New Technique for Enhancing Oil Recovery from Low-Permeability Reservoirs: The Synergy of Silica Nanoparticles and Biosurfactant
Di Wang, Yijing Luo, Ruiqiu Lai, Kai Cui, Hailan Li, Zhongzhi Zhang, Ying Zhang, Rongjiu Shi
Abstract
Low-permeability reservoirs are characterized by small pore size and a complex strata structure that present challenges and opportunities in recovering petroleum. In this study, a new nanofluid composed of biosurfactant and silicon dioxide (SiO2) nanoparticles, hereby called bionanofluid, was proposed as potentially enhanced oil recovery agent to investigate the synergy of biosurfactant and nanoparticles on oil displacement from low-permeability reservoirs. Turbiscan Lab was used in stabilization analysis, wherein the concentration of biosurfactant and SiO2 nanoparticles must be below the critical micelle concentration and 1000 mg/L, respectively, thereby maintaining the ideal state of the nano-system. Numerous tests, including spontaneous imbibition, interfacial tension, micromodel test, and coreflooding experiment were performed to evaluate oil displacement efficiency of the bionanofluid. Sandstone pore plugs with different permeability values were utilized during the study to ensure the represent ativeness for the experiment. The results of spontaneous imbibition revealed the potential of nano-flooding, depending on the composition of bionanofluid. The experimental results showed the bionanofluid prepared by nanoparticle and biosurfcant can alter the interface property of oil and water better. The core flooding investigated that nanofluid composition, exposure time, and injection scheme significantly affect the oil recovery efficiency. In addition, the optimum various scenarios of bionanofluid flooding were selected on the basis of the permeability of the core plug. The mechanisms of nano-flooding for several typical residual oils were expressed based on the micromodel test. This study shows that using a biosurfactant stabilizes the nanoparticle suspension and reduces the interfacial tension of oil and water, which has a synergy with nanoparticles on oil displacement.