3D numerical simulation of the enhanced oil recovery process using nanoscale colloidal solution flooding

Abstract

The purpose of this study is to model nanoscale colloidal solution injection into porous media with the aim of enhancing oil recovery (EOR). In the present study, by focusing on the mechanism of changing the thermophysical properties of the injected fluid, including its viscosity due to the presence of nanoparticles, and using the FEM method, a model is developed. Finally, with the aid of the proposed model, the effect of nanofluid injection flow rate, nanoparticle volume fraction and the effect of media porosity on the EOR process have been investigated. According to the results, an increase in the injection nanofluid flow rate from 0.1 to 0.5 ml/min, there has been a sensible positive effect on accelerating the EOR process. Nanofluid with the flow rate of 0.3 ml/min selected as the optimum flow rate with 94% success in trapped oil extraction at the same time with 0.5 ml/min. On the other hand, three solid volume fractions of nanofluids analyzed and according to results increasing the nanoparticle volume fraction even though it has a significant effect on the change in the thermophysical properties of the base fluid, but in the end, it has had a poorly positive impact on the enhanced oil recovery process. According to the results of the model at a constant flow rate the medium with a lower porosity (0.217 in present study), oil recovery by nanoscale colloidal solution occurs max 36% faster that oil extraction in medium with high porosity (0.4 in present study) after the same time from the start of flooding. It should be noted that in all three simulated porosity in present study, the oil extraction was fully completed after 4200 s from the start of flooding. In order to have more real simulation, the problem is defined time dependent and the porous medium simulated for about 90 min time period.