Multi-scale pore fractal characteristics of differently ranked coal and its impact on gas adsorption

作     者：Zhongbei Li Ting Ren Xiangchun Li Ming Qiao Xiaohan Yang Lihai Tan Baisheng Nie Zhongbei Li;Ting Ren;Xiangchun Li;Ming Qiao;Xiaohan Yang;Lihai Tan;Baisheng Nie

作者机构：School of CivilMiningEnvironmental and Architectural EngineeringUniversity of WollongongNew South Wales 2522Australia School of Safety EngineeringChina University of Mining and TechnologyXuzhou 221116China School of Emergency Management and Safety EngineeringChina University of Mining and Technology-BeijingBeijing 100083China State Key Laboratory of Coal Mine Disaster Dynamics and ControlSchool of Resources and Safety EngineeringChongqing UniversityChongqing 400044China 

出 版 物：《International Journal of Mining Science and Technology》 (矿业科学技术学报（英文版）)

年 卷 期：2023年第33卷第4期

页      面：389-401页

核心收录：

学科分类：0820[工学-石油与天然气工程] 08[工学] 082002[工学-油气田开发工程] 

基　　金：The first author would like to express sincere appreciation for the scholarship provided by China Scholarship Council(No.202006430006)and University of Wollongong financially supported by the ACARP Project C28006 the National Key Research and Development Program of China(No.2018YFC0808301) the Natural Science Foundation of Beijing Municipality,China(No.8192036) 

主　　题：Multi-scale pore structure Fractal theory Fractal characteristics Differently ranked coal Coalbed gas adsorption 

摘      要：Well-developed pores and cracks in coal reservoirs are the main venues for gas storage and *** investigate the multi-scale pore fractal characteristics,six coal samples of different rankings were studied using high-pressure mercury injection(HPMI),low-pressure nitrogen adsorption(LPGA-N2),and scanning electron microscopy(SEM)test *** on the Frankel,Halsey and Hill(FHH)fractal theory,the Menger sponge model,Pores and Cracks Analysis System(PCAS),pore volume complexity(D_(v)),coal surface irregularity(Ds)and pore distribution heterogeneity(D_(p))were studied and evaluated,*** effect of three fractal dimensions on the gas adsorption ability was also analyzed with high-pressure isothermal gas adsorption *** show that pore structures within these coal samples have obvious fractal characteristics.A noticeable segmentation effect appears in the Dv1and Dv2fitting process,with the boundary size ranging from 36.00 to 182.95 nm,which helps differentiate diffusion pores and seepage *** D values show an asymmetric U-shaped trend as the coal metamorphism increases,demonstrating that coalification greatly affects the pore fractal *** three fractal dimensions can characterize the difference in coal microstructure and reflect their influence on gas adsorption *** volume(V_(L))has an evident and positive correlation with Dsvalues,whereas Langmuir pressure(P_(L))is mainly affected by the combined action of Dvand *** study will provide valuable knowledge for the appraisal of coal seam gas reservoirs of differently ranked coals.