Inocean has previously been responsible for analyzing part of the operational plans for refitting of thrusters on the Leiv Eiriksson as well as on Eirik Raude.
These operations are crucial because of the values at play. Each 80-tonne thruster represents a huge investment on its own. But the essential cost is the lay-up time while the rig is away from the field.
The procedure
The work is done with the rig at quay or moored. With the aid of a heavy-lift vessel and an advanced pipe and wire system, the old thruster is being lowered to the seabed before being salvaged and removed. Then a new thruster follows the same procedure, but in reverse order. The entire replacement operation could be completed in a day.
Inocean's task
When the next two thrusters on Leiv Eiriksson (built 2001) will be exchanged, its expected that Inocean's task will include making structural modifications of the heavy-lift gear and guidance of the thrusters as well as assisting in design- and analyzing issues.
60 tonnes
The submerged weight of each thruster is 60 tonnes. The entire lifting process involves consideration of mighty forces at play and the loads borne by all the components.
The Leiv Eiriksson is currently drilling at Norway's Ormen Lange offshore field.
Key technical specifications of Leiv Eiriksson
(The Bingo 9000 Consept):
. Water depth capacity of 10,000 feet
. Variable deck load of 7,000 tonnes
. Dynamic positioning system - DP Class 3
. Total vessel power of 6 x 7,500 kilowatts
. Thruster capacity of 6 x 5.500 kilowatts