SAGD laboratory experimental and numerical simulation studies: A review of current status and future issues

With around 7 trillion-barrel reserves and recent increases in oil demand, there is no doubt that there will be a tremendous demand on the development of heavy oil/bitumen (HO-B) reservoirs in the coming decades. Yet the in-situ recovery of HO-B is still not a simple process and there are many technical challenges accompanying it. Two major techniques, namely thermal and miscible, have been considered in HO-B development. along with several other auxiliary methods (chemical, gas, electromagnetic heating, etc.) for different well configurations, with steam assisted gravity drainage (SAGD) being the most popular. Miscible techniques are not highly recognized as a commercial option, while thermal techniques have by far a more stable foundation in the industry. Despite a remarkable amount of laboratory experiments and computational studies on thermal techniques for HO-B, specifically SAGD, there was no extensive and critical literature review of the knowledge gained over almost three decades. We believe that this kind of review paper on the status of the SAGD process will shed light on the critical aspects. challenges, deficiencies and limitations of the process. This will open doors to further development areas, and new research topics. This paper focuses mainly on laboratory and numerical simulation studies, not field experiences. The attempt is to draw a picture of the developments on the physics and technical aspects of the process and its future needs. Specific attention, was given to (a) the effect of geological environment on the physics of the process, (b) evaluation of the laboratory scale procedure and results, (c) problems faced in numerical modelling (capturing the physics of the process, relative permeability curves, dynamics of gravity controlled countercurrent flow), and (d) operational and technical challenges. (C) 2009 Elsevier B.V. All rights reserved.