Pore structure and fractal characteristics of coals by μCT technology
Author(s): YAN Ji-wei, YAO Hui-fang, LI Wei, KANG Zhi-qin, FENG Zeng-chao
Pages: 151-156
Year: 2015 Issue: 6
Journal: China Mining Magazine
Keyword: pore structure; Micro-CT; fractal dimension; box-counting method;
Abstract: Pore structure is one of important factors affecting the gas adsorption and transportation of coal .The advanced ,nondestructive ,and quantitative characterization of pore distribution for 4 coal samples was obtained through a micro‐CT system μCT225kVFCB .The influence of coal rank ,maceral composition and ash content on pore structure was also discussed .The sequence of divisors algorithm of box‐counting method was applied to quantify the complex and irregular pore structure and the relationship between porosity ,permeability and fractal dimension was explored .The results show that the maceral composition contents control the pore distribution for the coal studied .The mineral‐matter filling also contributes to the reduction of porosity ,the mean pore diameter and pore numbers . The variation of fractal dimension is closely related to the characteristics of pore distribution ,which effectively reflects the heterogeneity of pore structure .There is a strong positive correlation between porosity ,permeability and the fractal dimension . Hence ,the fractal dimension of coals obtained by μCT segmentation method can be used as one of the quantitative indexes for evaluation of pore characteristics and permeability of coal reservoir .
Pages: 151-156
Year: 2015 Issue: 6
Journal: China Mining Magazine
Keyword: pore structure; Micro-CT; fractal dimension; box-counting method;
Abstract: Pore structure is one of important factors affecting the gas adsorption and transportation of coal .The advanced ,nondestructive ,and quantitative characterization of pore distribution for 4 coal samples was obtained through a micro‐CT system μCT225kVFCB .The influence of coal rank ,maceral composition and ash content on pore structure was also discussed .The sequence of divisors algorithm of box‐counting method was applied to quantify the complex and irregular pore structure and the relationship between porosity ,permeability and fractal dimension was explored .The results show that the maceral composition contents control the pore distribution for the coal studied .The mineral‐matter filling also contributes to the reduction of porosity ,the mean pore diameter and pore numbers . The variation of fractal dimension is closely related to the characteristics of pore distribution ,which effectively reflects the heterogeneity of pore structure .There is a strong positive correlation between porosity ,permeability and the fractal dimension . Hence ,the fractal dimension of coals obtained by μCT segmentation method can be used as one of the quantitative indexes for evaluation of pore characteristics and permeability of coal reservoir .
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