The hydrocarbon prospectivity of the Faeroe–Shetland White Zone, located in the area between the Shetland and Faeroe Islands, was assessed in a regional study that integrated seismic and well interpretations with detailed source-rock geochemistry and predictive basin modelling.The Faeroe Basin formed during a Barremian rifting event followed by subsidence during the Late Cretaceous. The Paleocene began with a period of thermal uplift of basement highs and rapid sedimentation which infilled the submarine topography formed during the Cretaceous, and produced marked overpressuring in the basin. Gradual subsidence continued through the Tertiary except for a significant mid Tertiary inversion event that formed several interesting structures in the basin.New thermal models of basins and a new pressure mechanism for inducing hydrofractures that allow vertical hydrocarbon migration from Jurassic source rocks through Cretaceous mudrocks to Tertiary reservoirs, which we call the ‘whoopee cushion effect’, provide the key controls on the hydrocarbon charge mechanism, timing and petroleum composition.The other crucial elements, source, reservoir, and traps which are present at several stratigraphic levels in the White Zone, are summarized in this paper.The interplay of overpressure, hydrocarbon generation and migration during a complex basin evolution makes the White Zone a highly prospective frontier petroleum province.

Predicting the mineralogical composition of shales is crucial for drilling operations related to hydrocarbon exploration/production as well as for the assessment of their sealing capacity as hydrocarbon or CO2 barriers. For example, hydrocarbon exploration in the Northern Carnarvon Basin, North-West Shelf, Australia is hindered by the presence of a thick (up to 1 km) smectite-rich shale seal that spreads regionally. Complex structures of the channelised oil and gas fields in the area make it necessary to drill deviated wells through that seal. The maximum deviation angle at which successful drilling is possible depends strongly on the clay mineralogy and, in particular, on the smectite content in the shale. Here, we introduce a novel workflow combining seismic data, well logs and laboratory measurements to infer shale composition at the reservoir scale. It is applied to the Duyfken 3D seismic survey in the central part of the Northern Carnarvon Basin. Interpretation results are verified against the laboratory X-ray diffraction measurements from the test well that was not used for the interpretation. The results match the test data well within the determined uncertainty bounds.