Surfactant-Based Fluids Containing Copper-Oxide Nanoparticles for Heavy Oil Viscosity Reduction

Abstract

Abstract Limited research is reported in the area of nano-fluids applicability in heavy oil recovery. Some of the largest reserves in the world are heavy oil reservoirs. Thermal and chemical methods are widely used for heavy oil recovery. This research work investigates the viscosity reduction of heavy oil by adding a surfactant-based fluid containing nanoparticles. The viscosity reducing effect of only the nano-sized copper-oxide particles without surfactant-based fluid on heavy oil is also examined. Copper (II) oxide particles were selected due to their higher thermal conductivity, easy availability, and lower cost compared to metal nanoparticles. Two heavy oil samples (20-21 API°) having different viscosities and acquired from two different wells located in Oklahoma, USA were used for testing. Heavy oil samples mixed with nano-emulsion containing copper-oxide nanoparticles were investigated at different nanoparticle concentration and oil to emulsion volume ratio. Oil to emulsion volume ratio of (1:0.25) was used to determine optimum nanoparticle concentration. The optimum nanoparticle concentration was found to be 0.02% wt., exhibiting the maximum viscosity reduction.The viscosity of oil samples was measured at various temperatures. The performance of this nano-emulsion was also compared to an industrial viscosity reducer. In addition interfacial tension tests were performed with the oil samples. A significant reduction in the interfacial tension of heavy oil was observed after the formation of oil-in-water emulsion. Inherent properties of copper-oxide nanoparticles in tandem with the oil-in-water emulsion might utilize the advantages of both thermal and chemical recovery methods to obtain an enhanced heavy oil viscosity reduction. In conclusion, this nano-emulsion can be an effective oil recovery enhancement option in a heavy oil reservoir.