This document is a supporting document to deliverable MS6.1 UK Storage Appraisal Final Report.
All the aquifer storage Units identified in Work Package 1 have been assessed under two technical categories of risk: containment and operational.The method adopted to evaluate risk is based on a ‘Features, Events and Processes’ approach similar to the methods used or recommended in other geological storage site evaluation projects. Containment risk refers to leakage from the storage Unit, while operational risk is concerned with the likelihood that injection operations will be disrupted due to subsurface conditions. Likelihood and confidence data were collected and interpreted for each storage Unit.
The highest frequency containment risk items in terms of impact on storage capacity include all faults, lateral migration and wells, and the risk of seal degradation.The latter reflects geological variability in seal quality across laterally extensive storage Units, while the former, partly the result of the conservative approach to fault risk assessment also shows that faults are a key feature at the majority of storage sites and consequently deserve immediate attention in site appraisal. Cost impact assessment using the same likelihood data leads to an elevation of lateral migration risks, with structural, depositional and dip magnitude controls the most important i.e. most frequent high risk items. Identification of the most common high risk items across the UKCS helps provide direction for future study to characterise the impact of the most important risk items.
All the aquifer storage Units identified in Work Package 1 have been assessed under two technical categories of risk: containment and operational.The method adopted to evaluate risk is based on a ‘Features, Events and Processes’ approach similar to the methods used or recommended in other geological storage site evaluation projects. Containment risk refers to leakage from the storage Unit, while operational risk is concerned with the likelihood that injection operations will be disrupted due to subsurface conditions. Likelihood and confidence data were collected and interpreted for each storage Unit.
The highest frequency containment risk items in terms of impact on storage capacity include all faults, lateral migration and wells, and the risk of seal degradation.The latter reflects geological variability in seal quality across laterally extensive storage Units, while the former, partly the result of the conservative approach to fault risk assessment also shows that faults are a key feature at the majority of storage sites and consequently deserve immediate attention in site appraisal. Cost impact assessment using the same likelihood data leads to an elevation of lateral migration risks, with structural, depositional and dip magnitude controls the most important i.e. most frequent high risk items. Identification of the most common high risk items across the UKCS helps provide direction for future study to characterise the impact of the most important risk items.