复合乳液延缓交联体系的研究

Research on Composite Emulsion Delayed Crosslinking System

李海涛

LI Haitao

为了克服常规调剖体系存在的交联时间短、易吸附损失等问题，以煤油为油相、交联剂水溶液为内水相、聚合物溶液为外水相，Span-80和Tween-20分别为亲油性乳化剂和亲水性乳化剂，通过两步乳化法制备了具有多重结构的复合乳液交联体系。按照现场对调剖体系交联时间可控、强度可调和低损耗的要求，对复合乳液交联体系的延缓性、增黏性以及吸附成胶性能进行考察。研究结果表明，与未包裹的交联体系相比，复合乳液体系交联 时间可延长1倍以上，可达到12~48 h；在相同的聚合物浓度、相同的交联剂有效浓度下，复合乳液交联体系与未包裹的交联体系具有相近的增黏性，成胶黏度都可达到60~700 mPa·s；经吸附处理后，未包裹的交联体系成胶黏度的损失在25%以上，而复合乳液交联体系成胶黏度的损失仅有14.4%；岩心封堵率实验结果表明，复合乳液交联体系对渗透率为5 μm2左右的岩心的封堵率可达98%，高于未包裹的交联体系的封堵率。复合乳液交联 体系独特的多重结构，使其具有很好的缓释和保护作用，可以为油井的调剖作业提供一种有效的技术手段。图3 表6参12

In order to overcome the problem of short crosslinking time and adsorption loss of conventional profile control system，the composite emulsion crosslinking system with multiple structure was prepared by the way of two-step emulsion，using kerosine as oil phase，crosslinking agent solution as inner water phase，polymer solution as external water phase，with Span-80 and Tween-20 being lipophilic and hydrophilic emulsifiers，respectively. According to the requirements of profile control system with controllable crosslinking time，adjustable strength and low loss in field，the delayed crosslinking，viscosity increasing and adsorption performance of the composite emulsion crosslinking system were investigated. The results showed that，compared with the uncoated crosslinking system，the crosslinking time of the composite emulsion system could be extended more than one time，reaching up to 12—48 h；under the same polymer concentration and effective crosslinker concentration，the composite emulsion crosslinking system and the uncoated crosslinking system had similar viscosity，and the complex viscosity could reach 60—700mPa·s；after adsorption treatment，the uncoated crosslinking system lost more than 25% ，while the composite emulsion crosslinking system lost only 14.4%. The experimental results of core plugging rate showed that the plugging rate of the composite emulsion crosslinking system for about 5 μm2 permeability cores could reach up to 98%，which was higher than that of the uncoated crosslinking system. The composite emulsion crosslinking system with unique multiple structural features， had good sustained-release and protection，and it could provide an effective technical means for the well profile control task.

10.19346/j.cnki.1000-4092.2019.04.009