This thesis is focused on the study of non-condensing gases (nitrogen, carbon dioxide and flue gas) injection to assist steam assisted gravity drainage (SAGD) in oil sands reservoirs. Reservoir simulation results indicate that the oil recovery factor of SAGD with non-condensing gases injection is higher than that of the conventional SAGD method. The conventional SAGD and the SAGD with non-condensing gases are compared in oil sands reservoirs with initial water. SAGD with nitrogen or carbon dioxide injection is superior in terms of cumulative oil recovery and a steam-oil ratio. With an increase in the initial water saturation the advantages of SAGD with nitrogen or carbon dioxide become even more significant.
Nitrogen stays at the edge of a steam chamber and reduces the amount of steam that penetrates into the initial water in a formation. This is validated by changes in the steam chamber during production. Carbon dioxide concentrates at the top and edges of a steam chamber as nitrogen, but more importantly it reduces the oil viscosity and increases the oil flow rate in the steam chamber.
Flue gas is comprised of 85% nitrogen and 15% carbon dioxide. We compare four models based on the simulation results and economic benefits in this thesis: conventional SAGD, SAGD with nitrogen, SAGD with carbon dioxide and SAGD with flue gas and. The parameters are optimized to serve the practical production.