• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of natural gas science and engineering >Distribution of methane enrichment zone in abandoned coal mine and methane drainage by surface vertical boreholes: A case study from China
【24h】

Distribution of methane enrichment zone in abandoned coal mine and methane drainage by surface vertical boreholes: A case study from China

机译：废弃煤矿瓦斯富集区分布及地表垂直钻孔排放瓦斯：以中国为例

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

Many abandoned mines with small gobs were produced by the old mining method in China. These gobs with different widths contain a considerable amount of methane. In this paper, FLAC(3D) software is used to investigate the rock mass stress distributions. Based on the stress distribution results, the methane enrichment zones (MEZ) are identified in different gobs with various widths ranging from 30 m to 180 m. The results show that the MEZ of these gobs consistently exhibit a "crab shell" shape, and the range of the MEZ in the roof of each gob is larger than that in the floor. The ranges of the MEZ increase as gob widths grow; however, the gob widths have limited impact on the ranges of the MEZ in coal pillars close to gobs. The ranges of the upper and lower boundaries of the MEZ both increase as gob widths increase, and they decrease as the distance from the middle of gobs increases. The gas can flow freely in the MEZ of gobs, and once the MEZ of a gob is extracted, the methane in the MEZ of adjacent gobs flows into that gob. Based on these results, a method is proposed and first applied to an abandoned coal mine in China by drilling surface vertical boreholes into the upper part of the MEZ of gobs. A low negative pressure of approximately -3 kPa is used for gob methane drainage. The methane in the MEZ where the borehole is located flows rapidly into the borehole at first, with a peak gas flow rate of 6.4 m(3)/min. Then, as the methane in this MEZ is exhausted and the methane in the MEZ of adjacent gobs fails to quickly resupply the first MEZ, the flow rate begins to decline sharply. Finally, the methane from the MEZ of adjacent gobs around the borehole flows slowly through the coal pillars. Thus, the flow rate in the borehole is stabilized at approximately 2.5 m(3)/min. The overall average flow rate reaches 3.5 m(3)/min, and the whole borehole methane extraction period lasts more than 346 days. The methane concentration is generally more than 80% and remains relatively stable. (C) 2016 Elsevier B.V. All rights reserved.
机译：在中国，许多废弃的，带有小料滴的矿山都是通过旧的采矿方法生产的。这些具有不同宽度的料滴包含大量的甲烷。在本文中，FLAC（3D）软件用于研究岩体应力分布。根据应力分布结果，可以在宽度从30 m至180 m的不同采空区中识别出甲烷富集区（MEZ）。结果表明，这些料滴的MEZ始终呈现“蟹壳”形状，并且每个料滴顶部的MEZ范围大于地板的MEZ范围。 MEZ的范围随着料滴宽度的增加而增加;但是，采空区宽度对靠近采空区的煤柱中MEZ范围的影响有限。 MEZ的上下边界的范围都随着料滴宽度的增加而增加，并且随着与料滴中间距离的增加而减小。气体可以在料滴的MEZ中自由流动，一旦提取料滴的MEZ，相邻料滴的MEZ中的甲烷就会流入该料滴。基于这些结果，提出了一种方法，该方法首先通过在采空区MEZ的上部钻出垂直的垂直井孔而应用于中国的一个废弃煤矿。约-3 kPa的低负压用于滴漏甲烷。钻孔所在的MEZ中的甲烷首先迅速流入钻孔，峰值气体流速为6.4 m（3）/ min。然后，由于此MEZ中的甲烷已被耗尽，并且相邻料滴的MEZ中的甲烷无法快速补充第一个MEZ，因此流量开始急剧下降。最后，井筒周围相邻料滴的MEZ中的甲烷缓慢地流过煤柱。因此，钻孔中的流速稳定在大约2.5 m（3）/ min。总体平均流速达到3.5 m（3）/ min，整个钻孔甲烷提取期持续346天以上。甲烷浓度通常超过80％，并保持相对稳定。 （C）2016 Elsevier B.V.保留所有权利。

著录项

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