After long-term water injection, the injection well pressure increases, the validity of conventional acidification measures is short and its adaptability is poor. A new heterogemini surfactant GXS-2 was prepared by two-step method with alkyl dimethyl tertiary amines and alkyl halides as main raw materials. Its interface activity, temperature tolerance and salt tolerance were evaluated as well as the synergistic effect with other conventional surfactant, and the effect of decompression and augmented injection. The results show that the heterogemini surfactant has high interfacial activity, and the interfacial tension is 0.028 mN/m when the addition amount is 0.05%, which can meet the requirement of ultra low interfacial tension. When the temperature is 150℃, mineralization degree is 100000 mg/L, the solution still has a lower surface tension value, and has good temperature resistance and salt resistance. Mixed with common surfactant DTAB, the compatibility is good, and the surface / interfacial tension is lower than that of single surface active agent, and it plays a certain role in coordination. Core flooding experimental results show that injecting 5 PV solution with 0.05% concentration of GXS-2, the pressure reduction rate can reach about 35%, which indicates it has better effect of decompression and augmented injection.%针对注水井长期注水后压力升高、酸化等常规增注措施有效期短、适应性差等问题,以烷基二甲基叔胺、卤代烷烃为主要原料,通过两步法制备出了一种适用于注水井降压增注的杂双子表面活性剂GXS-2,室内评价了其界面活性、耐温性、耐盐性、与其他常规表面活性剂的协同性以及降压增注的效果.结果表明,该杂双子表面活性剂具有较高的界面活性,加量为0.05%时界面张力为0.028 mN/m,达到了超低界面张力的要求.当温度为150℃、矿化度为100000 mg/L时,表面活性剂溶液仍具有较低的表面张力值,具有较好的耐温性和耐盐性.与普通表面活性剂DTAB进行复配后,配伍性较好,表面/界面张力均比单一表面活性剂有所降低,起到了一定的协同作用.岩心驱替实验结果表明,注入5 PV浓度为0.05%的杂双子表面活性剂溶液后,压力降低率可达35%左右,起到了明显的降压增注作用.
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