BP said on Monday it has doubled its interest in the Maersk-operated $4.5 billion Culzean gas development in the UK central North Sea after acquiring an additional interest from JX Nippon.

The acquisition increases BP’s interest in the megaproject from 16% to 32%.

The Culzean field — 145 miles east of Aberdeen — was the largest hydrocarbon discovery in the UK North Sea for over a decade.

“We are pleased to have deepened our interest in Culzean and we look forward to helping Maersk make this important central North Sea development a success,” said Mark Thomas, BP regional president North Sea region.

“This is a challenging time for the industry and we must continue to work together to ensure that when developments like Culzean, or other projects such as BP’s Quad 204 and Clair Ridge, come online they can be run as efficiently as possible.”

The Maersk-operated Culzean field is expected to produce enough gas to meet 5% of total UK demand at peak production in 2020/21.

“BP has been focusing and refreshing its North Sea portfolio by bringing new fields into production, redeveloping and renewing existing producing facilities and divesting some of its more mature or less strategic assets,” Thomas added.

“Our deepening in Culzean further demonstrates our commitment to supporting the development of another UK field for the future.”

Discovered in 2008, the gas condensate field has resources estimated at 250-300 million barrels of oil equivalent.

Production is expected to start in 2019 and continue into the 2030s, with plateau production of 60,000-90,000 barrels of oil equivalent per day.

BP said that along with its co-venturers, it is in the middle of a five year, £7 billion investment programme in the North Sea, including major projects in the Central North Sea and Shetland area.

BP said it is continuing to invest in its major projects west of Shetland – Clair Ridge and Quad 204 – both of which will bring important new oil into production.