Application of long-reach directional drilling boreholes for gas drainage of adjacent seams in coal mines with severe geological conditions

作     者：Grzegorz Lesniak Daniel JBrunner Tomasz Topòr Malgorzata Slota-Valim Renata Cicha-Szot Bartlomiej Jura Jacek Skiba Arnold Przystolik Ben Lyddall Grzegorz Plonka Grzegorz Le?niak;Daniel J.Brunner;Tomasz Topór;Ma?gorzata S?ota-Valim;Renata Cicha-Szot;Bart?omiej Jura;Jacek Skiba;Arnold Przystolik;Ben Lyddall;Grzegorz Plonka

作者机构：Oil and Gas Institute-National Research InstituteLubicz 25A31-503 KrakówPoland REI DrillingINC.250 West Berger Lane84107 Salt Lake CityUTUSA Central Mining Institute40-166 KatowicePoland Polish Mining Group(PGG)Powstańców 3040-039 KatowicePoland 

出 版 物：《International Journal of Coal Science & Technology》 (国际煤炭科学技术学报（英文）)

年 卷 期：2022年第9卷第6期

页      面：75-88页

核心收录：

学科分类：0819[工学-矿业工程] 081903[工学-安全技术及工程] 08[工学] 

基　　金：Coal Mine Staszic-Wujek European Commission Research Fund for Coal and Steel Research Fund for Coal and Steel, RFCS 

主　　题：Coal Mine methane Methane control strategy In-seam horizontal boreholes Long reach directionally 

摘      要：This study aimed to demonstrate the application of Long Reach Directionally Drilled Boreholes(LRDD)for gas drainage of adjacent seams before and during the longwall face operations of low permeability-high gas content coals Staszic-Wujek Hard Coal Mine in the Upper Silesia Coal Basin(Poland).Five LRDD Boreholes(TM1a-TM5)with a length of 300 and 400 m were located over coal seam 501 in the fractured zone and monitored over six months of longwall face *** Boreholes were combined with Cross-Measured *** characterization and geological modeling supported the results obtained from gas *** drainage efficiency of LRDD Boreholes was the approxi-mately 70%level,while conventional Cross-Measured Boreholes were only 30%.The highest goaf gas quality(94%methane concentration)was reported for TM4,placed at an average elevation of 41 m above coal seam *** highest goaf gas production(average 6.2 m^(3)/min)was reported for LRDD Borehole *** borehole was placed within the fracture zone(average elevation of 24.4 m)and drilled through the sandstone lithotype with the best reservoir properties,enhancing drainage *** Boreholes TM2 and TM4 achieved similar *** three LRDD Boreholes were drilled close to the maximum principal horizontal stress direction,providing borehole stability during *** lowest goaf gas production was reported for LRDD Boreholes TM1a and *** Boreholes were placed in the rubble zone.