Risk Assessment of the Geological Storage of CO2: A Review

Abstract

The geological storage of carbon dioxide (CO2) is a key approach that responds to climate change by reducing the emission of anthropogenic greenhouse gases. However, the CO2 that is injected into deep geological formations can possibly leak into the paths of wells, cap rock, geological faults, and fractures. Such leakage could allow the CO2 to move into shallow geological formations or into the atmosphere, thereby polluting shallow underground water, soil, rivers, lakes, and air, all of which could damage the ecological system and cause hazards to human health. Risk assessment studies have identified the main risk scenarios and identified the potential threats and vulnerabilities in order to guarantee the safe and secure storage of captured CO2. Many qualitative and quantitative methods have been developed and used in existing CCS/CCUS (Carbon dioxide Capture and Storage/Carbon dioxide Capture, Utilization and Storage) projects or assumed sites, such as CO2-FEP (Feature, Event, and Process), Certification Framework, RISQUE (Risk Identification and Strategy using QUantitative Evaluation), and others. Risk assessment is the overall process of identifying, analyzing, and evaluating potential risks. In this chapter, the health, safety, and environmental risks associated with the geological storage of CO2 are addressed in detail. Various assessment methods for different stages of the risk management are discussed, including the application of risk assessment practices in various field cases. The risk management measures, which include monitoring, remediation, and emergency plans, also are reviewed for use by engineers, technicians, and policy makers.