Saipem 7000

Career
Name: Saipem 7000 ex Micoperi 7000
Operator: Saipem
Ordered: 1985
Builder: Fincantieri Monfalcone Yard
Laid down: 1985
Launched: 1986
Completed: 1987
In service: 1988-to date
Status: Operational
General characteristics
Class and type: Semi-submersible crane vessel
Displacement: 172,000 t (heavy lift)
Length: 198 m (overall)
Beam: 87 m
Height: 43.5 m (keel to deck)
Draft:

10.5 m (34 ft) (transit)
18.0 m (59 ft) (survival)

27.5 metres (90 ft) (heavy lift)
Installed power: 70,000 kW
Propulsion: 12 thrusters
Speed: 9.5 knots (18 km/h)
Crew: Up to 700 persons

Saipem 7000 is the world's second largest crane vessel, after the Thialf. The crane radius of the Saipem 7000 grants a lifting capability of 14,000 tonnes at 42 meters while the Thialf can lift 14,200 tonnes at 31.2 meters. It is owned by the oil and gas industry contractor Saipem S.p.A.

Contents

Concept

The Saipem 7000, originally named the Micoperi 7000, was conceived in the mid 1980s by its original owners Micoperi as a multipurpose offshore oil platform installation vessel that would be able to install very large oil production platform decks (known as integrated decks) as well as the decks' supporting structures (known as jackets) using its two very large fully revolving cranes. It would also be able to support the offshore completion of the platform by providing hotel and workshop facilities for large construction crews. Saturation Diving facilities would support subsea connection work. The vessels size and semi-submersible form would allow it to operate in worse weather conditions than smaller and conventionally shaped vessels.

The huge cost of a vessel of this size would be offset by the cost and time savings made by the oil company as the large integrated decks could be completed, tested and commissioned onshore. Prior to the introduction of the large crane vessels offshore oil platforms were made up of 1000 - 2000 tonne modules which were lifted into place individually by smaller SSCV's or monohull crane vessels and then connected together offshore, tested and then commissioned, this often took over a year. Other savings in the installation of the jackets could also be made.

Original specification

Heavy lift

Two fully revolving cranes with 140-metre-long booms fitted with 4 hooks. Each crane is capable of lifting up to 7,000 tonnes at 40 m lift radius using the main hook. The auxiliary hook capacities are 1st Auxiliary 2,500 tonnes at 75 m and 2nd Auxiliary 900 tonne at 115 m. The whip hook has a capacity of 120 tonnes at 140 m. The 2nd Auxiliary hook can be deployed to a water depth of 450 m.

Each crane was fitted with 15,600 hp (11,630 kW) engines to power the boom and load hoists, 9 tugger lines and the crane slewing system. The cranes use 48 miles (77 km) of wire rope of various diameters.

Ballast system

The S7000 was fitted with two ballast systems: A conventional pumped system which could transfer up to 24,000 tonnes of water per hour using 4 pumps and a free flooding system. The free flooding system used 2 m diameter valves to open certain compartments to the sea thus trimming or heeling the vessel. This allows the vessel to lift cargoes from barges much faster than if just the crane hoists are used.

Power system

The vessel's main power is provided by eight 12 cylinder 8400 hp diesel engines built by Grandi Motori Trieste a former Fincantieri company. Later Grandi Motori was purchased by the Finnish Wärtsilä. They provide up to 47,000 kW of electric power at 10,000 V 60 Hz for propulsion and positioning. Auxiliary power is provided by two 6 cylinder 4,200 hp (3,130 kW) GMT diesel engines. There is also an emergency generator.

Total power that can be supplied is 57,000 kilowatts (76,000 hp).

Mooring system

The vessel was supplied with 16 anchor lines, 4 at each corner. The lines are made up of 3350 m of 96 mm wire rope, 50 m of 92 mm chain and a 40-tonne Norshore Mark 3 anchor. The mooring system can be used in water depths of up to 450 m.

Thrusters

The vessel was fitted with 10 thrusters—5 on each hull. They are, per hull:

Dynamic positioning system

The vessel was equipped with a dynamic positioning system which used either the thrusters or the mooring system or a combination of both, controlled by a number of computers, to hold the vessel in a predefined location.

Platform installation equipment

Accommodation

The accommodation designed for 800 people contains 30 triple cabins, 335 double cabins, 35 singles and 5 suites. The accommodation also contains a large galley and mess rooms, a hospital, cinema and lounges.

