Just ahead of its lifetime extension, Allseas’ pipelay vessel Lorelay has completed a platform-to-platform pipeline off Trinidad’s southeastern coast in just ten days. For the first time in the company’s forty-year pipelay history, Allseas successfully deployed the innovative “bowstring” start-up method.

Awarded in mid-2024, the fast-track project in the Caribbean involved engineering and installing the 22-kilometre, 16-inch multiphase line to meet first gas commitments for an offshore development in 2025.

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Bowstring start-up method

Running at depths of 60–70 metres, the concrete-coated pipeline connects a newly installed platform to existing infrastructure. Allseas‘ Lorelay kicked off operations in December, expertly placing 139 mattresses to cross and protect existing subsea pipelines.

The innovative bowstring start-up method that was used entails connecting the pipeline start-up head directly to the platform jacket leg.

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Lifetime extension and Porthos

With the pipeline delivered on time and to spec, the Lorelay has now returned to Rotterdam for its lifetime extension. The Lorelay was launched in 1986 and is a versatile vessel optimised for the execution of small and medium diameter pipeline projects of any length in unlimited water depths. In addition, the vessel is suitable for associated work, such as the installation of risers and subsea protection frames.

Its ship-shape allows for a high transit speed, while a large pipe storage capacity means it is less dependent on offshore pipe supply. In 1996, the pipelayer set a new record for deepwater pipeline installation, laying a steel pipe to a depth of 1645 m (5400 ft) in the Gulf of Mexico.

In addition to the lifetime extension, the Lorelay will also be prepared for new jobs, including Porthos, the world’s first commercial carbon capture pipeline.

Picture: The Lorelay near Rotterdam (photo by Kees Torn, Flickr, CC BY-SA 2.0).

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