Viscoelastic Oil Displacement System of Modified Silica Nanoparticles/Zwitterionic Surfactant for High Salinity Reservoir

Abstract Polymer flooding and polymer/surfactant have achieved good efficiency in the application of conventional reservoir, but existed chemical technology cannot address issues requirements high salinity reservoir. Under condition due to increase calcium magnesium ions, increasing viscosity effect oil displacement system is lost. In order study feasibility applying nanomaterials field enhanced recovery under conditions develop a low-concentration high-efficiency system. EAPC solution has advantages reducing interfacial tension, its not good. Therefore, hydrophobically modified silica nanoparticles (SiO2 NPs) were added carboxylic acid–type erucic acid amide propyl betaine (EAPC) solution. The interaction between hydrophobic carbon chains led exposure carboxyl groups, thus making more stable. activity zeta potential studied, mechanism SiO2 NPs was obtained. results show that when concentration 0.3%, apparent composite can reach 40 mPa·s, oil-water tension be reduced 10-2 mN/m. micro-visualization model simulated experiment proved (0.3%)/EAPC (0.3%) variety mechanisms. reservoir (total 25000 mg/L, ion 500 70 °C), it had viscoelasticity improved washing efficiency. guiding significance for effectively enhancing