An Introduction to the IEA GHG International Research Network on Risk Assessment

Regulators, industry and other stakeholders will need to have confidence in the predictions made by risk assessment studies for CO₂ capture and storage (CCS) activities. To gain such confidence it will be necessary to understand the different approaches available for risk assessments and the underlying assumptions. This led to the establishment of the IEA GHG Risk Assessment network in 2005. The purpose of the network is to bring together the key groups wo rking on risk assessment for CO₂ storage from around the world and to address what the regulators are expecting in regard to CCS assurance and whether risk assessment can provide the answers they require. At the launch meeting, it was agreed that the network should aim to address the expectations of regulators, and determine whether risk assessment can satisfy these expectations. The scope of the network was divided into separate areas of interest; data management and risk analysis, regulatory engagement, an d environmental impacts. Corresponding working groups focus on these issues, running alongside the research network, and report back to the whole group at the network meetings. Network activities include overviews of other related international research activities that may impact on the risk assessment network, such as the IEA GHG wellbore integrity network, provision of feedback to the working groups, reviewing risk assessment status using case studies, assessing the role of risk assessment in a risk man agement framework and determining communication strategies for results of risk assessment studies. Site characterisation was identified as an element of CCS that was heavily reliant on risk assessment, and risk assessment plays an important role in all stages of site characterisation and selection from the initial pre-screening to permitting and implementation. Natural analogues have been identified as a means of instilling confidence in CCS by generating a better understanding of leakage and trapping mecha nisms, providing verification of numerical models, and helping to communicate the safety of CO₂ storage. The network has also raised the questions of the role of risk assessment guidelines in CCS, the confidence that can be felt in numerical modelling results, the length of time monitoring programmes are required for after injection has stopped, and what value does the accident/worst case scenario hold for risk assessment. The future work for the network will be maintaining the individual working groups, and continuing to monit demonstration projects as these will provide valuable information to support numerical models and verify t worthiness of studies on analogues.