Expronews.com talked to their CEO, Niels C. Arveschoug, about their Devil’s Hole Horst Prospect in the Central North Sea on the UKCS in Licence P2321.
According to Arveschoug, this is an overlooked basin margin play concept, where the migration play is already proven to work in the giant Johan Sverdrup oil field on the NCS, with hydrocarbons migrating from the same “kitchen”, the Central Graben.
On a Paleozoic High, NSNR mapped out reservoir levels in Jurassic sands, Upper and Lower Permian dolomites, and in Devonian sands, altogether adding up to an impressive 1.4 Bboe in the company’s P50 estimate.
“These numbers are verified by an external consultant company,” says Arveschoug.
The prospect is a stratigraphic trap, with the other reservoirs being structural traps. According to Arveschoug, there are remaining uncertainties on the porosity distribution and net to gross.
And, the prospect is in fact already a discovery, but was overlooked by Amoco back in the 1967 and 70, Arveschoug continues.
The two wells that were drilled on or close to the Devil’s Hole Horst targeted Rotliegendes sands that were proven absent. Amoco found oil but failed to test the oil zone correctly because of filling the hole with cement and creating a 2” cement sheath barrier to the reservoir, before running a DST, according to Arveschoug.
Arveschoug sees the need for a properly designed well that targets the Permian Dolomite. There could even be karst porosity in these levels. Reef build-ups are seen on the vintage 2D seismic.
As part of the work programme, they will gather a high-resolution 2D-seismic and later a contingent high-resolution 3D-seismic acquisition, before a drill or drop-decision is to be made in 2021.
The prospect was presented in a talk by NSNR at APPEX 2020.
Text: TERJE SOLBAKK