摘要
钻孔瓦斯抽采是最经济、有效的煤层瓦斯综合利用与灾害防治手段之一。为研究煤层瓦斯抽采过程中主控因素演化机制,建立瓦斯运移多物理场耦合模型,并借助COMSOL Multiphysics软件求解。结果表明,受煤体孔、裂隙网络结构影响,基质瓦斯压力与裂隙瓦斯压力变化存在异步性,基质内瓦斯难以析出。裂隙系统与基质系统共同控制煤体的瓦斯运移能力,在瓦斯抽采初期,瓦斯运移过程由裂隙系统主控,此时增加煤层渗透率可有效提高瓦斯抽采效率;随着抽采的进行,瓦斯运移过程逐渐转为基质系统主控,此时单纯增加煤体渗透率难以有效提高瓦斯抽采效率,应采取措施提高煤基质扩散性能。
Borehole gas extraction is one of the most economical and effective methods for comprehensive gas utilization and disaster prevention.To study the evolution mechanism of the main control factors in coal seam gas extraction process,a multi-field coupling model for gas migration was established and solved using COMSOL Multiphysics software.The results indicate that,due to the influence of coal pore and fracture network structure,there is an asynchrony between the changes in matrix gas pressure and fracture gas pressure,making it difficult for gas to migrate from the matrix.The fracture system and matrix system jointly control the gas migration ability of the coal body.In the early stage of gas extraction,the gas migration process is mainly controlled by the fracture system.At this time,increasing the permeability of the coal seam can effectively improve the gas extraction efficiency.As the gas extraction processing,the gas migration process gradually shifts to be controlled by the matrix system.It is hard to effectively improve the gas extraction efficiency by just increasing the permeability of the coal body.Measures should be taken to improve the diffusion performance of the coal matrix.
作者
李鹏
王衍海
周爱桃
张迪
闫昌帅
陈瀚轩
LI Peng;WANG Yanhai;ZHOU Aitao;ZHANG Di;YAN Changshuai;CHEN Hanxuan(China Energy Shendong Coal Group Co.,Ltd.,Yulin 719315,China;School of Emergency Management and Safety Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China)
出处
《煤炭工程》
北大核心
2024年第8期165-171,共7页
Coal Engineering
基金
国家自然科学基金项目(52130409,52121003)。
关键词
瓦斯抽采
主控因素
多场耦合
瓦斯扩散
数值模型
gas extraction
main control factors
multi-field coupling
gas diffusion
numerical model
