工程科学学报.第43卷,第7期:903-914.2021年7月 Chinese Journal of Engineering,Vol.43,No.7:903-914,July 2021 https://doi.org/10.13374/j.issn2095-9389.2020.05.27.005;http://cje.ustb.edu.cn 复杂应力路径下裂隙泥岩渗透演化规律试验研究 张 玉1,2)四,于婷婷),张通》,刘书言”,周家文) 1)中国石油大学(华东)储运与建筑工程学院.青岛2665802)四川大学深地科学与工程教育部重点实验室,成都6100653)安徽理工大 学深部煤矿采动响应与灾害防控国家重点实验室,淮南232001 ☒通信作者,Email:zhangyu@upc.edu.cn 摘要油气主要储集在岩石孔隙和缝洞内,深部复杂应力环境下储层岩石裂隙渗透演化直接影响油气的运移规律,是油气 勘探开发的重要研究对象.为了解复杂应力路径下含裂隙岩石的渗透演化特性,利用高精度渗流-应力耦合三轴实验设备, 对含随机分布裂隙泥岩开展了单试样-复杂应力路径加卸载过程中的渗透性演化试验研究,试验方案依次为:(①围压递增条 件下渗透性测试:()渗透压力递增条件下渗透性测试:(而偏应力循环加卸载条件下渗透性测试:()围压、偏应力同步增长 条件下渗透性测试.结果表明裂隙泥岩中的渗流可视为低渗流速度的层流;裂隙发育丰富岩样(2)渗透率及应力敏感性明 显较高.渗透率随渗透压力、围压分别呈正、负的指数函数变化.偏应力加载导致渗透率降低,卸载引起渗透率上升,但整体 呈不可逆降低;围压、偏应力同步增长引起渗透率呈下降趋势,并逐步趋于稳定:围压10.3MP作用下,渗透率基本保持恒 定.由此,基于裂隙双重介质模型,考虑泥岩变形过程中裂隙系统和基质系统的相互作用以及外部应力作用下的裂隙膨胀变 形,构建了裂隙泥岩渗透率演化力学模型:模型模拟结果与试验结果具有较好的一致性.相关成果可为裂隙泥岩渗透性演化 预测和油气高效开采提供重要的理论依据 关键词岩石力学:复杂应力路径:裂隙泥岩:渗透性试验:渗透性演化:渗透率演化力学模型 分类号TU458+ Experimental study of the permeability evolution of fractured mudstone under complex stress paths ZHANG Yu2),YU Ting-ting,ZHANG Tong,LIU Shu-yan,ZHOU Jia-wen 1)College of Pipeline and Civil Engineering.China University of Petroleum(East China),Qingdao 266580,China 2)Key Laboratory of Deep Earth Science and Engineering(Sichuan University),Ministry of Education,Chengdu 610065,China 3)State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines,Anhui University of Science and Technology, Huainan 232001,China Corresponding author,E-mail:zhangyu@upc.edu.cn ABSTRACT The main reservoirs of oil and gas are in the pores and fractures of rocks.Under deep and complex stress environments, reservoir rock fracture permeability evolution directly affects the flow of oil and gas,which is an important research object of oil and gas exploration and development.In order to study the permeability evolution of fractured rock under complex stress paths,a permeability test of a single sample in the process of loading and unloading complex stress paths was performed using high-precision hydro- mechanics coupled with triaxial experimental equipment.The experimental scheme entails permeability tests under (i)increasing confining pressure;(ii)increasing liquid pressure;(iii)cyclic loading and unloading deviatoric stress;and (iv)increasing confining pressure and deviatoric stress synchronously.The results show that liquid flow in fractured mudstone can be regarded as laminar flow 收稿日期:2020-05-27 基金项目:国家自然科学基金资助项目(51890914):山东省自然科学基金资助项目(ZR2019MEE001):深地科学与工程教育部重点实验室 (四川大学)开放基金资助项目(DESE201903)复杂应力路径下裂隙泥岩渗透演化规律试验研究 张 玉1,2) 苣,于婷婷1),张 通3),刘书言1),周家文2) 1) 中国石油大学 (华东) 储运与建筑工程学院,青岛 266580 2) 四川大学深地科学与工程教育部重点实验室,成都 610065 3) 安徽理工大 学深部煤矿采动响应与灾害防控国家重点实验室,淮南 232001 苣通信作者,Email:zhangyu@upc.edu.cn 摘 要 油气主要储集在岩石孔隙和缝洞内,深部复杂应力环境下储层岩石裂隙渗透演化直接影响油气的运移规律,是油气 勘探开发的重要研究对象. 