页岩破坏过程的声发射特性实验及数值模拟研究
发布时间：2018-08-15 17:52
【摘要】：页岩气为非常规油气资源,开发页岩气对于缓解能源危机意义深远。页岩的力学特性及破坏规律是影响页岩气开采全局的关键因素。通过监测页岩破坏过程的声发射特性,可以推断页岩裂纹的发展过程。本文通过UTM5000微机控制电子万能试验机和PCI-2声发射系统对江西省赣北地区的页岩进行单轴压缩试验,获得了不同地域和不同层理方向的页岩力学特性和声发射特性,并利用单参数和参数关联分析法对不同地域和不同层理方向的页岩在单轴压缩下的力学特性和声发射特性之间差异进行了分析;研究了页岩在渐进加卸载试验下的声发射特性;采用真实破坏过程模拟软件RFPA2D对页岩单轴压缩破坏过程及其声发射特性和渐进加卸载条件下的页岩kaiser效应进行了数值模拟。研究结果表明:不同地域的页岩在单轴压缩下的力学特性和声发射特性具有明显的差异;页岩的抗压强度越小,破坏过程声发射活动越强,声发射累计计数越大;页岩层理方向对单轴压缩抗压强度和声发射特性有显著影响;0o层理方向抗压强度最高,90o层理方向其次,45o层理方向抗压强度最低;90o层理方向在整个变形破坏过程中AE振铃累计计数和能量累计数最大,AE计数率和能率也最大,AE活动水平最强,45o层理方向页岩的AE振铃累计计数和能量累计数最小,计数率和能率也最小,AE活动水平最弱;通过渐进加卸载试验得到的应力-时间-声发射能率图验证了页岩的凯瑟效应存在;通过RFPA2D软件数值模拟动态显示了页岩材料变形破裂的整个过程,其声发射图形象地表征了试样裂纹的位置和扩展过程;采用渐进加卸载方法进行数值模拟,验证了页岩具有明显的Kaiser效应。
[Abstract]:Shale gas is an unconventional oil and gas resource, and the development of shale gas is of great significance in alleviating the energy crisis. The mechanical properties and failure law of shale are the key factors affecting the overall situation of shale gas production. The development process of shale cracks can be inferred by monitoring the acoustic emission characteristics of shale failure process. In this paper, UTM5000 microcomputer controlled electronic universal testing machine and PCI-2 acoustic emission system are used to carry out uniaxial compression tests on shale in the north of Jiangxi Province. The mechanical and acoustic emission characteristics of shale in different regions and different bedding directions are obtained. The differences between the mechanical and acoustic emission characteristics of shale in different regions and different bedding directions under uniaxial compression were analyzed by single parameter and parameter correlation analysis, and the acoustic emission characteristics of shale under progressive loading and unloading tests were studied. The real failure process simulation software RFPA2D was used to simulate the uniaxial compression failure process of shale and its acoustic emission characteristics and the shale kaiser effect under progressive loading and unloading conditions. The results show that there are obvious differences in mechanical and acoustic emission characteristics of shale under uniaxial compression in different regions, the smaller the compressive strength of shale is, the stronger the AE activity is during the destruction process, and the larger the cumulative number of AE is. Shale bedding direction has significant influence on uniaxial compression compressive strength and acoustic emission characteristics. The highest compressive strength in the 0 o bedding direction is the highest in 90 o bedding direction, and the lowest compressive strength is in the 45 o bedding direction. During the whole deformation and failure process, the compressive strength is the lowest. AE ringing accumulative count and energy accumulative count the maximum AE counting rate and energy rate are also the largest. The AE ringing accumulative count and energy accumulative count are the smallest in the shale in the direction of 45o bedding direction. The counting rate and energy rate are also the smallest and the activity level of AE is the weakest, and the stress-time-acoustic emission energy ratio diagram obtained from the progressive loading and unloading tests verifies the existence of the Cather effect in shale. The whole process of shale-material deformation and fracture is shown by numerical simulation of RFPA2D software, and its acoustic emission diagram vividly characterizes the crack location and propagation process of the sample, and the incremental loading and unloading method is used to carry out the numerical simulation. It is proved that shale has obvious Kaiser effect.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE21
本文编号：2184963
[Abstract]:Shale gas is an unconventional oil and gas resource, and the development of shale gas is of great significance in alleviating the energy crisis. The mechanical properties and failure law of shale are the key factors affecting the overall situation of shale gas production. The development process of shale cracks can be inferred by monitoring the acoustic emission characteristics of shale failure process. In this paper, UTM5000 microcomputer controlled electronic universal testing machine and PCI-2 acoustic emission system are used to carry out uniaxial compression tests on shale in the north of Jiangxi Province. The mechanical and acoustic emission characteristics of shale in different regions and different bedding directions are obtained. The differences between the mechanical and acoustic emission characteristics of shale in different regions and different bedding directions under uniaxial compression were analyzed by single parameter and parameter correlation analysis, and the acoustic emission characteristics of shale under progressive loading and unloading tests were studied. The real failure process simulation software RFPA2D was used to simulate the uniaxial compression failure process of shale and its acoustic emission characteristics and the shale kaiser effect under progressive loading and unloading conditions. The results show that there are obvious differences in mechanical and acoustic emission characteristics of shale under uniaxial compression in different regions, the smaller the compressive strength of shale is, the stronger the AE activity is during the destruction process, and the larger the cumulative number of AE is. Shale bedding direction has significant influence on uniaxial compression compressive strength and acoustic emission characteristics. The highest compressive strength in the 0 o bedding direction is the highest in 90 o bedding direction, and the lowest compressive strength is in the 45 o bedding direction. During the whole deformation and failure process, the compressive strength is the lowest. AE ringing accumulative count and energy accumulative count the maximum AE counting rate and energy rate are also the largest. The AE ringing accumulative count and energy accumulative count are the smallest in the shale in the direction of 45o bedding direction. The counting rate and energy rate are also the smallest and the activity level of AE is the weakest, and the stress-time-acoustic emission energy ratio diagram obtained from the progressive loading and unloading tests verifies the existence of the Cather effect in shale. The whole process of shale-material deformation and fracture is shown by numerical simulation of RFPA2D software, and its acoustic emission diagram vividly characterizes the crack location and propagation process of the sample, and the incremental loading and unloading method is used to carry out the numerical simulation. It is proved that shale has obvious Kaiser effect.
【学位授予单位】：南昌大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE21
【参考文献】
相关期刊论文 前1条
1 李庆辉;陈勉;金衍;;含气页岩破坏模式及力学特性的试验研究[J];岩石力学与工程学报;2012年S2期
，本文编号：2184963
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