GEOLOGICAL AND GEOMECHANICAL CHARACTERISTICS OF THE POTENTIAL CO2 STORAGE RESERVOIRS, EASTERN GULF OF MEXICO

Ensuring effective long-term storage is vital for the success of offshore CO₂ storage. Recent studies indicate that vast CO₂ storage capacity exists in Cretaceous through Neogene sandstone in the east-central Gulf of Mexico. Understanding the structural styles and geomechanical characteristics of the associated carbonate stacks and seals is therefore essential for safe and effective CO₂ storage.

The structural framework in the study area includes the DeSoto Canyon Salt Basin, the Middle Ground Arch, and the Tampa Embayment moving northwest to southeast with an overall background of a gentle shelf slope. The Central DeSoto Canyon Salt Basin contains high structural complexity due to the presence of the Destin fault system, salt domes, salt rollers, and salt diapirs. Multiple faults associated with salt structures truncate and displace the potential reservoir and seal intervals. Reactivation tendency analysis of the major faults shows that while the slip tendency is mostly small, the dilation tendency is relatively high. Results of reservoir and seal integrity analysis indicate that all of the potential reservoirs and associated seals are stable within a range of injection scenarios. Cretaceous reservoir units contain competent limestone and chalk caprocks as confining seals overlapping the sandstone sinks. Favorable CO₂ injection sites are over the western stable shelf of the DeSoto Canyon Salt Basin avoiding the Destin faults with high dilation tendency. Future development should focus on geomechanical simulation of the potential reservoirs and associated seals.