• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Energy >Experimental study on gas diffusion dynamics in fractured coal: A better understanding of gas migration in in-situ coal seam
【24h】

Experimental study on gas diffusion dynamics in fractured coal: A better understanding of gas migration in in-situ coal seam

机译：裂隙煤中瓦斯扩散动力学的实验研究：对原位煤层瓦斯运移的更好理解

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In-situ coal seam is generally under the stress constraint condition. However, the powder coal is often adopted to study gas diffusion dynamics in the laboratory, in this case, the stress cannot be imposed on the coal sample. So the question is, can the laboratory test results with the powder coal reflect the gas diffusion behaviors in the in-situ coal seam? Does the confining stress affect the gas diffusion behaviors in fractured coal? To address these questions, in this work, we first investigated the effect of coal size on gas diffusion dynamics with powder coal and lump coal under unconstrained conditions. The results show that there exists an obvious scale effect for gas diffusion in coal, and a critical value of coal size has been found for the scale effect. When the coal particle size is smaller than the critical value, the effective diffusivity decreases with an increase of the particle size; and when the particle size is larger than the critical value, no obvious change can be found in the effective diffusivity. The critical value for gas diffusion corresponds to the size of the coal matrix. The essential reason for the existence of the scale effect is the differences among the pore structures of coals with various sizes. Based on the research results under the unconstrained conditions, a coal core was selected to study the effect of confining stress and pore pressure on gas diffusion under constraint condition. The results indicated that the confining stress and pore pressure have significant impact on gas diffusion in fractured coal. With an increase of the confining stress and a decrease of the pore pressure, the effective diffusivity reduces gradually. Therefore, to get an accurate understanding of the gas diffusion behavior in in-situ coal seam, during the test in the lab, both the scale effect and confining stress should be considered. The research results obtained in this work have important guiding significance to reveal gas migration in in-situ coal seams during CBM depletion, CO_2-ECBM and geological sequestration of CO_2.
机译：地层煤层通常处于应力约束条件下。但是，粉煤通常在实验室中用于研究气体扩散动力学，在这种情况下，不能对煤样品施加压力。因此问题是，粉煤的实验室测试结果能否反映出原位煤层中的瓦斯扩散行为？围压是否会影响压裂煤中的瓦斯扩散行为？为了解决这些问题，在这项工作中，我们首先研究了在不受约束的条件下，煤粉大小对粉煤和块煤的气体扩散动力学的影响。结果表明，煤中瓦斯扩散存在明​​显的尺度效应，煤尺度的临界值已经达到临界值。当煤的粒径小于临界值时，有效扩散系数随粒径的增加而降低;当粒径大于临界值时，有效扩散率没有明显变化。气体扩散的临界值对应于煤基质的大小。产生尺度效应的根本原因是各种尺寸煤孔结构之间的差异。基于无约束条件下的研究结果，选择了一个煤芯来研究约束条件下的围压和孔隙压力对气体扩散的影响。结果表明，围压和孔隙压力对压裂煤中的瓦斯扩散影响显着。随着围压的增加和孔隙压力的减小，有效扩散率逐渐减小。因此，为了准确了解原位煤层中的瓦斯扩散行为，在实验室测试期间，应同时考虑结垢效应和围压。这项工作获得的研究结果对于揭示煤层气耗竭，CO_2-ECBM和CO_2的地质隔离过程中原煤层中的瓦斯迁移具有重要的指导意义。

著录项

  • 来源
    《Energy》 |2020年第15期|117005.1-117005.10|共10页
  • 作者

    Ting Liu; Baiquan Lin; Xuehai Fu; Yabin Gao; Jia Kong; Yang Zhao; Haoran Song;

  • 作者单位

    School of Safety Engineering China University of Mining and Technology Xuzhou 221116 China Key Laboratory of CBM Resources and Dynamic Accumulation Process China University of Mining and Technology Ministry of Education Xuzhou Jiangsu province 221008 China;

    School of Safety Engineering China University of Mining and Technology Xuzhou 221116 China;

    Key Laboratory of CBM Resources and Dynamic Accumulation Process China University of Mining and Technology Ministry of Education Xuzhou Jiangsu province 221008 China;

    College of Safety and Emergency Management Engineering Taiyuan University of Technology Taiyuan Shanxi 030024 China;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Gas diffusion; Scale effect; Granular coal; Fractured coal core; In-situ coal seam;

    机译：气体扩散;规模效应;粒状煤;煤芯破裂;现场煤层;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号