There is immense potential to use our underground environment in a responsible manner as we move towards a net zero carbon society. For example, deep rock formations can store captured CO2 emissions, and there is increasing flexibility in the ways that geothermal energy can be recovered.
However, our move towards these technologies should be made carefully since we need to reliably predict how the ground will react, especially given the difficulty of gathering a full picture of conditions at large depths.
This project will improve our fundamental understanding of the interplays between fluid injection and the induced microseismicity and permeability evolution of fractured rocks.
Laboratory experiments will be carried out to study the behaviour of critically stressed fractures under fluid injection, with any slippage being monitored by direct block deformation measurements in each direction, and by Acoustic Emission (AE) monitoring.
The research programme will extend this study via numerical modelling towards linking the geomechanical behaviour of fault reactivation with fluid injection.
Geomechanical behaviour during fracture slip will include the fracture opening and closure, and the shear displacement with any associated shear dilation. The flow regime and the global induced seismicity and permeability of the model domain will be investigated towards an improved understanding of injection-induced seismicity and interactions between fractures.
Outcomes from this project will lead to more accurate prediction and reduced risk of induced microseismicity, currently of practical importance to industry and public stakeholders for the development of geothermal energy and CO2 sequestration, as well as being a topic of significant interest to the general public.