In-Situ, Solvent-Assisted Gravity Drainage of Bitumen: Nonlinear Numerical Analysis

Abstract

Summary The use of condensing solvents, especially propane vapor, has been proposed for the low-temperature recovery of bitumen by gravity drainage. A full numerical analysis of such a process is presented. A hybrid spectral/finite-difference method was implemented to solve equations simultaneously. The results show that the hydrodynamics of a miscible front was highly dependent on the characteristics of the porous medium and also on the properties of the miscible fluid. As a significant factor, the dependency of the production flow rate on the thickness of the porous medium was measured. The order of dependency was found to be a function of time and cannot be considered as a constant. Hydrodynamic dispersion was also found to decrease this dependency. More-detailed results, along with quantitative analyses, are also discussed to indicate how the hydrodynamics was influenced by other porous-medium characteristics and fluid properties, such as dissolution rate and molecular diffusion.