Work has begun at operator Statoil on qualifying technology for the record-long umbilical which will link its Snøhvit development in the Barents Sea with the land facilities in northern Norway.
“We expect to sign a contract this summer for the subsea system and umbilical,” reports staff engineer Inge Polden in the Snøhvit project.
“This job will be awarded to one of three suppliers we have frame agreements with.”
Statoil and the subsea system suppliers are now testing existing technology for the 160-kilometre bundle of control lines and cables. This verification will continue until the end of 2002.
All the wells planned for Snøhvit – 21 for gas and condensate and one for carbon dioxide injection – will be remotely controlled from land through the umbilical.
The distance involved requires a voltage of 3,000 volts – three times the conventional level for a subsea facility.
With a diameter of roughly 11 centimetres, the umbilical will contain high-voltage power lines, fibre-optic cables and hydraulic piping.
The fibre-optic cables will be used to transmit control signals to subsea valves and to return information from sensors mounted in the wells.
Snøhvit will involve the world’s longest distance between the control station on land and the first subsea installation on the field.
By comparison, the maximum umbilical length on Statoil’s Åsgard field in the Norwegian Sea is 50 kilometres. And the group’s nearby Mikkel project will involve a span of 87 kilometres.
Plans call for gas deliveries from Snøhvit to start in 2006. Snøhvit will be developed in three phases. When these have been completed in 2018, the longest distance over which remote control is exercised will be 210 kilometres.