Assessing CO2 EOR Potential of Three Strategically Located Oil Fields in the Illinois Basin
Carbon dioxide enhanced oil recovery (CO2 EOR) has the potential to significantly increase production from mature oil fields in the Illinois Basin (ILB) while providing the additional benefit of storage of anthropogenic CO2. However, there are currently no commercial CO2 EOR operations in the ILB. The main challenges to implementation include negative perception of CO2 EOR viability at ILB fields, absence of a CO2 supply, and lack of infrastructure.
The absence of readily available CO2 could be ameliorated by the development of commercial sources of anthropogenic CO2. One potential source is located in Decatur, Illinois. The CO2 compression equipment at an ethanol plant, which is currently used for CO2 storage demonstration projects, could provide a commercial source of CO2. A second source may become available in Coles County, Illinois, where there is ongoing interest in construction of a zero emissions power plant.
Successful field-scale, multi-year CO2 EOR pilots are critical to gaining acceptance of CO2 EOR in the ILB. The Illinois State Geological Survey recently evaluated the CO2 EOR potential of three oilfields that are located near these potential CO2 sources that might facilitate commercial demand for CO2 EOR. The study included characterization of reservoir architecture, simulation of CO2 EOR scenarios, experimental determination of minimum miscibility pressures (MMPs), and economic analysis of CO2 EOR projections.
Results indicate that all three fields could be viable candidates for CO2 EOR pilots. Different strategies were required for CO2 EOR to be effective at each of the fields, leading to variation in results. The incremental oil produced as a result of CO2 EOR ranged from 5.9 to 19% of the original oil in place over 15–20 years. The total amount of CO2 stored ranged from 154,000 to 1,090,000 tons (140,000 to 993,000 tonnes). Net utilization of CO2, or the amount of CO2 stored divided by the incremental oil production, ranged from 1.4 to 6.4 mscf/stb. Economic analysis indicated that CO2 EOR projects at these fields were likely to be profitable (depending on the development strategy) at oil prices exceeding $80bbl. In addition, the project facilitated dialogue between oilfield operators and potential suppliers of CO2.
AAPG Datapages/Search and Discovery Article #90218 © 2015 Eastern Section Meeting, Indianapolis, Indiana, September 20-22, 2015