Study on the evaluation of effectivenessof cross-seam gas drainage boreholes and secondary plugging technology
GUO Zhibing
HU Zuxiang
Abstract：In order to solve the problems of fast attenuation and low concentration of gas extraction in the bot-tom extraction roadway.The research focuses on the working face 15-17-33190 of the Pingdingshan No.10 Mine in Henan Province.A dedicated gas leakage detection device is developed and an absolute leakage rate index is employed.A quantitative evaluation standard for gas leakage in boreholes is established to assess the sealing quality and determine"effective boreholes".For ineffective boreholes,a hole-plugging and leakage-repairing technology is proposed and applied.Post-grouting repairs are inspected and analyzed for gas drainage boreholes.Results indicate that at measurement points 19.5 meters away from the borehole mouth,the average gas concentration exceeded 70%.Within the range of 15 meters to 19.5 meters from the borehole mouth,gas concentration decreased significantly with proximity to the mouth.Leakage within 15 meters is not prominent,defining the repair segment as 15 to 19.5 meters.After repairs,gas concentration in the boreholes increased by 1 to 3 times,with gas concentrations at the borehole mouth reaching 52%to 72%.The gas purity is increased by more than 1 times.The proposed evaluation method and repair technology of drilling gas leak-age provide a reference basis for gas control.
Keywords：gas extractionborehole repairextraction failureair leak detectionair leakage regularity
Publication Date：2024-10-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 6-11 )