Semi-analytical modeling of steam-solvent gravity drainage of heavy oil and bitumen: Steady state model with linear interface

The model is validated against CMG-STARS® thermal simulator and also SAGD experimental results for hexane co-injected with steam. It is shown that by adjusting a few parameters using SAGD results, the model can fairly predict the oil production and cumulative steam-to-oil ratio for the solvent-aided process with average absolute deviations up to 7% and 20%, respectively. The results suggest that the steady state model can be used as a screening tool for SA-SAGD. Also, it may be employed to find the optimum solvent candidate and the operational variables to maximize the flow rate of the SA-SAGD process. The model can also be applied for a mixture of solvents provided that the equilibrium experimental phase behavior data are available for a given solvent-bitumen system.