An Assessment of Geologic Carbon Sequestration Options in the Illinois Basin: Phase III

Abstract

The Illinois Basin – Decatur Project (IBDP) successfully demonstrated the safe geologic storage of carbon dioxide (CO2) at the near commercial-scale. The IBDP was carried out by the Midwest Geological Sequestration Consortium (MGSC), one of seven USDOE NETL RCSPs that were formed to evaluate the safety and effectiveness of geological storage of CO2 as a mitigation tool to address global climate change. The MGSC was formed and led by the Illinois, Indiana, and Kentucky geological surveys of the Illinois Basin. The Illinois State Geological Survey (ISGS) at the University of Illinois was the principal investigator for and managed the IBDP, with the Indiana Geological Survey (IGS) (now Indiana Geological and Water Survey) and the Kentucky Geological Survey (KGS) as key partners. Many other organizations and individuals were involved and contributed to the success of the project, including Archer Daniels Midland (ADM), Schlumberger, Trimeric, and several academic and industry partners. The main goals of Phases I and II of the RCSP were to characterize the regional geology, identify geologic units that could be used as storage reservoirs for CO2, and to identify CO2 emitters (industrial sources). The overarching deliverable for Phase III of the RCSP was to demonstrate safe and effective storage through injection of 1 million tonnes of CO2. IBDP was the MGSC Phase III project, which began in 2007. After extensive geological screening work throughout the central Illinois Basin, the ADM facility in Decatur, Illinois was selected by the MGSC as the source of CO2 and the storage site of the IBDP. ADM operates an agricultural industrial facility with several product processing plants in Decatur, Illinois. The corn processing plant at ADM generates CO2 as a byproduct of the production of fuel ethanol. The storage complex at Decatur includes the Mt. Simon Sandstone, the lower third of which contains fluvial deposits with excellent reservoir quality. The Mt. Simon is overlain by low permeability shales and mudstones of the Eu Claire Formation that serve as a caprock/seal for the Mt. Simon reservoir. This report summarizes the IBDP Phase III project workflow from pre-injection site characterization, through injection and monitoring, to post-injection. The pre-injection period (2007–2011) included additional regional characterization, site characterization, design, permitting, site infrastructure development, and baseline monitoring and modeling. Outreach and education also began in 2007 and continued throughout the life of the project. The injection period included CO2 capture, transport, and injection, and injection monitoring and modeling. The final period of the project (post-injection, 2014–2021) included post-injection monitoring and modeling, and project closeout. The IBDP demonstrated that CO2 injection in a saline reservoir, with the objective of long-term storage, is safe and secure. Safety was achieved through extensive site characterization before injection began to ensure reservoir porosity and permeability were sufficient at this location; that safe injection pressure ranges were known by determining the fracture pressure of the reservoir rock; and that the geologic layers sealing the reservoir lacked permeability, were laterally continuous and were not penetrated by faults. A robust static geologic model was constructed as the framework for a reservoir (flow) model to predict CO2 behavior. These models were updated through the course of the project as new data was obtained. ADM monitored data from a combination of pressure, flow, temperature, and other sensors in the surface system and injection well so that they could proactively make any corrections needed to maintain safe operating conditions. Extensive subsurface and surface monitoring before, during, and after injection allowed for effects of the injected CO2 plume to be detected. Other Indicators of project safety and success include: The injectivity and storage capacity of part of the lower Mt. Simon Sandstone predicted by geophysical assessment, coring, and modelling have been confirmed at the IBDP site by the injection of approximately 1 million tonnes of CO2 over 3 years. Detection and monitoring of the movement of CO2 and the associated pressure front within the storage reservoir using time-lapse 3D surface seismic surveys, pressure and temperature measurements in CCS1 and VW1, pulsed neutron logging in CCS1, VW1, and GM1, 3D VSP imaging, deep fluid sampling (VW1), and passive seismic monitoring. Reservoir simulation suggests that in 2114—100 years after injection ceased—the injected CO2 still will not have migrated upward to the base of the primary seal (the Eau Claire Formation). Extensive coring has revealed the presence of thin silty mudstone layers in the Mt. Simon, over 984 ft (300m) below the Eau Claire seal, which act as baffles to upward pressure and CO2 migration. Data gathered from all monitoring networks and experimental stations above the CO2 plume show that there has been no leakage of CO2 or brine out of the storage reservoir. There is little to no risk that induced seismicity at IBDP could cause fault slippage through the caprock and compromise the reservoir seal based on the very low magnitudes of measured microseismic events and their locations well below the Eau Claire Formation. An extensive outreach program built informed and supportive constituencies, shared technical knowledge gained through project activities, and promoted carbon capture and storage (CCS) technology. Hundreds of technical presentations were delivered to foster the scientific collaboration necessary to CCS on a commercial scale. Publications are available at http://carbon.americangeosciences.org/vufind.