摘要 |
Recovery of viscous hydrocarbon by hot fluid injection into subterranean formations is assisted by using a specially designed and under-reamed vertic al wellbore with multiple injection perforations separated from the production perforations by a moveable packer. In this oil recovery method the operator drills a typical vertical well, in which a cavity is developed below the pay zone by under-reaming the vertical wellbore to form a collection cavity. This und er- reaming can be made up to several feet in diameter using standard reaming technology and tools. Steam is injected into the upper perforations and is prevented from bypassing the cold formation by a vertical hydraulic seal developed in an annular communication zone. Hot oil is produced into the lower perforations and is collected in the reamed out production cavity. A producing mechanism including pumping equipment lifts the produced oil from the central cavity to the surface.
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