ETPM committed to deepwater construction capability

North Sea, Africa projects lead off global effort

Reel lay vessel Norlift, now owned 100% by ETPM [43,905 bytes].

The site in Lobito where ETPM and Sonangol are building a new construction yard capable of handling topside and deepwater subsea structures [24,179 bytes].

Following the dissolution of its joint venture with McDermott, ETPM will be free once more to act globally. The two had worked together since 1989, with ETPM managing offshore projects for the western territories of Africa, the North Sea, the Mediterranean and South America. McDermott managed projects over an eastern swathe stretching from Tanzania across to New Zealand.

By retrenching from Europe and Africa, McDermott claims it can concentrate more effectively on deepwater and subsea markets. Those are targets for ETPM too, although it wants to remain a powerhouse in pipelaying and fabrication for shallower waters.

The two parties have agreed to fulfill contracts signed before the split, involving each other's tools. So for example, McDermott's derrick barge DLB 1601 will plow ahead with a gas line installation this spring for Conoco in the UK southern North Sea, but under ETPM's supervision, followed by Elf's 470 km, 34-in. trunkline from the Shearwater/Elgin area to Bacton.

In Sharjah and West Africa, ETPM is left in charge of four fabrication yards and logistics bases, but currently lacks capability to build large, integrated decks. However, the former jointly owned yard in Jebel Ali, UAE which performed these tasks will continue to be made available to ETPM by McDermott, as will its yard in Morgan City, Louisiana.

North Sea strategy

On top of the DLB 1601, McDermott received $105 million in cash under the dissolution accord. In return, ETPM held onto the laybarge LB 200, and also acquired McDermott Subsea Construction. This company's main assets were the reel lay vessel Norlift and the umbilical trenching vessel Northern Explorer. Both work mainly in the North Sea, but are also available for winter work elsewhere.

Should Australia and Indonesia feel the need for an ultra-long submarine gasline link, LB 200's services may one day be rendered. But it still has many avenues to pursue in the North Sea. The vessel, which can handle pipe diameters up to 60-in., is currently filling the breach on Statoil's Ekofisk bypass line vacated by Allseas recently, due to the Solitaire not being ready for service. According to Hugues Villedey, ETPM's North Sea commercial engineer, Ekofisk is a routine 15-km, 36-in. job only complicated by several crossings over existing pipelines.

LB 200 then moves on to tackle its third major Norwegian trunkline installation in three years - the Statoil-operated Aasgard transport line. This will be Europe's most northerly offshore gas evacuation system, stretching 697 km from the new Asgard B production semisubmersible off Mid-Norway to the Kaarstoe terminal just above Stavanger.

From the lower end of the route, up to 400 km should be completed this year followed by the northern section next year. ETPM is also responsible for pull-ins at the tunnel approach to Kaarstoe. Diameter of the main line is 42-in., with maximum wall thickness of 32.3 mm, making it one of the thickest offshore lines yet welded.

Use of heavier tubes than on previous trunklines has meant adding a fifth tensioner to the laybarge to achieve pulling capacity of 340 tons. There have also been modifications to the fixed ramp. Water depths along the route peak at 370 meters, and the seabed is rugged in stretches.

Long distance work in spurts has become routine for ETPM, which completed NorFra, the world's largest marine trunkline (826 km), last year. Between them, LB 200 and DLB 1601 achieved a world record day's pipelay of 8,621 meters last year.

In 1999, LB 200 is also designated for the Asgard flowlines. More work will come up for tender off Norway as gas projects around Heimdal, Haltenbanken South and elsewhere take shape. Infrastructure growth must continue, with so many gas export commitments for Norway across Europe. But this is not the case with new oilfield development, which the government has largely blocked for a year in an attempt to stop the nation's economy overheating.

In the UK sector, the industry itself is putting some subsea developments on hold while the UK government continues to ponder petroleum tax increases. Norlift is currently unaffected - it has two North Sea jobs in prospect for Maersk's Kraka and Esso's Jotun projects. But any serious downturn in the UK could lead to more away trips for the vessel, such as potential upcoming work off Africa or Latin America.

Both the Norlift and Northern Explorer are dynamically positioned. No further equipment add-ons are planned following the takeover. The reel-lift base at Teesside, UK and the core engineering team have been retained, but ETPM will work with other design houses should clients so wish.

Deepwater conversion

These vessels are among the assets of ETPM's new Subsea Development division, headed by Olivier Carre in Paris. There is also a four-strong fleet serving West Africa at present. At the lower end are two derrick laybarges, the CLB 101 and the DLB 1, dedicated to small diameter, shallow water pipelaying with 200-ton capacity cranes, and the PL 6, suited to installations in very shallow swamp or near coastal waters.

While no changes are planned to this trio, the DLB Polaris will be further transformed. A couple of years back, its lifting capacity was raised by 200 tons to 1,600 tons to handle Mobil's Ekpe jacket installation. A little earlier, it was fitted with Saturnax automated welding equipment for an 18-in. diameter pipeline on Chevron Angola's Nemba project.

