Geomechanical characteristics of potential carbon dioxide sinks and seals in the DeSoto Canyon Salt Basin, eastern Gulf of Mexico

Abstract

Recent studies indicate vast storage capacity exists in Cretaceous and Paleocene–Miocene sandstones in the eastern Gulf of Mexico. Understanding the geomechanical integrity of reservoirs and associated seals is useful for reducing the risk of migration of injected CO2 out of the storage complex. In this study, we investigated the rock mechanical properties and reservoir-seal integrity of three potential reservoir units in the DeSoto Canyon Salt Basin using geophysical well logs. Geomechanical analysis shows the Cretaceous reservoir units contain competent carbonate cap rocks that arrest possible fracture propagation from injection. Results of reservoir and seal integrity analyses indicate all three potential reservoirs and associated seals are geomechanically stable. The injection pressure of CO2 should stay below the minimum horizontal stress to prevent the occurrence of tensile hydraulic fractures. The three candidate reservoir units are ranked according to reservoir geomechanics for long-term commercial carbon storage. Future work should focus on geomechanical simulation of the reservoir units and additional assessment of leakage risk to further ensure safe carbon storage during and after CO2 injection. Laboratory core tests are recommended to confirm the accuracy of the empirical geomechanical analysis of the candidate reservoir and seal rocks.