VISCOUS OIL RECOVERY METHOD

摘要

VISCOUS OIL RECOVERY METHOD In a thermal method for the recovery of oil from a subterranean, viscous oil-containing formation, a predetermined amount of steam in an amount not greater than 1.0 pore volume is injected into the formation via an injection well and oil is produced from the formation via a production well. The injection well is then shut in for a variable time to allow the injected steam to dissipate its heat throughout the formation and reduce oil viscosity while continuing production of oil. A predetermined amount of hot water or low quality steam in an amount not greater than 1.0 pore volume is. injected into the formation with continued production but avoiding steam breakthrough. Thereafter, production is continued until there is an unfavorable amount of water or steam in the fluids recovered.