{"title":"Comparative Analysis of the Gas Extraction Effects With Different Numbers and Spacings of Boreholes Drilled Along a Coal Seam","authors":"Yuexia Chen, Tingxiang Chu, Xuexi Chen, Peng Chen, Haidong Wang, Boning Jiang, Jialin Cao","doi":"10.1002/ese3.2050","DOIUrl":null,"url":null,"abstract":"<p>The number and spacing of boreholes drilled along a coal seam are important parameters of the borehole layout. Despite the previous extensive research by many experts, quantitative and visual comparisons of the gas extraction effects with different borehole spacings and numbers are rare. Here, the effective gas extraction range, delimited by the 0.74 MPa isobaric surface and lines, was simulated. The 0.74 MPa isobaric surface around multiple sets of boreholes at 60 days of gas extraction is wavy. At 50 days, the isobaric lines around a single set of boreholes are approximately circular, whereas those around multiple sets of boreholes are approximately elliptical. When five sets of boreholes are used, the short semiaxis of the elliptical contour around the middle borehole is approximately 59% greater than the effective extraction radius of a single borehole. Among the spacings investigated, the effective extraction volume V5 peaks at a borehole spacing of 5 m at 90 days; but, the isobaric lines at the top and bottom of the working face are concave inwards, that is, certain gas pressures exceed 0.74 MPa, thereby increasing the likelihood of gas emissions. Thus, at 90 days, the efficiency of gas extraction in this studied working face is higher as the borehole spacing is 4 m. This approach, which takes into account the superimposed effect of boreholes drilled along a coal seam, the radius of gas extraction, isolines, isobaric surface and the effective extraction volume, offers theoretical guidance for the arrangement of boreholes.</p>","PeriodicalId":11673,"journal":{"name":"Energy Science & Engineering","volume":"13 2","pages":"944-954"},"PeriodicalIF":3.5000,"publicationDate":"2025-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/ese3.2050","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Energy Science & Engineering","FirstCategoryId":"5","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/ese3.2050","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENERGY & FUELS","Score":null,"Total":0}
引用次数: 0
Abstract
The number and spacing of boreholes drilled along a coal seam are important parameters of the borehole layout. Despite the previous extensive research by many experts, quantitative and visual comparisons of the gas extraction effects with different borehole spacings and numbers are rare. Here, the effective gas extraction range, delimited by the 0.74 MPa isobaric surface and lines, was simulated. The 0.74 MPa isobaric surface around multiple sets of boreholes at 60 days of gas extraction is wavy. At 50 days, the isobaric lines around a single set of boreholes are approximately circular, whereas those around multiple sets of boreholes are approximately elliptical. When five sets of boreholes are used, the short semiaxis of the elliptical contour around the middle borehole is approximately 59% greater than the effective extraction radius of a single borehole. Among the spacings investigated, the effective extraction volume V5 peaks at a borehole spacing of 5 m at 90 days; but, the isobaric lines at the top and bottom of the working face are concave inwards, that is, certain gas pressures exceed 0.74 MPa, thereby increasing the likelihood of gas emissions. Thus, at 90 days, the efficiency of gas extraction in this studied working face is higher as the borehole spacing is 4 m. This approach, which takes into account the superimposed effect of boreholes drilled along a coal seam, the radius of gas extraction, isolines, isobaric surface and the effective extraction volume, offers theoretical guidance for the arrangement of boreholes.
期刊介绍:
Energy Science & Engineering is a peer reviewed, open access journal dedicated to fundamental and applied research on energy and supply and use. Published as a co-operative venture of Wiley and SCI (Society of Chemical Industry), the journal offers authors a fast route to publication and the ability to share their research with the widest possible audience of scientists, professionals and other interested people across the globe. Securing an affordable and low carbon energy supply is a critical challenge of the 21st century and the solutions will require collaboration between scientists and engineers worldwide. This new journal aims to facilitate collaboration and spark innovation in energy research and development. Due to the importance of this topic to society and economic development the journal will give priority to quality research papers that are accessible to a broad readership and discuss sustainable, state-of-the art approaches to shaping the future of energy. This multidisciplinary journal will appeal to all researchers and professionals working in any area of energy in academia, industry or government, including scientists, engineers, consultants, policy-makers, government officials, economists and corporate organisations.