Opalinus Clay

 

The Opalinus clay has been investigated thoroughly over the last forty years at the Mont Terri site (Switzerland), to analyze its hydrogeological, geochemical and rock mechanical properties. The research is aimed to provide important input for assessing the feasibility and safety of deep geological disposal of radio active waste in argillaceous formations.

This research will have its focus on the determination of the in-situ porosity of the Opalinus clay by using BIB/FIB milling techniques in combination with SEM and cryo-SEM microscopy. Detailed investigation of the morphology of the pore space in clay is a key factor in the understanding of the sealing capacity, coupled flow, capillary processes and associated deformation present in an argillaceous formation.

Maartje Houben

Sponsored by Nagra

Boom clay

 
Boom Clay is being investigated as a potential host rock for radioactive waste disposal in underground geological repositories in Belgium.
Knowing the porosity of the potential host rock is of interest, since transport of water and other fluids occurs throughout the connected pore space and thus a high interconnectivity of pores would decrease the sealing capacity of the Clay as a potential host rock for radioactive waste.

Detailed investigation of the morphology of the pore space in clay is a key factor in understanding the sealing capacity, coupled flows, capillary processes and associated deformation present in mudstones. Actually, the combination of ion milling tools (FIB and BIB), cryogenic techniques and SEM imaging offers a new alternative to study in-situ elusive microstructures in wet geomaterials and has the high potential to make a step change in our understanding of how fluids occur in pore space. By using this range of techniques, it is possible to quantify porosity, stabilize in-situ fluids in pore space, preserve the natural structures at nm-scale, produce high quality polished cross-sections for high resolution SEM imaging and reconstruct accurately microstructure networks in 3D by serial cross sectioning.

Susanne Hemes
Guillaume Desbois

Sponsored by SCK-CEN

Clay rich geo-materials

 
The wet, in-situ, high resolution porosity in clay rich geo-materials is studied by BIB-Cryo-SEM techniques. I study an immature shale from the Middle East. I will study shale samples from Jurassic shales in the US.

Jop Klaver

Sponsored by Shell

Pictures

 

BIB cryo SEM

JEOL BIB

Pore types

Microbreccia in faul...

Porosity in Boom Cla...

Porosity in BC-EZE55

Pyrite dragon

Small sample volume ...

WM injected OPA

WM in BC-EZE64 (over...

FIB-SEM sample volum...

Extracted pore netwo...

WM filled porosity B...