Performance Evaluation of Zinc Oxide/Copper Oxide Hybrid Nanofluids in Chemical Enhanced Oil Recovery Using Microfluidic Technique

The significance of this study is rooted in the urgent need for advanced, efficient, and sustainable enhanced oil recovery (EOR) techniques to meet rising global energy demands as conventional oil reserves decline, with current chemical EOR methods facing challenges related to efficiency, cost, and environmental impact. The aim of this research is to synthesize and systematically evaluate hybrid zinc oxide/copper oxide (ZnO/CuO) nanofluids with varying ratios for their potential to improve chemical EOR performance, specifically targeting enhanced stability, wettability alteration, interfacial tension reduction, and oil recovery efficiency under reservoirmimicking conditions using a microfluidic approach. The methodology involved synthesizing CuO nanoparticles and hybrid ZnO/CuO nanocomposites in different ratios, preparing nanofluids with a surfactant-based aqueous solution, and assessing their stability, wettability alteration, interfacial tension, and oil recovery through core flooding experiments in microfluidic devices. The major conclusion drawn is that the 50/50 wt% ZnO/CuO nanofluid demonstrated the best overall performance, achieving superior stability, the most significant reduction in interfacial tension (from 25.0 mN/m to 12.50 mN/m), the greatest wettability alteration (contact angle reduction from 92.34° to 46.14°), and the highest oil recovery rate (79%), highlighting the importance of optimizing nanocomposite composition for EOR applications and demonstrating the potential of hybrid ZnO/CuO nanofluids to improve oil recovery in challenging reservoirs.