Storage Capacity Constraints in Unconfined Saline Aquifers - Insights from the Humberside Prospect, Offshore UK

The Humberside CCS licence is ideally positioned close to major emitters and targets stacked Permian and Triassic storage units. However, despite the large theoretical capacity estimated at a play level, effective storage capacity is contingent upon addressing subsurface constraints such as plume extent; legacy wells; geological leak pathways; caprock strength; fault reactivation; and pressure interference. Transitioning from play to lead to prospect level storage resource estimation requires understanding development limits and injectivity constraints imposed by these containment risks. Additional surface constraints, including shipping routes; windfarms and cables; fisheries; and protected areas, can further limit storage potential.

Uncertainty in subsurface parameters, particularly in aquifer plays with limited data, significantly impacts capacity estimation. Acquiring appraisal data is crucial for de-risking containment and evaluating the project’s economic attractiveness, thereby reducing the chance of commercial failure. Post-appraisal residual uncertainty necessitates phased development and underscores the importance of monitoring and adaptive injection management.