DEEPWATER E&P: BP contracts for five Gulf of Mexico spars in 1,220-1,830 meter depths

CSO Aker Maritime has been awarded a contract to deliver up to five truss spar platforms for BP's Gulf of Mexico developments, representing the largest order in scope and value for the CSO Group.

CSO Aker Maritime's Mantyluoto yard is constructing three deepwater spar floating production platform hull and mooring systems all bound for the Gulf of Mexico. Two are for Kerr McGee's Nansen and Boomvang Fields and the third has been awarded by Vastar Resources for its Horn Mountain Field.

All are based on the company's new "truss" spar concept, a development of the three caisson spars which have so far been built in the yard. The truss spars have the same classic cylindrical shape as the caisson spars in the top section, which are joined to a lightweight open space-frame truss section made up of jacket-type structures with tubulars. The lower "bottle-leg" or tank section holds the required fixed ballast giving stability to the whole structure.

According to CSO Aker's Sales Manager, Jarmo Eerola, the truss spar has distinct advantages over the earlier spar structures built at Mantyluoto. "The truss design has an overall lower weight and it also allows more resistance to wave motion and sub-surface currents which gives it ever greater stability. The design also allows for the possibility of using smaller mooring systems."

The Nansen and Boomvang spars are both being built in conjunction with J Ray McDermott. While CSO Aker is delivering the platform risers, McDermott is producing the platform decks.

Nansen, Boomvang

The Nansen Field, located in the Gulf of Mexico's East Breaks area at a water depth of around 3,700 ft, is the fourth to be developed using spar technology and the first to utilize the tubular truss system which replaces the lower part of the hull. The Nansen hull is 165.6 meters tall with a diameter of 27.4 meters and a displacement of 30,000 metric tons.

With completion expected towards the end of August, delivery of the spar - which will be transported to East Breaks site in one complete section - is expected to take place in the fourth quarter of 2001.

The truss spar for the Boomvang Field, also located in the East Breaks region, has the same dimensions as the Nansen hull and will be delivered towards the end of the fourth quarter.

Horn Mountain

For the Vastar Horn Mountain project, CSO Aker Maritime is facing its largest spar construction to date since the field is located at a water depth of approximately 5,400 ft in Mississippi Canyon Block 127.

The hull for Horn Mountain will be 170 meters high with a diameter of 32 meters, and with a displacement of 37,000 metric tons. Completion is due for May 2002 to enable first oil to be achieved later that year, which is two years earlier than the original development plans.

Five spars for BP

Earlier this year, CSO Aker Maritime's parent company, Coflexip Stena Offshore, announced that BP had awarded a contract for delivery of multiple spar floating production platforms for its deepwater developments in the Gulf of Mexico. The contract is expected to involve up to five spar hulls and mooring systems for BP deepwater operated prospects in water depths ranging from 1,220 meters to 1,830 meters. Options for additional spars are to be exercised in line with BP's operational requirements.

With the first delivery due in 2003, it is as yet unclear whether the company's Mantyluoto yard will be used to build all or part of the order, but with the Kerr McGee hulls leaving the yard late this year and the Vastar spar due for completion in mid 2002, there will clearly be available capacity there.

For Coflexip, this order goes a long way to justifying its decision to acquire Aker Maritime's deepwater operations - which it completed early this year - and its confidence in the Gulf of Mexico as a strategic development area. The size of the order is expected to result in maximizing manufacturing efficiencies resulting from serial deliveries and product standardization. Coflexip Chief Operating Office, Tom Ehret adds "This award demonstrates the confidence that major operators have in this key technology for their deepwater developments."

While CSO Aker Maritime has no ongoing projects in the Caspian region, it is in the process of bidding for one large project in the area. In Russia, the company is currently upgrading a jackup rig in the Murmansk area for AMNGR, which is bound for the Barents Sea. Work on the rig includes modernization and enhancement of the drilling capabilities.