Numerical simulation and optimization of biological nanocomposite system for enhanced oil recovery

Abstract

Abstract Nanofluid flooding is a novel technology with potential for enhanced oil recovery. In this study, a biological nanocomposite system was formed by mixing hexamethyldisilazane-modified hydrophobic nano-SiO2 with a biosurfactant produced by Bacillus. The stability of the system, its influence on rock wettability, and fluid interfacial tension were investigated experimentally. Numerical simulation methods were employed to simulate the displacement efficiency of the biological nanocomposite system and optimize the injection parameters. Finally, the application effects of the system in the field were evaluated. Results indicated that the biological nanocomposite system could change rock wettability and significantly reduce the interfacial tension to 1.8 mN/m at low concentrations. The core flooding results showed that the maximum oil recovery factor of the system reached 47.07%. Numerical simulations optimized the optimal injection concentration to be 7,000 ppm and the volume of injection to be 1.75 × 10–2 pore volumes, resulting in an oil increment exceeding 10,000 m3 in field application. This study provides a solution for the green development of oil reservoirs and provides effective technical support for the numerical simulation and process scheme optimization of biological nanocomposite systems.