钻杆钻进扰动下顺层瓦斯抽采钻孔孔壁失稳机制  

Borehole wall instability mechanism of gas drainage in-seam borehole under disturbance of drill pipe drilling

作　　者：韩晓明[1,2] 刘炳余[1,2] 薛刘冰 张小明 HAN Xiaoming;LIU Bingyu;XUE Liubing;ZHANG Xiaoming(School of Mechanical and Power Engineering,Henan Polytechnic University,Jiaozuo 454000,Henan,China;Henan Province Coal Mine Ma-chinery Equipment Engineering Technology Research Center,Henan Polytechnic University,Jiaozuo 454000,Henan,China)

机构地区：[1]河南理工大学机械与动力工程学院,河南焦作454000 [2]河南理工大学河南省煤矿机械装备工程技术研究中心,河南焦作454000

出　　处：《河南理工大学学报（自然科学版）》2023年第3期18-26,共9页Journal of Henan Polytechnic University（Natural Science）

基　　金：国家自然科学基金资助项目(51975189);河南省高等学校重点科研项目(22A440013);河南理工大学机械工程重点学科研究项目。

摘　　要：为了探讨钻杆钻进扰动对顺层瓦斯抽采钻孔孔壁失稳破坏的影响规律,基于赫兹接触理论,推导钻杆与瓦斯抽采钻孔发生摩擦时滑动接触应力分量计算公式,建立钻杆钻进扰动下孔壁附近复合应力场的分析计算模型,分析孔壁的复合应力场,运用有限元分析软件Abaqus对计算结果进行验证;最后,依据Mohr-Coulomb强度准则,对防止孔壁失稳的临界钻进参数进行分析。结果表明:钻杆位于瓦斯抽采钻孔正下方时,孔壁复合应力场中的最大主剪应力取得最大值;最大主剪应力位于接触表面,若超出煤岩的抗剪强度,则会在此处发生剪切破坏;降低钻杆公转率以及钻杆与瓦斯抽采钻孔孔壁的摩擦系数可以提高钻进过程中孔壁的稳定性;钻杆与瓦斯抽采钻孔之间的环空间隙越大,临界钻压越小。研究结果可为顺层瓦斯抽采钻孔钻进工艺参数选择提供理论指导。In order to study the influence of the disturbance of the drill pipe drilling on the borehole wall in-stability and failure of the gas drainage in-seam borehole,the calculation formula of the stress component of the friction sliding contact between the drill pipe and borehole wall was derived based on the Hertz contact theory.The analysis and calculation model of the composite stress field near the borehole wall under the dis-turbance of drill pipe drilling was established,the composite stress field of borehole wall of the gas drainage bedding hole was analyzed,and the calculation results were verified by the finite element analysis software Abaqus.Finally,according to the Mohr-Coulomb strength criterion,the critical drilling parameters to prevent the borehole wall instability were analyzed.The results showed that the maximum principal shear stress of the borehole wall reached the maximum when the drill pipe was located directly below borehole.The maxi-mum principal shear stress was located on the contact surface.If it exceeded the shear strength of coal,the shear failure would occur.Reducing the revolution rate of the drill pipe and the friction coefficient between the drill pipe and the borehole wall could improve the stability of borehole wall during the drilling process of the gas drainage bedding hole.The larger the annulus gap between the drill pipe and the borehole wall was,the smaller the critical axial pressure was.The research results provided theoretical guidance for the se-lection of drilling process parameters of the gas drainage in-seam borehole.

关 键 词：钻杆扰动 顺层瓦斯抽采钻孔 孔壁失稳 MOHR-COULOMB准则 赫兹接触 

分 类 号：TD712[矿业工程—矿井通风与安全]