An experimental investigation of nanoemulsion enhanced oil recovery: Use of unconsolidated porous systems

Utilization of nanoparticles in oil and gas industry has attracted considerable attention of engineers and researchers. In this article, the feasibility of nanoemulsion flooding is investigated as a method for Enhanced Oil Recovery (EOR) through coreflooding experiments, using a packed bed and real reservoir fluids. Nine different mixtures of the solvent, surfactant, and nanoparticles in the form of a nanoemulsion phase are generated and used to recover the oil in the context of an EOR process. Various tests are conducted to determine the properties of porous medium and fluids. To study the production performance of this EOR technique, pressure drop across the packed bed are measured, along with the volumetric measurements of the produced fluids. A baseline injection scheme using seawater is also performed. All the nanoemulsion fluids are synthesized using the same base seawater. The Taguchi experimental design approach is employed in this research to design the experiments. The effects of nanoparticles concentration, along with those of surfactant and solvent components of the injection fluid on the oil recovery at the laboratory scale are investigated using the Analysis of Variance (ANOVA) method. Comparing the performance of waterflooding (WF) and nanoemulsion flooding, enhancement in the Recovery Factor (RF) by using emulsions is between 40-107%. Both the pressure and pressure fluctuations are surprisingly higher in the case of WF in comparison to the emulsion flooding. It is also found that under optimal concentration conditions (0.01 g of nanoparticles, 0.015 mL of surfactant, and 1 mL of solvent per one liter of brine), a recovery factor of up to 60% is achieved.