Despite showing a great success in the UK and Dutch sector, the Paleozoic intervals are still underexplored in the Norwegian sector of the North Sea, see figure A and B below. Some of the biggest discoveries in the UK sector is within in the Devonian sandstones and lacustrine sediments, while for the Dutch and southern North Sea the Carboniferous play model has proven successful.

Figure (A) shows the distribution of known Devonian rocks in the North Sea (Marshall and Hewett, 2003). Red rectangle shows the location of the 3D dataset used by Doudouh (2017) where Paleozoic half grabens have been interpreted; (B) Distribution of Carboniferous rocks in the North Sea (Bruce and Stemmerik, 2003)

According to Monaghan et al. (2015), the distribution of the mature source rock is the key controlling factor in the Paleozoic petroleum system. A Paleozoic petroleum system has been proven in the southwestern Norwegian North Sea, in the Embla Field (Pedersen et al. 2006, Ohm et al., 2012, Abay et al., 2014) see figure below. This field was the first development of a Paleozoic reservoir in the Norwegian sector of the Central Graben, in the Ekofisk area (see figure above). The field has experienced two charge events; the first suggested to have a Devonian source (now heavily degraded) and the second and currently produced oil is Jurassic (Ohm et al., 2012).

Interpreted seismic line showing the geological setting of the Embla field in the southern part of the North Sea, Norwegian sector (Doudouh, 2017).


Bruce, D.RS and Stemmerik, L., 2003, Carboniferous. The Millennium Atlas. Petroleum geology of the central and northern North Sea. Evans, D., Graham, C., Armour, A. and Bathurst, P. (Eds.). The geological Society of London, p. 83-89

Doudouh, L., 2017. Paleozoic-Holocene tectonostratigraphic evolution of the Sørvestlandet High and the Åsta Graben, Southern Norwegian North Sea. Master thesis

Marshall, J.E.A. & Hewitt, A.J., 2003, Devonian. In Evans, D., Graham, C., Armour, A. & Bathurst, P. (eds) The Millennium Atlas: Petroleum Geology of the Central and Northern North Sea. Geological Society, London, p. 65-81.

Ohm, S.E., Karlsen, D.A., Phan, N.T., Strand, T. and Iversen, G. 2012, Present Jurassic petroleum charge facing Paleozoic biodegraded oil: Geochemical challenges and potential upsides, Embla field, North Sea. AAPG Bulletin, 96, p. 1523–1552.