Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal Seams

Slicing fully mechanized caving mining is a standard high-efficiency mining method for ultrathick coal seams. However, the effectiveness of gas control has accentuated the difficulty in fully mechanized top coal caving of low-permeability ultrathick coal seams. This study focused on mining the No. 9...

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Main Authors: Bangyou Jiang, Shitan Gu, Wenshuai Li, Guangchao Zhang, Jihua Zhang
Format: Article
Language:English
Published: Wiley 2021-01-01
Series:Geofluids
Online Access:http://dx.doi.org/10.1155/2021/5558678
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author Bangyou Jiang
Shitan Gu
Wenshuai Li
Guangchao Zhang
Jihua Zhang
author_facet Bangyou Jiang
Shitan Gu
Wenshuai Li
Guangchao Zhang
Jihua Zhang
author_sort Bangyou Jiang
collection DOAJ
description Slicing fully mechanized caving mining is a standard high-efficiency mining method for ultrathick coal seams. However, the effectiveness of gas control has accentuated the difficulty in fully mechanized top coal caving of low-permeability ultrathick coal seams. This study focused on mining the No. 9-15 coal in Liuhuanggou Coal Mine, Xinjiang Province, China. To this aim, the results of theoretical analyses and field tests were combined to explore a comprehensive gas control method for fully mechanized caving of low-permeability ultrathick coal seams. The No. (9-15)06 panel was a top-slicing panel of the No. 9-15 coal with a mining height of 9 m. Gas analysis results revealed that gas emissions in the No. (9-15)06 panel are mainly sourced from the coal wall, caving top coal, goaf, and neighboring coal seams. Based on gas source separation, a comprehensive gas control method was proposed. The proposed method was based on the combination of gas predrainage alongside the coal seam, high-position drilling on the top, preburial of pipes in the goaf, and pressure-balancing ventilation. The permeability and gas predrainage were enhanced by hydraulic fracturing in low-permeability coal seams. According to the characterizations of coal seam and crustal stress distribution, the arrangement of the boreholes and backward-segmented fracturing technology were designed. From the field results, the coal seam presented a remarkable prefracturing under hydraulic fracturing. Besides, the mean gas predrainage from the boreholes was enhanced by four times compared to the prehydraulic fracturing state. Finally, using the proposed comprehensive control method based on the gas sources, field tests were performed in the No. (9-15)06 panel. The measured results demonstrated that gas concentration in the return airflow is fluctuated within a range of 0.05% to 0.35%. The proposed gas control method can provide an insightful reference for other similar projects.
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institution Kabale University
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publishDate 2021-01-01
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spelling doaj-art-1bc6d6b34b094a6c9c84fcd5cd229e6f2025-08-20T03:54:43ZengWileyGeofluids1468-81151468-81232021-01-01202110.1155/2021/55586785558678Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal SeamsBangyou Jiang0Shitan Gu1Wenshuai Li2Guangchao Zhang3Jihua Zhang4State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao 266590, ChinaState Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao 266590, ChinaShandong Provincial Key Laboratory of Civil Engineering Disaster Prevention and Mitigation, Shandong University of Science and Technology, Qingdao 266590, ChinaState Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao 266590, ChinaFaculty of Architecture and Civil Engineering, Huaiyin Institute of Technology, Huai’an, Jiangsu 223001, ChinaSlicing fully mechanized caving mining is a standard high-efficiency mining method for ultrathick coal seams. However, the effectiveness of gas control has accentuated the difficulty in fully mechanized top coal caving of low-permeability ultrathick coal seams. This study focused on mining the No. 9-15 coal in Liuhuanggou Coal Mine, Xinjiang Province, China. To this aim, the results of theoretical analyses and field tests were combined to explore a comprehensive gas control method for fully mechanized caving of low-permeability ultrathick coal seams. The No. (9-15)06 panel was a top-slicing panel of the No. 9-15 coal with a mining height of 9 m. Gas analysis results revealed that gas emissions in the No. (9-15)06 panel are mainly sourced from the coal wall, caving top coal, goaf, and neighboring coal seams. Based on gas source separation, a comprehensive gas control method was proposed. The proposed method was based on the combination of gas predrainage alongside the coal seam, high-position drilling on the top, preburial of pipes in the goaf, and pressure-balancing ventilation. The permeability and gas predrainage were enhanced by hydraulic fracturing in low-permeability coal seams. According to the characterizations of coal seam and crustal stress distribution, the arrangement of the boreholes and backward-segmented fracturing technology were designed. From the field results, the coal seam presented a remarkable prefracturing under hydraulic fracturing. Besides, the mean gas predrainage from the boreholes was enhanced by four times compared to the prehydraulic fracturing state. Finally, using the proposed comprehensive control method based on the gas sources, field tests were performed in the No. (9-15)06 panel. The measured results demonstrated that gas concentration in the return airflow is fluctuated within a range of 0.05% to 0.35%. The proposed gas control method can provide an insightful reference for other similar projects.http://dx.doi.org/10.1155/2021/5558678
spellingShingle Bangyou Jiang
Shitan Gu
Wenshuai Li
Guangchao Zhang
Jihua Zhang
Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal Seams
Geofluids
title Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal Seams
title_full Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal Seams
title_fullStr Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal Seams
title_full_unstemmed Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal Seams
title_short Case Studies of Comprehensive Gas Control Method during Fully Mechanized Caving of Low-Permeability Ultrathick Coal Seams
title_sort case studies of comprehensive gas control method during fully mechanized caving of low permeability ultrathick coal seams
url http://dx.doi.org/10.1155/2021/5558678
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