Abstract

This study presents a numerical investigation for evaluating the potential applicability of the SAGD recovery process under complex reservoir conditions such as shale barriers, thief zones with bottom and/or top water layers, overlying gas cap, and fracture systems in the McMurray and Clearwater formation. The simulation results indicate that the near well regions are very sensitive to shale layers, and only long, continuous shale barriers (larger than 50m or 25%) can affect the SAGD performance in these well regions. In addition, the thief zones have a strongly detrimental effect on SAGD. The results also show that the SAGD recovery process is enhanced in the presence of vertical fractures but horizontal fractures are harmful on the recovery. Fracture spacing is not a very important parameter in the performance of a steam process in fractured reservoir and the increasing of horizontal fractures extension will reduce ultimate oil recovery in the SAGD process. This paper is a worthy guideline for SAGD operations in complex geological reservoirs.