Multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress

Gas permeability (k) and porosity (f) are the most important parameters in CBM/ECBM and CCS in deep unmineable coal seams. k and f depend on the coal microstructure, and k and f significantly change with varying effective stress. However, how the coal microstructure is related to such permeability a...

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Main Authors: Zhang, Yihuai, Xu, X., Lebedev, Maxim, Sarmadivaleh, Mohammad, Barifcani, Ahmed, Iglauer, Stefan
Format: Journal Article
Published: 2016
Online Access:http://hdl.handle.net/20.500.11937/17959
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author Zhang, Yihuai
Xu, X.
Lebedev, Maxim
Sarmadivaleh, Mohammad
Barifcani, Ahmed
Iglauer, Stefan
author_facet Zhang, Yihuai
Xu, X.
Lebedev, Maxim
Sarmadivaleh, Mohammad
Barifcani, Ahmed
Iglauer, Stefan
author_sort Zhang, Yihuai
building Curtin Institutional Repository
collection Online Access
description Gas permeability (k) and porosity (f) are the most important parameters in CBM/ECBM and CCS in deep unmineable coal seams. k and f depend on the coal microstructure, and k and f significantly change with varying effective stress. However, how the coal microstructure is related to such permeability and porosity changes is only poorly understood. We thus imaged sub-bituminous coal samples at two resolutions (medium - 33.7 µm and high - 3.43 µm voxel size) in 3D with an x-ray micro-computed tomography as a function of applied effective stress; and investigated how cleat morphology, k and f are influenced by the changes in effective stress and how these parameters are interrelated. In the images, three phases were identified: microcleats (void), a mineral phase (carbonate) and the coal matrix. When effective stress increased, the cleats became narrow and closed or disconnected. This resulted in a dramatic permeability drop with increasing effective stress, while porosity decreased only linearly.
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institution Curtin University Malaysia
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spelling curtin-20.500.11937-179592018-09-04T01:45:38Z Multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress Zhang, Yihuai Xu, X. Lebedev, Maxim Sarmadivaleh, Mohammad Barifcani, Ahmed Iglauer, Stefan Gas permeability (k) and porosity (f) are the most important parameters in CBM/ECBM and CCS in deep unmineable coal seams. k and f depend on the coal microstructure, and k and f significantly change with varying effective stress. However, how the coal microstructure is related to such permeability and porosity changes is only poorly understood. We thus imaged sub-bituminous coal samples at two resolutions (medium - 33.7 µm and high - 3.43 µm voxel size) in 3D with an x-ray micro-computed tomography as a function of applied effective stress; and investigated how cleat morphology, k and f are influenced by the changes in effective stress and how these parameters are interrelated. In the images, three phases were identified: microcleats (void), a mineral phase (carbonate) and the coal matrix. When effective stress increased, the cleats became narrow and closed or disconnected. This resulted in a dramatic permeability drop with increasing effective stress, while porosity decreased only linearly. 2016 Journal Article http://hdl.handle.net/20.500.11937/17959 10.1016/j.coal.2016.08.016 fulltext
spellingShingle Zhang, Yihuai
Xu, X.
Lebedev, Maxim
Sarmadivaleh, Mohammad
Barifcani, Ahmed
Iglauer, Stefan
Multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress
title Multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress
title_full Multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress
title_fullStr Multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress
title_full_unstemmed Multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress
title_short Multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress
title_sort multi-scale x-ray computed tomography analysis of coal microstructure and permeability changes as a function of effective stress
url http://hdl.handle.net/20.500.11937/17959