矿业科学学报2025，Vol.10Issue(5)：996-1008,13.DOI:10.19606/j.cnki.jmst.2025073
超深埋低渗透高地应力粉煤层钻孔扰动特性研究
Borehole disturbance of ultra deep-buried pulverized coal seams with low-permeability under high ground stress
摘要
Abstract
The M1-7 to M1-9 coal seams traversed by the Zhaotong Tunnel feature high ground stress,low permeability,and gas outburst risks.Frequent borehole collapse and drilling jamming during con-struction severely constrain gas drainage efficiency due to inadequate borehole completion rates.This study therefore attempts to investigate the instability mechanisms of boreholes in high-stress pulverized coal seams and optimize drilling parameters(diameter and depth)for enhanced gas extraction via a multidisciplinary approach.Specifically,this study(1)developed a mechanical model for borehole disturbance under non-isobaric stress fields and,analytically characterized the"dumbbell-shaped"plastic zone under lateral pressure coefficients(λ＞1);(2)employed COMSOL Multiphysics simula-tions to analyze stress distributions for boreholes with diameters of 350/500 mm and depths of 5～20 m;(3)conducted dual-aperture field tests and borehole imaging quantify fracture development and gas drainage dynamics.We found that under high ground stress,lateral pressure coefficient λ governs plas-tic zone morphology;at λ=1.6,a dumbbell-shaped stress concentration zone forms,with disturbance ranges extending to 1.29 times the borehole depth.The plastic zone of a 500 mum aperture borehole ex-pands to 1.9 times that of a 350 mum borehole,with gas drainage volume in the tunnel construction sec-tion increased by 60％,though requiring enhanced support for transverse fractures.关键词
高地应力/侧压系数/瓦斯突出/钻孔孔径/钻孔深度Key words
high ground stress/lateral pressure coefficient/gas outburst/borehole diameter/borehole depth分类
矿业与冶金引用本文复制引用
王子奇,吴华,袁勋,谢毅,杨昌宇,王小岐..超深埋低渗透高地应力粉煤层钻孔扰动特性研究[J].矿业科学学报,2025,10(5):996-1008,13.基金项目
云南省科技厅重点研发计划(202303AA080004) （202303AA080004）
中铁二院工程集团有限责任公司科技发展计划(KSNQ241001) （KSNQ241001）
