龙马溪页岩各向异性变形破坏特征及其机理研究  

Anisotropic mechanism and characteristics of deformation and failure of Longmaxi shale

作　　者：何柏[1,2] 谢凌志 李凤霞[3] 赵鹏 张瑶[1,4] HE Bo XIE LingZhi LI FengXia ZHAO Peng ZHANG Yao(Key Laboratory of Energy Engineering Safety and Disaster Mechanics, Sichuan University, Chengdu 610065, China Institute of New Energy and Low-Carbon Technology, Sichuan University, Chengdu 610207, China Sinopec Petroleum Exploration and Production Research Institute, Beijing 100038, China College of Architecture and Environment, Siehuan University, Chengdu 610065, China)

机构地区：[1]四川大学能源工程安全与灾害力学教育部重点实验室,成都610065 [2]四川大学新能源与低碳技术研究院,成都610207 [3]中国石化石油勘探开发研究院,北京100038 [4]四川大学建筑与环境学院,成都610065

出　　处：《中国科学：物理学、力学、天文学》2017年第11期103-114,共12页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：四川省科技支撑计划(编号:2012FZ0124);四川省科技计划项目-应用基础计划(编号:2015JY0280)资助

摘　　要：页岩是由硬物质与软物质相互嵌混沉积成具有复杂薄层状结构的岩石,其页理面内、面外的性质差异明显,具有复杂的变形、破坏机理.通过对川渝地区龙马溪组露头页岩开展室内宏观力学行为研究,系统地分析了页岩体积变形规律,得到了页岩在压缩应力作用下的4个变形阶段,为研究页岩复杂的破坏规律奠定了基础,同时探讨了不同加载方向与页理面法线方向的夹角对页岩强度、脆性、各向异性等的影响.研究结果表明龙马溪组页岩是一种脆性较高、低孔隙度的岩石,具有各向异性特征但并非十分显著.所得研究结果进一步丰富了页岩数据库,为全面认识页岩的室内力学性质提供了支撑,其相关参数也可为储层压裂改造设计提供参考.Although spectacular advances shale in shale gas reservoir stimulation,enough.i.e.,hydraulic fracturing,the deformation contains behavior and failure named mechanism bedding of are its not understood well The basic reason is that shale stratified shale structure plane and the complicated petrophysical significantly properties.different The mechanical behavior of as the loading direction the is parallel plane.to bedding work plane is to from that as the loading direction is perpendicular failure to bedding This is devoted characterization deformation of the are Longmaxi obtained shale and deformation and mechanism through experiments,from which 4 different stages volumetric strain deformation behavior defined is analyzed systematically.between Then the effects of confinement as well as bedding layer on orientation,which is as the and angle the loading are direction and The normal direction of bedding plane,the the elastic modulus,peak strength,constant,cohesion of shale investigated.the analytical results bedding the illustrate layer that volumetric its strain dilatation high is a which is independent is on confining pressure also and that orientation;brittleness is to from（0.55.0.85,B1）and described porosity modulus small than（4.7%.5.2%）.be It is by found anisotropic degree of shale is better be by 60 Young’s MPa,to characterized decreases peak strength.1.16,As the confining pressure increases 0.1 MPa to the rock also anisotropy according provide degree to from 1.36 to which declare that not the Longmaxi shale belongs to low anisotropy the standard introduced by Ismael.These results only enrich these experimental results database of shale,but references laboratory for reservoir hydraulic fracturing design.Moreover,will help us to further understand shale mechanical properties.

关 键 词：页岩 力学 变形 各向异性 

分 类 号：TE31[石油与天然气工程—油气田开发工程]