Application of ZnO Nanostructures in Improvement of Effective Surface Parameters in EOR Process

ZnO nanosphericals and nanorods have interesting potential applications in various fields such as antibacterial and enhanced oil recovery process. In this work, it was shown that 30 ml of a water-based solution containing 3% of ZnO nanofluids could significantly change the wettability of a carbonate reservoir rock from a strongly oil-wet alter to a strongly water-wet condition, after 3 days aging of the rock at 70 degrees C in the designed solution. Moreover, we have studied air-water and oil-water interfacial tensions of system containing nanofluids. Fluids included ZnO nanoparticles and quantum dots nanostructures (QDOTs ZnO) could effectively decrease the n-decane/water interfacial tension and air/water surface tension. So their efficiency is much higher in comparison with distilled water. The stabilization of various aqueous ZnO nanostructured in mixtures of NaCl, CaCl2, MgCl2 and Na2SO4 salts were investigated, and 50000-163000 ppm transparent and stable nanosalt fluids were fabricated. Wettability of an oil-wet carbonate rock aged for 3 days at 70 degrees C in the designed ZnO nanosalt fluids was studied by measuring the contact angles. The results show a strong change in wettability of carbonate rocks from oil-wet to more water-wet condition. These nanosalt fluids performed an excellent trend of surface tension and IFT reduction in comparison with distilled water too.