Hybrid steam/solvent processes have gained importance as a thermal-recovery process for heavy oils in recent years. Among the identified physical mechanisms that play a role during these processes are heat-transfer phenomena, gravity drainage and viscous flow, solvent mass transfer, and mass-diffusion/-dispersion phenomena. In this paper, a study of sensitivity to grid size is described. Ideally, this work will provide some insight into methodological aspects to be considered when hybrid steam/solvent processes are modeled.

Introduction

Recent studies concerning the size of the liquid-solvent-rich zone where ­molecular diffusion and dispersion occur have implied that a detailed representation of the solvent/steam-­chamber edge is necessary in the numerical model. To represent this front appropriately, the authors propose application of fine-grid models to represent the steam/solvent condensation zone and, in parallel, activation of the adaptive-mesh refinement (AMR) option for amalgamating the internal and external portions of the steam chamber zone. It is expected that, with this simulation strategy, a detailed representation of the front will be caught by a fine model, while a coarse model will be sufficient to represent the heat-transfer phenomenon that dominates in the noncritical zone. For a discussion of the amalgamation process, please see the complete paper.