• 论文
主办单位:煤炭科学研究总院有限公司、中国煤炭学会学术期刊工作委员会
不同围压下页岩三轴压缩声发射能量分布特性研究
  • Title

    Study on distribution characteristics of shale triaxial compression acoustic emission energy under different confining pressures

  • 作者

    韩兵杨宏伟

  • Author

    HAN Bing,YANG Hongwei

  • 单位

    煤科集团沈阳研究院有限公司煤矿安全技术国家重点实验室

  • Organization
    1.Shenyang Research Institute,China Coal Technology and Engineering Group,Shenyang ,China;2.State Key Laboratory of Coal Mine Safety Technology,Fushun ,China
  • 摘要

    低压、低孔及低渗一直制约着页岩气的开发,随着水力压裂技术在页岩气开采工艺中的广泛应用,使得应力状态下页岩的变形破坏机制的研究具有重要意义。为揭示页岩破坏过程中的演化机理,笔者以重庆地区罗惹坪组页岩为研究对象,在不同围压条件下对采集的岩石样本进行常规三轴压缩声发射试验,记录岩石变形破坏过程的力学参数及声发射数据,利用临界模型定量分析页岩的声发射能量统计分布规律,确定临界特性及临界幂律分布规律,采用最大似然估计法确定幂率分布指数。试验结果表明:页岩在三轴压缩破坏过程中可分为平静阶段、破坏阶段、峰后阶段和稳定阶段;在不同围压条件下页岩声发射能量概率密度遵循幂率无尺度分布规律,3种围压条件下,临界指数分别为1.34、1.40和1.55;临界指数随着围压的升高而增大,围压的存在限制了岩石内部裂隙的产生,降低了岩石内部的“混乱度”,减弱了岩石内部结构的劣化。

  • Abstract
    The development of shale gas has always been restricted by low pressure, low porosity and low permeability. With the wide application of hydraulic fracturing technology in shale gas mining, the study of deformation and failure mechanism of shale under stress state is of great significance. In order to reveal the evolution mechanism of shale failure process, the author took the Luoreping Formation shale in Chongqing City as the research object, and carried out the conventional triaxial compression acoustic emission test on the rock samples collected under different confining pressure conditions, with the aim of recording the mechanical parameters and acoustic emission data about rock deformation and failure process. The critical model was used to quantitatively analyze the statistical distribution of acoustic emission energy of shale, and determine the critical characteristics and the critical power law distribution, and the maximum likelihood estimation method was used to determine the Power Rate Distribution Index. The test results show that the failure process of shale under triaxial compression can be divided into the calm stage, the failure stage, the post-peak stage and the stable stage; the probability density of acoustic emission energy of shale under different confining pressure follows the distribution law of non-scale power law and the critical exponents under three confining pressures are 1.34, 1.40 and 1.55 respectively; the critical components increase as the confining pressure increases; the existence of confining pressure limits the generation of cracks inside the rock, and reduces the "degree of chaos" inside the rock and weakening the deterioration of internal rock structure.
  • 关键词

    声发射围压压缩试验能量分布临界特性临界指数

  • KeyWords

    acoustic emission; confining pressure; compression tests; energy distribution; critical characteristics; critical components

  • 图表
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主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会

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