Synergistic Effect of Biosurfactant and Nanoparticle Mixture on Microbial Enhanced Oil Recovery

Recently, nanoparticles have become an attractive agent for enhanced oil recovery (EOR). Because much of the work on nanoparticles for enhanced oil recovery is still at the laboratory stage and to gain a better understanding of this technique, it is essential to study the effect of nanoparticles on EOR. In addition, the world is now more environmentally aware, presenting the opportunity to use biosurfactants for EOR. In this paper, the synergistic effect of biosurfactant and nanoparticles on the removal of oil in a glass micromodel was evaluated. In this study, an aqueous solution of emulsan biosurfactant with addition of SiO2 nanoparticles was used as a nanofluid. The emulsan biosurfactant was produced by Acinetobacter calcoaceticus PTCC1318. The production of emulsan was confirmed by FTIR and H-1 NMR analysis. According to our results, the use of the mixture of biosurfactant and nanoparticle (nanofluid) permitted a 90% reduction of interfacial tension in comparison with biosurfactant solution alone. Micromodel oil displacement experiments with kerosene showed around 10 and 20% recovery of residual oil after water flooding when the emulsan and nanofluid were injected, respectively. These results are useful in extending the application of nanostructures in ex situ microbial enhanced oil recovery.