THE ROLE OF FAULTS IN THE MISSISSIPPI CANYON AREA, CENTRAL GULF OF MEXICO: POTENTIAL FOR MIGRATION OF CO2 FROM THE STORAGE COMPLEX

A central goal of designing offshore carbon dioxide (CO₂) storage programs is to minimize the risk of injected CO₂ migrating out of the storage complex. CO₂ migration pathways may occur along faults in reservoirs or seals, and in extreme cases could result in seepage at the seafloor. With approximately 40% of anthropogenic CO₂ emissions in the United States produced in the southeast, it is important to assess secure offshore CO₂ storage potential in adjacent geologic provinces such as the Mississippi Canyon Area. Previous studies show that strata in the Mississippi Canyon Area contain multiple faults that displace potential reservoirs and sealing strata. The sandstone reservoirs are overlain by thick and regionally correlated sections of tight mudrock, sandstone, limestone, and chalk that form effective seals.

The main objectives of this research are to evaluate storage and trapping mechanisms by 1) interpreting fault geometry, orientation and density, in order to analyze fault zones 2) defining stratigraphic juxtapositions and seal potential by mapping reservoir and seal distributions on fault planes, and 3) analyzing fault reactivation tendency. This project uses existing 2-dimensional and 3-dimensional seismic surveys and geophysical well logs from the Bureau of Ocean Energy Management to evaluate the structural framework of the Mississippi Canyon Area. The detailed structural and stratigraphic analysis of faults provide insight about the potential for cross-formational fluid migration and induced fault dilation and slippage. Critical storage opportunities in these structures include saline formations as well as mature oil and gas reservoirs with potential for enhanced resource recovery.