The 22,000-tonne topside for the drilling platform was lifted into position in one single lift on the Johan Sverdrup field last weekend. Equinor and the Johan Sverdrup partners are the first users in the world of this ground-breaking technology.
On Thursday 31 May the topside for the Johan Sverdrup drilling platform sailed from the Aibel yard in Haugesund to B?mlafjorden at Stord.
Here the 22,000-tonne steel structure was transferred from the barge to Pioneering Spirit, the world’s biggest heavy-lift vessel. All set for the eleven-hour journey to the jacket waiting for its topside on the Johan Sverdrup field.
After initial preparations, the actual installation job took only three hours. This makes it likely the fastest ever installation of a large, fully completed topside. The second of four platforms in the first development phase of the giant Johan Sverdrup field is thus installed.
“This is an important milestone in the Johan Sverdrup installation campaign. Two of the four Johan Sverdrup platforms are now in place. The power cables to the field were rolled out last week, and so far, the installation of Norway’s biggest oil pipeline has gone very well, so this is definitely moving in the right direction,” says Trond Bokn, senior vice president for Johan Sverdrup at Equinor.
“At the same time, much work remains, and we must maintain extra focus on safety and quality in the execution phase. But we can breathe a bit more easily now that the drilling platform is installed – this is the first ever such operation in the world,” Bokn adds.
A game changer
Stale Hanssen, project manager for Johan Sverdrup jackets, installation and commissioning, describes the technology enabling single-lift installation of big platforms as a game changer for the industry.
Up until now big topsides have been modular in design. No crane vessels have been able to lift more than 12,000 tonnes in one lift. The brand new lifting technology on Allseas‘ Pioneering Spirit vessel, however, allows entire topsides of up to 48,000 tonnes to be lifted in one, single lift.
The technology was initially developed for the removal of scrapped platforms. Equinor is the first user of the technology for the installation of big, new topsides. This allows for great savings in the construction and installation phases, both in terms of manhours and costs, and, not least, reduces risks related to health, environment and safety.
“Equinor and the Johan Sverdrup partnership, working closely with Allseas, make a break-through for the industry here. The safety-, schedule- and cost-related benefits are substantial, and we expect that many others will follow suit,” says Hanssen.
“At the same time making the Johan Sverdrup planning puzzle so dependent on a vessel that was in fact at the time not even fully completed was no easy decision. We of course spent much time with the Johan Sverdrup partnership before coming to this conclusion,” he says.
Pioneering Spirit will return to the Johan Sverdrup field in the spring of 2019, to install the two last topside structures in the first phase of the development, for the processing platform and the utility and accommodation platform.
Overall the use of Pioneering Spirit will help cut one million manhours offshore. This enabled the Johan Sverdrup partnership to deliver a Plan for development and operation (PDO) for Phase 1 of the development which included a three-to-six months earlier start-up of the field than would have been possible with the alternative topside installation solution. At the same time this helped cut the estimated costs for the PDO by almost NOK 1 billion.
The drilling platform on stream from the autumn of 2018
The Johan Sverdrup drilling platform is now fully completed and 85 percent fully tested. The last phase - hook-up and testing – starts now. The platform is due to become operational this autumn, and the tie-back to the platform of eight wells pre-drilled by the Deepsea Atlantic semi-submersible in 2016 starts towards the end of the year.
“We look forward to putting the drilling platform on stream, and completing the pre-drilled wells towards the end of the year and next year, preparing for first oil in late 2019,” says Stig Atland, head of drilling and well for Johan Sverdrup.
Then the drilling platform will start drilling new wells on the field, both for the first and second phase of the Johan Sverdrup development. Overall, as many as 48 wells may be drilled.