Does Performance of Secondary Recovery in Waterfloods Help Predict CO₂ EOR in Michigan Niagaran Reefs?

William B. Harrison, III, G. Michael Grammer, and David A. Barnes
Michigan Geological Repository for Research and Education Department of Geosciences, Western Michigan University, Kalamazoo, MI 49008 [email protected]

The Silurian, Niagaran Pinnacle reef trend in Michigan has produced over 475 million barrels of oil and 2.7 trillion cubic feet of natural gas from around 2500 wells in approximately 1200 fields. There are 717 fields classified as oil fields, the rest are designated as gas or gas condensate producers. Sixty-five of the oil fields have had operations beyond primary production to improve oil recovery. Waterflood operations have been undertaken on 44 of the fields. Fifteen of the fields have undergone gas reinjection/pressure maintainence or gas reinjection followed by waterflooding. Five of the fields are currently undergoing CO₂ EOR.

It is common in other producing fields throughout the U.S. to waterflood first, then use CO₂ as a tertiary recovery process. In Michigan, none of the waterflooded fields have had CO₂ EOR. The 5 CO₂ EOR fields currently active have never been waterflooded. Two of the CO₂ floods commenced in 1997, whereas the other three are less than 4 years old. This is a short history compared to some of the water floods that began as early as 1970. Statistics for 33 of the waterflooded fields show an average additional secondary recovery of about 55% of the primary oil volume and 12% of the estimated original oil in place. The best CO₂ EOR field production to date has recovered 38.1 % of primary production. The larger number and longer production history of waterflooded Niagaran reef fields in Michigan suggest potentially large volumes of additional oil can be recovered using CO₂ EOR.

AAPG Search and Discovery Article #90095©2009 AAPG Eastern Section Meeting, Evansville, Indiana, September 20-22, 2009