主办单位：煤炭科学研究总院有限公司、中国煤炭学会学术期刊工作委员会
A new pore classification method based on the methane occurrence and migration characteristics in coal
CHENG Yuanping，HU Biao
煤中复杂的多尺度孔隙结构是瓦斯赋存的空间和运移的通道，厘清甲烷在不同孔隙中的赋 存和运移特性对煤层瓦斯的抽采利用以及灾害防治具有重要意义。 在过去的几十年中，学者们对 煤中复杂孔隙结构进行了大量的研究与分类。 随着孔隙测试技术的发展，以及对煤中甲烷赋存和 运移特性的进一步认识，发现现有的煤孔隙分类方法存在不足。 因此，对以往的孔隙分类方法进行 全面回顾，并基于最新的煤中甲烷赋存和运移特性的研究成果，提出了一种新的针对煤和甲烷系统 的孔隙分类方法。 将煤中孔隙结构划分为不可达孔(<0.38 nm)、填充孔(0.38~1.5 nm，吸附相扩 散)、扩散孔(1.5~100 nm，游离相扩散)和渗流孔(>100 nm)4 类，且煤中不同孔隙(填充孔、扩散孔 和渗流孔)形成顺序串联，相同孔隙形成相互并联为主的连接模式。 煤中甲烷主要以微孔填充形 式吸附于填充孔中，填充孔中的吸附态甲烷作为煤层瓦斯运移的源头，以吸附相扩散的形式为扩散 孔中的游离相扩散提供源源不断的甲烷分子，而扩散孔中运移的甲烷也汇总至渗流孔并不断渗流 到抽采钻孔或煤壁表面。 新的煤孔隙分类方法总结了甲烷分子在不同尺寸孔隙结构中的赋存形 式(微孔填充吸附态、单分子层吸附态和游离态)及其运移特性，为从微观和宏观相结合角度进一 步研究甲烷在煤中的赋存和运移规律提供了理论基础。
The multi⁃scale pore structures in coal are the occurrence and migration space of coalbed methane (CBM). Therefore，the research on the pore structures in coal is of great significance for the extraction and utilization of CBM and disaster prevention. In the past few decades，the complex pore structures in coal have been extensively studied and classified. However，with the development of pore testing technology and the further understanding of the CBM oc⁃ currence and migration characteristics in coal，the existing pore classification methods of coal have their own defects. Therefore，previous pore classification methods of coal are reviewed systematically. Based on the authors′research re⁃ sults on the CH4 occurrence and migration characteristics in coal， a new pore classification method is proposed for the coal⁃CH4 system. The pore structures in coal are divided into four types: inaccessible pores ( 100 nm). In addition，the existence mode of different pores in coal (filling pores，diffusion pores and seepage pores) is formed in series with each other，and the existence mode of the same pores is formed in parallel with each other. As the source of CBM migration in coal，the CH4 molecules are mainly adsorbed in the filling pores in the form of mi⁃ cropore filling. The adsorbed CH4 in the filling pores continuously provides constant CH4 molecules for the CBM migra⁃ tion in the diffusion pores. The flowing CH4 molecules in the diffusion pore are also aggregated into the seepage pore and continuously seep into the drainage hole or coal roadway. This new pore classification method more intuitively summarizes the CBM occurrence forms in the pore structures of different sizes (micropore filling adsorption state，mon⁃ olayer adsorption state，and free state) and its migration laws.It provides a theoretical basis for further studying the CBM occurrence and migration in coal from the perspective of combining micro and macro.
coal;methane;micropore filling;diffusion;seepage;pore classification
1 煤孔隙分类方法综述
2 新孔隙分类方法基础
2.1 甲烷微孔填充理论
2.2 甲烷渗流流动
2.3 甲烷扩散流动
3 新孔隙分类方法
3.1 孔隙分类
3.2 煤中不同孔隙的分布特征
3.3 不同孔隙中瓦斯的赋存特性
3.4 不同孔隙中瓦斯的运移特性
4 结论
图(9) / 表(0)
主办单位：煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会
煤炭学报 
2023年第01期 
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