Method and apparatus for improved recovery of oil and bitumen using dual completion cyclic steam stimulation

摘要

A method and apparatus whereby recovery from heavy oil and bitumen reservoirs may be increased over that achieved in the later stages of cyclic steam stimulation (CSS) operations. Two sets of perforations perforate a steam chamber in a reservoir surrounding a well. The two sets of perforations are isolated hydraulically from each other within the casing by a thermal packer. Steam is then injected down the casing annulus into the upper set of perforations. After a period of steam injection, steam injection is halted and hydrocarbons are produced from the lower set of perforations through one of two strings of tubing extending through the thermal packer. The second string of tubing serves to vent the well during production. This process may be repeated over the life of the well, alternately injecting steam and producing hydrocarbons.