BP, along with its partners Royal Dutch Shell, ConocoPhillips and Chevron, has decided to begin drilling of five appraisal wells at the Clair field , west of Scotland’s Shetland Islands, North Sea.

The company and its partners have so far invested nearly $10bn for the giant Clair development and are now planning to spend over $500m in the two-year appraisal programme.

BP in an e-mail statement said that the programme will look at the possibility of developing a third phase, while the drilling of first well has already commenced, reported Bloomberg.

In the statement, UK Energy Secretary Edward Davey said, "It shows the industry’s commitment to maximize the potential in this area, which could hold up to 17 percent of our oil and gas reserves."

"Greater Clair proves there is still a long future for oil and gas production in the North Sea," Davey added.

As part of the programme, additional eight to twelve appraisal wells can be drilled, depending on results from the first wells.

In 2011, the companies decided to jointly invest nearly £4.5bn in Clair Ridge to develop second phase of the project at the field, which was discovered in 1977 and expected to produce over 120,000 barrels of oil a day.

Designed to continue until 2028, the production from the field began from the first phase facilities in 2005 and has produced about 90 million barrels so far.

Output from the second phase is anticipated to commence in 2016, peak production of which is estimated to be around 120,000 barrels a day.