nvestigation of the Effects of Miscibility, Wettability, Injection Rate during CO2 Injection in Pore Scale of Reservoir Rocks

Investigation of the effective factors on the two fluid flow of CO2 injection in the reservoir rocks is important for optimizing such a process. In this study, the geometry extracted from a 2D section of the micro CT images of a real sandstone sample is used, and simulation of the two-phase flow (CO2 and oil) with the phase field approach have been implemented with Comsol software. In particular, the effect of miscibility, wettability, and injection rate is investigated, and the results of simulation such as oil recovery  and its dependence on the wettability, surface tension, and injection rate are evaluated. The results showed that surface tension and wettability have significant effects on the two-phase displacement so that, for example, more wettability towards the injected fluid improves the efficiency of the displacement process up to a 25%. The rate of CO2 injection can have different effects at various surface tension values, so the results of this study can be helpful in choosing the appropriate wettability condition and evaluating the optimal rate for real carbon dioxide injection.