A New Look at the Geology and Prospectivity of a North Sea Frontier Area with Modern Seismic - The East Shetland Platform

The greater East Shetland Platform (ESP) area is characterized by numerous proven Devonian-Eocene fields, but is still one of the few remaining underexplored regions of the UK Continental Shelf. In particular, Permo-Carboniferous carbonates and sandstones, Devonian sandstones and fractured basement in prominent structural traps have been successful, proving these units to be viable reservoirs. Some of these are large producing fields in nearby areas (e.g., Buchan, Clair, Auk, with >100 MMboe). The improved imaging of the 3D broadband dual-sensor towed streamer data has allowed the interpretation of the Paleozoic horizons over the entire outer ESP region (17,500 km2), enabling interpreters to spread new light on its evolution. Possible Paleozoic structural traps are often sealed by the overlying Cretaceous strata. Source rocks could be provided by the classical upper Jurassic Kimmeridge Clay (lateral migration from the basin depocenters lying further east). Potential additional oil-prone sources may be provided by middle Devonian shales (c.f., Beatrice Field). Burial history modelling indicates that the best case scenario (late generation) did occur over parts of the study area. This supports previous geochemical analyses in analogue areas, which suggested a contribution from the Devonian source for the oils of large fields (e.g., Claymore and Clair fields).