Application of long-reach directional drilling boreholes for gas drainage of adjacent seams in coal mines with severe geological conditions
Grzegorz Le?niak1
Daniel J.Brunner2
Tomasz Topór1
Ma?gorzata S?ota-Valim1
Renata Cicha-Szot1
Bart?omiej Jura3
Jacek Skiba3
Arnold Przystolik3
Ben Lyddall2
Grzegorz Plonka4
1.Oil and Gas Institute-National Research Institute,Lubicz 25A,31-503 Kraków,Poland2.REI Drilling,INC.250 West Berger Lane,84107 Salt Lake City,UT,USA3.Central Mining Institute,40-166 Katowice,Poland4.Polish Mining Group(PGG),Powstańców 30,40-039 Katowice,Poland
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 operations.LRDD Boreholes were combined with Cross-Measured Boreholes.Reservoir characterization and geological modeling supported the results obtained from gas drainage.The 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 501.The highest goaf gas production(average 6.2 m3/min)was reported for LRDD Borehole TM3.This 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 performance.LRDD Boreholes TM2 and TM4 achieved similar performance.These three LRDD Boreholes were drilled close to the maximum principal horizontal stress direction,providing borehole stability during under-mining.The lowest goaf gas production was reported for LRDD Boreholes TM1a and TM5.Both Boreholes were placed in the rubble zone.
机标关键词：applicationconditionsmineswithadjacentboreholescoaldirectional
论文发表日期：2022-12-28
在线出版日期：2025-08-15（本平台首次上网日期，不代表文献的发表时间）
页数：14( 75-88 )
英文信息