Exploration in the UK Brent province has not been seen for a while. Instead, fields being taken out of production and platforms being decommissioned form the headline news from this part of the UKCS these days. For that reason, it is interesting to see that TotalEnergies is now planning to drill an exploration well from the North Alwyn field.
The North Alwyn field produces since 1987. Similar to many Brent fields in the Northern North Sea, it is in the tail end of its producing life, with daily volumes less than 5% of the peak production (~150,000 boe/d) in the early 1990’s.
In order to extend the life of the field, which is part of TotalEnergies’ cluster of producing assets including Dunbar, Ellon, Grant, Nuggets, Forvie North, Jura and Islay, the operator has now identified the Alwyn East prospect as a potential tie-back to North Alwyn.
To be drilled from the Alwyn North Alpha Platform, the well will be a 5.8 km extended reach side track from an existing well (slot N43). The target reservoir is another Brent succession, situated at a depth of approximately 4,800 m. Given the depth of the prospect, reservoir quality may be one of the key risks, as well as seal integrity.
Curious to know about exploration in the Norwegian Brent province? Attend the NCS Exploration Strategy Conference, 17-18 November in Stavanger, and hear from all the main players how they envisage further exploring the Northern North Sea.
In the most optimistic case for Alwyn East’s reserves, as written in the Environmental Statement, production from the field remains technically possible until 2040, even though this is more a theoretical than a realistic scenario as Alwyn North will likely undergo COP before that date. Using the forecast oil production from the Environmental Statement, up to around 25 MMbo could be produced until 2040, with a more likely figure of 19 MMbo when a COP at 2030 is assumed.
Another factor at play for North Alwyn is the fact that an alternative hydrocarbon transport route will need to be found after 2024, when the Cormorant Alpha facility will not be available for throughput of liquids from the North Alwyn cluster any more. TotalEnergies writes that an alternative means of export is being investigated.
Extending the life of North Alwyn is not a recent development. As the production profile above illustrates, TotalEnergies started to produce from the Triassic in the mid 1990’s after the overlying Brent and Lower Jurassic Statfjord reservoirs started to rapidly decline. Even though the recovery factor for the Triassic (18%) is much lower than the Jurassic reservoirs (50-60%), it is the Triassic that formed an important contributor especially from the late 1990’s to around 2006. As this Devex presentation from 2018 alludes to, the Triassic still presented future drilling targets at the time, helped by Ocean Bottom Node surveys carried out that permitted identification of remaining pay.
HENK KOMBRINK