This mid-size barge currently handles diameters from 4 in. to 48 in. It beat its own daily output records last year on two projects off Nigeria - 4,042 meters of a 12-in.line in one day for Elf's Ofon, and 4,857 meters of an 8-in. line for Chevron's Escravos. Next March it will undergo conversion to a DP vessel in preparation for the coming wave of deepwater developments off West Africa, with S-lay, J-lay and reel lay ramps also fitted for operations in up to 2,000 meters of water.

ETPM bills itself as Africa's first EPCI contractor, and that could extend to subsea EPCI once new facilities in southern Angola are fully operational. In association with Sonangol and Intels, ETPM is building a new logistics base at Lobito harbor on the site of a former iron ore terminal, 400 km south of Luanda. The base will be operated by the joint venture company Sobilog. The partners are optimistic of signing up BHP, Mobil, Chevron Petrofina, Ranger and Texaco as clients.

On the same site, is Sonamet, a new fabrication venture with Sonangol for shallow and, ultimately, deepwater developments. ETPM, with 55%, will manage the yard, but the rest belongs basically to Sonangol , giving it a higher share than in any of its other Angolan joint ventures.

Dredging of the quayside should be completed this October, allowing the first platform to be delivered in June 1999. So far five conventional platforms have been ordered, with construction able to start this July. About 240 people will be employed, including workers transferred from ETPM's Warri yard in Nigeria, where the offshore development scene is quieter currently.

First contracts for Elf's Girassol deepwater project may already have been placed. Pending an award, Sonamet was waiting to invest $10 million in a bundle construction and launching base at Lobito, which would be built on territory stretching 1 km inland. Girassol's development is expected to involve use of a tower for the bundled risers, devised by Doris and Stolt-Comex Seaway to provide insulation against anticipated wax formation.

The sequence for deepwater tenders to come offshore Angola after Girassol is expected to be led by Elf's Dalia Phase 1, followed by Chevron's Kuito, Esso's Kissange and Marimba and Chevron's Landana - all candidates for FPSOs. Further in the future are Elf's Rosa and Dalia Phase 2. Lobito will be in the frame for all these, and may also bid for deepwater work up the coast off Gabon and Nigeria.

ETPM's outlay on the Polaris, Norlift and Northern Explorer has forced it to postpone plans to build a new subsea well intervention vessel for the region, although these could be revived if an oil company or two came in either with sponsorship, or a long-term maintenance contract for a group of fields.

Smart Leg, ETPM's patented floatover method for large integrated decks, has not been shelved. McDermott has undertaken to build large decks suited to this technique should contract wins arise. According to ETPM, the technique could also be adapted to some of the upcoming shallower water projects off West Africa, provided there is room for the cargo barge to float.

To penetrate other emerging markets such as the CIS, ETPM may have to form other strategic alliances. However, it was coping independently anyway on Total's Sirri platform due to the US embargo on American contractors working in Iran.

Software integration aids floater, line analysis

Oceanos, the engineering software suite for design of all types of offshore structures, has been updated to improve the integration of its various modules. The result, claims Bureau Veritas' Advanced Technology Department director Pierre Besse, "is the most comprehensive product available for tackling dynamic interaction between floaters, risers and mooring lines". That includes deepwater floaters such as deep draft semis, spars and TLPs, as well as monohull FPSOs.

Development of Oceanos has been led over the years by Bureau Veritas (which also markets it worldwide) in partnership with Institut Francais du Petrole, Principia, and Caltec Informatique. Among the new features, the most important is the full coupling of the Diodore and Deeplines programs.

DeepLines is said to be the first commercialized software for computing dynamic behavior of all types of lines in varying configurations - flexible or rigid drilling and production risers, pipelines, mooring lines and TLP tethers - taking into account the wake effect on the lines and the behavior of the floater itself. Computational methods include frequency domain analysis and time domain simulation.

Now that it has been interfaced with Oceanos' Diodore hydrodynamic software, in addition to the interactive graphical modeling tool Isymost, the user should achieve a more rounded analysis of FPS motions and stresses. Environmental load criteria available include wave histories from model tests performed by French R & D group Hydlines, in situ measurements plus variation of the current magnitude and direction with depth.

Another addition to Oceanos is Ariane 3Dynamic, which arose from the incorporation of MCS' cable dynamics module Cable 3D into Bureau Veritas' existing mooring analysis program Ariane, which has 40 users worldwide. Features of the new tool include time domain dynamic response (TDDR) of the mooring system, including buoys and clump weights, under the action of wave drift and wave frequency forces, wind and current drags. TDDR can also be applied to an FSO and shuttle tanker in tandem mode.

Oceanos has been deployed by Bouygues Offshore and for Elf's Girassol FPSO offshore Angola. DeepLines was also used for modeling improvements to the production riser for Bouygues Offshore's multifunction barge concept for the Gulf of Guinea.