驱油用两性离子型双子表面活性剂的合成及应用

Synthesis and application of zwitterionic gemini surfactant flooding agent

针对低渗油藏水驱及常规表面活性剂驱开发效果较差的问题,通过实验研制了一种新的两性离子型双子表面活性剂LSN-104,并在室内评价了其界面活性、耐温性能、抗盐性能、润湿性能以及驱油效果。性能评价结果表明:LSN-104具有良好的界面活性以及耐温抗盐性能,当LSN-104质量分数为0.5%时,在温度为120℃或NaCl质量浓度为60 g/L或CaCl_2质量浓度为5 g/L的条件下,界面张力仍能维持在10^(-3)mN/m数量级;LSN-104的加入能明显减小石蜡片表面的接触角,使亲油性表面转变为亲水性,具有良好的润湿反转能力;注入0.5 PV质量分数为0.5%的LSN-104溶液,能使低渗岩心水驱后的采收率提高15.65百分点。现场应用结果表明,注入表面活性剂LSN-104后,采油井见效率达100%,各采油井均呈现出产油量上升、含水率下降的趋势,增油效果显著,取得了明显的施工效果。

In view of the poor development effect of water flooding and conventional surfactant flooding in low permeability reservoirs,a new type of amphoteric ion gemini surfactant LSN-104 was developed by experiment,and its interfacial activity,temperature resistance,salt resistance,wettability and oil displacement effect were evaluated in the laboratory.The results show that the zwitterionic gemini surfactants have good interfacial activity and good temperature resistance and salt resistance.When the amount of LSN-104 is 0.5%,the interfacial tension can remain within the range of 10^-3 mN/m at the temperature of 120℃,the concentration of 60 g/L NaCl and 5 g/L CaCl2.The addition of surfactant can reduce the contact angle of the surface of the paraffin surface obviously,making the oil-based surface change to hydrophilic,and have good wetting reversal ability.When 0.5 PV of 0.5%LSN-104 is injected,the recovery rate of the low permeability rock after water flooding can be increased by 15.65%.The results of field construction show that the efficiency of production well is 100%after the injection of gemini surfactants.All production wells show the trend of increasing oil production and water cut.The cumulative effect of oil increase is remarkable,and obvious construction effect has been achieved.