An exploration and production firm has hailed the "incredible achievement" of delivering first oil from its flagship North Sea field on time and within budget.

Hurricane Energy said this is just the start of its work to develop the "considerable resources" at its Lancaster field, to the west of Shetland.

London-headquartered Hurricane was set up to deliver hydrocarbons from naturally fractured basement reservoirs.

Lancaster, discovered in 2009, is believed to hold recoverable resources of more than 500 million barrels of oil and is wholly-owned by Hurricane, which also has a base in Aberdeen.

On Tuesday, the Aoka Mizu floating production and storage ship completed a 72-hour production test and reached the target flow from two wells of 20,000 barrels of oil per day.

The company now intends to gradually ramp up production.

Dr Robert Trice, chief executive of Hurricane Energy, said: "I am delighted to announce that first oil has been achieved and that the Lancaster field is now on production, beginning the phased development of Hurricane's considerable resources on the Rona Ridge.

"Lancaster is the UK's first producing fractured basement field and the fact that Hurricane has delivered this industry milestone on time and within budget is an incredible achievement.

"I would like to thank the staff of Hurricane, our Tier 1 contractors, and our shareholders for having the vision to make Lancaster happen.

"We have successfully achieved our start-up data acquisition objectives and commenced the evaluation of this material.

"Up to 12 months of stable production will be required in order to provide a clear view of the reservoir and enable us to plan for associated full field development scenarios."