非均质孔隙介质中循环驱替对两相渗流及毛细捕获的影响  

Effect of cyclic injection on two-phase flow and capillary trapping in disordered porous media

作　　者：邓汉鑫 武东生[1,2] 王晓光 王东坡 DENG Han-xin;WU Dong-sheng;WANG Xiao-guang;WANG Dong-po(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Tianfu Yongxing Laboratory,Chengdu,Sichuan 610213,China;College of Energy,Chengdu University of Technology,Chengdu,Sichuan 610059,China)

机构地区：[1]成都理工大学地质灾害防治与地质环境保护国家实验室,四川成都610059 [2]天府永兴实验室,四川成都610213 [3]成都理工大学能源学院,四川成都610059

出　　处：《岩土力学》2025年第2期505-514,共10页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.52009048);四川省科技计划(No.2023NSFSC0293,No.2023ZYD0159);广东省基础与应用基础研究基金(No.2019A1515110990,No.2022A1515011144)。

摘　　要：孔隙介质中的两相渗流和毛细捕获是深部咸水层中二氧化碳(CO_(2))封存的重要过程和关键机制。尽管已有研究对两相流驱替模式及其判据进行了深入探讨,但循环驱替过程中两相渗流特性和毛细捕获机制的研究仍相对不足。通过孔隙尺度的水-油两相循环驱替可视化试验研究,分析了孔隙非均质性和循环驱替次数对两相渗流特性及毛细捕获效率的影响。试验结果显示,循环驱替破坏了非润湿相的连续性,使其分解为难以重新活化的孤立“液滴”,经过4次循环驱替后,毛细捕获效率最高可达40%。随着孔隙介质非均质性的增加,通过绕流机制大量捕获非润湿相,非均质孔隙结构中毛细捕获效率相比均质介质提高了32.5%。试验结果还揭示了循环驱替过程中4种典型的毛细捕获液滴类型:附着型、桥接型、团状型和簇状型液滴,其中,附着型液滴的数量占比最高,但其捕获体积较小,而簇状型液滴对毛细捕获效率贡献最大。该研究结果加深了对循环注入过程中毛细捕获机制的理解,并为提高深部咸水层CO_(2)地质封存的效率提供了理论支持和实践依据。Two-phase flow and capillary trapping are crucial processes and key mechanisms in geological CO_(2) storage within deep saline aquifers.Previous studies have extensively investigated the injection pattern and theoretical model in porous media,but research on two-phase flow characteristics and capillary trapping mechanism during cyclic injection is relatively limited.Through pore-scale water-oil two-phase cyclic injection visualization experiments,we investigated the effects of pore-scale disorder and cycle numbers on two-phase flow and capillary trapping characteristics.The experimental results show that cyclic injection disrupts the continuity of the non-wetting phase,breaking it into isolated“droplets”that are difficult to remobilize.After four cyclic injections,capillary trapping efficiency can reach up to 40%.As pore-scale disorder increases,the bypass mechanism significantly traps the non-wetting phase,with the capillary trapping efficiency in disordered porous media increasing by 32.5% compared to the homogeneous case.The experiments also reveal four typical types of capillary-trapped droplets during cyclic injection:bubble droplets,bridge droplets,ganglia droplets,and cluster droplets.Bubble droplets are the most numerous but contribute the least to trapping efficiency,whereas cluster droplets contribute the most.Our findings enhance the understanding of capillary trapping mechanisms during cyclic injection and provide theoretical support and practical insights for optimizing CO_(2) storage efficiency in deep saline aquifers.

关 键 词：非均质孔隙介质 两相渗流 循环驱替 毛细捕获 微流控试验 

分 类 号：TV139[水利工程—水力学及河流动力学]