The two final platform topsides have been installed at the Johan Sverdrup oil field in the North Sea, about 140 kilometers west of Stavanger, Norway, operator Equinor announced Friday, marking a key milestone toward first oil expected in late 2019.
A processing platform and living quarters topside were installed this week using single lift technology enabled by the world's largest heavy lift construction vessel, Allseas’ Pioneering Spirit. At nearly 26,000 metric tons, the processing platform lift set a new record offshore, and was carried out on Tuesday morning in four hours with a clearance of just 25 meters from the rest of the field center, Equinor said. The lift of the utility and living quarters topside, 18,000 metric tons, was completed early Friday morning in 3.5 hours. From the start of the lifting operation of the processing platform on Tuesday morning until the living quarters topsides had been lifted into place on Friday it took less than 72 hours.
During the same period, the final flare stack and the bridge that links the processing platform to the drilling platform were lifted into place by the Heerema Marine Contractors heavy lift vessel Thialf. Equinor said it plans to install the final bridge that will connect the utility and living quarters topside to the rest of the field center during the next possible weather window.
“We have completed the heaviest lift ever performed offshore. Over the course of just three days, we have lifted almost 47,000 [metric tons] into place. And the whole process was completed safely and efficiently, without harm to people or the environment,” said Ståle Hanssen, responsible for engineering, installation and commissioning in the Johan Sverdrup project.
“This was all made possible by in-depth planning and, not least, a high level of precision in execution in collaboration with our suppliers and partners,” he said.
The Johan Sverdrup offshore installation and completion phase began in August 2017 with installation of the jacket for the riser platform. After that, an additional three steel jackets, four topsides, two bridges, two flare stacks, 200 km of power cables and more than 400 km of pipelines have been put in place.
“Now we are in the process of concluding the installation campaign for the first phase of construction of Johan Sverdrup. Putting the final building blocks of this gigantic project into place is important to ensure start-up of the field as planned in November this year,” said Trond Bokn, senior vice president for Johan Sverdrup.
“We’re not finished just yet,” he added. “A lot of work remains, but with the installation campaign completed, we are on track to start production in November.”
Next will be the hook-up, testing and commissioning of the two final topsides, followed by testing and ensuring that all four platforms – and the field center as a whole – function as a single unit. Completing the tie-back of the eight pre-drilled production wells on the field to the drilling platform will also come in addition to this.
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