ISLAND WELLSERVER is designed by Rolls-Royce Marine and given the notation UT 767 CD. The development of the design is a result of a long time relationship between owners and consultants, both located in Ulsteinvik on the west coast of Norway.
The owners Island Offshore had a vision that the subsea oil well intervention market rather should be served by cheap vessels than expensive semisubmersible drilling rigs. The company teamed up with topside specialists FMC Technologies and Oceaneering who developed the unique equipment, and when Statoil (now StatoilHydro) tendered for a long time charter of an installation with such capabilities, Island Offshore deceided to offer for that tender. Based on the know-how achieved from other advanced vessels in the fleet, the UT 767 CD was developed in clos co-operation with Rolls-Royce Marine.
Island Offshore won the long-time time charter contract with Statoil (6 years – NOK 600m), and the newbuilding contract was placed with Aker Yards in October 2005, who assigned the work to Langsten Yard. The vessel was delivered from the yard in april 2008.
The main duties for the new vessel will be maintenance and repair of oil and gas wells with a riserless wireline intervention system. The vessel will also operate ROVs for other operations on the sea bed. She is tailor-made for continuous, uninterrupted services in one of the most severe environmental areas in the world, as the prime area of operation is the Norwegian continental shelf. The ship can operate light well intervention work in significant wave height of up to 6m with wind speed of 20,3 Vw(m/s) and in water depths ranging from 70 m to 2,500 m..
The topside integration unit is designed for down hole operations as well as subsea construction and support (inspection, maintenance and repair). For well intervention conditions the unit will be able to maintain continuous, unrestricted intervention operations in defined environmental conditions and in water depths ranging from 70 m to 2,500 m. The operation implies entry into live wells and a limited return of contaminated fluids to deck level. Tasks include production logging, plugging and gauging operations, re-perforations and downhole mechanical work.
During a light well intervention operation, accomodation is needed for 55 – 60 people and the ISLAND WELLSERVER has accomodation for a total of 95 persons i single cabins.
The deck arrangement is designed for safe and efficient operations and with comprehensive intergration of auxiliary systems and functions for optimum utilization of available deck areas. The deck is dominated by a module handling tower to launch and retrieve the lubricator package. A large working deck area has been specified so that all equipment can be handled horizontally on skids. The deck crane has a lifting capacity of 150 tons at 11 metres. The moon pool has a net opening of about 7,8 x 7,8m with a guiding system for launching and recovery of lubricator stack. The two ROVs are arranged in enclosed garages aft of accommodation.
The vessel’s propulsion is provided by a diesel electric system consisting of four main generator sets and one auxiliary genset. Two azipull thrusters with pulling propellers provide the main propulsion and manoeuvring forces. The vessel’s speed is about 14 knots at draft of 7.7m. ISLAND WELLSERVER is further equipped with two supersilent tunnel thrusters and one swing-up azimuth thruster, powered by a diesel engine which also drives a generator and provides yet another level of redundancy.