Developing a framework for managing the long term storage of CO2 in geological formations

Publisher Summary Risk assessment should be actively used at all stages, before, during and after injection. It is used to identify the key risks that require specific attention for all sites and to inform monitoring strategy. During site selection and evaluation, well and 3D seismic data must be considered essential, and more new data acquisition will normally be required for aquifer options. Understanding the processes and potential leakage mechanisms is vital in developing the framework for managing geological storage. In considering performance criteria, it is important to recognize that the amount of mobile CO2, with potential for leakage as a separate phase diminishes after injection, thereby reducing the risk of leakage. Leakage mechanisms are fairly well understood, although the kinetics and quantification require further research. The local risk of high flux leakage and release is primarily from wells, faults, and possible local overburden accumulators. Seal presence, trap integrity and fault presence and the risk from old wells need to be rigorously assessed in the site selection phase.