非离子表面活性剂对污水聚合物热稳定性的影响

Analysis of the experimntal study on nonionic surfactant effect to thermal stability of polymer mixed by produced water

陈莉 王伟 杨怀军

CHEN Li WANG Wei YANG Huaijun

中国石油大学地球科学与技术学院，山东青岛　266555 中国石油天然气股份有限公司勘探与生产分公司， 北京　100007 大港油田公司采油工艺研究院，天津　300280

School of Geosciences, China University of Petroleum, Qingdao 266555, China Exploration & Production Company,Petrochina Company Limited, Beijing100007, China

针对聚/表二元复合驱体系的长期热稳定性问题，在污水配制的聚合物溶液中加入非离子表面活性剂，研究其长期热稳定性及降低油水界面张力的程度。配制聚合物浓度为2 000 mg/L，非离子表面活性剂质量分数为0.10%和0.20%，在53 ℃无氧条件下恒温60 d。结果表明，非离子表面活性剂加入后，黏度保留率由22.3%提高到71.4%，恒温60 d后油水界面张力仍然保持在10?3数量级。现场采用该体系进行试注后发现，注入液可将油水界面张力降至2.59×10?3 mN/m；在油藏条件下，溶液经60 d老化后其黏度保留率达到72%；注入井注入压力较注聚/表二元体系前上升1 MPa。

To keep the thermal stability of polymer-surfactant dual-compound systems for a longer period. Some type of nonionic surfactant (0.10~0.20 wt%) is added to the polymer solution (2000 mg/L) diluted by produced water, and then, the system was aged for 60 days at 53 ℃ under the oxygen-deprived conditions. Following that, the thermal stability and the extent of reducing water-oil interface tension of the system were evaluated. The results showed that, after adding the surfactant and aging for 60 days, viscosity retention rate is improved from 22.3% up to 71.4%, and the water-oil interface tension is still within the order of 10?3 mN/m. The tentative practice which adopts this system to tentatively inject the solution combine polymer and surfactant into the reservior suggests that it reduce the water-oil interface tension down to the grade of 2.59×10?3; the viscosity of the solution remains the rate of 72%, even if the solution is kept in the same 53 ℃ for about 60 days; and the injection pressure enhances 1 MPa compared with the former conditions.