The prospectivity of the Vøring and Møre basins on the Norwegian Sea continental margin

Abstract

The focus of exploration activity on the Norwegian Sea Continental Shelf has shifted westwards from the shallow water areas over the Trøndelag Platform and Halten Terrace to the deep water areas over the Cretaceous Vøring and Møre basins. The basins, especially the Vøring Basin, have been involved in a complex tectonic development since the main extensional phase in the late Middle Jurassic to Early Cretaceous, including Cenomanian–Campanian and Maastrichtian–Eocene extension and thermal uplift and intermittent phases of compression/transpression. While the Jurassic is the prospective interval in the Trøndelag Platform and Halten Terrace, the potential in the Vøring and Møre basins is seen mainly in the Cretaceous and Paleocene – the Jurassic is too deeply buried. The two first deep water exploration wells in these basins, 6707/10-1 and 6305/5-1, have already proven two effective plays, with excellent reservoir sands in the Upper Cretaceous and lower Paleocene charged with thermogenic gas in structural traps in rotated fault blocks and compressional domes. Palaeogeographical reconstructions indicate that these reservoir rocks may be widespread within the basin areas. No good oil-prone source rock at a suitable depth of burial is so far proven, but the palaeogeographical reconstructions linked to surrounding well data and regional analyses indicate a chance for the existence of Upper Cretaceous oil source intervals. The thermal history of the basins is as complex as their tectonic history, and is further complicated by the possible effects of the Paleocene–Eocene magmatic activity, making any basin modelling results at the present stage unreliable.