This fantastic example of an unconformity, where steeply dipping Devonian strata meet Permian sediments, is exposed on the north side of Wegener Halvø in East Greenland (71° 44 ‘ north). It is actually not far from this exposure where the equivalent Permian formations are being explored for oil.
What follows is a short description of the characteristics of the Permian formations we see in the outcrop here, with reference to how equivalent strata are developed “across the mid-ocean ridge” in Norway.
The Permian Karstyrggen Formation is the better reservoir unit in the area, and at outcrop has common bitumen staining and vuggy to cavernous macro porosity due to extensive evaporite dissolution and karstification – hence the name. This is also the same play that is working on the Loppa High and has been imaged along the Finnmark Platform. It also has potential in Mid Norway.
The Wegener Halvø Formation has super nice reefal build-ups, but generally lacks karstification and secondary porosity. It also seems quite tight due to early transgressive cements, as also seen in Permian wells in Mid Norway.
The Ravnefjell Formation is an excellent intrashelf basin type source/top seal horizon – and is quite extensive along East Greenland based on the scattered outcrop work. This is partly proven in Mid Norway in the Helgeland Basin and Nordland Ridge wells, but has not been drilled in an optimal location to prove up a good source section. It could be a good secondary source – it is essentially age-equivalent to the Kupferschiefer of the Zechstein Basin.
The Schuchert Dal Formation are nice by-pass clastics that seem to fill in the lows between remnant Wegener Halvø reefal highs. These have also been proven in Mid Norway and Barents Sea wells, and in the latter proven decent reservoir quality/discovery. They are quite similar to the Delaware Basin Permian by-pass sands in the USA.
FEATURE YOUR OUTCROP
In this series, we show a range of outcrops to give more context to what core interpretation typically allows. Do you have a suggestion for an outcrop feature? Get in touch with Henk Kombrink – henk.kombrink@geoexpro.com.
