Equinor is testing the water on collaboration ahead of a potential extension to its flagship Mariner field.
An opportunity for a company to collaborate with the Norwegian energy giant on the Mariner East subsea tieback has been flagged on the energy pathfinder portal.
Developed and managed by industry regulator the North Sea Transition Authority (NSTA), the database aims to paint a clearer picture of new oil and gas field development work.
In doing so it gives supply chain companies early sight of work coming down the road, encouraging engagement with operators.
Mariner East is located to the east of the main Mariner field, Equinor’s first operated development in the UK North Sea.
Equinor has a 65.11% stake in Mariner, while JX Nippon and ONE-Dyas hold 20% and 6% respectively.
Siccar Point Energy, which was acquired earlier this year by Ithaca Energy, accounts for the remaining 8.89%.
According to the energy pathfinder, the “Mariner East joint venture are considering developing” the extension via a subsea tieback to the main platform.
Heavy oil would be mixed together with with production from Maureen and Heimdal, Mariner’s two existing reservoirs.
From there it would be exported to the Mariner B floating storage unit, and exported via shuttle tanker.
The scale of Mariner East’s recoverable reserves are currently not known.
By collaborating with interested parties, Equinor hopes to minimise the cost of the Northern North Sea tieback, while also achieving efficient well workovers.
Mariner started production in 2019 after a £6.4 billion investment from the Oslo-listed company, one of the largest in the UK sector for a decade.
At the time it was thought Mariner would be able to continue producing through to 2050, but a major downgrade to its recoverable reserves was announced earlier this year.
Equinor revised down its estimates from the field east of Shetland by nearly 35% from 275 million barrels to around 180m.