Case Study: Evaluation of Regional Lithology for Carbon Dioxide Storage Using a Single Test Well in Southeastern Ohio

Abstract

Abstract The purpose of this project is to investigate the feasibility of carbon sequestration using information gathered from a single test well at a coal-fired power plant in the Appalachian Basin. The effort to date includes site selection, preliminary test design and implementation, and development of data objectives consistent with overall program goals. An iterative approach was implemented to enhance our understanding of the local and regional geologic conditions and limits at each stage. First steps included building a geologic model of injection and caprock formations based on regional well logs and other existing data as well as performing a 2-D surface seismic survey around the proposed well location. This information was then used to design the stratigraphic test well and data collection methodology. The test well was drilled in early 2007 and completed in January 2008. Wireline logs and rock samples collected during the drilling are being used to refine the geologic model and to develop plans for the injection tests scheduled for fall 2008. The site is one of the three locations selected for testing geologic storage of CO2 under the Midwestern Regional Carbon Sequestration Program (MRCSP) led by Battelle. Information collected to date is being analyzed to indicate the potential for carbon sequestration in regional reservoirs. In general, the reservoirs are well-contained with good caprock. Drilling, logging, and collection and laboratory testing of sidewall cores have provided the data to design injection tests in up to three potential injection targets between approximately 5,000 and 8,000 feet below ground surface. Approximately 3,000 tons of supercritical-phase CO2 is planned to be injected in these formations. Targets include a Lower Silurian sandstone known regionally as a gas-producer; Silurian sequences consisting of interbedded layers of halite, anhydrite, limestone, and porosity-preserving dolomite; and a Lower Devonian sandstone. The upcoming injection tests will help to further refine local and regional injectivity and capacity in the target reservoirs; caprock integrity, and single-well monitoring techniques. Field projects like this add to knowledge and understanding of how to select and characterize potential injection reservoirs, establish familiarity of the technology with the public and regulatory agencies, and aid in the selection of appropriate testing and monitoring techniques for each location.