Mixed well steam drive drainage process

摘要

A thermal oil recovery process is disclosed for use in a heavy oil reservoir having a plurality of laterally separated, generally vertical wells whose use have left the reservoir characterized by a heated depletion zone, a channel, voidage, or mobility and communication. The process includes the steps of: drilling a well having a horizontal section and an opening therein that is located laterally between at least two of the vertical wells and at a depth within the lower part of the reservoir; injecting a steam through the two vertical wells to establish thermal communication with said horizontal well; and using the combination of steam drive and gravity drainage to recover oil from the reservoir through the horizontal well.