A process-led approach to framing uncertainty and risk in CO ₂ storage in the subsurface

Carbon capture and storage (CCS) requires the safe, long-term storage of CO 2 in the subsurface. This challenges subsurface practitioners to build on and adapt many of the techniques and processes developed for hydrocarbon exploration and production to create innovative approaches to assessing CO 2 storage risk and uncertainty. A wide-ranging and integrated understanding of the processes controlling CO 2 behaviour in the subsurface is required to facilitate effective risk identification and characterization. In this paper we explore the different physical processes acting within storage formations and their evolution throughout the injection project life cycle to illustrate key controls on CO 2 plume behaviour and frame risk identification and characterization. An approach applying wide-reaching premortem risk identification coupled with evidence-led uncertainty characterization is described to frame inputs for detailed risk characterization and management activity during early screening of prospects for CO 2 storage.