southeastern U.S. constitutes more than 40% of anthropogenic CO₂ emissions in the U.S., and most of this is emitted within 50 miles of the coast. Uniform government ownership, high capacity, and favorable source location indicate that the offshore continental shelf could be an attractive location for anthropogenic CO₂ storage.

The Southeast Offshore Storage Resource Assessment (SOSRA) Project, funded by National Energy Technology Laboratory (NETL) of the U.S. Department of Energy (DOE) aims to provide a high confidence characterization of the CO₂ storage capacity in the eastern Gulf of Mexico. This study focuses on Desoto Canyon Salt Basin (DCSB) encompassing Destin Dome, Mobile, Pensacola and Viosca Knoll regions offshore of Mississippi and Alabama. A rich public domain database including 2D reflection seismic, geophysical well logs, velocity surveys and reservoir temperature and pressure is being used to understand and interpret the subsurface geological architecture and identify potential CO₂ storage units.

Preliminary assessment of seismic reflection profiles and geophysical logs suggest that Miocene and Cretaceous sandstones are the most attractive storage units in this region. My study is focused on Cretaceous unit that includes Lower Tuscaloosa (Upper Cretaceous in age) sealed by Marine Tuscaloosa shale and Paluxy (Lower Cretaceous in age) sandstones. Geophysical well log analysis suggests that these reservoirs are quartzose, thick (>120 feet) and possess high effective porosity (~18-21%). Regionally extensive seismic lines and selected high quality digital wells logs are now being used for establishing regional seal integrity, defining reservoir architecture and quantifying pore volume capacity of the targeted storage units.