Shell will permanently shut down oil and gas production at the Brent Alpha and Brent Bravo platforms in the UK North Sea on November 1.
Production at the platforms has been halted since May due to inspection and maintenance work.
During the work Shell concluded that running the platforms would no longer be cost effective and decided to permanently stop production.
The shut downs are part of Shell’s decommissioning of the Brent field, a project that is expected to take several years.
The company is currently working on its decommissioning plan before it submits it to the UK government for approval.
Shell staff were informed of the shut downs earlier this weak, Upstream said.
Both platforms have been operating since the 1970s.
Brent Charlie will now be the only Brent platform still producing at the field. Shell has not disclosed when it plans to decommission Charlie.
The Brent Delta platform stopped production in 2011.
“As we reach this significant step, we the major contribution of Alpha and Bravo and the efforts of the many people associated with the platforms over the last 40 years in the UK Continental Shelf,” a Shell spokesperson said.
Shell said it has informed the appropriate authorities about its plan.
The Brent field is located 115 miles east of Lerwick, Scotland.
The field was discovered in 1971 and has produced over 4 billion barrels of oil equivalent.
Brent hit peak production in 1984 with 500,000 barrels per day.
Bravo was the first Brent platform to being production in 1976. Delta went online in 1977, Alpha started production in 1978 and Charlie started up in 1981.
Although the Brent field initially produced oil a $1.9 billion development project carried out in the mid 1990s switched production over to gas.