(Corrects age in headline, para 1)
* Peak production seen at 55,000 barrels per day
* To start producing in 2017
* Could recover more than 250 mlb barrels of oil
OSLO, Dec 21 (Reuters) - Norway's Statoil has taken a 31-year old British oil discovery off the shelf, approving a $7 billion development that could produce more than 250 million barrels of oil over a 30-year period, it said on Friday.
Statoil approved a $7 billion plan to develop the Mariner project, Britain's biggest offshore hyrdocarbon development in over a decade, and hoped to start production by 2017.
The field, 150 km southeast of the Shetland islands, will have peak production of around 55,000 barrels of oil per day between 2017 to 2020.
Discovered in 1981, Mariner was left dormant because its low well flow rates and other technical challenges would have made development prohibitively expensive.
But technical developments and oil prices in excess of $100 per barrel improved the project's economics.
Mariner is the second decades-old project Statoil has revived in two days.
On Thursday, the company approved spending $5.4 billion on its Dagny field in Norway, which was first discovered in 1974.
Mariner, consisting of two shallow reservoirs, is expected to create more than 700 long-term full-time jobs, Statoil said.
Statoil holds 65.11 percent of the project, JX Nippon Exploration and Production has 28.89 percent and Alba Resources, a unit of Cairn Energy 6 percent. (Reporting by Balazs Koranyi, editing by William Hardy)