Wei Peng, Liu Yahan, Dong Zheyong, Lv Bolin, Sun Hui
MOE Key Laboratory of Oil and Gas Fine Chemicals, College of Chemical Engineering and Technology, Xinjiang University, Urumqi 830046, China.
MOE Key Laboratory of Oil and Gas Fine Chemicals, College of Chemical Engineering and Technology, Xinjiang University, Urumqi 830046, China.
Int J Biol Macromol. 2025 May;308(Pt 2):142464. doi: 10.1016/j.ijbiomac.2025.142464. Epub 2025 Mar 23.
The development of hydrogels with water resistance, superb self-healing and mechanical performance that can adapt to the reservoir conditions to plug CO₂ channeling in reservoirs has a significant potential to boost the enhanced oil recovery and CO geo-sequestration. Herein, we present underwater self-healing and highly stretchable nano-cellulose composite hydrogels for plugging in CO flooding via in situ polymerization of acrylonitrile (AN) based solution with carboxyl-grafted nanocellulose (TOCNF) and tannic acid (TA), which exhibited a Young's modulus of 1.1 MPa, a stretchability of 1624 % and a toughness of 13.22 MJ/m. The presence of dipole-dipole interactions between the CN groups of the copolymer chains endowed this gel with excellent underwater repair with 98.9 % self-healing efficiency within 48 h. In the artificial porous media, the PAMN-TA-TOCNF systems (including the in-situ gel and the preformed particle gel) demonstrated remarkable efficacy and renewable plugging performance, which is attributed to their pore-scale remigrating behaviour (i.e., capture, healing-to-trapping, elastic deformation, and frictional migration). This "smart" gel could provide an environment-friendly and remarkably economic (no disposable) alternative to the current state of the CO plugging project in oilfields.
开发具有耐水性、卓越自愈性和机械性能的水凝胶，以适应油藏条件封堵油藏中的二氧化碳窜流，对于提高采收率和二氧化碳地质封存具有巨大潜力。在此，我们通过基于丙烯腈（AN）的溶液与羧基接枝纳米纤维素（TOCNF）和单宁酸（TA）原位聚合，制备了用于二氧化碳驱油封堵的水下自愈且高度可拉伸的纳米纤维素复合水凝胶，其杨氏模量为1.1兆帕，拉伸率为1624%，韧性为13.22兆焦/立方米。共聚物链的氰基之间存在偶极 - 偶极相互作用，使该凝胶在水下具有优异的修复性能，48小时内自愈效率达98.9%。在人工多孔介质中，PAMN - TA - TOCNF体系（包括原位凝胶和预制颗粒凝胶）表现出显著的功效和可再生封堵性能，这归因于它们的孔隙尺度迁移行为（即捕获、愈合到捕获、弹性变形和摩擦迁移）。这种“智能”凝胶可为油田目前的二氧化碳封堵工程提供一种环境友好且经济显著（无需一次性材料）的替代方案。
