Impacts of coal fracture roughness and aperture on the seepage of injected water: An experimental study

ObjectiveWater injection into coal seams is recognized as a critical technical measure for dust removal and the prevention and control of coal and gas outbursts and rock bursts in coal mines. The effectiveness of this measure is significantly influenced by the morphological characteristics of fractu...

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Main Authors: Gang WANG, Xuechang CHEN, Hao CHEN, Qingming LONG, Yixin LIU
Format: Article
Language:zho
Published: Editorial Office of Coal Geology & Exploration 2025-01-01
Series:Meitian dizhi yu kantan
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Online Access:http://www.mtdzykt.com/article/doi/10.12363/issn.1001-1986.24.06.0393
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author Gang WANG
Xuechang CHEN
Hao CHEN
Qingming LONG
Yixin LIU
author_facet Gang WANG
Xuechang CHEN
Hao CHEN
Qingming LONG
Yixin LIU
author_sort Gang WANG
collection DOAJ
description ObjectiveWater injection into coal seams is recognized as a critical technical measure for dust removal and the prevention and control of coal and gas outbursts and rock bursts in coal mines. The effectiveness of this measure is significantly influenced by the morphological characteristics of fractures, such as their roughness and aperture. MethodsThis study prepared coal samples containing fractures with different roughness and apertures using sandpaper and polyimide tape, calculated the fracture roughness parameters accurately using a confocal laser scanning microscope (CLSM), and tested the seepage rate of fractured coal samples. Results and ConclusionsThe results indicate that the roughness of a coal profile can be characterized using the surface height deviation (Ha), the maximum surface height (Hz), and the fractal dimension (Ds) of the 3D morphology. The seepage rate of coals decreased exponentially with an increase in Ha, Hz, and Ds. As the profile roughness increased from 4.69 to 18.43, the seepage rate of fractures decreased by up to 84.42%. In the case where fracture apertures ranged from 60 to 90 μm, the fracture roughness exhibited the most significant blocking effect on seepage. With a further increase in the fracture aperture, the blocking effect of roughness elements began to weaken, with the fracture aperture dominating the seepage process. The seepage rate of coals increased exponentially with an increase in the fracture aperture. As the fracture aperture increased from 30 μm to 150 μm, the seepage rate of fractures increased 355.88 times at most. Through a deep exploration into the relationships of the fracture aperture and roughness with seepage rate, this study determines the key mechanisms underlying the impacts of the fracture aperture and roughness on water injection into coal seams. The results suggest that it is necessary to fully consider the morphological characteristics of fractures in water injection practices. Proper water injection methods should be selected based on different fracture apertures and roughness to enhance the water injection efficiency effectively.
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issn 1001-1986
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series Meitian dizhi yu kantan
spelling doaj-art-263ea6cd47ba40f98d5fdd2ea25be6ef2025-02-12T07:20:17ZzhoEditorial Office of Coal Geology & ExplorationMeitian dizhi yu kantan1001-19862025-01-015319210110.12363/issn.1001-1986.24.06.039324-06-0393-Wang-GangImpacts of coal fracture roughness and aperture on the seepage of injected water: An experimental studyGang WANG0Xuechang CHEN1Hao CHEN2Qingming LONG3Yixin LIU4Mining Disaster Prevention and Control-Ministry of State Key Laboratory Breeding Base, Shandong University of Science and Technology, Qingdao 266590, ChinaMining Disaster Prevention and Control-Ministry of State Key Laboratory Breeding Base, Shandong University of Science and Technology, Qingdao 266590, ChinaMining Disaster Prevention and Control-Ministry of State Key Laboratory Breeding Base, Shandong University of Science and Technology, Qingdao 266590, ChinaState Key Laboratory of Gas Disaster Detecting, Preventing, and Emergency Controlling, CCTEG Chongqing Research Institute, Chongqing 400039, ChinaMining Disaster Prevention and Control-Ministry of State Key Laboratory Breeding Base, Shandong University of Science and Technology, Qingdao 266590, ChinaObjectiveWater injection into coal seams is recognized as a critical technical measure for dust removal and the prevention and control of coal and gas outbursts and rock bursts in coal mines. The effectiveness of this measure is significantly influenced by the morphological characteristics of fractures, such as their roughness and aperture. MethodsThis study prepared coal samples containing fractures with different roughness and apertures using sandpaper and polyimide tape, calculated the fracture roughness parameters accurately using a confocal laser scanning microscope (CLSM), and tested the seepage rate of fractured coal samples. Results and ConclusionsThe results indicate that the roughness of a coal profile can be characterized using the surface height deviation (Ha), the maximum surface height (Hz), and the fractal dimension (Ds) of the 3D morphology. The seepage rate of coals decreased exponentially with an increase in Ha, Hz, and Ds. As the profile roughness increased from 4.69 to 18.43, the seepage rate of fractures decreased by up to 84.42%. In the case where fracture apertures ranged from 60 to 90 μm, the fracture roughness exhibited the most significant blocking effect on seepage. With a further increase in the fracture aperture, the blocking effect of roughness elements began to weaken, with the fracture aperture dominating the seepage process. The seepage rate of coals increased exponentially with an increase in the fracture aperture. As the fracture aperture increased from 30 μm to 150 μm, the seepage rate of fractures increased 355.88 times at most. Through a deep exploration into the relationships of the fracture aperture and roughness with seepage rate, this study determines the key mechanisms underlying the impacts of the fracture aperture and roughness on water injection into coal seams. The results suggest that it is necessary to fully consider the morphological characteristics of fractures in water injection practices. Proper water injection methods should be selected based on different fracture apertures and roughness to enhance the water injection efficiency effectively.http://www.mtdzykt.com/article/doi/10.12363/issn.1001-1986.24.06.0393coalfracture aperturefracture roughnessfracture roughness characterizationseepage ratemine dust removal
spellingShingle Gang WANG
Xuechang CHEN
Hao CHEN
Qingming LONG
Yixin LIU
Impacts of coal fracture roughness and aperture on the seepage of injected water: An experimental study
Meitian dizhi yu kantan
coal
fracture aperture
fracture roughness
fracture roughness characterization
seepage rate
mine dust removal
title Impacts of coal fracture roughness and aperture on the seepage of injected water: An experimental study
title_full Impacts of coal fracture roughness and aperture on the seepage of injected water: An experimental study
title_fullStr Impacts of coal fracture roughness and aperture on the seepage of injected water: An experimental study
title_full_unstemmed Impacts of coal fracture roughness and aperture on the seepage of injected water: An experimental study
title_short Impacts of coal fracture roughness and aperture on the seepage of injected water: An experimental study
title_sort impacts of coal fracture roughness and aperture on the seepage of injected water an experimental study
topic coal
fracture aperture
fracture roughness
fracture roughness characterization
seepage rate
mine dust removal
url http://www.mtdzykt.com/article/doi/10.12363/issn.1001-1986.24.06.0393
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AT xuechangchen impactsofcoalfractureroughnessandapertureontheseepageofinjectedwateranexperimentalstudy
AT haochen impactsofcoalfractureroughnessandapertureontheseepageofinjectedwateranexperimentalstudy
AT qingminglong impactsofcoalfractureroughnessandapertureontheseepageofinjectedwateranexperimentalstudy
AT yixinliu impactsofcoalfractureroughnessandapertureontheseepageofinjectedwateranexperimentalstudy