Integration of Steam-assisted Gravity Drainage Fundamentals with Reservoir Characterization to Optimize Production

Abstract Traditionally, in-situ oil sands operators use the simple approach of placing steam-assisted gravity drainage (SAGD) well pairs as close to the base of pay as possible, with the expectation that the effects of reservoir heterogeneity will be mitigated by the use of longer well pairs. It has been proven, however, that the geometry associated with the top and base of the SAGD pay interval and the distribution of reservoir lithofacies within the pay interval have a significant impact on SAGD performance. This chapter proposes that optimal well placement and selective completion strategies can more effectively address reservoir heterogeneity issues, provided that a three-dimensional (3-D) model of the SAGD reservoir and an ultimately fuller understanding of the evolution of the steam chamber over time exist. By applying strong scientific principles and consistent SAGD strategies, top operators have demonstrated that improved reservoir performance is possible, evidenced by higher production rates, lower steam-oil ratios, and maximized recoverable reserves.