Figure 1
Map showing the Open Door area (red outline) in Faroese sector. The inserted box outlines the region of the map shown in Fig. 2. (Download the shapefile for the area here)


Area: 540 km2
Crest: 3100 mss (wd: 900 m)
Closure: 1200 m
– Fractured volcanics
– Siliciclastic sandstone
– Lamba shale/volcanics

Figure 2
Bouguer anomaly gravity map and b) Structural map of the area in question. Both maps are from Ritchie et al. (2011). The black outlined features indicate four-way dip closures in the area along the border to UK, at Lamba Level (see Fig. 3). See Fig. 1 for location.

Figure 3
This map shows the predicted depth to the Lamba Level in meters. The Lamba Formation  is time equivalent to the onshore volcanic Beinisvørð Formation which represents the pre-breakup volcanism. The three four-way dip closures shown on the map are as follows: Kúlubøkan (KB), Slættibøkan (SB) and Døglingurin (D). The maximum closure is 2200 m, 800 and 400 m, respectively. Closures have been mapped on other levels also.

Figure 4
SW-NE orientated seismic profile across the Kúlubøka and Slættibøka areas on Fugloy Ridge. See Fig. 3 for location of the seismic profile.

Figure 5
NW-SE orientated seismic profile going crossing Fugloy Ridge at Kúlubøkan area.

Figure 6
A summary map of all seep data covering the Faroese Continental Shelf. East of the Faroe Islands the three largest four-way dip closures in the area; Kúlubøkan, Slættibøkan and Døglingur located on the Fugloy Ridge and in Guðrun Sub-basin, are shown at Lamba Level depth. The seep data is based on; SAR seep data, air laser fluorescence, seabed cores, well data and outcrops.

Kúlubøkan Potential
(Brugdan, Slættibøkan and Døglingurin)

Likely there is a working hydrocarbon system based on seep data and likelihood for Kimmerigde Clay source rock.

Several large 4-way dip closure can be found on the Faroes Continental Shelf.
Kúlubøkan might be the larges one with its 540 Km2. Possibility for stacked reservoir with various lithology´s.

Reservoir quality:
Likely to be favorable, but a larger risk factor.

Largest risk factor, but is possible (shale/volcanics).

Deep burial:
Possible due to e.g. overpressure and clorite coating.

Maturity model of a 1D pseudo well located on the crest of Kúlubøkan

Model input includes: Lithostratigraphy, SWIT based on Wygrala (1989) (Present Day:  -1 °C), Assumed PWD, Tectonic heat flow model and Source rock properties: Upper Jurassic SR: Type II, TOC : 6%, Mid Jurassic SR: Type III, TOC : 7.3%, Kinetics: Burnham (1989)


  • Ritchie, J.D., Ziska, H., Kimbell, G., Quinn, M. & Chadwick, A. 2011. Structure. In: Ritchie, J.D., Ziska, H., Johnson, H. & Evans, D. (eds.) Keyworth, Nottingham, UK: British Geological Survey and Tórshavn, Faroe Islands: Jarðfeingi,. Keyworth, Nottingham, UK: British Geological Survey and Tórshavn, Faroe Islands: Jarðfeingi,, 9–70.