Climatic contrasts

David Morgan
Monday, August 9, 2010

Newly merged contractors Royal Boskalis Westminster and Smit Internationale got a foretaste of the operational synergies expected to stem from this move when their activities coincided earlier this year in the Strait of Magellan at the remote southernmost tip of Argentina.

Boskalis, in a 50:50 joint venture with pipelay contractor Allseas, was completing installation of the strategically important and technically challenging final stretch of Argentina's ‘Transmagallanica' pipeline, designed to carry some 18mmcm/d from the gas fields in the south to the distribution network in the north (see at bottom of page). Smit, as a subcontractor to Boskalis, performed all the associated diving work, a capability that along with others now forms part of a greatly expanded Boskalis maritime service offering.

In financial and legal terms at least, the merger of the two companies was completed in April; the complex process of integration continues although it is anticipated that the two strong brand names will be retained and they will remain separate entities at some level in their respective business areas.

‘We complement each other well,' says Boskalis Offshore area manager Bas van Bemmelen. ‘What we recognised some time ago and is now really becoming apparent, especially in the oil & gas sector, is that clients are asking for a more integrated approach; they are looking for a wider range of services and closer interaction with the client as engineering questions arise. Following the merger, and with our focus on port and terminal construction as well as offshore installation, we now see ourselves as a complete maritime service provider. Internally, we also see many synergies in areas such as vessel fleet utilisation.'

One strategically placed Royal Boskalis Westminster vessel, the trailing suction hopper dredger Stuyvesant, recently landed the group a major contract for sand berm construction work to help protect the Louisiana coast from the Deepwater Horizon oil spill. Sailing under the American flag and with US crews, the vessel was able to comply with Jones Act requirements and brings with it – courtesy of Boskalis and the Rijkswatersrand (the Dutch public works ministry) – sweeper arm expertise and technology introduced years ago for European oil cleanup contingencies.

That contract award rather hogged the headlines last month but, as Bas van Bemmelen points out, the company is involved in much else besides, especially in the LNG terminal and offshore pipeline sectors. The company has recently secured LNG terminal construction contracts running in both Poland and Mexico, and is stepping up to execution phase for similar work with an onshore/ offshore infrastructure mix in Australia. At the other climatic extreme, the company's dredgers continue to service Arctic offshore infrastructure work, returning to the Kara Sea in convoy with a Russian icebreaker and pipelay barge between July and October each year to trench two 48in, 70km-long pipelines that will ultimately bring Gazprom's Yamal gas into the twin Nord Stream trunklines connecting Russia to northern Germany via the Baltic (OE August 2008).

Boskalis has been responsible for no fewer than 18 pipeline landfalls over the last two years, and coming up soon are the company's second Saudi landfall and two 48in pipe pulls in German waters for Nord Stream. Boskalis was awarded the seabed preparation contract for these gas pipelines in January 2009. In May this year, it was confirmed that the company and its partner also now had a letter of intent for the installation of rock berms at critical sections along the 1220km Nord Stream route. With a total value of around €100 million, this was hailed as one of the largest single rock installation contracts ever awarded.

In its official statement, Boskalis Offshore said executing this work, using course gravel sourced from countries on the Baltic Sea coast, would involve ‘at least two, potentially three' fallpipe vessels, leaving the door open for its newbuild vessel to join Sandpiper and Seahorse on this job should the pipeline installation sequence allow. The project is scheduled to start next year and be completed in 2012. Construction of the 24-25,000t capacity newbuild began recently at Keppel's Singapore shipyard and the vessel is due for commissioning around the end of 2011.

Boskalis says its first newbuild will have a large, flat back deck enabling it to operate, like Seahorse, in multi-purpose mode and that fallpipe design will benefit substantially from the company's learnings with the Seahorse and Sandpiper fallpipe systems over the past ten years, with more automation, a lot less manual handling and a strong focus on making the system less susceptible to weather. Bas van Bemmelen confirms that the fallpipe vessel will be able to operate in the 1500-2000m water depth range but is keeping other operational details about the newbuild fairly close to his chest. ‘We have a number of alternative installation methods under review for up to 2500m using a concept currently under patent application.'

But the potential market for rock placement in appropriate volumes in those greater water depths remains shrouded in uncertainty. ‘That's why we are taking a diverse approach,' explains van Bemmelen. ‘We are looking to have a solid working system in a water depth range that we absolutely see a 100% market for, while at the same time keeping under development the versatile means to extend that range. Why carry all the added investment and weight to go to 3000m if it's not going to be needed for ten years?

‘We prefer the Swiss pocket knife approach,' he adds. ‘When the newbuild goes into service at the end of 2011 we will have a range of capabilities ready – with plans on the shelf, feasibility established and all the equipment tested – but not necessarily installed on the vessel.' OE

The 6.5km pipe pull

‘Extremely complex, technically and logistically,' is how Boskalis Offshore project director Arie Smits sums up the pipeline project his team completed in the notorious Strait of Magellan this April on a fast-track, eight-month schedule.

As equal joint venture partners with Allseas, Boskalis was tasked with completing the final section of the 24in Transmagallanica gas line between Cape Espiritu Santo and Cape Virgines, requiring the pipeline to be laid on the seafloor at a depth of 80m, with some of it in transition from land to water, over a distance of 37km. One of the achievements along the way, recalls Smits, was a pipepull of no less than 6.5km.

Water depth in the area is about 15m, although tidal variations can bring this closer to 24m. Trailing suction hopper dredger Prins der Nederlanden dug a 20km trench, its suction pipe having been lengthened to around 80m for the purpose. Allseas' Solitaire laid the pipeline to a depth of about 20m but could not continue beyond a 1km-long stretch of beach some 6.5km off the coast which is completely dry at low tides and offers just 6m draft at high tide.

Here, two teams of divers from subcontractor Smit were brought in to install a customized 27t spool piece to bring the two pipe sections together, operating from the pontoon Pontra Maris and supplied with electricity and two decompression chambers by Boskalis. The pipeline was welded onshore and then pulled into the water by Pontra Maris, converted into a pull barge for the occasion with the installation of a 300t crane and a linear winch capable of pulling 800t.

Categories: Pipelines South America Construction Installation

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