Construction

The vessel was designed by Gusto Engineering during 1984.

The vessel was built between 1985 and 1987 by Fincantieri-Cantieri Navali Italiana S.p.A. at their Monfalcone yard, Trieste in north-eastern Italy. The vessel was built in two halves in a long dry dock. The halves were then floated out from the dry dock and mated. During the mating operation the halves were supported by temporary pontoons.

The hull mating was complete in early 1987 and the two cranes built by Officine Meccaniche Reggiane under subcontract to American Hoist & Derrick Company (Amhoist) were installed in sections by the Saipem crane vessel Castoro Otto in April of that year. The sea trials, which took two months, started in September, and on 15 December the vessel was handed over to Micoperi.

The cost of the vessel was not released by Micoperi but it was estimated in the technical press as being up to 400 million US dollars

Early projects

The vessel's first work was for Petrobras the Brazilian state oil company. The project consisted of the installation of 7 platforms in the Campos Basin. During this project the S7000 was also involved in the fighting of a well fire on the Enchova Platform. The Micoperi 7000 then proceeded to the Gulf of Mexico where it installed the Jolliet Template for Conoco. In 1989 the Micoperi 7000 arrived in the North Sea for the first time where it completed several projects in the Norwegian sector of the North Sea. These were the Gyda Platform for BP, the Togi Template for Norsk Hydro and the Veslefrikk platform for Statoil.

Whilst the vessel remained busy, Micoperi were struggling financially as the low oil price prevalent in the late 1980s curtailed oil company investment. In 1991 Micoperi were forced to sell a number of their major assets including the Micoperi 7000 to another Italian contractor Saipem. Saipem took over the running of the vessel though they retained the vessel crew and the shorebased engineering support. Saipem renamed the vessel the Saipem 7000.

The vessel continued to work, installing oil and gas production platforms, in the North Sea, Gulf of Mexico, off the Canadian east coast and the west coast of Africa throughout the nineties. It was also involved in the removal of one platform, the Esso Odin. During the late nineties Saipem planned an upgrade to the vessels DP system and installation of a J-Lay system.

1999 vessel re-fit

During the winter of 1999-2000 the Saipem 7000 underwent a refit to enhance its positioning and power systems and add a J-lay system.

The power system was upgraded to provide up to 70,000 kW using 12 diesel generators. To improve the vessel's resilience the generators are distributed between four separate engine rooms.

Two 5,500 kW retractable azimuthing thrusters were added, one below the forward part of each hull. The DP system control computers were also replaced.

The hull, deck and deck structures were modified to accept the Gusto designed J-lay tower and its support equipment. The J-lay tower can lay pipe from 4" to 32" diameter with a tension of up to 525 tonnes (5.15 MN) using the tensioners and up to 2,000 tonnes (20 MN) when using friction clamps. The deck can used to store up to 10,000 tonnes of pipe.

To allow space for the increased equipment some items from the original specification were removed, including 2 anchor winches from the bow, all the moon pools, and the boilers used to provide steam for the steam hammers.

Recent work

The Saipem 7000 has completed 4 J-Lay pipe projects Diana, Blue Stream, Ormen Lange and Medgaz,but its main work continues to be heavy lift in the North Sea and the Gulf of Mexico. This includes both platform installation and removal and the addition of modules to existing platforms.

In July 2010, the Saipem 7000 broke another world record by lifting the new BP Valhall Production topside of approximately 11,600 tonnes on Dynamic Positioning. The previous world record set at Sabratha was performed on the vessel's anchoring system.

Lifting and pipelaying records

The Saipem 7000 set the world offshore lifting record of 12,150 tons for the Sabratha deck in the Mediterranean Sea. A local record for the Gulf of Mexico (Mexican area) was set with the 10,473 tons of the PB-KU-A2 deck.

The Saipem 7000 laid the 24" pipeline for the Blue Stream project between Russia and Turkey up to the record depth of 2,150 meters in the Black Sea. This was broken at the end of 2005 by the Balder which laid a pipeline in 2,200 meters of water.

References

Synder, Robert E.; McCabe, Charles R., "Micoperi 7000:The world's largest SSCV goes to work", Ocean Industry (July 1988) 

Saipem S.p.A., Saipem 7000 Brochure, Saipem S.p.A. 

External links