Reservoir Simulation of Cyclic Steam Stimulation in the Cold Lake Oil Sands

Abstract

Summary Steam injectivity during cyclic steam stimulation (CSS) at Cold Lake can be achieved only by injecting at pressures high enough to fail the formation mechanically. The reservoir also exhibits water/oil relative permeability hysteresis. This paper describes enhancements made to a thermal reservoir simulator to incorporate these Cold Lake physics. The geomechanical model allows both localized fracturing and global reservoir deformation (dilation and history-dependent recompaction). This representation allows the simulator to match injection and production pressures that are otherwise difficult to reproduce. The history-dependent relative permeability hysteresis model calculates gridblock relative permeabilities that always lie on or between input imbibition and drainage bounding curves. The model makes it possible to use laboratory-derived relative permeabilities in a simulation and still match field WOR's.