三次采油用新型两性离子表面活性剂性能评价及应用

PERFORMANCE EVALUATION OF NEW AMPHOTERIC SURFACTANT FOR TERTIARY OIL RECOVERY

针对高温高盐油藏在三次采油过程中存在表面活性剂配伍性差、驱油效率低等问题,研究开发出一种新型两性离子表面活性剂DS-115,室内考察了其界面活性、耐温抗盐性、吸附性能、与碱和聚合物的配伍性以及模拟岩心驱油效率。结果表明,在DS-115加量为0.3%时,能使表面张力降低至25 mN/m以下,使油水界面张力值达到10-3 mN/m数量级,具有良好的界面活性;当温度达到100℃、NaCl浓度达到50000 mg/L时,油水界面张力值仍较低,具有良好的耐温抗盐性能;表面活性剂在80℃、12 h的吸附量小于1 mg/g;DS-115与碱、聚合物具有良好的配伍性,在二元复配和三元复配体系中均能保持良好的降低油水界面张力的能力。岩心驱油实验结果表明,注入浓度为0.3%的DS-115溶液0.3 PV后,能使岩心水驱后的采收率提高10%以上,起到了良好的驱油效果。

A new amphoteric surfactant ds-115 has been developed to solve the problems of poor compatibility of surfactant and low displacement efficiency in the process of tertiary oil recovery in high temperature and high salt reservoirs,and its interfacial activity,temperature and salt resistance,adsorption performance,compatibility with alkali and polymer,and displacement efficiency of simulated core have been studied indoors.The results show that when ds-115 dosage is 0.3%,the surface tension can be reduced to less than 25nM/m,and the interfacial tension value of oil and water can reach the order of 10-3mn/m,with good interfacial activity.When the temperature reaches 100℃,the concentration of NaCl reaches 50000 mg/L,the interfacial tension value of oil and water is still low,with good temperature and salt resistance.The adsorption capacity of surfactant at 80℃and 12h is less than 1 mg/g.Ds-115 has good compatibility with alkali and polymer,and can keep a good ability to reduce the interfacial tension of oil and water in binary and ternary systems.The core flooding experiment results show that after injecting 0.3pv ds-115 solution with concentration of 0.3%,the recovery of water flooding in core can be increased by more than 10%,which has a good oil displacement effect.