岩石孔隙对两性离子聚合物凝胶成胶效果影响

利用黏度计、动态光散射仪以及岩心流动实验研究交联聚合物体系在磨口瓶和多孔介质中的成胶效果及体系与岩心的配伍性能。结果表明:在磨口瓶中体系黏度大幅上升,分子线团尺寸明显增加,具有良好的成胶效果,且体系先发生分子内交联,然后发生分子间交联,当体系发生大范围分子间交联前分子线团尺寸较小,与岩心配伍性良好,而交联后分子线团尺寸大幅增加,难以注入岩心;静态条件下,体系能够在岩心内成胶,但成胶强度明显低于在磨口瓶内的强度,且体系的残余阻力系数随着时间的增加先增大后降低,随岩心渗透率增加而增大;动态条件下,体系的阻力系数与同浓度聚合物溶液的几乎相等,说明该体系在多孔介质内动态条件下难以发生交联反应,原因是流动会干扰交联聚合物溶液体系中交联基团的运移、取向和定位,降低交联体系在适当位置形成交联的概率。

Influence of rock pores on gel-forming of amphion polymer gel

The Bush viscometer, dynamic light scattering, and core flow experiment were used to study the gelling effect of cross-linked polymer systems in the jar and porous media, and the compatibility of the system and the core. The results show that the viscosity of the system increases greatly, and the molecular coil dimensions of the system increases clearly, which indicates the gelling effect of the system is good. And the intra-molecular cross-linked of the system takes place firstly, and then the inter-molecular cross-linked. When a wide range of inter-molecular cross-linked reaction does not take place in the system, the molecular clew size is smaller, and has good compatibility with the core. However, when the cross-linked reaction takes place, the compatibility obviously deteriorates (the molecular clew size increases significantly), which results in the difficulty of injecting the core. Under static conditions, cross-linked polymer system could gel in the core, but the gelling effect is significantly lower than that of the beaker. And with the time increasing, the residual resistance coefficients of the inter-molecular cross-linked system first increases, then decreases. And with the core permeability increasing, the residual resistance coefficient of the cross-linked polymer systems increases, which shows the increase of time and space can improve the gelling effect of the cross-linked polymer systems. Under dynamic conditions, the resistance coefficient of the cross-linked system and the polymer solution are almost the same, which means that the cross-linked reaction of such cross-linked polymer system can not occurr. The shift rate and locating ability of polymer and cross-linker in cross-linked polymer system can be disturbed with the flow of the system, which leads to the decrease of the gelatin rate, the reduction of the cross-linking degree, or even the elimination of the gel formation.