耐温抗盐型水凝胶的设计合成及功能强化机制研究

Design,Synthesis and Functional Enhancement Mechanism of Heat-resistant and Salt-resistant Hydrogel

为克服目前3次采油中水凝胶耐温抗盐性能差、机械强度低等问题,以丙烯酰胺(AM)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)为聚合单体,通过水溶液聚合法合成水凝胶PBZD-1,基于单因素实验确定最佳制备工艺,并辅以常规改性和纳米改性两种实验方法进行功能强化改性,制备深度调剖用水凝胶PBZD-1-C和PBZD-1-M。采用FTIR、XRD、TG等表征水凝胶的化学结构、热稳定性等,进一步探究其吸水、耐温和抗盐等性能,并结合宏观性能和微观结构揭示其功能强化机制。结果显示:PBZD-1-C和PBZD-1-M的化学结构符合预期设计,热稳定性良好,350℃失重约20%,且具有良好的耐温抗盐性能,吸水倍率分别为198和249,可有效抵抗70000 mg/L Na+、10000 mg/L Ca^(2+)和Mg^(2+)矿化度水;纳米二氧化硅、超细碳酸钙等材料主要通过自身三元刚性环状结构、成核剂及反应中心等赋予水凝胶优异的应用性能,使水凝胶的吸水、耐温和抗盐性能大幅提升。

In order to overcome the problems of poor temperature,salt resistance and low mechanical strength of smart hydrogel in tertiary oil recovery.The smart hydrogel was prepared by aqueous solution polymerization with acrylamide(AM)and 2-acrylamide-2-methylpropanesulfonic acid(AMPS)as polymerization monomers.Based on the single factor experimental method,the optimal preparation process was firstly determined.Moreover,the functional strengthening modification was passed by two methods,namely,conventional modification and nano modification,and the deep profile control of smart hydrogel PBZD-1-C and PBZD-1-M was prepared.Firstly,the chemical structure and thermal stability of the smart hydrogel were characterized by FTIR,XRD and TG.Then,the water absorption,temperature resistance and salt resistance of the smart hydrogel were further explored,and the function strengthening mechanism was revealed combined with the macro properties and microstructure.As a result,the chemical structures of PBZD-1-C and PBZD-1-M meet the expected design,with good thermal stability,weight loss of about 20%at 350℃,good temperature and salt resistance,water absorption of 198 and 249 respectively,and effective resistance to 70000 mg/L Na+and 10000 mg/L Ca^(2+) and Mg^(2+) mineralized water.Additionally,the results of function strengthening mechanism show that nano silica,ultra-fine calcium carbonate endows the PBZD-1-C and PBZD-1-M with excellent application performance mainly through its own ternary rigid ring structure,nucleating agent and reaction center.