STEAM-FOAM DRIVE EXPERIMENTS IN ONE-8 OF A 5-SPOT PATTERN

Two experiments, Tests SSM01 and SSM02, involving steam-foam drive pro cesses have been performed in 3-D physical models. The physical models which simulated one-eight of a 2 ha five-spot pattern for a Cold Lake oil sands deposit with a pay zone thickness of approximately 20 m, we re designed using a thermal high-pressure scaling approach. Both exper iments were carried out successfully with a steam-only injection perio d followed by steam-foam injection (i.e., steam-surfactant-nitrogen co injection) periods. The formation of foam in situ was identified by th e increase in pressure drop between the injection and the production w ells after steam-foam injection. Evidence of the injected steam being diverted from the steam swept zone into the oil rich zone due to the b locking effect of foam could be observed in the measured temperature p rofiles. Enhancement in oil production due to the diversion of steam w as observed. In addition, the effect of surfactant injection strategy on the propagation of foam was studied in Test SSM02. It was found tha t after the foam has been formed, it was more able to propagate away f rom the injection well by reducing the injected surfactant concentrati on.