HEAVY OIL RECOVERY PROCESS USING CYCLIC CO.SUB.2- STEAM STIMULATION

摘要

HEAVY OIL RECOVERY PROCESS USING CYCLICCARBON DIOXIDE STEAM STIMULATIONABSTRACTA method for the recovery of viscous oil from subterraneanformations including tar sands by the injection of a mixture ofcarbon dioxide and steam into the formation through an injectionwell, after which formation fluids are recovered from the well in acyclic manner, using the well alternately for injection andproduction. Incremental recovery is optimized by maintaining theratio of carbon dioxide to steam within the range 200 to 300,preferably 230 to 270 SCF carbon dioxide per barrel of steam (withwater equivalent) in the injected mixture.