This poster on the UKCCSRC Call 1 project Fault Seal Controls on Aquifer CO2 Storage Capacity was presented at the CSLF Call project poster reception, London, 27.06.16. Grant number: UKCCSRC-C1-14. Structural traps for storage of supercritical CO2 will commonly rely on a component of fault seal. Faults are among the most important natural potential migration pathways for buoyant fluids stored in reservoir rocks. Failure of storage integrity may occur either by mechanical failure or by flow across faults due to geometric juxtaposition of the reservoir against similarly permeable rocks and/or lack of a low permeability fault gouge. This project aimed to reduce uncertainty relating to the sealing capacity of faults affecting prospective North Sea saline aquifers, by: • Studying the controls on fault seal capability in naturally-occurring fault-bound CO2 accumulations (Fizzy and Oak), • Assessing the geomechanical stability of faults affecting an important saline aquifer offshore UK (Captain Sandstone), • Investigating the characteristics of apparently hydraulically-conductive faults in the North Sea (Netherlands).