三元复合驱对储层伤害及其作用机理研究

Damage of Alkali/surfactant/polymer Flooding to Reservoir Rock

胡淑琼 李 雪 卢祥国 苏延昌

HU Shu-Qiong LI Xue LU Xiang-Guo SU Yan-Chang

三元复合驱能够大幅度提高原油采收率，但它所引起的结垢问题一直困扰着该技术的大规模推广应用。本文以大庆喇嘛甸油田储层岩石和三元复合体系为实验对象，开展了碱驱后岩石结构的可视化研究以及含碱驱油剂流动特性研究。实验结果表明，碱对储层岩心中黏土矿物溶蚀作用比较明显，对石英和长石等骨架成分的溶蚀作用较小；采出液中钙镁离子浓度较低，硅离子浓度却较高，前者成垢作用难以对储层渗透率造成显著影响，后者易在迁移过程中发生沉积，在地层和生产系统中形成大量硅垢。进一步分析表明，随碱浓度增加，三元复合体系对地层伤害程度加剧。表面活性剂和聚合物都可以减弱碱的溶蚀作用，但前者比后者减缓溶蚀作用的能力弱。

Alkali/surfactant/polymer (ASP) flooding can enhance oil recovery greatly, but the scaling problem restricts its large-scale application. The experiments were performed on reservoir rocks in Daqing Lamadian Oilfield and ASP system, visual research on rock structure after alkali flooding and research on alkaline driving agent flowing property were carried out in this paper. The microscopic experiments results showed that, alkali mainly dissolved clay minerals and had little impact on feldspar framework. The flow experiments results showed that in produced fluid, the concentrations of calcium ion and magnesium ion were low and had little impact on the core penetration, the concentration of silicon ion was high and deposition easily during migration would form a large of silicone scale in layer and production systems. Further analysis of the results showed that the damage of ASP flooding to the reservoir rock became severer as alkali concentration increasing, both surfactant and polymer could reduce dissolution, however, the effect of the former was weaker.