摘要
为探究不同地应力条件对煤层瓦斯抽采流动规律的影响,基于流固耦合模型,通过COMSOL建立相应的数值模型,分别对该模型施加不同的地应力条件,探究垂直地应力、侧压系数等对煤层瓦斯压力和渗透率的影响。研究表明:当煤层埋深越深垂向地应力越大时,煤层内挤压有效应力也相应增大,煤层渗透率减小,导致瓦斯抽采效果变差;随着侧压系数的增大,煤层内水平方向挤压有效应力显著增大,煤层渗透率变小,导致瓦斯抽采效果变差;在抽采钻孔处,竖直方向挤压有效应力随侧压系数的增大而减小,甚至出现对煤体的拉伸现象,致使该区域渗透率随侧压系数的增大而增大。
In order to investigate the influence of different in-situ stress conditions on the flow laws of coal seam gas extraction,based on the flow-solid coupling model,the corresponding numerical model was established by COMSOL.With different in-situ stress conditions being applied to the model respectively,the influences of vertical in-situ stress and lateral pressure coefficient on coal seam gas pressure and permeability were investigated.The research shows that,with the vertical in-situ stress being greater at the deeper coal seam,the effective extrusion stress in the coal seam increases,and the permeability of the coal seam decreases,leading to a poorer gas extraction effect.With the increase of the lateral pressure coefficient,the effective extrusion stress in the horizontal direction in the coal seam increases significantly,and the permeability of the coal seam becomes smaller,leading to a poorer gas extraction effect.However,the effective extrusion stress in the vertical direction at the extraction borehole decreases with the increase of the lateral pressure coefficient and even the tensile phenomenon of the coal body occurs,resulting in the increase of permeability in this area with the increase of lateral pressure coefficient.
作者
张子翔
李雨成
张欢
任建业
ZHANG Zixiang;LI Yucheng;ZHANG Huan;REN Jianye(College of Safety and Emergency Management Engineering,Taiyuan University of Technology,Jinzhong,Shanxi 030600,China)
出处
《矿业研究与开发》
CAS
北大核心
2023年第8期66-72,共7页
Mining Research and Development
基金
国家自然科学基金青年科学基金项目(52004170)。
关键词
煤层瓦斯
钻孔抽采
地应力
侧压系数
瓦斯流动特性
Coal seam gas
Gas extraction from boreholes
In-situ stress
Lateral pressure coefficient
Flow characteristics of gas
