The Design of Surfactant Multiplex System for Lowering Threshold Pressure
In order to increase surfactant compound system injection in low permeability reservoir of Chaoyanggou oilfield, we do research into formula of surfactant compound system according to reservoir condition. By contrasting to interfacial tension of different kinds of surfactants, we choose petroleum sulfonate surfactant T720-40# as main agent. As equilibrium interfacial tension of this surfactant cannot meet the requirements, so we add Na2CO3 as auxiliary agent to decrease interfacial tension. The results of laboratory experiment research show that equilibrium interfacial tension of this multiplex surfactant system can reach 2×10-2mN/m. It has good thermal endurance, salt resistance, and also has good compatibility with Chaoyanggou injection water and formation water. It can make rock wettability reverse, reduce threshold pressure and displacement pressure and it can improve recovery by 5% contrasting to water flooding.
D. Y. Yin et al., "The Design of Surfactant Multiplex System for Lowering Threshold Pressure", Applied Mechanics and Materials, Vols. 229-231, pp. 665-669, 2012