A New Analytical Model for the SAGD Production Phase

Abstract Steam chamber (SC) control during steam-assisted gravity drainage (SAGD) has a great impact on the efficiency of heavy oil and natural bitumen recovery. An optimal production rate and corresponding bottomhole temperature and pressure should be maintained to improve SAGD cumulative oil recovery and the steam-oil ratio. SAGD optimization work includes simulation results and real-time data monitoring. Existing analytical models1,2 are mainly dedicated to describing the ability of a reservoir to drain heated oil and do not depict all details of real SAGD processes. In the present work a new analytical model of the SAGD production regime is described. The initial stage of oil production is considered before SC reaches the production well. The model accounts for mass and heat transfer during the process of heavy oil recovery and establishes a significant correlation between production rate and the dynamic of SC evolution. The model that was developed was compared with simulation done by commercial reservoir simulation software.