交联聚合物溶液在岩心内成胶效果及机理

Mechanism and gelling effects of linked polymer solution in the core

采用黏度计、动/静态激光光散射仪、扫描电镜和岩心流动实验装置,对两性离子聚合物溶液和两性离子交联聚合物溶液黏度、分子线团尺寸、分子聚集态和多孔介质内静态成胶效果及其影响因素进行实验研究,分析交联聚合物溶液在岩心内成胶机理。结果表明,随溶剂水矿化度增加,交联反应速度加快;放置时间越长,岩心内交联反应增强并趋于稳定;剪切时间延长,聚合物分子定向排列趋势加剧,岩心孔隙内成胶效果变差;渗透率较低条件下,岩心孔隙内交联反应以"分子内"交联为主;随岩心渗透率增加即孔隙尺寸增大,岩心内成胶效果变好,发生"分子间"交联概率增大。实验数据和理论分析表明,在两性离子交联聚合物溶液中,交联反应首先发生在同一分子的不同支链间,即"分子内"交联,形成局部性网状聚集态,然后扩展到不同聚合物的分子链间,即"分子间"交联,形成区域性网状聚集态。

By using Bush viscometer, dynamic and static laser scatter instrument, scanning electron microscope and core flow experimental apparatus, experiments were conducted to study the viscosity, molecular coil dimensions, molecular configuration and static gelation of amphotedc polymer solution and linked amphoteric polymer solution in porous media and affecting factors, and to analyze the gelation mechanism of linked polymer solution in the core. The results showed that with the increase of solvent water salinity, the cross-linking reaction rate increases; with increase of aging time, the gelling effect gets stronger and stable; with the increase of shear time, the lineation of polymer molecules gets more obvious, the gelling effect in pores gets worse; under the condition of low permeability, the cross-linking reaction mainly is intmmolecule cross-linking; with the increase of core permeability, i.e. the increase of pore size, the gelling effect gets better in the core, and inter-molecular cross linking reaction is more likely to take place. The experimental data and theoretical analysis showed that in the linked amphoteric polymer solution, the cross-linking reaction occurs between the different branched-chain of the same molecule firstly （intra-molecular cross-linking）, then the cross-linking reaction extends to different polymer molecules （i.e. inter-molecular cross-linking）.