Nanofluid Assisted-Chemical Oil Recovery Process at High Temperature and High Salinity Conditions: Nanofluid Stability, Interfacial Tension, Contact Angle, Microscale Experimental Investigation

Abstract One of the most important aspects to use the nanofluid flow through the oil recovery process is physical and chemical constraints at high salinity and temperature, harsh conditions, leading to the instability and further problems. In this study, the stability of various nanoparticles, Al2O3, SiO2, ZrO2, TiO2, Fe2O3, nanoclay, and ZnO, were examined upon the concentration (0.01 to 3 wt%), temperature (ambient and 75℃), salinity (20,000 to 80,000 ppm), pH (2 to 12), and stabilizers of polyethylene glycol, polyvinylpyrrolidone, guar gum, Triton X-100, sodium dodecyl sulfate, cetrimonium bromide. Then, the most stable nanofluid was nominated to investigate the oil recovery mechanisms by performing interfacial tension (IFT), wettability alteration, and micromodel flooding analyses. Zinc oxide and silicon dioxide nanofluids were maintained their stability at the harsh conditions and guar gum showed a good performance in stabilizing nanofluids, compared to other nanofluids agglomerated. According to the results of the IFT reduction upon the nanofluid and reservoir crude oil (1.64 mN/m), wettability alteration of carbonate cores (113.68 degree) and micromodel experiments (additional recovery of 32.23% and 6.27% in the secondary and tertiary flooding, respectively) all compared to the seawater, the ZnO nanofluid stabilized by guar gum was an excellent candidate to use in the oil recovery projects.