Patent ID: 9551207
Date: 2017-01-24
CPC Classifications: E21B

Claim:
1. A method of extracting oil from an oil sand reservoir comprising: an initial step of drilling first and second well pairs separated by a predetermined separation, each well pair comprising: a first well within the oil sand reservoir; and a second well within the oil sand reservoir at a predetermined vertical offset to the first well, substantially parallel to the first well and at a predetermined lateral offset to the first well; a further step, prior to any production, of operating the first and second wells as a steam assisted gravity drainage (SAGD) well pair by selectively injecting a first fluid into at least the first well of each well pair according to a first predetermined schedule to create a zone of increased mobility within the oil sand reservoir; and drilling an infill well within the oil sand reservoir at a predetermined location between the first and second well pairs and generating a large singular zone of increased mobility between the well pairs by injecting a second fluid into the infill well according to a second predetermined schedule to establish thermal communication between the infill well and the zone between the SAGD well pairs prior to merging of steam chambers created by concurrent operation of adjacent SAGD well pairs; and the second predetermined schedule comprising converting the infill well for extracting reservoir fluids from the oil sand reservoir via the infill well; and continuing to operate the SAGD well pairs according to the first predetermined schedule.