Optimization of methane use in cyclic solvent injection for heavy-oil recovery after primary production through experimental and numerical studies

Based on the outcome of the methane and methane-propane mixture experiments, it was of more importance to further study the way to enhance the foaminess in methane-live oil recovery. Different pressure depletion rates, namely −0.23, −0.51, and −1.53 psi/min, were applied and more oil was produced with increasing depletion rates. These experimental results were simulated at the core scale and the change of reaction coefficients was considered with varying decline rates. In field-scale modelling, sensitivity analyses were done with a variety of scenarios by changing injection/soaking period and pressure decline rates. The ratio of injection to soaking period was observed to be more critical than the injection period itself in terms of production efficiency. Also, the influence of pressure depletion rate as a new constraint in the simulation work was studied.