Influences of surface tension of acid solution and contact angle of rock on the cleanup efficiency of surfactant

The influence of different kinds of surfactant on the surface tension of acid solution and the contact angle of rock is different.The relationship between the cleanup efficiency and the surface tension and the contact angle is studied.The surface tension and the contact angle and the cleanup efficiencies of nonionic surfactant,fluorcarbon surfactant and cationic surfactant are measured.The results indicate that and the increase of the contact angle has the same importance as the decrease of the surface tension to the cleanup efficiency of the acid containing surfactant.The quantitative relationship between the cleanup efficiency and the surface tension and the contact angle is presented.The study result of this paper is applied to the development of high-performance cleanup additive,and the optimized experiments show that the cleanup efficiency can reach to 90% when the mass ratio of FX-2 to CTAB to OP-8 is 1∶2∶2 and the concentration of surfactant is 800 mg/L.