Assessment and Communication of Leakage Risk in Underground CO2 Storage

Abstract

As commonly known, carbon dioxide is one of the climate gases that contribute to greenhouse effect on the earth, thereby causing serious climate issues. So, to prevent large release of the gas into the atmosphere, storage is an option. CO2 storage is the process of capturing waste carbon dioxide (CO2) from big point sources, such as fossil fuel power plants, transporting it to a storage site, and depositing it where it does not reach the atmosphere, usually an underground geological formation. A geological formation could be an abandoned oil or gas reservoir, a salt formation or any other impermeable formation. A major concern is to ensure the possibility of leakage from these underground storages is small, when being plugged and abandoned. Most of the risk assessment methods for underground storage methods focus more on consequences and probability concept of risk, with little mentioning of quantifying uncertainties. The purpose of this thesis is to provide an overview of risk assessment methods for underground storage that has already taken place and to establish the basis for a risk management framework and risk analysis methods. Communication of risk is vital in the understanding of the situation in question and to support decision-making process; so possible recommendations will be mentioned.