The semi-submersible Kristin production platform is now being towed north from the Aker Kvaerner yard at Stord south of Bergen to the Statoil development in the Norwegian Sea.
Setting off on 25 March, the unit is due to arrive on the Halten Bank in the early hours of 29 March with the assistance of five of the world’s largest seagoing tugs.
The latter are all owned by Mærsk, and include one towing forward of the platform, one at each side and one aft. Tug number five is serving as an escort.
“The platform was towed out of the Stord yard to the Bømla Fjord by four Buksér og Berging tugs on 23 March,” explains Geir Edvardsen, Statoil’s marine operations manager.
“A number of tests were carried out on such equipment as fire pumps and lifeboats before the green light was given for the journey north.”
For safety reasons, the platform – which has no engines of its own – is being towed in the open sea and cannot be observed from land during its voyage.
After its arrival on the field, the floater will be moored with the aid of two tugs while the three others keep it in position.
A total of 16 mooring lines are to be connected to the unit and tightened up. This job will be done by installing pairs of lines diagonally and should take four-five days.
“Once the platform is moored, it will be formally handed over to the operations organisation,” Mr Edvardsen explains.
“Six pre-installed risers lying on the seabed will be retrieved to the floater over a short period, and another six plus two umbilicals are due to be pulled in by mid-May.”
Plans call for installation work to be completed by 15 May, with the first gas due to arrive topside on 1 July and production scheduled to start on 1 October.
The Kristin gas and condensate field is being developed with a total of 12 subsea-completed wells. These include seven which will be highly deviated and have an extended reach.
Located 4,500 metres beneath the seabed, the reservoir features record pressure and temperature – 911 bar and 170°C respectively.