METHOD OF RECOVERING HEAVY OIL FROM A SUBTERRANEAN PERMEABLE, HEAVY OIL-CONTAINING FORMATION

摘要

F-0937 A METHOD OF RECOVERING HEAVY OIL FROM A SUBTERRANEAN, PERMEABLE, HEAVY OIL-CONTAINING FORMATION A method of recovering heavy oil from a subterranean, permeable, heavy oil-containing formation comprises injecting steam into the lower portion of the formation, injecting a controlled amount of unheated water into the upper portion of the formation and displacing the oil through the formation towards a production well where the oil is recovered. The steam injection releases heat to the heavy oil and formation reducing the viscosity of the oil and increasing its mobility for recovery. The unheated water improves the oil recovery per BTU injected by scavenging heat from the steam heated formation so as to increase the volume of the formation subjected to heating and by diverting the flow of steam through the formation so as to increase the vertical sweep.