西安科技大学学报2025，Vol.45Issue(2)：305-316,12.DOI:10.13800/j.cnki.xakjdxxb.2025.0209
三轴条件下递增瓦斯压力和煤样孔隙结构对瓦斯解吸-渗流影响研究
Effects of increasing gas pressure and pore structure of coal samples to gas desorption-seepage laws under triaxial conditions
摘要
Abstract
The pore structure of coal is the root factor affecting mine gas extraction,and gas extraction involves the migration stages such as gas desorption and seepage,so it is necessary to study the influ-ence of coal pore structure on gas desorption-seepage law under the condition of triaxial in-situ occur-rence.The desorption-seepage experiments of five representative coal samples were carried out through the coalbed methane fluid-solid interaction test platform,the variation of desorption and seepage rate of different coal samples with time under increasing gas pressure was studied,and the correlation between absorption and seepage rate and increasing gas pressure was analyzed.The results show that under the conditions of axial compression of 4.0 MPa and confining pressure of 3.5 MPa,the desorption capacity and seepage rate of five typical coal samples can be divided into such stages as rapid growth,slow growth and stable maintenance.In the gas desorption stage,the desorption time of coal samples from Zhaogu No.2 Mine(ZG)is much greater than that of other coal samples,but its desorption capacity was much smaller than that of other coal samples.Because there are more pore throat structures between micropores and medium and large pores,and the proportions of small pore throats and closed pore throats is larger.The gas pressure increases from 1.5 MPa to 2.7 MPa,and the desorption rate of DLT coal samples increases by 54%at the maximum,while the desorption rate of ZG coal samples fluctuates around 40%(less than 4%),indicating that the damage of gas pressure to the pore structure of ZG coal samples is much lower than that of other coal samples.In the gas seepage stage,the gas seepage rate of coal samples is significantly linear and positively correlated with the increase of gas pressure,mainly because the expansion effect of high gas pressure on the pores and fissures of coal samples is stronger.The gas seepage rate determines the on-site gas extraction efficiency,and the gas desorption capacity affects the gas extraction capacity,which jointly determines the gas extraction effect.Based on the pore structure of coal samples and the conditions of increasing gas pressure,a triaxial coal sample gas de-sorption-seepage mechanism was proposed,which has certain reference significance for on-site gas ex-traction and gas disaster prevention.关键词
解吸-渗流/瓦斯压力/三轴受载条件/孔隙特征/煤样Key words
desorption-seepage/gas pressure/triaxial loading conditions/pore characteristics,coal sam-ples分类
矿山工程引用本文复制引用
蔡雨初,李树刚,孔祥国,杨送瑞,季鹏飞,和递..三轴条件下递增瓦斯压力和煤样孔隙结构对瓦斯解吸-渗流影响研究[J].西安科技大学学报,2025,45(2):305-316,12.基金项目
国家自然科学基金项目(52404243,52474251,52374227) （52404243,52474251,52374227）
