新型延时增黏聚合物的制备及性能评价

Preparation and Property Evaluation of a Delayed Viscosifier

创新设计了具有缓释型阳离子基团、缓慢释放后超分子增黏的高黏聚丙烯酰胺分子结构,优化了最佳合成参数,评价了该延时增黏聚合物溶液的耐温耐盐性、延时增黏特性、电位及粒径,并考察了该延时增黏聚合物的驱油效果。研究表明:在温度90℃、矿化度32864 mg/L的情况下,质量浓度为1500 mg/L的延时增黏聚合物溶液的黏度可达15.4 mPa·s,展现了很好的耐温抗盐性能;随着老化时间的延长,常规聚合物溶液的黏度不断下降,而延时聚合物溶液的黏度不降反升,老化90 d的黏度为常规聚合物溶液的2~4倍,黏度保留率达107.7%,展现了良好的增黏特性和高黏度稳定性;延时增黏聚合物溶液的Zeta电位随放置时间的延长逐渐由负向正偏移,粒径增大,验证了延时增黏聚合物的延时增黏机理。室内物理模拟实验结果表明,在水驱(采收率41.2%)基础上注入0.3 PV的2000 mg/L的延时增黏聚合物溶液可提高采收率达27.7%,矿场实践亦取得良好增油降水效果。该成果为降低聚合物用量,进一步提高高温高盐水驱油藏采收率提供了新的技术支撑。图9表2参11。

In this paper,a high-viscosity polyacrylamide molecular structure with slow-released cationic groups and delayed supramolecular thickening action was designed,the synthetic parameters were optimized,and the solution performance of temperature and salt resistance,delayed viscosification,potential and particle size,were evaluated,and the oil displacement effect of the new delayed polymer was also investigated.The results showed that the viscosity of the delayed polymer could reach up to 15.4 mPa·s at the temperature of 90℃and at the salinity of 32864 mg/L,showing good temperature resistance and salt resistance.With the increase of aging time,the viscosity of BM solution decreased continuously,but the viscosity of the delayed polymer solution increased instead of decreasing.Moreover,the viscosity of the delayed polymer solution after aging for 90 d was 2—4 times that of conventional polymer BM solution,and the viscosity retention rate reached up to 107.7%,showing good viscosification performance and high viscosity stability.With the prolongation of aging time,Zeta potential of the delayed viscosifier solution gradually shifted from negative to positive,and the particle size increased,which verified the delayed viscosification mechanism.The oil recovery on the basis of water flooding(recovery factor 41.2%)could be enhanced by 27.7%by injecting 0.3 PV 2000 mg/L delayed viscosifier solution.The field test also achieved a good effect of increasing oil.This technique provides a new method for reducing polymer dosage,and also provides a strong technical support for enhancing oil recovery in high temperature high brine flooding reservoir of Shengli oilfield.