Abstract
The increased interest in secondary production (or post-cold production) of heavy oil and the current rise of oil prices has renewed interest in solvent-based methods for heavy oil recovery. Although the Vapor Extraction (VAPEX) process is the most heavily favored process for potential field application, other methods are also worth investigating. Moreover, the relative merit of mass transfer and viscous mechanisms in the overall recovery efficiency remains a topic of debate in the literature.
This paper is a small part of a greater effort to study mass transfer phenomena in heavy oil/bitumen solvent systems. A series of core flooding experiments were performed whereby liquid solvents (octane, pentane) displaced heavy oil (12Pa.s). Different configurations and displacement rates were employed and heavy oil recovery factors were determined. Solvent concentrations in the effluent oil-solvent mixtures were accurately evaluated using the non-intrusive Nuclear Magnetic Resonance (NMR) technique and conventional density measurements.
Mass transfer analysis was performed in an effort to determine dispersion coefficients.