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Laying down a track record

Saipem’s flagship pipelay vessel sailed out of the shipyard five years ago with a docket of high-profile jobs in its sights. Upstream Technology takes stock of the Castorone’s work to date, the lessons learned, and the mighty vessel’s next challenges.

At 330 metres from stem to stern, Saipem’s Castorone immediately joined the ranks of the world’s largest pipelay vessels upon delivery in 2012.

Its current topsides equipment, installed at the Keppel Offshore & Marine yard in Singapore, includes an S-lay system with three tensioners for an overall pulling capacity of 750 tonnes in normal lay mode.

It has 67 MW of installed power to fuel both the high capacity lay equipment and the dynamic positioning (DP) class 3 system.

Up to 18,000 tonnes of pipe joints, from conventional 40-feet-long sections to 60-feet-long joints, may be stored in the hull.

1709.inauguration1.jpg BRAND NEW: The Castorone during an inauguration ceremony at the Keppel Shipyard in Singapore, September 2012. After completing its first deep-water pipelay operations in the US Gulf of Mexico the vessel set sail for the Ichthys project off Western Australia.  Photo: Saipem

Joints are welded and coated in two pre-fabrication areas into “triple joints” and conveyed into a firing line, which is configured according to the demands of the job - water depth, pipe diameter, and welding and coating specifications.

The articulated stern ramp, or “stinger”, adds 120 metres to the vessel’s overall length during S-lay operations.

Roberto Faldini calls Castorone “a real offshore factory” that integrates state-of-the-art technology, automated interconnected machines and live data analytics.

Faldini, an installation engineer at Saipem for more than 20 years, was heavily involved in the vessel’s early stages and more recently in upgrades and modifications designed “to improve performance where we see opportunities, including operations”, he says.

To formulate those improvements, Saipem is drawing on more than four years of work, starting in ultra-deep Gulf of Mexico waters, where the Castorone installed the 219-kilometre long, 24-inch Walker Ridge export pipeline for Chevron’s Jack/St Malo development, in 2140-metre water depths, and the Big Foot export pipeline.

1709.line1.jpg JOINT EFFORTS: Saipem used lessons learned in Castorone’s first years of operation to improve pipeline fabrication and other systems.  Photo: Saipem
 

The project was “a real challenge for a vessel being used for the first time,” Faldini says, because it included the installation of dynamic risers and several complex inline tees for future tie-ins.

Following a flowline installation at the Burullus field in the Egyptian sector of the Mediterranean Sea, Castorone sailed to Australia for its next big job - installation of the 42-inch outer diameter, 884-kilometre long pipeline for Inpex’s Ichthys development.

“The full potential of the Castorone was proven on the Ichthys project,” Faldini says.

“This was the first large diameter trunk line for the Castorone, which performed well with a noteworthy peak daily production.”

The crew learned much about the influence of rigid lines on the DP system, he says, as the vessel moved from shallow waters near the pipeline’s onshore terminus and the field depth of around 300 metres.

The vessel returned to the Mediterranean to install eight-inch, 14-inch and 26-inch lines for Eni's Zohr gas project, where “the client’s stringent welding specifications were the only issue worthy of note”, he says.

Fine-tuning

Last year, the Castorone returned to Keppel Shipyard for a series of upgrades that included new switchboards to improve the vessel's power distribution systems, maintenance work on 45 kilometres of electrical cables, pipelay system upgrades, new water ballast tanks and the conversion of existing ballast tanks into fuel oil tanks.

This summer, the vessel docked at Fincantieri’s shipyard in Palermo, Italy, for further upgrades in preparation for upcoming jobs.

1709.inauguration4.jpg  Photo: Saipem
“Most of the improvements were, I would say, small modifications to reduce maintenance time, to improve the capacity of the equipment, and to do things in a quicker way to reduce downtime and be more productive when we are working,” Faldini says.

Saipem implemented a vessel improvement programme around the time Castorone entered service.

The company sought to incorporate “major and minor” lessons learned, he says, to increase safety and operational efficiency in different weather conditions.

The crew worked on other “fine-tuning measures” with colleagues in engineering and asset operations.

“During works, our vessel management team started with a prudent approach on the move-up speed, then built greater confidence through a careful action on the electronic control system, all of which meant that the move-up time was significantly reduced,” he says.

“Change of pipe diameter mode was subjected to a review, enhancing the method of pipe support inside the cargo hall,” Faldini continues.

Saipem studied “a profoundly new approach” for its proprietary welding system and field joint application. In addition to the technological improvements, he says, engineers designed “smart” rollers to protect just-made field joints from potential damage during cool-down.

Engineering and operations personnel worked together to optimise abandonment and recovery systems and to make minor modifications to other equipment where deemed necessary.

And the company used its internal weather management expertise to better plan operations — optimising forecasts, for example, to avoid unnecessary abandonment or determine whether a necessary abandonment may be partial or complete.

Data-driven

A storm during the Zohr project provided a good test of the vessel’s seakeeping capacity, as 6.5-metre waves forced the crew to suspend operations temporarily.

“However, the vessel performed only a partial abandonment, holding its position brilliantly and encountering a limited time loss,” Faldini says.

Saipem uses data collected from such operations to improve pipelaying performance and ensure safety on board the Castorone.

A live database of more than 12,000 variables is distributed in a network of more than 30 nodes, where all machines are interconnected and behave in a co-ordinated way, Faldini says.

The company has implemented what it calls a “Big Data Vision” across its different business units and is seeking new ways to use the huge amount of data that an asset like Castorone generates — real-time production data and equipment condition monitoring, for example, combined with metocean data gathered during offshore operations.

1709.inauguration2.jpg  Photo: Saipem
“The prize would be huge,” Faldini says, for the safety, commercial and tendering disciplines and to improve production and increase automation onboard the vessel.

The company is touting the vessel’s versatility and Saipem’s track record in a competitive offshore construction market.

“The vessel has proven in practice that it is capable of uploading, handling and laying a large quantity of pipes in a single day, granting production rates that offset vessel costs,” Faldini says.

“The Castorone is relatively young, and thus has further margins of improvement to play with. It is and will be a state-of-the-art vessel and was designed to work on the most challenging projects, in extreme environments, by combining the high production of S-Lay process with the ultra-deepwater J-Lay capabilities on the same vessel.”

From Sicily, the Castorone will return to Egypt for the “optimised ramp-up” phase at Zohr, which includes installation of a 30-inch gas export pipeline.

The next big challenge will come next year, when the vessel is scheduled to install export pipelines for Statoil’s Johan Sverdrup development off Norway.

The project includes a 156-kilometre, 18-inch gas export line to the Karsto gas terminal and a 36-inch oil export pipeline, about 282 kilometres long, to the Mongstad terminal.

“With all of these projects, the Castorone has learned how to tackle complex tasks by handling lines of various diameter, thickness and materials, all of which require increased flexibility of the production process as well as accurate planning for pipe logistics,” Faldini says.

“All the equipment is tested now. We know that we can manage a lot of pipe joints per day. We know that we can reach very high productivity.”

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