Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering Hydraulic-Mechanical Coupling Effect

Owing to the exhaustion of shallow coal resources, deep mining has been occupied in coal mines. Deep buried coal seams are featured by the great ground stress, high gas pressure, and low permeability, which boost the risk of gas disasters and thus dramatically threaten the security about coal mines....

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Main Authors: Chaojun Fan, Haiou Wen, Sheng Li, Gang Bai, Lijun Zhou
Format: Article
Language:English
Published: Wiley 2022-01-01
Series:Geofluids
Online Access:http://dx.doi.org/10.1155/2022/5198227
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author Chaojun Fan
Haiou Wen
Sheng Li
Gang Bai
Lijun Zhou
author_facet Chaojun Fan
Haiou Wen
Sheng Li
Gang Bai
Lijun Zhou
author_sort Chaojun Fan
collection DOAJ
description Owing to the exhaustion of shallow coal resources, deep mining has been occupied in coal mines. Deep buried coal seams are featured by the great ground stress, high gas pressure, and low permeability, which boost the risk of gas disasters and thus dramatically threaten the security about coal mines. Coal seam gas pressure and gas content can be decreased by gas extraction, which is the primary measure to prevent and control mine gas disasters. The coal mass is simplified into a continuous medium with dual structure of pores and fractures and single permeability. In consideration of the combined effects of gas slippage and two-phase flow, a hydraulic-mechanical coupling model for gas migration in coals is proposed. This model involves the equations of gas sorption and diffusion, gas and water seepage, coal deformation, and evolution of porosity and permeability. Based on these, the procedure of gas extraction through the floor roadway combined with hydraulic punching and ordinary drainage holes was simulated, and the gas extraction results were used to evaluate the outburst danger of roadway excavation and to verify the engineering practice. Results show that gas extraction can reduce coal seam gas pressure and slow down the rate of gas release, and the established hydraulic-mechanical coupling model can accurately reveal the law of gas extraction by drilling and punching boreholes. After adopting the gas extraction technology of drilling and hydraulic punching from the floor roadway, the remaining gas pressure and gas content are reduced to lower than 0.5 MPa and 5.68 m3/t, respectively. The achievements set a theoretical foundation to the application of drilling and punching integrated technology to enhance gas extraction.
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id doaj-art-2dbfcbd8c5e04d398d89198a09a98bf4
institution Kabale University
issn 1468-8123
language English
publishDate 2022-01-01
publisher Wiley
record_format Article
series Geofluids
spelling doaj-art-2dbfcbd8c5e04d398d89198a09a98bf42025-02-03T05:54:30ZengWileyGeofluids1468-81232022-01-01202210.1155/2022/5198227Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering Hydraulic-Mechanical Coupling EffectChaojun Fan0Haiou Wen1Sheng Li2Gang Bai3Lijun Zhou4College of MiningCollege of MiningCollege of MiningCollege of Safety Science and EngineeringCollege of Safety Science and EngineeringOwing to the exhaustion of shallow coal resources, deep mining has been occupied in coal mines. Deep buried coal seams are featured by the great ground stress, high gas pressure, and low permeability, which boost the risk of gas disasters and thus dramatically threaten the security about coal mines. Coal seam gas pressure and gas content can be decreased by gas extraction, which is the primary measure to prevent and control mine gas disasters. The coal mass is simplified into a continuous medium with dual structure of pores and fractures and single permeability. In consideration of the combined effects of gas slippage and two-phase flow, a hydraulic-mechanical coupling model for gas migration in coals is proposed. This model involves the equations of gas sorption and diffusion, gas and water seepage, coal deformation, and evolution of porosity and permeability. Based on these, the procedure of gas extraction through the floor roadway combined with hydraulic punching and ordinary drainage holes was simulated, and the gas extraction results were used to evaluate the outburst danger of roadway excavation and to verify the engineering practice. Results show that gas extraction can reduce coal seam gas pressure and slow down the rate of gas release, and the established hydraulic-mechanical coupling model can accurately reveal the law of gas extraction by drilling and punching boreholes. After adopting the gas extraction technology of drilling and hydraulic punching from the floor roadway, the remaining gas pressure and gas content are reduced to lower than 0.5 MPa and 5.68 m3/t, respectively. The achievements set a theoretical foundation to the application of drilling and punching integrated technology to enhance gas extraction.http://dx.doi.org/10.1155/2022/5198227
spellingShingle Chaojun Fan
Haiou Wen
Sheng Li
Gang Bai
Lijun Zhou
Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering Hydraulic-Mechanical Coupling Effect
Geofluids
title Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering Hydraulic-Mechanical Coupling Effect
title_full Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering Hydraulic-Mechanical Coupling Effect
title_fullStr Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering Hydraulic-Mechanical Coupling Effect
title_full_unstemmed Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering Hydraulic-Mechanical Coupling Effect
title_short Coal Seam Gas Extraction by Integrated Drillings and Punchings from the Floor Roadway considering Hydraulic-Mechanical Coupling Effect
title_sort coal seam gas extraction by integrated drillings and punchings from the floor roadway considering hydraulic mechanical coupling effect
url http://dx.doi.org/10.1155/2022/5198227
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AT shengli coalseamgasextractionbyintegrateddrillingsandpunchingsfromthefloorroadwayconsideringhydraulicmechanicalcouplingeffect
AT gangbai coalseamgasextractionbyintegrateddrillingsandpunchingsfromthefloorroadwayconsideringhydraulicmechanicalcouplingeffect
AT lijunzhou coalseamgasextractionbyintegrateddrillingsandpunchingsfromthefloorroadwayconsideringhydraulicmechanicalcouplingeffect