Steam Assisted Gravity Drainage (SAGD):Influence of Geomechanical Processes on Absolute Permeability

Abstract

Alberta is recognized by its vast oil sands reserves. The applications of established thermal processes, such as SAGD, are commonly required to achieve economic hydrocarbon recovery. Steam injection causes pore pressure and temperature changes that influence the reservoir geomechanical properties with a related impact on flow properties such as absolute permeability. Drained triaxial compression tests were conducted to investigate the impact of SAGD on the petrophysical properties of unconsolidated sands at low stress conditions. The testing program included stress-strain and permeability tests run under two main stress paths: isotropic compression and triaxial compression. Isotropic compression produced small magnitude changes in absolute permeability while triaxial compression test resulted in a substantial increase of permeability. In general, lower permeability gain was reported at higher level of effective confining pressure. An empirical correlation linking absolute permeability to effective confining stress and volumetric strain change was developed for use in reservoir geomechanical simulations.