Overburn process for recovery of heavy bitumens

摘要

A method for the production of bitumen from a subterranean reservoir having a zone of increased effective permeability therein. In particular, a first well is in fluid communication with the zone of increased effective permeability at a first level in the reservoir. Fluid communication is established between a second well and the zone of increased effective permeability at a second level above the first level in the reservoir. In-situ combustion is initiated in the reservoir proximate the second well. Combustion sustaining fluid is injected through the second well into the zone of increased effective permeability so that bitumens in the reservoir are mobilized by the in-situ combustion and flow downward through the reservoir towards the first well, through which they are recovered. By using this method, a stable in-situ combustion process is established which avoids fingering and channelling and accompanying early oxygen breakthrough, consequently improving the efficiency of bitumen production from the reservoir.