Topseal Leakage in Mounded Cenozoic Northern North Sea Sediments: Implications for Containment of Injected CO2

Summary Buoyant fluids appear to flow through caprock sequences in discrete flowpaths rather than in pore networks above Oligocene and Miocene sandstones in the Northern North Sea. This result stems from analyses of seismic data in the overburden rocks. It is consistent with observations of hydrocarbon composition in shallow sediments and with observations from other basins. These findings suggest that the risk of leakage of CO2 stored in these sediments can be reduced but not removed.