Using CO2 Flooding to Rejuvenate Old Fields in a Mature Basin: History, Results, and Lessons Learned
Rex Knepp, John P. Grube, James R. Damico, and Beverly Seyler
Illinois State Geological Survey, Champaign, IL
With more than one hundred years’ continuous hydrocarbon production; the Illinois Basin of Illinois, Indiana, and Kentucky clearly qualifies as a mature basin. Although exploration for new and unconventional targets within the Basin continues today, hydrocarbon production peaked more than sixty years ago and the current rate of 12 million bbl/year is less than one-tenth of that historical peak. Waterflooding in many fields commenced in the 1950s and 1960s, and today even the largest among them produce at water cuts approaching or even exceeding 99%. The use of CO2 as a flooding medium, however, may hold promise for a new generation of enhanced oil recovery in this and similar mature basins. Industry experience in CO2 projects elsewhere suggests that the technique’s use basin-wide could yield up to a billion barrels of incremental oil recovery from the Illinois Basin, while having the added benefit of sequestering anthropogenic CO2 in the process.
To test the suitability of CO2 for flooding in the Illinois Basin, the Midwest Geologic Sequestration Consortium scheduled four test projects within the basin: a huff-n-puff, conversion of an existing water injector, and two additional CO2-injection pattern-flood projects. The first test is complete, and the second is in progress. This work details first the processes of designing, modeling, and siting CO2 floods in mature fields developed during the mid-twentieth century. Second, the work presents the results of the tests, placing those results in the context of a mature basin and the possibilities for rejuvenating fields long since relegated to stripper status. Third, the work addresses some potential pitfalls of working with old wells and old data.
AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas