Simulation of carbonated water injection coreflood experiments: an insight into the wettability effect

In this paper, our previously developed model (simulator) has been used to simulate and study a different CWI coreflood experiment from the literature performed in a mixed-wet sandstone core. The developed model that was based on mass transfer kinetics had been used before to simulate a coreflood experiment performed in a water-wet sandstone rock. In this paper, a different procedure has been applied for the simulation of CWI in the mixed-wet core. That is, in contrast to the water-wet coreflood test where only mass transfer parameter was tuned, here, both mass transfer parameter and relative permeability curves have been obtained through a history matching experiment applying our genetic algorithm (GA) based optimization program. Furthermore, using the simulation results, it has been observed that in addition to oil swelling and contrary to the water-wet core, wettability alteration is also an important recovery mechanism for the mixed-wet core. The potential of CO₂ storage during the mixed-wet CWI coreflood experiment has also been investigated. The results obtained in this paper can help to crosscheck and verify the performance of the developed simulator and also to explore its generic capability. Moreover, the results of this paper give an insight into different recovery mechanisms contributing during CWI coreflood experiments.