Norway Developed for deepwater support of umbilicals and risers in the oil & gas industry, Trelleborg Distributed Buoyancy Modules (DBMs) are now being tested in the North Sea at Statoil’s site for its Hywind floating turbines off the coast of Norway.
“People see the tower and turbine, but forget that the expertise in designing the subsea portion is also critical, as ultimately it keeps the whole turbine afloat,” said Gary Howland, Renewables sales manager for Swedish firm Trelleborg Offshore.
“The dynamic floating structure weighs 5300 tonnes and is 165 metres tall; with a total of 65 metres above sea surface. The 13 km of power offtake and communications cabling attached to the structure further adds to its weight.”
Trelleborg Offshore designed and supplied 45 polymer-coated syntactic foam DBMs to support a 3-tonne, 100-metre section of cable as it exits the turbine spar and descends to the sea bed 220 metres below the surface in a Lazy Wave configuration that accommodates natural movements.
Statoil is now testing this technology at its site in the North Sea 10 km from the coast of Norway. The Hywind, which the firm describes the world’s first full-scale floating turbine, features a steel cylinder filled with a ballast of water and rocks that extends 100 metres beneath the sea’s surface and is attached to the seabed by a three-point mooring spread.
In related news, Scotland’s First Minister Alex Salmond recently met with Statoil to discuss the possibility of developing the world’s first floating wind farm.
Statoil has reportedly identified two potential testing sites in Scotland.