STATOIL and its partners have chosen an unmanned wellhead platform as the concept for the Oseberg Future development phase I project in the North Sea.

To be developed with no living quarters, helicopter deck or lifeboats, the platform will be controlled from the Oseberg field centre.

Three various concept studies have been developed for the project so far.

Statoil said would use service vessels connected to the wellhead platform by gangways during maintenance campaigns after the jack-up drilling platform has completed its well drilling operations.

Statoil’s senior vice president of projects, Anders Opedal said the alternative option for a platform was to place the wells on the seabed, but this was a more costly option considering the costs of subsea wells had tripled during the last decade.

“We have therefore chosen a jacket-based unmanned wellhead platform that will reduce costs by several hundred million kroner,” he said.

The company said the total cost for an unmanned wellhead platform was found to be very competitive to a subsea concept, once all elements of construction, equipment, wells and maintenance considered.

“Based on prognoses the costs of subsea systems are still rising. We challenge the industry to cooperate with us so we can turn this trend and develop smart solutions, both above and below water,” Ivar Aasheim, senior vice president of field development in Statoil said.

Statoil said unmanned wellhead platforms without facilities were a new concept in Norway, but have been used in the sector for some time internationally, such as, the Danish and Dutch continental shelves.

The support vessels would provide all the necessary facilities.

Mr Aasheim said high-quality equipment would reduce the need for maintenance during the operations phase, with Statoil planning for only two short maintenance campaigns per year.

Statoil and its licence partners will be carrying out pre-studies of the unmanned wellhead platform.

The company said a final investment decision on the project was expected next winter.