Method of improving the areal sweep efficiency of a steam flood oil recovery process

Abstract From the Canadian patent

A method for the recovery of oil from a subterranean oil-containing formation by a cyclical steam flood-pressurization and production program. During the first cycle steam is injected, into the formation and oil is recovered until there is steam breakthrough at the production well. Thereafter a pressurization, cycle is initiated by throttling or shutting-in the production well while continuing injection of the steam until the bottomhole injection pressure is greater than the vertical pressure created by the overburden thereby causing the formation to fracture horizontally. After the horizontal fracture is formed the third, cycle or production cycle is initiated in which oil is recovered …