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| Titel |
BIB-SEM of representative area clay structures paving towards an alternative model of porosity |
| VerfasserIn |
G. Desbois, J. L. Urai, M. Houben, S. Hemes, J. Klaver |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250059264
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| Zusammenfassung |
| A major contribution to understanding the sealing capacity, coupled flow, capillary processes and associated deformation in clay-rich geomaterials is based on detailed investigation of the rock microstructures. However, the direct characterization of pores in representative elementary area (REA) and below µm-scale resolution remains challenging. To investigate directly the mm- to nm-scale porosity, SEM is certainly the most direct approach, but it is limited by the poor quality of the investigated surfaces. The recent development of ion milling tools (BIB and FIB; Desbois et al, 2009, 2011; Heath et al., 2011; Keller et al., 2011) and cryo-SEM allows respectively producing exceptional high quality polished cross-sections suitable for high resolution porosity SEM-imaging at nm-scale and investigating samples under wet conditions by cryogenic stabilization. This contribution focuses mainly on the SEM description of pore microstructures in 2D BIB-polished cross-sections of Boom (Mol site, Belgium) and Opalinus (Mont Terri, Switzerland) clays down to the SEM resolution. Pores detected in images are statistically analyzed to perform porosity quantification in REA. On the one hand, BIB-SEM results allow retrieving MIP measurements obtained from larger sample volumes. On the other hand, the BIB-SEM approach allows characterizing porosity-homogeneous and -predictable islands, which form the elementary components of an alternative concept of porosity/permeability model based on pore microstructures.
Desbois G., Urai J.L. and Kukla P.A. (2009) Morphology of the pore space in claystones - evidence from BIB/FIB ion beam sectioning and cryo-SEM observations. E-Earth, 4, 15-22.
Desbois G., Urai J.L., Kukla P.A., Konstanty J. and Baerle C. (2011). High-resolution 3D fabric and porosity model in a tight gas sandstone reservoir: a new approach to investigate microstructures from mm- to nm-scale combining argon beam cross-sectioning and SEM imaging . Journal of Petroleum Science and Engineering, 78: 243-257.
Heath J.E., Dewers T.A., McPherson B.J.O.L., Petrusak R., Chidsey, Jr. T.C., Rinehart A.J., and Mozley P.S. (2011) Pore networks in continental and marine mudstones: Characteristics and controls on sealing behavior. Geosphere; 7, 429–454.
Keller L.M., Holzer L., Wepf R., Gasser P. (2011). 3D geometry and topology of pore pathways in Opalinus clay: Implications for mass transport, Apllied Clay Sciences, 52, 85-95. |
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