Abstract
In solvent aided Steam-Assisted Gravity Drainage (SAGD), steam-solvent injection, which is a different process from that of a pure-steam process, significantly affects the steam-solvent phase behavior near the vapor-liquid interface.
In this thesis, the phase behavior of the steam-solvent-bitumen system is studied in detail through simulation. It is discovered that solvent is dissolved in oil by gas-oil equilibrium near the vapor-liquid interface, rather than the mixing of bitumen and solvent condensate. The dissolved solvent is convectively delivered to the oil sand through the gravity drainage process, rather than the process of diffusion or dispersion. The effects of the solvent injection concentration and injection pressure on steam-solvent-bitumen behavior are analyzed. In addition, this study proposes a steam-solvent injection strategy to improve solvent aided SAGD performance through analysis of solvent concentration, pressure, solvent-type and solvent injection start time.
