Abstract The Denver Unit CO2 flood, one of the largest in the world, was implemented in 1984. CO2 injection was subsequently expanded in 1989 and again in 1991. By 1994, this 10 year old CO2 flood had a well-established decline in its production function. Through infill drilling and pattern conversion, the mature CO2 flood in the Denver Unit was revived. The redevelopment program depended heavily on the reservoir simulation technology and the multi-discipline team concept to ensure its technical and economical success. Thus far, the redevelopment program has added approximately 6600 barrels of oil per day to the existing production at peak rate, and approximately 14.2 million barrels of oil to the ultimate reserves. This report reviews the infill drilling and pattern reconfiguration simulation studies, the pilot program, which led to full field development, and the results of the project to date.