SCALED MODEL EXPERIMENTS OF FIREFLOODING IN TAR SANDS.

Fireflooding of tar sand reservoirs following a preheating phase utilizing a reservoir heterogeneity was investigated in three-dimensional physical models. The research strategy for applying the results and the experimental facility developed for this work are discussed along with the results from four tests. Three different types of reservoir heterogeneities were used: communicating and noncommunicating bottom water zones and a thin, heated layer simulating a fracture. The results from this investigation demonstrate the usefulness of three-dimensional modeling of fireflooding processes. The tests show that poor sweep efficiency can result when fireflooding is applied to reservoirs containing high-mobility streaks. Transverse combustion is shown to assist in sweeping the reservoir, but only to a limited extent.