Norwegian state-owned major Statoil has awarded Aker Solutions a FEED (front-end engineering and design) contract to design the world’s largest deepwater Spar platform in the Norwegian Sea.

The FEED study will be completed in the third quarter 2012 with the contract value not disclosed. The floating production facility is destined for the Aasta Hansteen (formerly called Luva) field development, and will be located in a water depth of 1,300 m (4,265 ft). Statoil confirmed last month that it was opting for a spar development of the field.

With a total hull length of 193 m (633 ft) and a draught of 170 m (558 ft), the platform will be the largest of its kind, said Aker.

Aasta Hansteen’s spar platform will also be the world’s first spar with condensate storage capacity – a so called ‘Belly-Spar.’

The concept is an exclusive Aker Solutions design, with the ‘belly’ referring to the increased diameter of part of the cylindrical-shaped hull, where the condensate storage tanks will be located. This gives the Belly-Spar its characteristic shape.

Henning Østvig, head of front-end and technology at Aker Solutions, commented, “The Aasta Hansteen Spar will be the first production platform on the NCS with steel catenary risers (SCRs). With a water depth of 1,300 m, this is probably the only riser technology that can meet the challenges on the Aasta Hansteen field.”

The SCRs are made of self-supporting steel pipes in a bow shape between the platform and the seabed. The shape helps the risers compensate for the motions on the floating facility.

“The Belly-Spar concept is a result of the innovative spirit and culture among our engineers, who have come up with the right solutions for the challenging conditions on the Aasta Hansteen field,” added Valborg Lundegaard, head of Aker’s engineering business area.

The mooring system for the platform consists of a set of polyester lines.

“There are currently no installations on the NCS with polyester mooring. Aasta Hansteen may be the first, and it will definitely be operating in the deepest water,” said Østvig.

The field itself was discovered in 1997 and lies 300 km offshore in the Vøring area. The license partners are Statoil (75%), ExxonMobil (15%) and ConocoPhillips (10%).

Aker Solutions’ contract party is Aker Engineering & Technology AS.

The field has recoverable reserves estimated at 40-60 billion cubic meters (1.4-2.1 trillion cubic feet) of gas, and is expected onstream in 2016.

Statoil said last month that the development could “represent the start of deepwater production in the Norwegian Sea, and it will enable the tie-in of other discoveries in the same area,” according to Ivar Aasheim, the operator’s senior vice president for NCS field development.

The field development concept includes two subsea templates with four wells on each and one satellite template with one well. The platform will house accommodation quarters for a permanent crew, as well as the condensate storage unit and a gas processing facility with a capacity of 812 MMcf/d.

Meanwhile, the Norwegian Sea Gas Infrastructure (NSGI) project also recently chose a gas transport concept that includes a 480-km long, 30-to-36-inch pipeline from the Aasta Hansteen field to an onshore processing facility at Nyhamna. The pipeline will also be connected to the Linnorm field and tied in to the Zidane field.

In addition, connection to the Åsgard Transport line via the Kristin platform will be possible, and there are plans for tying in other fields and discoveries. The concept also includes the expansion of the Ormen Lange field’s Nyhamna gas plant with the intention of converting it into a gas terminal.

NSGI would not only provide gas export solutions for Luva, Linnorm and Zidane but also help to open up a new gas region on the NCS, making it possible to develop existing and potential future discoveries in the area.

Contact the author, Mark Thomas, at mthomas@hartenergy.com.