Fault seal analysis of a natural CO2 reservoir in the Southern North Sea

A geomechanical and fault seal analysis of the fault-bound natural CO2 reservoir of the Fizzy Field, Southern North Sea, shows that reactivation of, and leakage along the bounding fault is unlikely. Reservoirs are juxtaposed along the fault but shale-gouge ratio calculations indicate that the fault rock prohibits across-fault leakage of CO2. This study illustrates that, even though the fault is orientated favourably for reactivation relative to present day stress and uncertainties about the geometries remain, fault seal is not the limiting factor in retention of CO2 at the Fizzy field.