Factors influencing methane diffusion behaviors in micro-nano coal pores: a comprehensive study

作     者：Xianglong FANG Dameng LIU Yingfang ZHOU Xiaobo LIU Yidong CAI Xianglong FANG;Dameng LIU;Yingfang ZHOU;Xiaobo LIU;Yidong CAI

作者机构：School of Energy ResourcesChina University of GeosciencesBeijing 100083China Coal Reservoir Laboratory of National Engineering Research Center of CBM Development&UtilizationChina University of GeosciencesBeijing 100083China School of EngineeringFraser Noble BuildingKing's CollegeUniversity of AberdeenAB243UE AberdeenUK Postdoctoral Workstation of Applied Technology Research InstituteNortheast Petroleum UniversityDaqing 163318China 

出 版 物：《Frontiers of Earth Science》 (地球科学前沿（英文版）)

年 卷 期：2023年第17卷第1期

页      面：71-86页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：This research was funded by the National Natural Science Foundation of China(Grant Nos.41922016,41830427,and 41772160) the Fundamental Research Funds for the Central Universities(No.2652019264) 

主　　题：coalbed methane reservoir micro-characteristic diffusion coefficient grey relational analysis 

摘      要：Gas diffusion in the coal matrix plays a significant role in forecasting the production performance of coalbed methane(CBM)*** better understand methane diffusion behavior,a systematic study was performed on various rank coals with vitrinite reflectance(Ro,m)ranging from 0.46%to 2.79%.Multiple experiments,including coal petrographic analysis,field emission scanning electron microscopy(FESEM),low-temperature N2 adsorption/desorption,and mercury intrusion porosimetry(MIP),were conducted to quantitatively characterize the multiscale micro-nano pore system in different rank coals,which showed that the pore structure of coals exhibited a multimodal pore size and volume *** adsorption-diffusion experiments using the volumetric method were also performed to understand the methane diffusion characteristics in the micro-nano pores of the coal *** applicability of the multiporous diffusion model is verified,and methane diffusion in the multi-scale pores of coal reservoirs exhibits the characteristics of early fast diffusion,transitional diffusion in the medium term,and slow diffusion in the later *** addition,the factors affecting methane diffusion in coals were systematically analyzed,and gray relational analysis(GRA)was employed to analyze and identify the importance of these factors on methane *** results show the impact ranking of factors,in order from the most important to the least:particle sizemoisturesurface areapore volumepressurecoal ranktemperature in all of three diffusion *** findings are helpful for forecasting production performance and enhancing the production efficiency of CBM.