The Rosa deepwater field in block 17 off the Angolan coast in which Statoil has a 13.33% interest, is now on stream. Sonangol is block 17's concessionaire and Total is its operator.

"The development of Rosa is vital for maintaining production from the Girassol production ship in the years ahead," says Georg Gundersen, Statoil Angola's country president.

"Our participation in block 17 is a success story."

Rosa was discovered in 1998, 135 kilometres off the Angolan coast in a water depth of 1,350 metres. Rosa is the second satellite field tied back to Girassol which is stationed 15 kilometres away. The Jasmim field was tied back to the ship in 2003.

Daily output from Girassol, including Rosa, will be 270,000 barrels of oil at plateau. Rosa's reserves are estimated at 370 million barrels of oil and will contribute to Girassol maintaining plateau production for several years yet.

Rosa has been developed with 25 subsea wells of which 14 are production wells and 11 for water injection. All produced water from Rosa, Jasmim and Girassol is injected into the reservoir.

"The biggest challenge has been the comprehensive modifications carried out to the Girassol production ship before pull-in to Rosa," Mr Gundersen says.

"To ensure transfer of experience from modification projects in the North Sea, there has been close collaboration between Total and Statoil in the planning of this project."

On Girassol, which is a floating production, storage and offloading (FPSO) vessel, 5,600 tonnes of new equipment has been installed in the last two years. The work has involved 400 people. Girassol has a storage capacity of around two million barrels of oil and is among the world's biggest production ships.

In all, 30 finds have been made in block 17, four of which are producing. The Dalia oil field was brought on stream with its own FPSO in December 2006. Block 17 lies 200 kilometres north-west of the Angolan capital, Luanda.

"In a few years, there could be four FPSOs in the block," says Mr Gundersen.

"In addition to Girassol and Dalia, the Pazflor field and a development of CLOV (comprising the Cravo, Lirio, Orquidea and Violeta finds) is under evaluation. Exploration in the block is ongoing."

Block 17 partners are operator Total with a 40% interest, Statoil (13.33%), ExxonMobil (20%), BP (16.67%) and Hydro with 10%.

Angola is the biggest contributor to Statoil's output off the Norwegian continental shelf.