Moorings Systems has completed the installation of a flexible export flowline to transfer water to a DP tanker at the BP Valhall platform complex in the Norwegian North Sea. The project involved installation of 1,160 metres, 6” flexible flowline, front end engineering, mobilisation of equipment, and offshore installation team.
Located in 70 m of water, the Valhall complex consists of five separate, bridge-connected, steel platforms for quarters, drilling, wellheads, production and water injection respectively. In addition the field has two unmanned flank platforms, one in the south and one in the north, both around 6 kilometers from the field centre.
From its Montrose quayside facility, Mooring Systems deployed a 150t spooler containing five sections of Manulli hose (3 x 300m, 120m and 140m) on the DP vessel Olympic Zeus. The flowline was connected to the production platform using a specially designed ‘hang off spool’ fitted to the end of the hose and the 1,160 m hose laid along the sea bed away from the platform.
A 20” Pusnes connector was fitted to the end of the hose, and laid on the sea bed complete with pick up rope and marker buoys, for subsequent retrieval by DP tanker. The flowline was then leak tested and covered with concrete mud mats.
“Our Montrose team has considerable experience of this type of project in the North Sea, and so we were able to quickly respond to BP’s flowline installation request,” says Doug Davidson, managing director, Mooring Systems Ltd.
Offshore Energy Today Staff, December 23, 2011; Image: Mooring Systems