Field-Scale Numerical Simulation Of Bitumen Mobilization With Solvent Slugs

Abstract

A comprehensive numerical simulator is developed from an existing bitumen leaching model to incorporate the effects of asphaltene precipitation during bitumen mobilization with a solvent. Such mobilization is required prior to any thermal enhanced oil recovery (EOR) application. Numerical simulation results indicate that the presence of a bottom-water zone, often considered to be detrimental to oil production, enhances bitumen mobilization to a great extent. The bottom-water zone acts as a transporting medium for initial movement of the solvent and invokes solvent leaching of bitumen. Asphaltene precipitation reduces permeability of the bottom-water zone, thus, controlling excessive fluid influx into the bottom-water zone. This role of asphaltene is particularly important for relatively higher bottom-water permeabilities. A series of numerical simulation runs was conducted to study the effect of a wide range of parameters, such as, the bitumen-to-water zone permeability ratio, type of solvent, the bitumen-to-water zone thickness ratio, flow rate, and others.