SCOPE: Soil Gas Geochemistry--Assessment of Geological Carbon Sequestration Options in the Illinois Basin-Phase II & III

The Kentucky Geological Survey is a research partner in the Midwest Geological Sequestration Consortium-Illinois Basin (MGSC) Phase II Regional Carbon Sequestration Partnership to determine the ability, safety, and capacity of geological reservoirs to store carbon dioxide (CO2) in deep coal seams, mature oil fields, deep saline reservoir formations, and organic-rich shales of the Illinois Basin. With funding from the U.S. Department of Energy, the Illinois Office of Coal Development, and the Kentucky Office of Energy Policy, and led by the geological surveys of Illinois, Indiana, and Kentucky, MGSC will focus on testing the ability of these types of reservoirs to serve as sinks for some of the 276 million tons of annual CO2 emissions from fixed sources in the Illinois Basin. A series of six small-scale field tests are proposed. They include the testing of deep, unminable coal seams to adsorb gaseous CO2, the ability to coax more oil from old fields by CO2 flooding, and the injection of CO2 into salt-water filled rock units some 7,000 to 9,000 ft below the surface. Injection into deep coals and organic shales may help produce methane to augment natural gas supplies. Injection into old oil fields will help recover some of the approximately 10 billion barrels of oil remaining in Illinois Basin reservoirs. These activities will accomplish sequestration while also helping to meet the nation's need for fossil fuels. Led by the Illinois State Geological Survey, the MGSC-Illinois Basin Phase II is a consortium of the three geological surveys joined by industry, government, and business associations who will assess all aspects of geological CO2 storage in the Illinois Basin. During Phase I, existing data have indicated that the geology of the Basin is favorable for CO2 storage, or sequestration. In some localities, two or more potential CO2 sinks are vertically stacked. We will continue our investigations into the methods and economics of CO2 capture at facilities such as coal-fired power plants and examine the costs of transportation of large quantities of CO2 via pipeline. We are particularly focused, however, on the properties of the rock units that control injectivity of CO2, the total capacity for storage near major CO2 sources, the safety of injection and storage processes, and the sealing characteristics of the overlying rock units that act as seals for the reservoirs. The overall integrity of the storage and sealing rock units is critical from the viewpoint of safety and of effectiveness in isolating CO2 from the atmosphere and thereby avoiding the potential for adverse climate change. Each of our field tests will have an extensive monitoring program for air, shallow ground water, oil and water produced from oil reservoirs, and saline water produced from deep reservoirs to understand the fate of injected CO2 at our test sites. The integrity of the entire process will be scrutinized in detail to understand what contribution Illinois Basin geological sinks can make to national and international goals in accomplishing carbon sequestration and what technology developed here can be extrapolated to other regions. Given that the original oil in place in the Illinois Basin is now understood to be about 14.7 billion barrels, 2-3 billion barrels greater than before Phase I MGSC Partnership studies, CO2 flooding of mature oil reservoirs will lead to both CO2 storage and to incremental oil production. The value of the incremental production will help offset costs associated with collection and delivery of CO2 to oil field operators. In unminable coal beds, any methane produced as CO2 replaces adsorbed gas in the coal adds to natural gas supplies and similarly offsets costs. Coalbed methane production in the Illinois Basin is in its infancy, however, and the most likely near-term economic benefits will come from enhanced oil recovery (EOR). Understanding of EOR processes in conventional oil and gas reservoirs is much further along than that of enhanced coalbed methane production. Extrapolation of EOR performance parameters from West Texas to the Illinois Basin suggests that the Basin's EOR potential is substantial. Saline reservoirs offer the largest volume of storage capacity and CO2 verifiably sequestered in such reservoirs may represent tradable carbon credits in the future. The MGSC Phase II Partnership will carry out extensive public outreach with regard to its activities and to carbon sequestration generally. We will arrange presentations to industry, government, and the general public to provide information of the progress of our research and the importance of the Phase II field tests. We have 11 companies that have nominated 34 potential field test sites in the Basin for Phase II, and we have 16 companies, trade associations, and government agencies from Illinois, Indiana, Kentucky, and across the nation that serve on the MGSC's Project Advisory Group. We have a growing body of information on our web site, www.sequestration.org, that we will continue to add to in order to keep our sponsors, team members, and the general public informed of our Phase II progress.