Effect of Nanofluid Treatment on Water Sensitive Formation to Investigate Water Shock Phenomenon, An Experimental Study

Permeability reduction in porous media as a result of frail and tenuous fine particles migration would decrease the productivity index in the subterranean reservoirs. During reservoir stimulation by injecting fluids into the reservoir, as the salinity condition of the formation brine changes, fine particles initiate the triggering process. In this study, MgO-based nanofluid as a fines fixation agent was stably prepared based on the particle size distribution and characterized through transmission electron microscopy analysis. Afterward, several core flooding tests were performed using Berea sandstone cores to study the effect of nanofluid injection on fines fixation in the water shock phenomenon. Permeability reduction occurred up to 95% of inchoate permeability for no treatment case, which was also confirmed by scanning electron microscopy analysis. Finally, MgO nanofluid with 0.03 wt% concentration and 120 minutes soaking time in the core mitigated the fine particles release and fixed them on the pore walls' surfaces critically reducing the formation damage. The analysis shows that outweighing the attraction potentials compared to repulsions was the main mechanism after nanofluids treatment.