Understanding fluid transport through ...
Document type :
Article dans une revue scientifique
Permalink :
Title :
Understanding fluid transport through claystones from their 3D nanoscopic pore network
Author(s) :
Song, Yang [Auteur]
Davy, Catherine [Auteur]
Bertier, Pieter [Auteur]
Troadec, David [Auteur]
Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Davy, Catherine [Auteur]

Bertier, Pieter [Auteur]
Troadec, David [Auteur]

Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 [IEMN]
Journal title :
Microporous and Mesoporous Materials
Volume number :
228
Pages :
64-85
Publication date :
2016-07-01
HAL domain(s) :
Chimie/Matériaux
English abstract : [en]
This paper investigates the complex and nanoscopic pore network of claystones, after their retrieval from the geological layer, and their further conditioning and drying, as it is usually done to assess their fluid ...
Show more >This paper investigates the complex and nanoscopic pore network of claystones, after their retrieval from the geological layer, and their further conditioning and drying, as it is usually done to assess their fluid permeability (i.e. their transport properties). Following the leading research of Keller et al. [1] on the Swiss Opalinus clay, and because no percolating pore network is obtained at bigger scales, we provide micrometric pore volumes for a French Toarcian claystone and for a Callovo-Oxfordian claystone [2], by Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) imaging. The voxel size ranges from 5.94 × 7.54 × 10 nm3 to 8.49 × 10.78 × 50 nm3, and the investigated volumes range between 28 and 553 μm3. Comparison with nitrogen adsorption data is proposed. One originality of our research is to prepare the samples as for the assessment of macroscopic fluid transport, by moderate drying at centimetric size. It is observed that, at the scale imaged by FIB/SEM, fluid transport occurs through very limited percolating parts of the pore network (0.7–2.1%). For both claystones, pore volumes generally percolate by sub-micrometric cracks, attributed to drying, and more seldomly by tortuous parts (not of a crack nature). Fluid transport is predicted by Katz–Thompson equation from the 3D geometry of the shortest percolating path. This provides permeability values on the order of 10−21–10−20 m2 (1–10 nD), in good agreement with experimental data. This study hints at a mechanism of fluid transport by fingering through pores as small as 20 nm diameter, rather than homogeneously through the whole claystone volume.Show less >
Show more >This paper investigates the complex and nanoscopic pore network of claystones, after their retrieval from the geological layer, and their further conditioning and drying, as it is usually done to assess their fluid permeability (i.e. their transport properties). Following the leading research of Keller et al. [1] on the Swiss Opalinus clay, and because no percolating pore network is obtained at bigger scales, we provide micrometric pore volumes for a French Toarcian claystone and for a Callovo-Oxfordian claystone [2], by Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) imaging. The voxel size ranges from 5.94 × 7.54 × 10 nm3 to 8.49 × 10.78 × 50 nm3, and the investigated volumes range between 28 and 553 μm3. Comparison with nitrogen adsorption data is proposed. One originality of our research is to prepare the samples as for the assessment of macroscopic fluid transport, by moderate drying at centimetric size. It is observed that, at the scale imaged by FIB/SEM, fluid transport occurs through very limited percolating parts of the pore network (0.7–2.1%). For both claystones, pore volumes generally percolate by sub-micrometric cracks, attributed to drying, and more seldomly by tortuous parts (not of a crack nature). Fluid transport is predicted by Katz–Thompson equation from the 3D geometry of the shortest percolating path. This provides permeability values on the order of 10−21–10−20 m2 (1–10 nD), in good agreement with experimental data. This study hints at a mechanism of fluid transport by fingering through pores as small as 20 nm diameter, rather than homogeneously through the whole claystone volume.Show less >
Language :
Anglais
Audience :
Internationale
Popular science :
Non
Administrative institution(s) :
ISEN
Univ. Valenciennes
ENSCL
CNRS
Institut Catholique Lille
Centrale Lille
Univ. Artois
Université de Lille
Univ. Valenciennes
ENSCL
CNRS
Institut Catholique Lille
Centrale Lille
Univ. Artois
Université de Lille
Collections :
Research team(s) :
Chimie, matériaux et procédés pour un nucléaire durable (CIMEND)
Submission date :
2019-09-25T14:38:06Z