Norway's Den norske stats oljeselskap AS (Statoil) has issued a letter of intent to Smedvig AS, Stavanger, for use of a drillship version of Statoil's multipurpose shuttle tanker (MST)/production ship design.
Statoil is building a fleet of MST vessels, which can be converted from shuttle tanker to production ship by addition of topsides on deck. The drillship variant represents a breakthrough for the concept.
New MST drillship
Statoil said the drillship will be called MST Odin and will be one of the world's largest, with the ability to drill in waters as deep as 2,500 m. It will also have capacity to store 585,000 bbl of oil.
The hull is already under construction at Samsung Heavy Industries in South Korea and will be outfitted as a drillship by Smedvig, with a RamRig drilling rig supplied by Aker Maritime AS, Oslo.
The contract is valued at 2 billion kroner ($310 million), and will run for 5 years with options for extensions of 3 years and 2 years. The ship will be operated jointly and owned by Statoil with the drilling equipment owned by Smedvig.
The drillship is expected to be used during development of Aasgard field in the Norwegian Sea. Statoil is developing Aasgard with 60 subsea wellheads producing into an oil production ship and a gas production semisubmersible.
The company had intended to use a novel light drilling rig concept to keep down well workover costs in the field, but failure of the design in wave tank trials led Statoil to opt for the MST drillship (OGJ, Aug. 5, 1996, p. 30).
MST Berg Hugin, currently under construction in South Korea, is a candidate for development of U.K. Pierce field, while MST Munin, also being built in Korea, is destined for development of Lufeng field in the South China Sea (OGJ, Oct. 21, 1996, p. 24).
Drilling package
Following receipt of the letter of intent from Statoil, Smedvig issued its own letter of intent to Aker Maritime for provision of the drillship's drilling package in a deal worth 280 million kroner ($43 million).
Aker said the package is due for delivery on Mar. 31, 1998, and will initially enable drilling in 750 m of water, although the rig will be upgraded later for operation in as much as 2,500 m of water.
The rig will be a dual RamRig unit, said the contractor, allowing two drilling operations to be carried out simultaneously and including a drillpipe handling system and blowout preventer package.
Aker Maritime's novel rig design is currently being taken up by drilling companies, with the first unit expected to begin operating this year for Reading & Bates Ltd., Aberdeen, on Iolair semisubmersible.
In a RamRig, hydraulic cylinder rams power the top drive unit. Mari- time claims the design is lighter, cheaper, safer, and more efficient than conventional designs.
New tankers
Statoil has also ordered three new shuttle tankers from Spain's Astilleros Espanoles SA, at a total cost of 1.7 billion kroner ($260 million).
The 125,000 dwt double-hulled tankers each will have capacity to carry 850,000 bbl of crude oil and will be used for unloading stored oil from production ships.
Because of the stricter safety requirements for ship-to-ship loading rather than loading from buoys, the new tankers will have two main engines, two main propellers, two rudders, and several side thrusters.
Statoil said this duplication reduces the risk of a ship becoming unmaneuverable due to failure of individual components: "They will be the world's best equipped and most modern shuttle tankers."
Statoil said the three ships will be used to export oil from Norne, Aasgard, and Njord fields in the Norwegian Sea, the first two of which are under development by Statoil and the latter by Norsk Hydro AS.
The ships will not be allocated to one particular field, however, Statoil said: "We have left the era of dedicated shuttle tankers. Some fields might require only a share of a shuttle tanker to lift their volumes. With a large fleet of shuttle tankers, an operator can optimize export logistics."
Two of the tankers will be delivered in fall 1998 after being built at Astilleros' Bilbao and Cadiz yards. The third will also be built at Bilbao and is scheduled for delivery in early 1999.
Statoil said it currently operates 18 shuttle tankers, taking oil from 12 fields offshore Norway and U.K.
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