The United States has a large natural resource of heavy oil deposits ranging from 85 to 100 billion barrels. The largest of these are in California and Alaska. Today over 80 percent of the oil from enhanced oil recovery (EOR) results from steamflooding techniques in these low gravity, high viscosity, oilcontaining reservoirs. Most of the commercial projects are in California. They use both the conventional steam drive and cyclic steam stimulation, and the mechanism of viscosity reduction by heating dominates the process. Another EOR technique for heavy oil reservoirs, and one receiving more extensive research and gaining wider acceptance, is the use of CO2 in immiscible flooding. This CO2 method also features viscosity reduction as the primary mechanism for mobilizing the heavy oil. This Phase I project combines the best heavy oil recovery methods in a field test for the first time. Two wells, producing from a heavy oil reservoir, will be given combination treatments with steam and CO2. Interspersed in each treatment will be aqueous slugs of foaming surfactant/gelled polymer. This concept has the beneficial effects of steam, CO2, and the foam surfactant/gelled polymer for improving overall conformance. In these tests a new thermally stable water-soluble polymer will be gelled in situ with an organic crosslinking system.Anticipated Results/Potential Commercial Applications as described by the awardee: This Phase I field research project will further develop and demonstrate the combination concept for the recovery of tar and heavy oil. It will also confirm the conclusions predicted for this combination process in mathematical model simulation studies. It offers an improved oil recovery method for much of the vast heavy oil resource in the United States.Topic 23: Enhanced Oil and Gas Recovery and Tar Sands
