Heavy Lifting

Marine
Date: 23.05.22
The assembly of a unique jacket lift system is taking shape on board the world’s largest construction vessel. Within the hydraulics, which are integral to the lift system, are advanced seal configurations supplied by Trelleborg Sealing Solutions.-By Donna Guinivan

IN SHORT

  • The cost of decommissioning an offshore oil rig runs into the millions of USD.
  • Huisman BV created a more cost-effective jacket lift system for Allseas' Pioneering Spirit, the world's largest construction vessel for installing and removing oil rigs.
  • Trelleborg Sealing Solutions closely collaborated with Huisman BV to supply a sealing configuration to meet operational conditions.

DESPITE THE EMERGENCE OF

floating oil & gas extraction equipment, jack ups or fixed platforms still make up the majority of rigs in operation and under construction, with Asia Pacific seeing the most new build activity. In 2020, 45 jack up rigs were being built and assembly of 73 percent of these were in Chinese shipyards.1
1. https://www.offshore-mag.com/drilling-completion/article/14178068/ihs-markit-offshore-rig-construction-market-suffers-repeated-blows

Lowering costs

With rigs taking two to three years to construct at around 650 million USD each,2 contractors and operators are always looking for ways of reducing costs. At the other end of the rigs' lives, as oil & gas fields around the world mature, there is a growing issue of decommissioning—the safe plugging and abandonment of wells and the removal of the platforms that have reached the end of their productive life.
2. https://interestingengineering.com/the-engineering-and-construction-of-offshore-oil-platforms


The UK North Sea, for instance, is one of the world’s most mature offshore production basins with hundreds of platforms, millions of tons of infrastructure, and thousands of
wells that will need plug & abandonment (P&A), removal, and recycling in the coming years. Decommissioning, estimated at between about nine million to 22 million USD per platform depending on size and location, is an expensive business and operators are looking for innovations like the complete jacket lift system to lower costs.3
3. https://www.ogv.energy/news-item/oil-gas-decommissioning-challenges-opportunities

Allseals

ABOUT ALLSEAS' PIONEERING SPIRIT

The jacket lift system will be fitted on the existing Allseas' Pioneering Spirit, the largest construction vessel in the world, which is designed for the single-lift installation and removal of large oil & gas platforms, as well as the installation of heavy pipelines. Built at the DSME shipyard in South Korea between 2011 and 2014, the twin-hulled vessel is 382 meters long and 124 meters wide.

The new hang-off and upend system will help to raise a couple of jacket lift system (JLS). Two upend skid units will lift beams that are 170 meters long; four large hydraulic cylinders drive these. The distance between JLS beams can be repositioned in transverse direction by means of four hydraulic cylinders located on the vessel stern to accommodate different jacket sizes.

https://allseas.com/equipment/pioneering-spirit/

A single lift

Allseas’ Pioneering Spirit, once completed, is the world’s largest construction vessel and boasts a hang-off and upend system manufactured by Huisman BV. This can lift a complete jacket – the steel frame supporting the decks of an offshore platform – with a single lift. Considering a single jacket can weigh up to 20,000 tons, which is equal to the weight of 200 space shuttles, this is an amazing engineering feat.

Not only will the vessel lower the costs of the installation of jackets, it will also generate large cost savings and significantly reduce safety and environmental risks in the decommissioning of old and outdated offshore rigs. Conventionally, when removing large jackets offshore, the structures require lengthy and complex cutting operations to create small sections suitable for crane lifts. Lifting a jacket off in one piece will make this unnecessary.
 

Collaboration is key

Huisman BV’s Czech subsidiary, Huisman Konstrukce s.r.o., engineered and manufactured the hydraulic cylinders.The engineering team in the Trelleborg Sealing Solutions
Customer Solution Center collaborated closely with the customer to design a sealing configuration in line with operational conditions.

“We’ve worked with Huisman Konstrukce, s.r.o. for many years and we are currently involved in several projects,” says Tomáš Pesr, Sales Engineer, at the Czech Customer Solution Center. “Supplying seals for the hydraulic cylinders of this unique jacket lift system was a very significant project. We made several designs based on the required parameters. Collaboration was at every step of the development process, from specification to the cylinder assembly, with simple assembly being one of the most important criteria.”

ABOUT HUISMAN BV

Huisman BV designs, manufactures and services heavy construction equipment for the world’s leading companies in the renewable energy, oil and gas, civil, naval and entertainment markets. Its products range from Cranes, Pipelay Equipment, Drilling Equipment and Winches, to Vessel Designs and Specials.


The history of Huisman is one of setting new industry standards; of making impact, since 1929. Its step changing technical solutions vary from stand-alone components to highly engineered integrated systems, from concept to installation and lifetime support.


www.huismanequipment.com

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HOW DOES THE JACKET LIFT SYSTEM WORK?
To remove an offshore platform jacket, first its foundation piles are cut near the seabed. Then hoisting blocks are lowered by two towering main beams on the construction vessel and connected to hooks on the top of the jacket. Following this, the jacket is pulled out of the water over the stern of the vessel, aligned with the beams, and tilted horizontally. A reverse of the operation installs the jacket.
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