RAFT水溶液聚合制备调驱用凝胶分散体及其性能评价

Preparation and Performance Evaluation of Gel Dispersion for Profile-controlling and Flooding by Aqueous RAFT Polymerization

杨子腾 张丰润泽 张艺夕 郑憬希 刘 灿 刘学敏 张 鹏 伍 波

YANG Ziteng ZHANG Fengrunze ZHANG Yixi ZHENG Jingxi LIU Can LIU Xuemin ZHANG Peng WU Bo

为解决传统调驱剂制备工艺复杂及需要添加有机溶剂的问题，提出基于可逆加成-断裂链转移（RAFT）水 溶液聚合制备调驱用微纳米级聚丙烯酰胺凝胶分散体。首先以硫代乳酸、二硫化碳、α-溴苯乙酸为原料制得水 溶性RAFT链转移剂；再将链转移剂与丙烯酰胺（AM）、交联剂 N，N'-亚甲基双丙烯酰胺（MBA）、引发剂过硫酸 铵反应，在纯水中一步制得聚丙烯酰胺凝胶分散体。表征了凝胶分散体的微观形貌及粒径，研究了反应物配比、 聚合温度、聚合时间及固含量对凝胶分散体性能的影响，考察了凝胶分散体的流变性和黏弹性特征，以及温度响 应性、盐度响应性和pH响应性。结果表明，凝胶分散体为不规则球状结构，分子尺度为微纳米级别，其中微米粒 径为0.92～6.13 μm、纳米粒径为48～87 nm。聚丙烯酰胺凝胶分散体接近牛顿流体特性，其黏弹性表现出黏性 流体特性，进一步证实了凝胶分散体是由微小的凝胶单元颗粒分散在水溶液中形成的。凝胶分散体的黏度随 温度和pH值的升高而降低，但降幅较小，其黏度几乎不受矿化度的影响。与传统调驱剂制备工艺相比，在纯 水相条件下制备凝胶分散体的方法具有时间短、制备条件简化、无需添加有机溶剂和产物分子尺度小的特点。

In order to solve the problems of complicated preparation processes of common profile-controlling and flooding agents and the addition of organic solvents，the micro/nano-polyacrylamide gel dispersions for profile-controlling and flooding were prepared based on reversible addition fragmentation chain transfer（RAFT）aqueous polymerization. First，water-soluble RAFT agent was synthesized using 2-mercaptopropionic acid，carbon disulfide and α-bromophenylacetic acid as raw materials. Then， the polyacrylamide gel dispersions were prepared in pure water by one-step method with RAFT agent，acrylamide，crosslinker N，N'-methylenebisacrylamide bis-acrylamide and initiator （NH4）2S2O8. The morphology and size of gel dispersions were characterized. The effects of reactant ratio，polymerization temperature，polymerization time and solid content on the properties of gel dispersions were investigated. The rheological and viscoelastic properties，temperature，salinity and pH responsiveness of gel dispersions were studied. The results showed that the gel dispersions had irregular globular structure and the molecular scale was micro/nano scale. The micron diameter of gel dispersions was 0.92—6.13 μm and the diameter of nanoparticles was 48—87 nm. The characteristic of polyacrylamide gel dispersions was close to the Newton fluid，and its viscoelasticity exhibited the characteristic of viscous fluid，which further confirmed that gel dispersions were formed by small gel unit particles dispersing in aqueous solution. The viscosity of gel dispersions decreased with the increase of temperature and pH value，but the degree of reduction was small， and their viscosity was almost not affected by mineralization. Compared with traditional preparation technology of profile-controlling and flooding agents，the method of preparing gel dispersions in pure water had the characteristics of short time， simplified preparation condition，without organic solvent and small molecular scale of product.

10.19346/j.cnki.1000-4092.2022.03.007