USING A SYSTEMS APPROACH TO UNDERSTANDING CARBON STORAGE POTENTIAL IN THE MIDWEST AND EASTERN UNITED STATES

Carbon capture, utilization, and storage (CCUS) systems have been defined for the eastern Midcontinent, Illinois Basin, Michigan Basin, Appalachian Basin, structural arches between these basins, and coastal and offshore mid-Atlantic Ocean in the eastern United States, as part of the Midwest Regional Carbon Initiative (MRCI). MRCI is a U.S. Department of Energy-sponsored project to accelerate the deployment of carbon capture, utilization, and storage in the Midwest and Northeast United States. CCUS systems within the region are defined similar to regional hydrogeologic units where emphasis is placed on subsurface reservoirs and regional seals, except that CCUS reservoirs are saline reservoirs and oil and gas reservoirs at greater depths than typical hydrogeologic units. CCUS systems are intervals of bedrock more than 2,600 ft deep (so that CO₂ stays in its volume-saving supercritical state), capped by regionally extensive, low-permeability confining units. Each system may include one or more reservoirs and confining intervals, but the upper limit is a well-recognized, regionally extensive, low-permeability shale. Because subsurface geology is different in different basins, carbon systems differ across the eastern U.S.

In order to better understand and communicate the regional variability in subsurface geology to potential CCUS stakeholders, the region has been divided into more than 60 subregions based largely on structure and state boundaries. Stratigraphic sections have been constructed for each subregion from the surface to basement. Units on stratigraphic sections are color coded by their reservoir and confining potential where they are more than 2,600 ft deep to help users quickly assess the names of units and their CCUS potential in their areas of interest. Subsurface maps, cross sections, and reports from previous research are also being compiled by CCUS systems.