Abstract:

According to the variation range of the mass concentration of the oil displacement agent in the produced fluid provided in the oil field, an ASP flooding simulated produced fluid was prepared in room. The influences of the type and concentration of the oil displacement agent in ASP flooding produced fluid on the system dehydration rate, backscattered light and stability characterization value （TSI value） were monitored from a macro perspective. At the same time, the rheology and interfacial film strength of the produced fluid were measured, and the mechanism of dynamic stability of the simulated produced fluid was analyzed from a micro perspective. The results showed that the influences of dehydration rate and TSI value on the stability of ASP produced fluid were consistent. The scanning measurement of the produced fluid system by TURBISCAN stability analyzer could obtain the dynamic and real-time changes in the process of emulsion instability. With the increase of alkali mass concentration, the interface viscoelasticity first increased and then decreased, and the influence of alkali on the viscosity of the system was small. The interface film strength first increased and then weakened, and the stability of produced fluid first improved and then decreased. When the alkali mass concentration was 900 mg/L, the produced fluid was most stable. With the increase of surfactant mass concentration, the elasticity of the interfacial film increased, the viscosity changed little, the strength of the interfacial film increased, and the stability of the produced fluid increased. With the increase of polymer mass concentration, the viscoelasticity of the oil-water interface increased, the interfacial film strength increased, and the stability of the produced fluid increased.

Key words: ASP flooding, W/O emulsion, dehydration rate, stability, viscoelasticity, interfacial film strength