Pioneering Spirit installs Sverdrup drilling platform topsides
Allseas’ multi-purpose construction vessel Pioneering Spirit has completed its first platform installation job, the single-lift 22,000-metric ton (24,251-ton) drilling platform topsides for Equinor’s Johan Sverdrup development in the Norwegian North Sea.
According to Allseas, this was the heaviest installation executed anywhere in a single lift offshore to date.
The vessel’s motion-compensated topsides lift system beams accurately positioned the topsides on the eight-legged steel jacket in 110 metres (361 feet) water depth. Thereafter, installation was completed according to plan.
On the 1st June, the 147-metre (482-foot) tall topsides was transferred from a barge to the Pioneering Spirit at the Bømlafjorden, outside Stord, western Norway. The vessel arrived nine hours later at the Johan Sverdrup field, 160 kilometres (99.4 miles) west of Stavanger and operations started immediately.
The installation programme, from manoeuvring around the jacket, setting down the topsides and then moving out of the 500-metre (1,640-foot) zone, lasted three hours.
The Pioneering Spirit will return to the field in spring 2019 to install the 26,000-metric ton (28,660-ton) process platform topsides and the 18,000-metric ton (19,842-ton) living quarters platform topsides.
According to Equinor, until now large topsides have been modular in design because no crane vessel has been able to raise more than 12,000 metric tons (13,228 tons) in one lift. However, the new lifting technology on the Pioneering Spirit allows entire topsides of up to 48,000 metric tons (52,911 tons) to be lifted in one operation.
The technology was also developed for the removal of decommissioned platforms, but 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, the company said, adding that use of the vessel will help cut one million man hours from offshore operations.
This allowed the Sverdrup partners to deliver a plan for development and operation for Phase 1 of the project which included a three-to-six months earlier start-up of the field than would have been possible using an alternative topsides installation solution.
Resultant savings were almost NOK1 billion (US$123 million).
Equinor expects the drilling platform, now into the hook-up and testing phase, to be onstream from the fourth quarter 2018.
Tieback to the platform of eight wells pre-drilled by the semi-submersible Deepsea Atlantic in 2016 will start toward the end of the year.
Following first oil in late 2019, drilling will continue with up to 48 wells set to be drilled during phases 1 and 2 of the project.
Source: Offshore Magazine