Wu Huimei, Lou Yishan, Zhai Xiaopeng, Li Zhonghui, Liu Bin
National Engineering Research Center for Oil & Gas Drilling and Completion Technology, Yangtze University, Wuhan 430100, China.
Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering, Yangtze University, Wuhan 430100, China.
ACS Omega. 2023 Sep 11;8(38):35066-35076. doi: 10.1021/acsomega.3c04466. eCollection 2023 Sep 26.
In this study, we present an innovative intelligent polymer sealant designed to mitigate CO leakage during underground geological storage (CCUS). This sealant is formulated by cross-linking CO-responsive polymers, specifically acrylamide (AM) and N-[3-(dimethylamino) propyl] methacrylamide (DMAPMA), with polyethylenimine (PEI) serving as the cross-linking agent. The polymer sealant's characteristics were systematically investigated, varying the CO-responsive polymer content (1.5 wt %) and PEI content (0.1-0.6 wt %). A comprehensive analysis encompassing the rheological properties, thermal behavior, conductivity, and microstructures was conducted. Experimental results indicate that the polymer sealant exhibits excellent injectability, rapid response kinetics, thermal stability, and robust mechanical strength. Upon encountering CO, the polymer system undergoes a transition from sol to gel state, forming a surface-smooth, uniformly porous three-dimensional (3D) network skeleton structure. Remarkably, the gel's modulus remains relatively unaffected by the shear frequency. Core fluid displacement experiments demonstrated a substantial sealing efficiency of 73.6% for CO and an impressive subsequent injection water sealing rate of 96.2%, underscoring its superior sealing and migration performance. In conclusion, the proposed CO-responsive gel sealant exhibits an exceptional potential for successful utilization in CCUS operations. This advancement introduces a novel avenue to enhance the effectiveness of CO-responsive gel sealants, thereby contributing to the advancement of CO leakage mitigation strategies in geological storage scenarios.
在本研究中，我们提出了一种创新的智能聚合物密封剂，旨在减轻地下地质封存（CCUS）过程中的二氧化碳泄漏。这种密封剂是通过将二氧化碳响应性聚合物，特别是丙烯酰胺（AM）和N-[3-(二甲氨基)丙基]甲基丙烯酰胺（DMAPMA）交联而成，聚乙烯亚胺（PEI）作为交联剂。系统地研究了聚合物密封剂的特性，改变了二氧化碳响应性聚合物含量（1.5 wt%）和PEI含量（0.1 - 0.6 wt%）。进行了包括流变学性质、热行为、导电性和微观结构的综合分析。实验结果表明，该聚合物密封剂具有优异的可注射性、快速响应动力学、热稳定性和强大的机械强度。遇到二氧化碳时，聚合物体系从溶胶态转变为凝胶态，形成表面光滑、均匀多孔的三维（3D）网络骨架结构。值得注意的是，凝胶的模量相对不受剪切频率的影响。岩心流体驱替实验表明，二氧化碳密封效率高达73.6%，随后注水密封率高达令人印象深刻的96.2%，突出了其卓越的密封和迁移性能。总之所提出的二氧化碳响应性凝胶密封剂在CCUS操作中成功应用具有巨大潜力。这一进展为提高二氧化碳响应性凝胶密封剂的有效性开辟了一条新途径，从而有助于推进地质封存场景中二氧化碳泄漏缓解策略。