为了解复杂应力路径下含裂隙岩石的渗透演化特性,利用高精度渗流−应力耦合三轴实验设备, 对含随机分布裂隙泥岩开展了单试样−复杂应力路径加卸载过程中的渗透性演化试验研究,试验方案依次为:(i) 围压递增条 件下渗透性测试;(ii) 渗透压力递增条件下渗透性测试;(iii) 偏应力循环加卸载条件下渗透性测试;(iv) 围压、偏应力同步增长 条件下渗透性测试. 结果表明裂隙泥岩中的渗流可视为低渗流速度的层流;裂隙发育丰富岩样(R2)渗透率及应力敏感性明 显较高. 渗透率随渗透压力、围压分别呈正、负的指数函数变化. 偏应力加载导致渗透率降低,卸载引起渗透率上升,但整体 呈不可逆降低;围压、偏应力同步增长引起渗透率呈下降趋势,并逐步趋于稳定;围压 10.3 MPa 作用下,渗透率基本保持恒 定. 由此,基于裂隙双重介质模型,考虑泥岩变形过程中裂隙系统和基质系统的相互作用以及外部应力作用下的裂隙膨胀变 形,构建了裂隙泥岩渗透率演化力学模型;模型模拟结果与试验结果具有较好的一致性. 相关成果可为裂隙泥岩渗透性演化 预测和油气高效开采提供重要的理论依据. 关键词 岩石力学;复杂应力路径;裂隙泥岩;渗透性试验;渗透性演化;渗透率演化力学模型 分类号 TU458+ Experimental study of the permeability evolution of fractured mudstone under complex stress paths ZHANG Yu1,2) 苣 ,YU Ting-ting1) ,ZHANG Tong3) ,LIU Shu-yan1) ,ZHOU Jia-wen2) 1) College of Pipeline and Civil Engineering, China University of Petroleum (East China), Qingdao 266580, China 2) Key Laboratory of Deep Earth Science and Engineering (Sichuan University), Ministry of Education, Chengdu 610065, China 3) State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines, Anhui University of Science and Technology, Huainan 232001, China 苣 Corresponding author, E-mail: zhangyu@upc.edu.cn ABSTRACT The main reservoirs of oil and gas are in the pores and fractures of rocks. Under deep and complex stress environments, reservoir rock fracture permeability evolution directly affects the flow of oil and gas, which is an important research object of oil and gas exploration and development. In order to study the permeability evolution of fractured rock under complex stress paths, a permeability test of a single sample in the process of loading and unloading complex stress paths was performed using high-precision hydromechanics coupled with triaxial experimental equipment. The experimental scheme entails permeability tests under (i) increasing confining pressure; (ii) increasing liquid pressure; (iii) cyclic loading and unloading deviatoric stress; and (iv) increasing confining pressure and deviatoric stress synchronously. The results show that liquid flow in fractured mudstone can be regarded as laminar flow 收稿日期: 2020−05−27 基金项目: 国家自然科学基金资助项目(51890914);山东省自然科学基金资助项目(ZR2019MEE001);深地科学与工程教育部重点实验室 (四川大学)开放基金资助项目(DESE201903) 工程科学学报,第 43 卷,第 7 期:903−914,2021 年 7 月 Chinese Journal of Engineering, Vol. 43, No. 7: 903−914, July 2021 https://doi.org/10.13374/j.issn2095-9389.2020.05.27.005; http://cje.ustb.edu.cn