Work package 2: Fault permeability and dynamic changes
The main objective of WP2 is to reduce the uncertainty in fault fluid migration both across and vertically along the faults by identifying and quantifying the critical aspects of fault properties that contribute most to leakage potential and pressure communication through a faulted system.
The starting point is field observations and experimental data, moving towards continuum/effective representation of sub-scale variation.
In the unlikely event of leakage, the most likely path is migration along pre-existing faults and fractures. The potential CO2 migration starts in the reservoir that is over-pressured due to decades of injection. To reach the fault zone, CO2 first needs to migrate past deformation structures in the storage reservoir close to the Vette bounding fault. Deformation structures in the reservoir is typical characterised by low-permeable bands, providing barriers or baffles to the flow.
The second part of the journey of the potentially leaking CO2 is upwards along the Vette fault. Fluid migration out of the reservoir may occur through the highly strained rock in the fault zone and along the slip surfaces. The hydraulic properties of the fault, particularly along the slip surface, are pressure dependent and associated with high uncertainty. Establishing likely scenarios and ranges for properties will be investigated in this work package.
Tore Ingvald Bjørnarå
Principal engineer Advanced Modelling tore.ingvald.bjornara@ngi.no+47 908 59 184