A regional CO ₂ containment assessment of the northern Utsira Formation seal and overburden, northern North Sea

[Containment Confidence (CC) analysis of the seal and overburden, applied to northern Utsira Fm. (a) Workflow followed provide a regional CC summary. (b) Schematic scenarios ond overburden bypass that could result in migration out through overburden. (c) Well data tied seismic showing typical response sandstone mudstone interfaces. URU, Upper Regional Unconformity; sandst., sandstone; int., interval , Abstract Upscaling Carbon Capture Storage requires identification suitable storage sites, with robust reservoir seals. The Formation North Sea has been flagged as target for further storage. However, there are no studies variability addressing heterogeneities facilitate bypass. This study aims to: identify, assess map elements promote or restrict fluid migration, develop matrix regionally containment confidence rank different areas CO2 across Formation. were mapped using high?resolution, pre?stack depth?migrated 3D broadband reflection dataset 141 exploration wells. Seal geometry, presence connectivity assigned relative scores, which summed overall Indicators shallow gas correlated other elements. Areas lowest west Here, sandstones within Interval connected via sandy submarine fans. In southeast, dipping stratigraphy downlaps onto Fm., increasing potential connection glacially?derived channel?lobe systems highest central northeast parts where is mudstone?dominated parallel reservoir, identified Overburden disconnected from reservoir. area coincides thick depocentre These results can be used inform site selection constrain future plume simulation analyses outlined here also adapted reservoirs any setting.]