Impact of Top Water on SAGD

Abstract

Canada’s heavy oil and oil sands resources are majorly exploited using SAGD (Steam-Assisted Gravity Drainage) and CSS (Cyclic Steam Stimulation). Its huge market opportunities may lead to exploitation of unconventional resources currently without booked reserves like the shallow unconfined top water resources. Managing water flow from aquifer, excessive heat losses and possible pollution are the challenges of producing this resource therefore Innovative, responsible and economic methods must be used. SAGD holds a potential for its exploitation since it can be operated at lower pressures although this may lower bitumen production rates because of higher bitumen viscosity. This research examines the impact of top water on SAGD in a reservoir simulation study of limited and unlimited top water models. Results show how steam injection pressures and composition of co-injected fluids affect the behavior of the steam chamber and SAGD performance. Also a clear view as to how mobility and location of fluid phases control the dynamics of SAGD is presented.