To assess the suitability of different sites for CO2 storage, and to track the progress of the selected site, a structured evidence-based screening is required. When large volumes of information are combined from multiple sources, there might be disputed or contradictory interpretations. Some evidence might be from hard quantitative data, while other evidence might arise from analogue reasoning or expert judgment. Therefore, in order to provide a justified interpretation of the available evidence it is necessary to make transparent judgments on both the quality of the data and their interpretation.
Quintessa has supported Shell through development of decision trees for siting of CO2 stores, including using Quintessa’s software TESLA to capture logic of decisions. TESLA analysis presented the assessment of CO2 storage sites in a logical tree-based structure with the top hypothesis supported by the key sub-hypotheses of CCS, which in turn were broken down into further sub-hypotheses component parts. Application of the TESLA tool ensured that all risks were covered, and it highlighted where a project’s weaknesses lay by tabulating the evidence supporting the main hypotheses, the evidence against the hypotheses and the uncertainty (current level of unknowns). This enabled the establishment of relative maturity and security of candidate sites within a portfolio of interest.
Quintessa has significant expertise in providing support to the decision-making process for the selection of geological sites for complex projects, including the storage of carbon dioxide and other substances. This expertise ensures all available evidence is incorporated in a structured approach and allows the transparency of the process to be demonstrated to all stakeholders.