Xi'an Research Institute,China Coal Technology and Engineering Gro

为实现井下煤层瓦斯抽采孔自推进旋转喷射钻进,研究能够实现自推进喷射式钻进的高压喷头,该喷头的前向及后向均布设喷孔,且前向喷孔喷射角度逐次增大,喷射钻进时后喷射力远大于前喷射力,且喷射水流沿喷头周向有一定偏斜角度。通过对该喷头进行水力学计算和30 MPa射流压力下模型射流钻进试验,得出了射流孔径、钻进速度与岩样强度的关系。研究结果表明:该喷头试验数据与理论计算结果较吻合,可实现自推进旋转喷射钻进,平均自推进力可达63 N,对于15 MPa以下的岩样射流孔径在60 mm以上,且钻进速度不小于8.16 m/h。同时对喷头下一步的改进提出建议。

in order to realize an auto feeding and rotary water jet drilig of the in seam gas drainage borehole in the underground mine,the paper had a study to realize an auto feeding and jet type drlig high pressure nzzle.The nozzle had jet orfices set at the forward direction and backward direction of the nozzle.The jetting angle ofthe forward orfice was successively increased.During the jetting drlling operation ,the backward orfice would have a jetting force higher than the forward jting force and the jet water fow had a certain angle along the nozze circumferenia.W ith the hydraulics calculation on the nozzle and the jetting riing experinent of the model under the jet pressure of 30 MPa.the relationship on the jting hole diameter rligspeed and rock sample strength was obtined.The study results showed that the nozzle experiment data and the theoretcal calculation results were wellfited,the auto feeding and rotry j t driling could be released and the average auto feeding force would reach at 63 N. With the pressure bellowed 15MPa.the jtting hole diameter in the rock sample would be over 60 mm and the drilig speed would not be less than 8.16 m/h.The paper had proposalson the further improvement of the nozzle.

中煤科工集团有限公司科技创新基金重点资助项目(2015ZD005)；中煤科工集团西安研究院有限公司科技创新基金重点资助项目(2014ZD017)；