Role of Nanoparticles in EOR: Comparative Efficiency of Al₂O₃ and TiO₂

Abstract

Nanotechnology has emerged as a promising approach to improve oil recovery by altering rock–fluid interactions and reducing interfacial resistance. This study investigates the effects of aluminum oxide (Al₂O₃) and titanium dioxide (TiO₂) nanoparticles on two critical parameters: wettability alteration and interfacial tension (IFT) reduction. Al₂O₃ nanoparticles were synthesized in the laboratory using the precipitation method, while commercial TiO₂ nanoparticles were employed for comparison. Nanofluids with varying concentrations were prepared and tested under controlled laboratory conditions, with performance evaluated over different exposure times. The results demonstrate that both Al₂O₃ and TiO₂ nanofluids effectively shifted rock surfaces toward more water-wet conditions, enhancing their potential for improved oil displacement. Al₂O₃ nanofluids showed optimal wettability alteration at 400 ppm after 24 hours, although efficiency declined at higher concentrations (1000 ppm) due to nanoparticle agglomeration. TiO₂ nanofluids achieved optimal wettability improvement at 800 ppm after 24 hours and displayed greater consistency across concentrations. In terms of IFT, both nanoparticles reduced interfacial tension significantly, with TiO₂ achieving the lowest value of 15.826 mN/m at 1000 ppm. Overall, TiO₂ nanofluids exhibited more stable and effective behavior, highlighting their suitability for enhanced oil recovery (EOR) applications.