BP said on Wednesday it will significantly increase its holding in the giant Clair field, 47 miles west of Shetland.

“BP has entered into an agreement to purchase from ConocoPhillips a 16.5% interest in the BP-operated Clair field, west of Shetland in the UK, buying a ConocoPhillips subsidiary that will hold this interest in the field,” sais BP.

“As a result, BP will hold a 45.1% interest in Clair and ConocoPhillips will retain a 7.5% interest.

“Separately BP has entered into agreements to sell to ConocoPhillips BP’s entire 39.2% interest in the Greater Kuparuk Area on the North Slope of Alaska as well as BP’s holding in the Kuparuk Transportation Company.”

BP Upstream chief executive Bernard Looney said: “This is a further step in focusing our portfolio around core assets and developments which have the potential for significant growth.

“Clair is a key advantaged oilfield for our North Sea business, a giant resource whose second phase is about to begin production and which holds great potential for future developments.”

BP said the Clair field has a “complex fractured reservoir” estimated to have had more than seven billion barrels of hydrocarbons originally in place.

Production from Clair’s first phase of development began in 2005 and the field produced an average of 21,000 barrels of oil equivalent a day (boed) in 2017.

A major second development phase, Clair Ridge, is expected to start production later this year with production capacity of 120,000 boed.

Appraisal has also identified potential for future stages of development of Clair.

Clair Ridge is targeting a further 640 million barrels of recoverable resources.

Construction of Clair Ridge’s two bridge-linked platforms was completed in 2016, commissioning activities are now underway and production from the project is expected to begin later in 2018.

The Clair partners are now evaluating a potential third phase of development of the field.

The current Clair partners are BP, ConocoPhillips, Shell UK Limited and Chevron North Sea Limited.