Research on the influence factors of surfactant imbibition in tight reservoirs
Tight reservoirs always show poor physical properties,resulting in difficulties to be effectively exploited by conventional water flooding.Imbibition with surfactant solutions is the main means for exploitation of tight reservoirs.In this work,the effects of rock wettability,surfactant types,interfacial tension(IFT)of imbibition solutions,oil viscosities,temperature and surfactant slug combinations on imbibition efficiencies were studied with Changqing tight outcrop cores by Amott cells.The results showed that,the higher the wettability of the rock was,the higher the imbibition recovery would be obtained.The imbibition recovery of different types of surfactants was decreased in the sequence:anionic surfactants>nonionic surfactants>cationic surfactants.When the oil-water IFT of imbibition liquid was at the level of 10-1 mN/m,the imbibition efficiency was the highest.Reducing the viscosity of crude oil and increasing temperature were both beneficial to the imbibition recovery.The earlier the surfactant imbibition was carried out,the higher the imbibition efficiency was.In addition,the imbibition efficiency could be further improved by using ultra-low IFT imbibition solution after primary imbibition with non-ultra-low IFT imbibition solutions.
国家科技期刊平台
NSTL
万方数据
维普
