Feasibility of surface and borehole time-lapse gravity for SAGD monitoring

Abstract

†† † ‡ ‡ SUMMARY We evaluate the feasibility of surface and borehole timelapse gravity for monitoring steam assisted gravity drainage, or SAGD, production. Results indicate that surface gravity should contain strong time-lapse signal during production, yet the details of the individual steam chamber geometries will likely be unrecoverable from surface data alone. We likewise evaluate the joint inversion of surface and borehole gravity data simulated within a set of vertical monitoring wells required during SAGD production, and a set of horizontal monitoring wells as a modern alternative. The latter case is in line with recent developments in borehole gravity technology capable of operating in horizontal wells. These results indicate that the joint inversion of surface and horizontal borehole gravity data may provide the most reliable recovery of steam chamber dynamics during SAGD production.