XANTHAN GUM AND SILICA OXIDE NANOPARTICLE SYNERGIZATION EFFECTS ON OIL RECOVERY

This study aims to evaluate the capability of synergised XG and SiO2 nanoparticles solutions to improve the solution viscosity, IFT reduction and analyse the effects on the recovery factor. Samples were prepared with 4000 ppm XG and five concentrations of SiO2 (1000, 3000, 5000, 7000, 9000 ppm). The samples were tested for viscosity and IFT reduction to determine the optimum concentration of the synergised solution. Then, a flooding test was conducted using a sand pack to measure oil recovery factors when different slug ratios of polymer and brine were injected. Results show viscosity of the solution increased with increasing SiO2 concentrations. The synergy has shown IFT reduction from 75.5 mN/m to 55 mN/m with increasing concentrations of the SiO2 added into the polymer solution. Thus, 4000 ppm of XG synergised with 3000 ppm SiO2 nanoparticles was chosen as the optimum concentration as the IFT reduction is achieved and can be correlated with the viscosity result. A slight viscosity difference is observed when 5000 ppm SiO2 nanoparticles were added to 3000 ppm SiO2 nanoparticles. Oil recovery increased from 27.5% to 56% using 4000 ppm XG, while the oil recovery was increased to 57.5% using the synergised solution with a similar slug ratio. Maximum oil recovery was 66.3%, using an optimum synergised solution with the highest slug ratio of 0.5:0.5 PV polymer flooding to water slug. These prove that SiO2 nanoparticles can help polymer flooding improve sweep and displacement efficiency by viscosity increment and IFT reduction to increase the oil recovery.