Equinor has set out its plan for developing the Cadet field in the UK North Sea.
The Norwegian firm intends to drill three production wells and a water injection well on Cadet.
All of the wells will be drilled from the Mariner A platform, 85 miles south-east of Shetland.
First oil from the huge Mariner project is expected in the third quarter of 2019.
Cadet production is expected to commence in 2026 and continue until 2049.
Equinor has submitted a letter of application to give the Oil and Gas Authority “preliminary notification” of its proposals for Cadet.
Equinor is the operator of Cadet with a 65% working interest.
Partners include JX Nippon (20%), Siccar Point Energy (8.9%) and One-Dyas (6%).
Oil, gas and water from Cadet will be separated on Mariner A.
Oil will then be exported via pipeline to the nearby Mariner B floating storage unit, from which it will be exported to shore via shuttle tanker.
Cadet gas will be used on Mariner A for power generation.
Produced water will be re-injected via the Cadet water injection well and several Mariner Field water injection wells.
Oil production is expected to peak at 1,245 tonnes per day in 2028, before declining rapidly to 249 tonnes per day in 2030, finishing at 17 tonnes per day in 2049.
Gas will peak at 940,000 cubic feet per day in 2028.