FRISK - Quantification of fault-related leakage risk

What we do

There is high uncertainty associated with assessing the sealing properties of faults in CO2 storage reservoirs. The impact of these uncertainties on CO2 containment can be better understood by new methods for characterizing the uncertainties in flow properties of faults and new simulation tools for incorporating along-fault leakage at the field scale. In this project, NORCE develops OPM Flow reservoir simulator to enable leakage assessment by improved modeling of transfer of flow from the reservoir to the fault zone. We also develop new algorithms to efficiently sample the uncertainty in fault flow properties when quantifying the probability of CO2 leakage rates.

Why is this important?

The planned CO2 storage site for the Longship CCS project is the Aurora site on the Horda Platform in the North Sea. The long-term business model for Longship aims to bring additional third-party CO2 sources within the Northern Lights transport and storage chain in the coming years. More sites on the Horda Platform for CO2 storage will eventually be needed to accommodate the expected increase in storage demand.

The research activities in FRISK are linked to several new storage prospects that are attractive sites for expansion but where faults have been deemed too risky given current understanding. We will focus on developing new methods for calculating how fluid migrates within faults in order to better quantify the risk of leakage for realistic scenarios, and reduce the uncertainty facing operators in maturing these sites. This work will enable decisions by operators and can contribute to unlocking faulted reservoirs in the North Sea for future use as CO2 storage sites.


The main objective in FRISK is to reduce the uncertainty in fault related leakage risk for large-scale CO2 storage by developing an improved fault derisking framework that includes dynamic pressure changes and along-fault fluid migration. NORCE activity will address this objective by developing effective fault flow models for use in reservoir simulation tools and carry out field-scale simulations to characterize along-fault leakage rates for realistic storage sites.

Project outcomes

  • Deformation bands are an important feature of the fault damage zone that may hinder fluid flow from the reservoir into the fault. We have developed a new model for estimating the effective permeability of the fault zone based on deformation band properties that can be taken from outcrop analogues and fault throw. The new model is implemented in the OPM Flow and PorePy flow simulators to accurately capture the impact of deformation bands in field-scale simulation. The results confirm that deformation bands significantly alter the fluid flow close to faults and may decrease the potential leakage of CO2 through faults.