Research highlight (UU) - mechanical and transport properties of simulated gouge-filled faults

In the context of studying the integrity of faulted and fractured clay-rich caprocks, UU has carried out experiments on the mechanical and transport properties of simulated gouge-filled faults

Evolution of the friction coefficient with shear displacement for the experiments on different Opalinus clay plus added calcite mixtures.

A systematic study of the coupled chemical-mechanical effect of calcite dissolution and precipitation through interactions with CO2 on the strength and slip stability of simulated fault gouges shows that the frictional strength increases with an increasing calcite content and can be characterised as stable, aseismic behaviour. Unstable, potentially seismogenic behaviour is only observed for gouges containing >90% calcite, a compositional shift from typical caprock mineralogy which is highly unlikely, even in worst-case leakage scenarios. Moreover, for typical clay-carbonate-quartz fault gouges, shearing causes a rapid reduction in gouge permeability from transient initial values. 

Dernière mise à jour le 18.08.2015