Equivalent Pore Channel Model for Fluid Flow in Rock Based on Microscale X-ray CT Imaging

Pore-scale modeling with a reconstructed rock microstructure has become a dominant technique for fluid flow characterization in rock thanks to technological improvements in X-ray computed tomography (CT) imaging. A new method for the construction of a pore channel model from micro-CT image analysis...

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Main Authors: Chae-Soon Choi, Yong-Ki Lee, Jae-Joon Song
Format: Article
Language:English
Published: MDPI AG 2020-06-01
Series:Materials
Subjects:
Online Access:https://www.mdpi.com/1996-1944/13/11/2619
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author Chae-Soon Choi
Yong-Ki Lee
Jae-Joon Song
author_facet Chae-Soon Choi
Yong-Ki Lee
Jae-Joon Song
author_sort Chae-Soon Choi
collection DOAJ
description Pore-scale modeling with a reconstructed rock microstructure has become a dominant technique for fluid flow characterization in rock thanks to technological improvements in X-ray computed tomography (CT) imaging. A new method for the construction of a pore channel model from micro-CT image analysis is suggested to improve computational efficiency by simplifying a highly complex pore structure. Ternary segmentation was applied through matching a pore volume experimentally measured by mercury intrusion porosimetry with a CT image voxel volume to distinguish regions denoted as “apparent” and “indistinct” pores. The developed pore channel model, with distinct domains of different pore phases, captures the pore shape dependence of flow in two dimensions and a tortuous flow path in three dimensions. All factors determining these geometric characteristics were identified by CT image analysis. Computation of an interaction flow regime with apparent and indistinct pore domains was conducted using both the Stokes and Brinkman equations. The coupling was successfully simulated and evaluated against the experimental results of permeability derived from Darcy’s law. Reasonable agreement was found between the permeability derived from the pore channel model and that estimated experimentally. However, the model is still incapable of accurate flow modeling in very low-permeability rock. Direct numerical simulation in a computational domain with a complex pore space was also performed to compare its accuracy and efficiency with the pore channel model. Both schemes achieved reasonable results, but the pore channel model was more computationally efficient.
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spelling doaj.art-99a81b164b6c41d3abf08bd2d54be7282023-11-20T03:11:57ZengMDPI AGMaterials1996-19442020-06-011311261910.3390/ma13112619Equivalent Pore Channel Model for Fluid Flow in Rock Based on Microscale X-ray CT ImagingChae-Soon Choi0Yong-Ki Lee1Jae-Joon Song2Department of Energy Resources Engineering, Research Institute of Energy and Resources, Seoul National University, Seoul 04750, KoreaDepartment of Energy Resources Engineering, Research Institute of Energy and Resources, Seoul National University, Seoul 04750, KoreaDepartment of Energy Resources Engineering, Research Institute of Energy and Resources, Seoul National University, Seoul 04750, KoreaPore-scale modeling with a reconstructed rock microstructure has become a dominant technique for fluid flow characterization in rock thanks to technological improvements in X-ray computed tomography (CT) imaging. A new method for the construction of a pore channel model from micro-CT image analysis is suggested to improve computational efficiency by simplifying a highly complex pore structure. Ternary segmentation was applied through matching a pore volume experimentally measured by mercury intrusion porosimetry with a CT image voxel volume to distinguish regions denoted as “apparent” and “indistinct” pores. The developed pore channel model, with distinct domains of different pore phases, captures the pore shape dependence of flow in two dimensions and a tortuous flow path in three dimensions. All factors determining these geometric characteristics were identified by CT image analysis. Computation of an interaction flow regime with apparent and indistinct pore domains was conducted using both the Stokes and Brinkman equations. The coupling was successfully simulated and evaluated against the experimental results of permeability derived from Darcy’s law. Reasonable agreement was found between the permeability derived from the pore channel model and that estimated experimentally. However, the model is still incapable of accurate flow modeling in very low-permeability rock. Direct numerical simulation in a computational domain with a complex pore space was also performed to compare its accuracy and efficiency with the pore channel model. Both schemes achieved reasonable results, but the pore channel model was more computationally efficient.https://www.mdpi.com/1996-1944/13/11/2619sandstonemicro-CT image analysiscoupled pore channel modelpermeabilitydirect numerical simulation
spellingShingle Chae-Soon Choi
Yong-Ki Lee
Jae-Joon Song
Equivalent Pore Channel Model for Fluid Flow in Rock Based on Microscale X-ray CT Imaging
Materials
sandstone
micro-CT image analysis
coupled pore channel model
permeability
direct numerical simulation
title Equivalent Pore Channel Model for Fluid Flow in Rock Based on Microscale X-ray CT Imaging
title_full Equivalent Pore Channel Model for Fluid Flow in Rock Based on Microscale X-ray CT Imaging
title_fullStr Equivalent Pore Channel Model for Fluid Flow in Rock Based on Microscale X-ray CT Imaging
title_full_unstemmed Equivalent Pore Channel Model for Fluid Flow in Rock Based on Microscale X-ray CT Imaging
title_short Equivalent Pore Channel Model for Fluid Flow in Rock Based on Microscale X-ray CT Imaging
title_sort equivalent pore channel model for fluid flow in rock based on microscale x ray ct imaging
topic sandstone
micro-CT image analysis
coupled pore channel model
permeability
direct numerical simulation
url https://www.mdpi.com/1996-1944/13/11/2619
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AT yongkilee equivalentporechannelmodelforfluidflowinrockbasedonmicroscalexrayctimaging
AT jaejoonsong equivalentporechannelmodelforfluidflowinrockbasedonmicroscalexrayctimaging