Evaluation of Synergetic Rheological Behaviour of Polymer and Silica Nanofluids for Enhanced Oil Recovery

Abstract

Reservoirs with partially hydrolyzed polyacrylamide (PHPA) aqueous displacing injected fluids improve the amount of oil produced noticeably. However, the medium's temperature and salinity significantly impact the viscosity of these fluids, which is critical in specific reservoir conditions for oil recovery. Thus, adding nanomaterials in PHPA solutions to prepare nanofluids has been shown to be a promising alternative to increase viscosity and improve performance in enhanced oil recovery. The dispersion of NPs in the aqueous polymer solution was characterized by DLS and zeta-potential measurements for stability. The contact angle measurement was also performed of silica nanofluid for examining the ability to wettability alteration. In the rheological studies, it was observed that there was an improvement in the viscosity by adding Silica Nanoparticles in the polymeric solution by 20%. Along with the improvement, silica polymer nanofluid also reduces the viscosity losses at reservoir temperature over 28 days. The experimental results showed that Silica Core flooding experiments were performed to observe the synergetic efficacy of the nanofluids with polymer in barea sandstone core at 90°C. The Silica NPs Assisted Polymer EOR Agent exhibit superior stability characteristics, to a lesser extent, viscosity losses after ageing and good stability, which are desirable for functional application in enhanced oil recovery (EOR) processes, which was confirmed by the result of EOR core flooding with maximum Incremental Oil Recovery of 28 % after water flooding.