Use of Air with Methane in Cyclic Solvent Injection Applications for Improved Foam Stability and Cost Effective Heavy Oil Recovery

Abstract

Foamy oil flow is commonly encountered in heavy oil production from homogeneous or heterogeneous (after cold heavy oil production with sands—CHOPS) reservoirs. This can be due to a drive mechanism in the primary production (depletion of methane saturated heavy-oil) and secondary stage (gas injection after primary production). In the primary stage, among other important parameters, the pressure depletion rate has been reported to be the most critical characteristic to control this type of flow. In the secondary stage, gas amount and type (sole injection of methane, carbon dioxide, propane, or a combination of these), and application conditions (soaking time on cyclic solvent injection (CSI) durations, depletion rate) are critical. The cornerstone of the foamy oil behavior during CSI relies on its stability, of which depends on parameters such as oil viscosity, temperature, dissolved gas ratio, pressure decline rate, and dissolved gas (solvent) composition. Although the process has been investigated and ana...