Nanoparticle and Surfactant Stabilized Carbonated Water Induced In-Situ CO2 Foam: An Improved Oil Recovery Approach

The enhanced oil recovery techniques are ever-evolving to cater to the need for increased oil demand. To improve the EOR efficiency, the new approach combines chemical additives such as nanoparticles and surfactants with carbonated water to address the issues of reduced mobility control, gravity segregation, and early breakout encountered in CO2 flooding. The in situ-generated CO2 foams are unstable structures depending upon additional additives to strengthen their lamella and improve their stability, which ZnO nanoparticles (NPs) provide in the current study. This research investigates the synergistic impact of sodium dodecyl sulfate (SDS) and ZnO NPs on the CO2 foam generated from carbonated water. The carbonated water flooding tests were conducted using optimal SDS and ZnO concentrations of 2500 ppm and 0.01 wt %, respectively. The processes underlying the synergistic action of SDS and ZnO are altering nanoparticle adsorption sites on the CO(2 )and liquid interface, enhancing the CO2 foam's interfacial characteristics, and lowering its liquid discharge and coarsening. Further, four flooding procedures were utilized on two sandstone cores with contrasting petrophysical characteristics to study the effect of foam-assisted carbonated water flooding. The oil recovery was influenced and increased by SDS and ZnO NPs. The outcomes show that CO2 foam flooding (nanoparticles included) generated using carbonated slug illustrates effective conformance control and enhances oil recovery from sandstone. It has been observed that nanosurfactant-added carbonated slug flooding gives a 50.00% and 194.72% recovery enhancement compared to regular carbonated water flooding for sandstone-1 and sandstone-2, respectively.