New seismic data unlocks Møre Basin reservoirs

Do the Møre Basin and Platform hold the next hydrocarbon giants on the Norwegian Continental Shelf?

Viridien’s Northern Viking Graben (NVG) seismic survey campaign in the North Sea recently celebrated 10 years of acquisition and imaging (Figures 1 and 2). Since its commencement in 2014, the survey has played a significant role in exploration in the Norwegian North Sea area. With the latest survey extension northwards, known as the NVG24 dataset, the NVG survey now covers parts of the Møre Basin and its bounding structures, the Marflo Spur, Kinn High, and the Møre Platform in the Norwegian Sea. The regional foldout line from the NVG survey intersects some of these struc­tures (Figures 1 and 3). The first phase of exploration activity on the Møre margin was driven by the desire to investigate the possible extension of the Jurassic-rotated fault blocks already successfully targeted in the North Sea. So far, the wells drilled have found only minor amounts of oil and gas in Jurassic and Cretaceous reservoirs. However, it was the presence of hydrocar­bons and reservoirs on the Manet Ridge and Møre Platform that encouraged Viridien to extend the NVG survey northward into the less explored Norwegian Sea and acquire the NVG24 data set (Figures 2 and 3). The streamer survey was acquired in an east-west direction with a broadband configuration. In the east, a grid of sparse ocean bottom nodes (OBN) was deployed; these results will be available later in 2025. This article outlines potential reservoirs that can be mapped with the new NVG24 imaging.

Reservoirs and play models Mesozoic reservoirs

Classic Mesozoic plays are seen both near the Manet Ridge in the west, extending north toward the Møre Basin, and in the near-shore structures on the Møre Platform in the east. These hold the potential reservoirs of Triassic and Jurassic sands. A three-way closure prospect in the Marulk Basin, toward the Manet Ridge, has possible reservoirs which are time-equivalent to Triassic-Jurassic Lunde and Stat­fjord formations (Figure 1).

The early NVG seismic survey vintages revealed half grabens with Jurassic deposits within the Måløy Slope. Similar half-grabens are found within the Møre Platform, which can be seen as a continuation of the Måløy Slope structure. Wells on the Møre Platform have proven both Triassic and Jurassic reservoirs in these half-grabens (Jongepier et al., 1996). On the inner part of the Møre Platform and the Måløy Slope, fault block crests were eroded to the basement level during the late Jurassic and Early Cretaceous (Figure 4). The redeposition of the erosional products are potential good reservoirs in the basins.

Cretaceous reservoirs

Cretaceous submarine sand reservoirs are identified on the Måløy Slope, Møre Platform, and in the Sløre­botn Subbasin (Figure 3). Locally, the Cretaceous unit is dominated by mud-rich, deep-water slope-to-basin-floor deposits interbedded with coarse-grained clastic sediments (Sømme et al., 2019). The unit has proven prospectivity with hydrocarbon discoveries in Lower Cretaceous (Albian-Aptian) and Upper Cretaceous (Turonian, and Campanian) sand reservoirs near the Måløy Slope and Møre Platform (Figures 4 and 5).

Sandstone units were identified in well 6204/11-1 in a thick Upper Cretaceous section, with debrites and slump deposits of Turonian and Coniacian age (Fig­ures 5a, c). A time-equivalent good-quality sandstone section has been interpreted to be stacked submarine channel complexes in well 6204/10-1, 17 km to the southwest (Prélat et al., 2015; Figure 5c). Toward the Slørebotn Subbasin, the submarine channels eroded into the underlying strata in which sediments were transported further into the basin and deposited in lobes. The north-south seismic sections and RGB frequency blending from spectral decomposition analysis show the confined channels and associated lobes (Figures 5a-d).

Cenozoic reservoirs

Various geologic details are revealed in the high-quality seismic dataset. Among these are proximal, thick basin-fill, polygonal faults, and an area with mounds and channels appear in the isochron of the Hordaland Group (Figure 6a). Above the polygonal fault systems, potential sand accumulations (residual sands, Utsira Formation) are observed as bright amplitudes (Figure 6b). The mounded structures can be interpreted to be the result of sinkites, where late Miocene-Pliocene sands have sunk into the polygonal faults, displacing highly porous diatomaceous ooze upwards (Rudjord and Huuse, 2024; Figures 6c, d). Bright-amplitude discordant reflections, interpreted as sand injections, are revealed in the Hordaland Group (Figure 6d).

Regional 3D seismic – A powerful tool

The regional knowledge Viridien has gained in the North Sea through its NVG imaging and velocity model build­ing work over the last decade has been applied to the new NVG24 dataset. Additional sparse OBN coverage acquired but not yet fully processed in the Slørebotn Subbasin and Møre Platform will also further enhance the velocity model used in the processing. Fast-track results from NVG24 are promising and already significantly better than existing public vintage data. The final data, processed with the latest seismic imaging technology, in­cluding advances in pre-processing, noise mitigation, and velocity model building, will benefit prospect evaluation in this area. The various prospective reservoirs described in the above sections demonstrate the variety of potential exploration models. With a high-quality modern seismic dataset, other play elements, such as trap and charge, can be evaluated and renewed exploration in this region can take place. Analog prospectivity extends further north and east, suggesting that acquisition should continue northward in this underexplored area of the Norwegian Continental Shelf. The potential to unlock the next giant hydrocarbon discovery may lie within the NVG24 or even further into the Norwegian Sea.