CCS research by the Fracture Physics Laboratory

Setting up the angled shear rig to look at fault reactivation during pressure changes during CCS.

Electronics engineer setting up National Instruments' LabView data logging system.

Led by Robert Cuss.

The fracture physics laboratory collaborates with other fluid processes researchers such as Caroline Graham in the Transport Properties Research Laboratory and will do future work with Simon Gregory in the Geomicrobiology Laboratory.

The areas of CCS that this laboratory is working on are outlined below.

Fractures and faults

CO2 is set to be stored underground in a geological formation known as a reservoir. To trap the CO2 and stop it from getting back to the surface, the reservoir rock must be located directly under a caprock. The caprock's physical properties restrict fluid flow so that it is difficult for anything to travel through easily.

It is important to ensure that the CO2 stays trapped where it should be, and this laboratory carries out research into caprock physical properties and investigates the physical limits to see when caprocks will fracture. The fracture physics laboratory has specialist equipment that allows us to study fluid flow along both natural and artificial fractures and faults. This helps us to understand the response of the rock during injection and storage. Knowing the strength limits of the caprock allows us to set pressure limits for the injection of CO2 in order to minimise earthquake and leakage risks.

Current projects

In the BIGCCS project, we are looking at the possibilities of movement in natural faults in underground storage (analogues). We are trying to gain an understanding of the natural faults when CO2 is injected: will the fault open and cause CO2 leakage or will it close and actually seal better than before? We do this by changing the pressure to see if the fault moves and studying the flow path of CO2 leakage to find out where the CO2 would go. We can then model this information to scale up the scenario.

The (Ultimate CO2) project (Understanding the Long-Term Fate of Geologically Stored CO2) is looking at the possibilities of movement in artificial faults in caprock samples. We are trying to gain an understanding of what the artificial faults do when CO2 is injected, compared to how natural faults react. We can trace the gas flow path along a fault in different caprock samples visually and using instruments that detect tiny earthquake-like responses as fault movement occurs.

Setting up the fracture visualisation rig to look at fracture growth in caprock material.