基于压汞法的宏观煤岩组分孔隙结构差异性研究  

Study on difference of pore structure in macroscopic coal rock composition based on mercury intrusion method

作　　者：贾雪梅[1] 蔺亚兵[2,3] 陈龙 张辉[2] JIA Xuemei;LIN Yabing;CHEN Long;ZHANG Hui(Shannxi Energy Institute,Xianyang 712000,China;College of Geology and Environment,Xi’an University of Science and Technology,Xi'an 710054,China;Center for Post-doctoral Studies of Geological Resources and Geological Engineering,Xi’an University of Science and Technology,Xi'an 710054,China;Shaanxi Coalbed Methane Development Company Limited,Xi'an 710119,China)

机构地区：[1]陕西能源职业技术学院,陕西咸阳712000 [2]西安科技大学地质与环境学院,陕西西安710054 [3]西安科技大学地质资源与地质工程博士后科研流动站,陕西西安710054 [4]陕西省煤层气开发利用有限公司,陕西西安710119

出　　处：《煤矿安全》2022年第6期19-25,共7页Safety in Coal Mines

基　　金：陕西省重点研发计划资助项目(2018GY-094)。

摘　　要：为了研究不同宏观煤岩孔隙结构及其差异性,采集了黄陇煤田和晋城矿区的8组煤样,对宏观煤岩组分中的镜煤和暗煤剥离处理,采用压汞实验方法并借助分形理论研究了镜煤和暗煤的孔隙结构差异性。研究结果表明:镜煤和暗煤压汞曲线形态差异明显;镜煤相比暗煤具有进汞饱和度和排驱压力低,退汞效率和中值压力高的特点;镜煤具有大孔和微裂隙发育且孔隙分选性好的特点,孔隙形态以半封闭型为主,具有较强的渗透能力,但大孔和小孔之间的联通性较差;暗煤孔隙结构具有平均孔径大,尤其是200 nm左右的扩散孔较为发育,致使大孔和小孔之间的孔隙联通性好,孔隙形态以开放型为主,具有较强的扩散能力;暗煤分形维数D2整体上要高于镜煤,说明暗煤大孔径段孔隙结构较镜煤复杂;镜煤和暗煤在煤层中呈互层状产出更有利于增强孔隙联通性,提高煤储层的解吸、扩散和渗流能力。In order to study the pore structures and their difference of different macroscopic coal rocks,eight groups of coal samples from Huanglong Coalfield and Jincheng Mining Area were collected,and the difference of pore structure between vitrain and durain was studied by mercury intrusion test and fractal theory.The results of the study show that the difference in the shape of mercury pressure curves between vitrain and durain is obvious.Compared with durain,vitrain has the characteristics of low mercury saturation and displacement pressure,high mercury removal efficiency and median pressure.Vitrain has the characteristics of macropores and micro-cracks development and good pore sorting characteristics.The pore shape is mainly semi-closed and has strong permeability,but the connectivity between macropores and transition is poor.The pore structure of durain has a large average pore diameter,especially the diffusion pores around 200 nm are relatively developed,which makes the pores between the macropores pores and the transition pores have good connectivity,and the pore shape is mainly open type with strong diffusion ability.The fractal dimension D2of the durain is higher than that of the vitrain in general,which shows that the large-scale pore structure of the durain is more complex than that of the vitrain.The mutual layered structure of the two coals in the coal seam is more conducive to enhance the pore connectivity and improve the ability of desorption,diffusion and seepage in the coal seam.

关 键 词：孔隙特征 宏观煤岩组分 非均质性 压汞法 分形理论 

分 类 号：TD712[矿业工程—矿井通风与安全]