Lithostratigraphic units (groups, formations and members) on the Norwegian continental sehlf. Includes exploration wellbores penetrating a particular unit and wellbores with core samples.
Not all the wells drilled on the Norwegian continental shelf are represented here. So far approximately 1100 released wells - mostly exploration wells - are included, among them all released wells in the Barents Sea and the Norwegian Sea. For some intervals in some wells only groups are interpreted and no formation tops have been assigned. Members have been assigned only in wells in the type well area. For wellbores with cores, core-log depth shifts are not taken into account. This shift is usually up to a few meters. Core intervals refer to the drillers depth, while lithostratigraphic tops refer to the loggers depth. Lithostratigraphy is always interpreted in the final wellbore.In rare cases cores have been taken in technical sidetracks which are not identical to the final wellpath.
Norwegian Offshore Directorate has compiled a set of charts of the names of lithostratigraphic formations on the Norwegian Continental shelf. Three charts have been prepared, one for each of the main regions of the continental shelf: the Norwegian North Sea, the Norwegian Sea and the Norwegian Barents Sea.