Journal of Canadian Petroleum Technology, Vol.44, No.1, 31-41, 2005
Laboratory screening for air injection-based IOR in two waterflooded light oil reservoirs
In the last two decades, air injection has proven to be an effective method for enhanced recovery from light oil reservoirs. This has led to a need for effective laboratory procedures for screening potential candidate reservoirs, many of which have been previously waterflooded. Experiments at the University of Calgary have shown the benefit of Accelerating Rate Calorimeter (ARC) tests in conjunction with traditional combustion tube testing at reservoir pressure for the planning of field scale implementations. In this study, four ARC tests and two combustion tube tests were performed on resaturated cores from each of the Avile and Troncoso waterflooded light oil reservoirs of Argentina. The paper reviews the characteristics of the two reservoirs, describes the tests that were performed on the reservoir samples, and summarizes the results obtained. The ARC tests provided Arrhenius-type kinetic rate data for the ignition and combustion reactions. The combustion tube tests were used to evaluate the air requirements and overall burn stability. For each reservoir, one combustion tube test was performed at the original oil and water saturation while the second test was performed at the waterflooded saturation. The effect of initial oil saturation on the burning characteristics and liquid recoveries is of particular interests to operators considering air injection-based oil recovery projects.