OVERVIEW OF ACTIVITIES FOR AN EOR CARBON SEQUESTRATION PILOT WITHIN THE ILLINOIS BASIN

Most Illinois Basin oilfields are mature and have been extensively water-flooded. In order to maximize oil production from these fields, new recovery techniques need to be researched and applied. CO₂ enhanced oil recovery (EOR) techniques have the potential to serve two goals by stimulating oil production while sequestering carbon dioxide. The Midwest Geologic Sequestration Consortium (MGSC) has completed two pilot tests examining the potential of Illinois Basin oil reservoirs for CO₂ sequestration and EOR. One of the test sites was the Sugar Creek Field in western Kentucky, which produces oil from the Jackson Sandstone (Mississippian). The site was chosen based not only on geological criteria, but also on practical considerations relating to the technological and organizational demands of a multi-faceted research program which included CO₂ injection, reservoir modeling, frequent geochemical testing, and long-term remote monitoring of pressure and temperature data at wellheads. The site is an older field which lacks modern log suite data, so development of a well-constrained model to understand CO₂ plume migration posed challenges. Further complicating the study, wells at Sugar Creek are irregularly spaced and produce oil from discontinuous sandstone bodies which were difficult to delineate using the limited data on hand. Geostatistical methodology was employed to generate useable geocellular models. Because petrophysical data were not widely available, different strategies were employed to estimate petrophysical properties from log data. A review of the modeling methodologies and results will be given as well as results from the pilot.