Simulation of Noncondensable Gases in SAGD Steam Chambers

Abstract

Abstract Cenovus Energy has been very successfully developing the Foster Creek and Christina Lake projects using the Steam Assisted Gravity Drainage (SAGD) process. The SAGD process at both these projects has been operated at well above the initial reservoir pressure for extended periods of time and this has been adequately simulated using dead oil models which omit solution gas from the simulations. As we move into later stages in the life of the more mature well pairs at these projects it is important to better understand the role of non-condensable gases on the development of the steam chambers in order to optimize the methane co-injection, steam ramp-down and ultimately blow-down phases of operations. Cenovus also plans on implementing reduced pressure SAGD and Solvent Aided Processes (SAP) at future projects and non-condensable gas is expected to play a significant role in these processes. Hence, understanding the flow behavior of non-condensable gases in SAGD steam chambers could have far-reaching consequences for lowering the energy intensity and associated costs as well as reducing the environmental impact of bitumen production while potentially increasing reserves. This paper presents the results of some recent simulations which are improving our understanding of the role of solution gas in SAGD and the impact of non-condensable gases on steam chamber development.