Study on Mechanism of Pressure Relief and Permeability Enhancement in Soft-hard Composite Coal Seam by Directional Hydraulic Flushing Technology

IF 2.2 4区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Acta Montanistica Slovaca Pub Date : 2022-07-28 DOI:10.46544/ams.v27i2.18

{"title":"Study on Mechanism of Pressure Relief and Permeability Enhancement in Soft-hard Composite Coal Seam by Directional Hydraulic Flushing Technology","authors":"","doi":"10.46544/ams.v27i2.18","DOIUrl":null,"url":null,"abstract":"The soft-hard composite coal seam composed of tectonic and primary structural coal has the problems, such as high gas content, high pressure, poor permeability and difficult extraction, which seriously affect the production safety in the mining. To study the evolution characteristics of pressure relief in soft-hard composite coal seam based on directional hydraulic flushing technology, taking Hudi coal mine in China as the engineering background, and the pressure relief effect of directional hydraulic flushing on 'two soft and one hard' composite coal seam was studied by theoretical analysis and numerical simulation. The stress evolution of the whole coal seam under a single hole and porous interaction of different flushing radii were analyzed. The field test of directional hydraulic flushing in tectonic soft coal seam similar to protective layer mining was conducted. Results show that when the flushing diameter is 3-4 m, the influence range of stress disturbance covers the whole coal seam, and the vertical stress relief of the primary coal seam is the largest, which provides a theoretical basis for coal seam pressure relief and permeability enhancement technology. The average daily gas extraction (ADGE) concentration has doubled, and the ADGE purity has increased from 0.03 m3/d to 1.07m3/d. The target period of gas extraction is shortened from the expected 6 months to 1 month, and the average daily driving speed of coal roadway increases from 2.32 m/d to 5.37 m/d. The gas extraction efficiency is significantly improved, and the risk of gas outburst is effectively reduced, which has important theoretical and practical significance for improving the pressure relief and permeability enhancement efficiency of the soft and low permeability coal seam.","PeriodicalId":50889,"journal":{"name":"Acta Montanistica Slovaca","volume":"1 1","pages":""},"PeriodicalIF":2.2000,"publicationDate":"2022-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Montanistica Slovaca","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.46544/ams.v27i2.18","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 2

Abstract

The soft-hard composite coal seam composed of tectonic and primary structural coal has the problems, such as high gas content, high pressure, poor permeability and difficult extraction, which seriously affect the production safety in the mining. To study the evolution characteristics of pressure relief in soft-hard composite coal seam based on directional hydraulic flushing technology, taking Hudi coal mine in China as the engineering background, and the pressure relief effect of directional hydraulic flushing on 'two soft and one hard' composite coal seam was studied by theoretical analysis and numerical simulation. The stress evolution of the whole coal seam under a single hole and porous interaction of different flushing radii were analyzed. The field test of directional hydraulic flushing in tectonic soft coal seam similar to protective layer mining was conducted. Results show that when the flushing diameter is 3-4 m, the influence range of stress disturbance covers the whole coal seam, and the vertical stress relief of the primary coal seam is the largest, which provides a theoretical basis for coal seam pressure relief and permeability enhancement technology. The average daily gas extraction (ADGE) concentration has doubled, and the ADGE purity has increased from 0.03 m3/d to 1.07m3/d. The target period of gas extraction is shortened from the expected 6 months to 1 month, and the average daily driving speed of coal roadway increases from 2.32 m/d to 5.37 m/d. The gas extraction efficiency is significantly improved, and the risk of gas outburst is effectively reduced, which has important theoretical and practical significance for improving the pressure relief and permeability enhancement efficiency of the soft and low permeability coal seam.

查看原文本刊更多论文

软硬复合煤层定向水力冲洗卸压增渗机理研究

构造煤与原生构造煤组成的软硬复合煤层存在含气量高、压力大、渗透性差、抽采困难等问题，严重影响了开采中的安全生产。为研究基于定向水力冲洗技术的软硬复合煤层卸压演化特征，以中国虎地煤矿为工程背景，通过理论分析和数值模拟研究了定向水力冲洗对“两软一硬”复合煤层的卸压效果。分析了单孔下全煤层的应力演化及不同冲刷半径下的孔隙相互作用。进行了类似保护层开采的构造软煤层定向水力冲刷现场试验。结果表明，当冲刷直径为3 ~ 4 m时，应力扰动影响范围覆盖整个煤层，且原生煤层竖向应力消除最大，为煤层卸压增透技术提供了理论依据。平均日采气浓度(ADGE)提高了一倍，ADGE纯度从0.03 m3/d提高到1.07m3/d。瓦斯抽采目标周期由预期的6个月缩短为1个月，煤巷平均日掘进速度由2.32 m/d提高到5.37 m/d。显著提高瓦斯抽采效率，有效降低瓦斯突出风险，对提高软低渗煤层卸压增透效率具有重要的理论和现实意义。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Acta Montanistica Slovaca 地学-地球科学综合

CiteScore

3.60

自引率

12.50%

发文量

审稿时长

30 weeks

期刊介绍： Acta Montanistica Slovaca publishes high quality articles on basic and applied research in the following fields: geology and geological survey; mining; Earth resources; underground engineering and geotechnics; mining mechanization, mining transport, deep hole drilling; ecotechnology and mineralurgy; process control, automation and applied informatics in raw materials extraction, utilization and processing; other similar fields. Acta Montanistica Slovaca is the only scientific journal of this kind in Central, Eastern and South Eastern Europe. The submitted manuscripts should contribute significantly to the international literature, even if the focus can be regional. Manuscripts should cite the extant and relevant international literature, should clearly state what the wider contribution is (e.g. a novel discovery, application of a new technique or methodology, application of an existing methodology to a new problem), and should discuss the importance of the work in the international context.