The firm hopes to be able to get 640 million barrels of oil from the Clair Ridge, with production expected to peak at 120,00 barrels a day.
The new development is the second phase of the Clair field, which was discovered just over 40 years ago with an estimated seven billion barrels of reserves.
To get the oil from the site, which is 75 kilometres west of Shetland, BP used its enhanced recovery technology for the first time offshore.
The technique involved is called “LoSal”, with the energy firm having estimated its use could result in up to 40 million additional barrels being removed over the lifetime of the project.
Two new oil platforms, which are linked by a bridge, with pipelines to take away the oil and gas have been installed there, with BP having invested more than £4.5 billion there.
Clair Ridge in the west of Shetland region is the sixth new upstream project to come on stream for BP this year. It is the second phase of development of the Clair field, which lies 75 kilometres west of Shetland and was discovered in 1977.
BP, on behalf of co-venturers Shell, Chevron and ConocoPhillips, said it was targeting 640 million barrels of oil reserves and peak production of 120,000 barrels of oil a day.
Bernard Looney, BP chief executive, upstream, said: “The start-up of Clair Ridge is a culmination of decades of persistence.
Clair was the first discovery we made in the west of Shetland area in 1977. But trying to access and produce its seven billion barrels proved very difficult.
We had to leverage our technology and ingenuity to successfully bring on the first phase of this development in 2005.
“Now, more than 40 years after the original discovery, we have first oil from Clair Ridge, one of the largest recent investments in the UK.
“This is a major milestone for our upstream business and highlights BP’s continued commitment to the North Sea region.”
Two new, bridge-linked platforms and oil and gas export pipelines have been constructed as part of the Clair Ridge project.
The new facilities, which required capital investment in excess of £4.5 billion, are designed for 40 years of production.
Ariel Flores, regional president for BP’s North Sea business, said: “Safely delivering first oil from Clair Ridge, in some of the harshest conditions in the [area], is the result of years of planning and hard work by BP, our partners and supply chain colleagues. We are proud to have played our part in this pioneering project and are excited for the Clair region’s continued potential.”
Oil & Gas UK chief executive, Deirdre Michie, added: “First oil at Clair Ridge represents a major milestone in BP’s developments west of Shetland, the frontier region which is likely to have the greatest potential to expand current UK production.
“It’s greatly encouraging to see one of the basin’s original explorers using new, ambitious approaches and pioneering technology to help lead a revival in production.”
She added: “This is another firm step towards maximising economic recovery from the basin.” Energy Minister Claire Perry said: “The North Sea is crucial for the UK’s energy security and helping businesses maximise economic recovery there is an aim for this government.
“Aided by the innovative use of technology developed in the UK and a strong UK-based supply chain worth £1.5bn, this will allow the North Sea to continue to be a hub for the high-skilled, well-paid jobs at the centre of our modern Industrial Strategy.”