This group studies rock deformation, fluid flow, tracer transport, and fluid-rock interactions under stress in the brittle field. We specialise in coupled physico-chemical processes, particularly their time-dependence. We use a variety of experimental, analytical, and numerical techniques to elucidate the fundamental processes at work, or to characterise constitutive rules that can be input into larger-scale models. Our unique equipment pool has allowed us to produce realistic deformation bands in the laboratory, to investigate primary diagenesis in carbonate and sandstone samples (see adjacent images), and to observe the 'suction pump' mechanism of fluid transport in rapidly-deforming rocks. Recently-completed projects have concentrated on experimental diagenesis, fault sealing mechanisms, contaminant transport in fracture systems, and stress sensitive relative permeabilities. As part of a major cluster of EU projects on the Gulf of Corinth site, we determined the mechanical and hydraulic properties of cores from a suite of boreholes in an actively-deforming extensional tectonic zone.
Our results have been used as input to a new suite of stress-sensitive hydrocarbon reservoir simulators, in collaboration VIPS Ltd, and to validate a new upscaling technique for fault sealing, in collaboration with Alastair Beach Ltd. Current projects include determining the effect of clay content on fault sealing in andstones, and the development of a post-yield damage mechanics model from observations of acoustic emissions.
As part of the Edinburgh Regional Partnership with heriot-Watt University in Subsurface Science & Engineering (ECOSSE), the group has recently been augmented by the arrival of Dr Ian Butler and a substantial equipment upgrade is now under way.
A conjugate pair of deformation bands in a 10-cm diameter core of a porous aeolian (Locharbriggs) sandstone, broken in the 'big rig'.
A limestone rock sample, injected with a sulphuric acid solution to form gypsum under conditions of constant flow rate. The reaction front is seen in the darker shades at the top of the diagram.