Viscous oil recovery method

Abstract From the Canadian patent

A viscous oil-bearing formation is produced by a steam flood technique in which the quality of the steam injected into the formation through an injection well is improved in-situ by the generation of an in-situ heat zone which trails along behind the front of the steam flood. This in-situ heat zone is generated by the injection of a non-condensable oxidant which reacts with the residual oil left behind the steam front in the steam swept zone. The oxidant injection is controlled so that the velocity of the heat zone through the formation is no greater than the velocity of the steam front, thereby preventing heat zone breakthrough of the steam front.