Horizontal Subzone Characteristics and Methane Seepage Properties of the Gas Flowing Fracture Zone above the Gob

Gas flowing fracture zone (GFFZ) is an active zone in the gob where pressure-relieved methane can move freely. However, there are very few research findings on the horizontal development characteristics and internal methane seepage properties of GFFZs. In this paper, based on the development height...

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Main Authors: Wei Qin, Jialin Xu
Format: Article
Language:English
Published: Wiley 2018-01-01
Series:Advances in Civil Engineering
Online Access:http://dx.doi.org/10.1155/2018/9071578
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author Wei Qin
Jialin Xu
author_facet Wei Qin
Jialin Xu
author_sort Wei Qin
collection DOAJ
description Gas flowing fracture zone (GFFZ) is an active zone in the gob where pressure-relieved methane can move freely. However, there are very few research findings on the horizontal development characteristics and internal methane seepage properties of GFFZs. In this paper, based on the development height of a GFFZ above the gob, the GFFZ was horizontally divided into the following: a lateral fracture subzone, an O-ring fracture subzone, and a compacted subzone. The identification criteria for all of these horizontal subzones were given by analyzing the influence of the stress in the coal rock mass on the development of mining-induced fractures. A numerical simulation study was conducted to determine the influences of the mining height and mining depth on the morphological development of all horizontal subzones of the GFFZ, and the simulation results showed that the mining height was the main factor influencing the development characteristics of horizontal subzones of the GFFZ. Both the maximum distance of the lateral fracture subzone beyond the mining boundary and the width of the O-ring fracture subzone increased with the increase of mining height. A physical simulation experiment was performed for extraction of gob methane through a surface borehole, and the experimental results showed that the gas flow state was laminar within the range of the lateral fracture subzone and the compacted subzone but that the gas flow state was turbulent, not following Darcy’s law, within the range of the O-ring fracture subzone.
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spelling doaj-art-4dc03e4752d743558f3c997bbaaee2da2025-08-20T03:36:22ZengWileyAdvances in Civil Engineering1687-80861687-80942018-01-01201810.1155/2018/90715789071578Horizontal Subzone Characteristics and Methane Seepage Properties of the Gas Flowing Fracture Zone above the GobWei Qin0Jialin Xu1State Key Laboratory of Coal Resources and Mine Safety, School of Mines, China University of Mining and Technology, Xuzhou, Jiangsu 221116, ChinaState Key Laboratory of Coal Resources and Mine Safety, School of Mines, China University of Mining and Technology, Xuzhou, Jiangsu 221116, ChinaGas flowing fracture zone (GFFZ) is an active zone in the gob where pressure-relieved methane can move freely. However, there are very few research findings on the horizontal development characteristics and internal methane seepage properties of GFFZs. In this paper, based on the development height of a GFFZ above the gob, the GFFZ was horizontally divided into the following: a lateral fracture subzone, an O-ring fracture subzone, and a compacted subzone. The identification criteria for all of these horizontal subzones were given by analyzing the influence of the stress in the coal rock mass on the development of mining-induced fractures. A numerical simulation study was conducted to determine the influences of the mining height and mining depth on the morphological development of all horizontal subzones of the GFFZ, and the simulation results showed that the mining height was the main factor influencing the development characteristics of horizontal subzones of the GFFZ. Both the maximum distance of the lateral fracture subzone beyond the mining boundary and the width of the O-ring fracture subzone increased with the increase of mining height. A physical simulation experiment was performed for extraction of gob methane through a surface borehole, and the experimental results showed that the gas flow state was laminar within the range of the lateral fracture subzone and the compacted subzone but that the gas flow state was turbulent, not following Darcy’s law, within the range of the O-ring fracture subzone.http://dx.doi.org/10.1155/2018/9071578
spellingShingle Wei Qin
Jialin Xu
Horizontal Subzone Characteristics and Methane Seepage Properties of the Gas Flowing Fracture Zone above the Gob
Advances in Civil Engineering
title Horizontal Subzone Characteristics and Methane Seepage Properties of the Gas Flowing Fracture Zone above the Gob
title_full Horizontal Subzone Characteristics and Methane Seepage Properties of the Gas Flowing Fracture Zone above the Gob
title_fullStr Horizontal Subzone Characteristics and Methane Seepage Properties of the Gas Flowing Fracture Zone above the Gob
title_full_unstemmed Horizontal Subzone Characteristics and Methane Seepage Properties of the Gas Flowing Fracture Zone above the Gob
title_short Horizontal Subzone Characteristics and Methane Seepage Properties of the Gas Flowing Fracture Zone above the Gob
title_sort horizontal subzone characteristics and methane seepage properties of the gas flowing fracture zone above the gob
url http://dx.doi.org/10.1155/2018/9071578
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