Emulsification and Stabilization of ASP Flooding Produced Liquid

Abstract Emulsification and stabilization of o/w ASP flooding produced liquid in Daqing Oilfield were studied on artificial produced liquid and oily water. The influences of alkaline (NaOH), surfactant and polymer (partially hydrolyzed polyacrylamide HPAM) on the stability of ASP flooding produced liquid and oily water were tested. Bulk phase rheology and interfacial properties such as interfacial tension, oil droplet Zeta potential and interfacial rheology were tested to reveal the mechanisms of the emulsification and stabilization of ASP flooding produced liquid. The experimental results showed that residual alkaline, surfactant and polymer in ASP flooding produced liquid all tend to increase the stability of o/w ASP flooding produced liquid; The emulsification of ASP flooding produced liquid is mainly caused by the reduction of dynamic oil-water interfacial tension by residual alkaline and surfactant, the increase of water-phase viscosity by residual polymer, and the mechanical shear experienced by ASP flooding produced liquid during production; The stabilization of ASP flooding produced liquid by residual alkaline, surfactant and polymer lies in the enhanced emulsification of produced liquid in which smaller oil droplets are produced, the increase of water phase viscosity by polymer which decreases the rising velocity of oil droplet and the hindrance of alkaline and surfactant on oil droplet coalescence.