耐温抗盐强乳化聚-表二元复合驱油体系研究及应用

Study and Application of Binary Composite Oil Displacement System of Polymer and Surfactant with Temperature Resistance,Salt Resistance and Strong Emulsification

针对高温高盐油藏采用常规聚合物和表面活性剂驱油效果较差的问题,将耐温抗盐型聚合物SPAM-1和阴-非离子复合型表面活性剂YANC-E进行复配,研制了一种适合高温高盐油藏的耐温抗盐强乳化聚-表二元复合驱油体系,并通过室内实验评价了驱油体系的综合性能。结果表明:该二元复合驱油体系的耐温性能较强,在115℃下老化后,体系的黏度保留率仍能达到90%以上,界面张力仍能达到10^(-3)mN/m数量级;体系具有良好的抗盐性能,当矿化度大于100000 mg/L时,体系仍能保持较高的黏度和较低的界面张力;体系具有良好的长时间老化稳定性能,在储层温度和矿化度条件下老化60 d后的黏度保留率在85%以上,界面张力始终维持在10^(-3)mN/m范围内;驱油体系与原油形成的乳状液稳定性较强,放置120 min后乳状液的分水率小于20%,具有较强的乳化性能;驱油体系在地层条件下吸附6次后仍能保持较高的黏度和较低的界面张力,具有良好的抗吸附性能。另外,岩心水驱结束后注入0.5 PV二元复合驱油体系,能使采收率继续提高25%以上,驱油效果较好。A区块内5口采油井在实施耐温抗盐强乳化聚-表二元复合驱油措施后,日产油量显著提高,含水率明显降低,取得了良好的现场应用效果。

In view of the poor oil displacement effect of conventional polymers and surfactants in high-temperature high-salt reservoirs,a binary composite oil displacement system with temperature resistance,salt resistance and strong emulsification suitable for high-temperature high-salt reservoirs was developed by using temperature and salt resistant polymer SPAM-1 and anionic--non-ionic composite surfactant YANC-E.The comprehensive performance of the oil displacement system was evaluated through experiments.The results show that the binary composite oil displacement system has strong temperature resistance.After aging at 115℃,the viscosity retention rate of the system can still reach more than 90%and the interfacial tension can still reach the order of 10^(-3)mN/m.The system has good salt resistance.When the salinity is greater than 100000 mg/L,the system can still maintain high viscosity and low interfacial tension.The system has good long-term aging stability.Under the conditions of reservoir temperature and salinity,the viscosity retention rate of the system is more than 85%after aging for 60 days,and its interfacial tension is always maintained in the range of 10^(-3)mN/m.The emulsion formed by the oil displacement system and crude oil has strong stability.After 120 min,the water separation rate of the emulsion is less than 20%,and therefore it has strong emulsifying performance.The oil displacement system can still maintain high viscosity and low interfacial tension after adsorption for 6 times under formation conditions,and therefore it has good anti adsorption performance.In addition,when the binary composite oil displacement system of 0.5 PV is injected into core after water flooding,the oil recovery can be enhanced by more than 25%,and the oil displacement effect is good.After the implementation of the binary composite flooding measure in 5 oil production wells in block A,the daily oil production was significantly increased,and the water cut was significantly reduced.Good field application results are achieved.