Neutron imaging of rock mechanics experiments

Understanding the mechanical behaviour of porous rocks and how this influences the fluid flow is key in a number of resource engineering challenges, in particular hydrocarbon production and CO2 sequestration. Deformation in these porous materials is, in general, not homogeneous, as deformation localises into narrow shear or compaction bands, which might then evolve into fractures. These local deformation features can act as barriers or conduits for fluid flow, depending on their evolution and resultant properties. This work focusses on achieving quantitative understanding of how localised deformation (shear or compaction bands and fractures) can change (local and global) permeability in porous rocks. In particular the aim is to overcome limitations of traditional methods for permeability measurement, which consider bulk sample measurements, and do not provide a good understanding of the permeability variations in the presence of material heterogeneity, e.g., localised deformations. Better understanding of the controlling factors on permeability evolution due to localised deformation requires mapping of the full permeability and strain fields through test specimens. Neutron tomography, in combination with 3D-volumetric Digital Image Correlation (3DDIC) is used to measure deformation and fast neutron radiography is used to visualise fluid-flow through the characterised deformed samples.