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Every corner of the jacket has a cluster of four sleeves (photo: PAS Publicaties).

“Problems have sometimes occurred with the foundations of offshore wind turbines at the connections between the piles and sleeves. Research is being done into possible solutions, which will possibly result in new regulations. However, we did not have time to wait for the results of the research and found a compromise by strengthening the sleeves using reinforced concrete. During the FEED study, the diameter and number of the piles were also investigated. Eventually, it was decided to use 60-meter-long, 84-inch-diameter foundation piles, four at each corner.” Facts and figures

Regarding the number of man-hours spent on the design and fabrication, Aren Bezuijen says: “The engineering took 50,000 man-hours, as did the



management. Fabrication required 300,000 man-hours, while the engineering and the fabrication of the wellhead module required 15,000 and 25,000 man-hours respectively. It took HFG Engineering and Heerema Vlissingen 2.5 years to engineer and build the jacket and 1.1 years to build the wellhead module. We will use Mammoet equipment for the load-out on 9 May. The jacket will be transported on the H-627 barge, which is fitted with three main supports. The piles, the wellhead module and five caissons will be transported on barge H-122. The wellhead module is 18 meters long, 25 meters wide, weighs 220 tons and has twenty conductor guides and more than 2,000 bolts. The module will be installed on the top of the jacket using box sections.” Statoil and partners have together

invested 2.5 billion euros in the development of the Valemon field. With the fabrication of the Valemon jacket that weighs 9,400 tons, Heerema Vlissingen has established a new record. The previous record was held by a jacket weighing 6,100 tons that was built in 2006 for the BritSats (BritanniaSatellites) Project of ConocoPhillips. The yard in Vlissingen is currently fabricating the 4,000-ton jacket for the Dolwin Alpha HVDC platform, the topside of which is being built at the Heerema yard in Zwijndrecht. The fabrication of two 6,000-ton jackets, each 130 meters high are also in the pipeline. These are a wellhead jacket and a PUQ (Production, Utilities, Quarters) jacket for the Nexen Petroleum UK Golden Eagle project. These are planned for delivery in the second quarter of 2013.

Offshore Holland 3 | 2012  

Offshore Holland is een hoogwaardig, Engelstalig relatie- en promotiemagazine voor de internationale olie- en gasindustrie. Het doel van het...