瓦斯抽采钻孔漏气通道快速检测方法

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中图分类号：TD712 文献标志码：A

Abstract： The sequential detection method is commonly used for detecting air leakage pathways in gas drainage boreholes.This method involves sequentially measuring the gas concentration at various measuring pointsand identifying the leakage location through comparative analysis.However，for long boreholes or those with numerous measuring points，the on-site detection eficiencyof the sequential detection method is low.To addressthis issue，this paper proposedarapid detectionmethodforair leakagepathways in gas drainage boreholes based on the bisection method.Multiple measuring points werearranged axially within the borehole.Aprobe rod and a gas drainage pipe were used to separate the gas at a specific measuring point from the mixed gas inside the borehole.First，thegas concentrationatthe borehole bottom measuring point was measured.Ifit was significantly higher than theaverage in-hole gas concentration，the presence of anair leakage pathway in the borehole was confirmed.Subsequently，the in-hole measuringpoints were bisected，and the gas concentration at the intermediate measuring point was measured.If this concentration was close to the average in-hole gas concentration，theair leakage pathwaywas determinedtobe located inthesection fromthat point totheborehole bottom;if it was significantly higher，the pathway was determined tobein the section from that point to the borehole collar.The section identified ascontaining the air leakage pathway underwent furtherrecursive bisection.By comparing the gas concentration at the intermediate measuring point within a section with the average in-hole gas concentration， the localization range was progressively narrowed， which ultimately achieved the precise and rapid localization of the air leakage pathway.The field experiment results showed that the proposed method accurately identified the location of the air leakage pathway. Compared with the sequential detection method， the detection time was shortened by 26.5% .This improvement demonstrates that the proposed method effectively improves detection efficiency.

Key words： gas drainage； borehole air leakage;air leakage pathway detection; bisection method; gas concentration

0引言

在煤矿瓦斯抽采过程中，钻孔漏气通道的存在会导致钻孔气密性失效，显著降低瓦斯抽采浓度和抽采效率，还会扰乱瓦斯抽采系统的整体压力分布，进而削弱瓦斯抽采网络的稳定性，严重时甚至可能诱发煤与瓦斯突出等重大安全事故[1-2]。（剩余10397字）