Ståle Hanssen was convinced we could lift a platform in one piece. But no-one had attempted it before.
No-one had ever attempted to lift a 22,000-tonne drilling platform in one piece before. But Ståle Hanssen was convinced it could be done — and in doing so, he saved us a million hours.
“It’s game changer,” says Ståle Hanssen, project manager for Johan Sverdrup substructure, installation and commissioning.
His job was to find a solution to the jigsaw puzzle of mounting the topsides of the Johan Sverdrup drilling platform, weighing 22,000 tonnes – with the jacket, or legs, of the platform, already installed offshore, in the most effective possible way.
Hanssen remembers his first meeting with Edward Heerema, the charismatic founder and owner of Allseas. Heerema travelled to Stavanger to meet him – and brought with him the drawings of the Pioneering Spirit, the world’s largest construction vessel, then being built.
Pioneering Spirit was designed to help with the scrapping of obsolete platforms, by lifting the top half of the platform, called the topside, off the supporting legs, called the jacket—in a single lift. That way topsides can be taken to shore for scrapping.
All other solutions require stripping down – piece by piece – prior to transportation ashore.
At the time, we were considering various plans for the removal of platforms such as Statfjord A and Huldra, and were therefore eager to learn about the latest technical advances.
But Ståle Hanssen, who had just started working on the Johan Sverdrup project, saw another opportunity. If the new vessel could remove a complete topside structure in a single lift, perhaps it could install one in a single lift as well?
No-one had lifted a platform on this scale before. But Equinor was willing to try.
Until now, big topsides have been modular in design, since no crane vessels have been able to lift more than 12,000 tonnes at a time. This has made it impossible to complete large topsides in yards onshore, and meant that the time-consuming and expensive processes of final hook-up of the modules had to be carried out offshore, where the health, environment and safety risks are higher than onshore.
Accelerating start-up by three to six months
For Johan Sverdrup, which would install four large platforms in Phase 1 of the project, in addition to an extensive hook-up programme, single-lift installation would allow for substantial savings, and a safer hook-up process.
The plans were far from complete. And the vessel was still being built. But the seeds of the idea had been sown.
“Equinor is a technology-led company that dares to invest in innovation and unknown technology. There was actually little resistance internally,” says Hanssen.
“Equinor is a technology-led company that dares to invest in innovation and unknown technology”
Ståle Hanssen, Project manager for substructure, installation and commissioning
Former Johan Sverdrup project director Kjetel Digre was positive, and so was Margareth Øvrum, executive vice president for technology, projects and drilling. There were still discussions in the company and in the partnership, he admits. The technology had not been qualified, and the vessel had not been built.
But it was simple maths. By cutting one million man-hours offshore, Allseas’ technological innovation could accelerate the start-up of Johan Sverdrup by three to six months. At the same time the price tag could be reduced by NOK one billion.
In March 2015, the day before the Pioneering Spirit naming ceremony, Equinor, then Statoil – on behalf of the Johan Sverdrup partnership – signed a contract with Allseas for the use of the gigantic new vessel for the installation of three of the four platforms in the first development phase in the North Sea. The fifth, and final platform, which will be installed in Phase 2 of the development, is also planned to be installed by the giant vessel.
The first platform, the riser platform, was ten metres too long for Pioneering Spirit and was therefore installed in the traditional way in April.
Extensive technology qualification programme
The biggest challenge associated with the vessel, which is 382 metres long and 124 metres wide, is performing the job close to the jacket – without touching it.
The pressurised lifting system on the two bows must be capable of installing the topside carefully on the jacket, while compensating for vessel movements. This places stringent requirements on the positioning system and control systems on board, according to Viktor Nilsen-Nygaard, head of the Pioneering Spirit technology qualification project at Equinor.
Together with a small team of Equinor experts on dynamic positioning, marine operations and control systems he last year delivered a report approving the technology for initial use.
The technology qualification process has been both exciting and challenging, and the collaboration with Allseas has been good.
“Equinor has the will, resources and expertise to implement this type of technology qualification projects, which is unusual,” says Nilsen-Nygaard.
Viktor Nilsen-Nygaard, head of the Pioneering Spirit technology qualification project at Equinor
Less restricted by the weather and seasons
In addition to lifting much heavier loads than other heavy-lift vessels, Pioneering Spirit also tolerates rougher weather.
Where others have to give up when the waves reach a significant (average) height of between one and one and a half metre for the heaviest lifts, Pioneering Spirit can operate in waves of up to 2.5 metres. This means that some waves may be as much as five metres.
Pioneering Spirit thus substantially extends the window for installation work offshore. Earlier, the rule of thumb has been that this could be done in the period April to September. Now installation work can in practice be performed year-round — assuming the weather is within operational criteria, of course.
Lift completed in three hours
At the end of May, Pioneering Spirit arrived in Bømlafjorden at Stord. There the 22,000-tonne complete topside, built by Aibel in Haugesund, was transferred from the barge it had been carried on, to the deck of Pioneering Spirit. After an eleven-hour voyage to the field, Pioneering Spirit carried out its first platform installation job. A world first.
The installation job took only three hours to complete.
Trond Bokn, JS project director, was positive that the vessel was capable of performing the job efficiently and safely.
“This technology has been tested repeatedly. But employing new technology is always exciting,” he says.
In addition to the drilling topside, Pioneering Spirit will also install the topsides for the processing platform and the living quarters. This will take place in the spring of 2019.
Ståle Hanssen admits that it has been an exciting process.
Pioneering Spirit had previously removed the Yme platform on the Norwegian continental shelf in August 2016 and performed a successful installation test on the Dutch shelf in the spring of 2017. The real test, however, took place in August 2017. The vessel then successfully removed the 24,000-tonne topside of Shell’s Brent Delta platform in the UK sector of the North Sea.
Now the vessel has proved that it is also capable of single-lift installation of entire topsides. A global first at Johan Sverdrup.
Standing on the bridge of the vessel, Edward Heerema said: “This has been 30 years in development. But it was worth it!”