METHOD AND APPARATUS FOR IMPROVED OIL RECOVERY OF OIL AND BITUMEN USING DUAL COMPLETION CYCLIC STEAM STIMULATION

摘要

A method and apparatus whereby recovery from heavyoil and bitumen reservoirs may be increased over thatachieved in the later stages of cyclic steam stimulation(CSS) operations. Two sets of perforations perforate asteam chamber in a reservoir surrounding a well. The twosets of perforations are isolated hydraulically from eachother within the casing by a thermal packer. Steam isthen injected down the casing annulus into the upper setof perforations. After a period of steam injection,steam injection is halted and hydrocarbons are producedfrom the lower set of perforations through one of twostrings of tubing extending through the thermal packer.The second string of tubing serves to vent the wellduring production. This process may be repeated over thelife of the well, alternately injecting steam andproducing hydrocarbons.