doi:10.16186/j.cnki.1673-9787.2021010044

Received:2021/01/09

Revised:2021/06/29

Published:2022/01/10

Research of long distance fixed-point sealed coring technology and application in underground coal seam

LONG Weicheng

Xi ’an Research Institute， China Coal Technology & Engineering Group Corp. ，Xi’ an 710077 ， Shaanxi， China

Abstract:  In view of the problems of inaccurate determination result and large deviation of sampling point trajectory due to long exposure time of coring coal samples in long-distance gas content measurement，a set of sealed coring device and technology suitable for long-distance gas content measurement in coal seam underground was developed． The device was small in volume and light in weight，with an outer diameter of only 89 mm，a seal gas pressure of 11.5 MPa and a coal core diameter of 38 mm． In a coal mine of Shanxi Province， the reliability verification and the evaluation index of gas drainage strip effect in coal roadway were determined． The short borehole conventional coring method and the directional long borehole sealed coring method were used to measure the gas content in the same place of the coal seam． The results showed that the gas con tent in the closed coring measuring point was about 0.97 ～ 1.06 times of that in the conventional coring measuring point． The comparative test results showed that the long-distance fixed-point sealed coring method was suitable for the underground coal seam，and the coring device and technology were reliable for the measurement of gas content in deep holes． The sealed coring and gas content measurement of 16 measuring points were carried out in the gas drainage roadway of the experimental area，and the maximum hole depth of coring reached 516 m，which expanded the scope of regional gas drainage effect to more than 400 m at a time． The research showed that the gas content determination technology of long-distance fixed-point sealed coring in coal mine realized the accurate measurement of coal seam drilling fixed-point，long-distance，sealed coring and gas content， which was applied in the test of gas drainage effect in the strip area of coal roadway，expanded the investigation scope of one-time regional gas drainage effect，reduced the cross operation times of tunneling and checking，and effectively promoted the mining efficiency．

Key words:sealed coring;gas content;fixed-point sampling;long-distance samplingcoal roadway strip

 井下煤层长距离定点密闭取心技术及应用研究_龙威成.pdf