Geologic framework for the national assessment of carbon dioxide storage resources: U.S. Gulf Coast

This report presents 27 storage assessment units (SAUs) within the United States (U.S.) Gulf Coast. The U.S. Gulf Coast contains a regionally extensive, thick succession of clastics, carbonates, salts, and other evaporites that were deposited in a highly cyclic depositional environment that was subjected to a fluctuating siliciclastic sediment supply and transgressive and regressive sea levels. At least nine major depositional packages contain porous strata that are potentially suitable for geologic carbon dioxide (CO₂) sequestration within the region. For each SAU identified within these packages, the areal distribution of porous rock that is suitable for geologic CO₂ sequestration is discussed, along with a description of the geologic characteristics that influence the potential CO₂ storage volume and reservoir performance. These characteristics include reservoir depth, gross thickness, net-porous thickness, porosity, permeability, and groundwater salinity. Additionally, a characterization of the overlying regional seal for each SAU is presented. On a case-by-case basis, strategies for estimating the pore volume existing within structurally and (or) stratigraphically closed traps are also presented. Geologic information presented in this report has been employed to calculate potential storage capacities for CO₂ sequestration in the SAUs that are assessed herein, although complete assessment results are not contained in this report.