The Viking Graben is one of the most prolific basins in Norway and the world. It contains a large part of Norway’s oil and gas production and yields new discoveries with a high success rate. Most fields are in Mid Jurassic reservoirs within fault blocks of the Mid Jurassic to Earliest Cretaceous rifting episode. A less tested play is the Upper Jurassic, which regionally is an important sealing cap rock, and occasionally contains local sediment gravity flows beside structural highs, presumed triggered by fault activation events in Late Jurassic rifting.
Equinor and AkerBP announced today another discovery that shows this area still holds undiscovered resources tied to existing infrastructure. The 25/7-13 well in PL 782 S found gas and condensate in the "Linga" prospect, within the Draupne Formation. The discovery sits 16 km northwest of the Balder oil field and 205 km west of Stavanger, according to SODIR. TGS Multi Azimuth streamer 3D data delivers high-resolution imaging on deeper targets (Figure 1). Towards the south of this well, the full azimuth Heimdal OBN dataset gives modern data quality over similar targets.
The Draupne Formation is one of the most important Upper Jurassic geological units in the Norwegian North Sea. It belongs to the Viking Group and is widely recognized as the principal source rock for many of the hydrocarbon accumulations in the Northern North Sea. The formation predominantly consists of organic-rich, dark grey to black claystones and shales, with localized sandstone and siltstone interbeds. These rocks were deposited during the Late Jurassic in relatively deep marine conditions and contain exceptionally high organic carbon content, which made them highly effective at generating oil and gas during burial and maturation.
In Quadrant 25, located in the central part of the Norwegian North Sea near the Balder area and the Ling Depression, the Draupne Formation plays a dual role. It acts both as a prolific hydrocarbon source rock and, in some areas, as a reservoir where sandstone bodies are developed within the shale-dominated succession. These sandstones are commonly interpreted as gravity-flow or submarine fan deposits that accumulated during both periods of active faulting and later basin subsidence. Such sand-prone intervals have been targeted by exploration wells seeking stratigraphic or combined structural-stratigraphic traps.
The formation is also considered one of the most important regional seals in the North Sea. Studies from the Ling Depression have shown that the Draupne shale generally exhibits extremely low permeability, making it an effective cap rock capable of retaining hydrocarbons. Research into fracture systems within the formation concluded that large-scale leakage is unlikely under subsurface conditions, reinforcing its importance as both a hydrocarbon seal and a potential caprock for future CO₂ storage projects.
Recent exploration success demonstrates the continuing prospectivity of the Draupne Formation in Quadrant 25.
Gas/condensate discovery in the North Sea (25/7-13) (Norwegian Offshore Directorate): https://hubs.ly/Q04v42h60
Deep Upper Jurassic play evaluation in the Southern Viking Graben using cost-effective multi-azimuth streamer technology: https://hubs.ly/Q04v437T0
North Sea Geology: https://hubs.ly/Q04v5brw0