煤矿安全2024，Vol.55Issue(6)：30-39,10.DOI:10.13347/j.cnki.mkaq.20231225
循环微波改性对无烟煤渗透率的影响
Effect on permeability of anthracite subjected to cyclical microwave modification
摘要
Abstract
Increasing the permeability via microwaves is one of the potential feasible reservoir modification technologies to improve the efficiency of coalbed methane extraction.The microwave oven is used to conduct 3 cycles of microwave modification experi-ments on No.15 anthracite in Jincheng area of Qinshui Basin.The gas permeability of anthracite samples before and after each modi-fication is tested using a self-built solid-gas coupling seepage platform.The pore properties are tested by micro CT scanning com-bined with image processing technology.In addition,the complexity index of pore-fracture network of coal samples before and after modification is discussed based on fractal theory.The results show that the gas permeability of anthracite sample increases with the increase of cycle times,and increases by 8.8 times after 3 cycles.The expansion and connection of pores/fractures in anthracite caused by microwave radiation is the fundamental reason for the increase of gas permeability.After three cycles,the total porosity of anthracite samples increases from 3.48%to 6.19%,in which the proportion of connected pores and fractures increases from 27.0%to 77.4%,and the proportion of isolated pores decreases from 73.0%to 22.6%.The pore number,pore volume,pore surface area and throat number,throat surface area and pore-throat coordination number of connected pores/fractures increase with the increase of cycle times,while the maximum throat length decreases,which confirms the"expansion and connection"effect of microwave modi-fication on pores/fractures in anthracite.The two-dimensional fractal dimensions of pores/fractures of three typical sections in anthra-cite samples increase with the increase of cycle times,and increase from 1.25,1.16,and 1.09 to 1.46,1.54,and 1.37 respectively after three cycles,which clarifies that the cyclical microwave modification will make the pore-fracture network(gas seepage channel)in coal samples more complex.关键词
瓦斯抽采/煤层渗透率/微波改性/孔隙结构/循环加载/分形维数Key words
gas drainage/coal seam permeability/microwave modification/pore structures/cyclical loading/fractal dimensions分类
矿业与冶金引用本文复制引用
张连昆,王月芳,张晓雨,李耿,周天白,尹博,密文天..循环微波改性对无烟煤渗透率的影响[J].煤矿安全,2024,55(6):30-39,10.基金项目
内蒙古自然科学基金资助项目(2023LHMS05052,2020LH05006,2022MS04008) （2023LHMS05052,2020LH05006,2022MS04008）
2022年度内蒙古自治区本级引进高层次人才科研支持资助项目(DC2300001429) （DC2300001429）
中央引导地方科技发展资金资助项目(2022SZY0482) （2022SZY0482）
内蒙古科研基本业务费资助项目(JY20220243) （JY20220243）
内蒙古研究生教育教学改革资助项目(JGCG2022080) （JGCG2022080）
内蒙古工业大学研究生教改资助项目(YJG2021010,YJG2020014) （YJG2021010,YJG2020014）
