Recently the 9,150 tonnes Statoil jacket set sail from the Heerema Vlissingen yard to its final destination at Valemon gas field on the Norwegian Continental Shelf in a water depth of approximately 135 metres and about 160 kilometers west of Bergen, Norway.
In less than 2 years, after contract award in September 2010, Heerema Fabrication Group designed and fabricated this gigantic 160 metres high jacket for the Valemon process platform. Additionally in March 2011 Statoil awarded HFG the contract to design and fabricate the 210 tonnes weighing wellhead module. The jacket and wellhead module were both designed by HFG’s in-house design company HFG Engineering and the fabrication contract awarded to Heerema Vlissingen yard.
The design of the Valemon jacket resulted in a very intensive process with critical design challenges. Control of the jacket weight to stay below the maximum lifting capacity of the crane vessel Thialf was the most critical one, which finally resulted in a successful design process as the jacket did not weigh a kilo too much steel. Another special feature is the wellhead module, which will be partly integrated in the topsides after its installation in 2014. Early installation of the wellhead module will enable Statoil to drill numerous wells before platform completion.
Cees Spaans, VP Technology of HFG Engineering, says: “Due to the close cooperation with our client Statoil and other partners in the design process, we managed to deliver the safest and largest ever liftable jacket of its kind. Important to mention is that this jacket contains numerous features, which makes it unique. To mention are the special strengthening of the foundations with reinforced concrete and the solution to minimize boat impact in case a vessel collides with the jacket. For this we involved TNO Technical Research Center Delft to work together with us to ensure that the Valemon jacket is capable of resisting severe boat impact criteria.”
Aren Bezuijen, Project Manager of Heerema Vlissingen, adds: “The various challenges during the fabrication process made this a major achievement of the workforce and project management to deliver a high quality jacket within 1 year and a wellhead deck in only 6 months. We hereby thank our client Statoil for the pleasant cooperation during the execution of this contract, which contributed to a successful delivery. This project shows the strength of HFG to manage the interfaces, thanks to the fabrication and installation-driven engineering focus of our in-house design company. The total Engineering, Procurement and Construction (EPC) contract provided 500,000 manhours with additional supply chain jobs.”
Kjell Arvid Tuen, Site Manager of Statoil, concludes: “Valemon jacket has been a very interesting and challenging project for us in the site team. We have had our challenges as mentioned before, but we have managed to mitigate and close them all in a good way. I will also emphasize that we have had an open and good communication with all levels in the HFG’s organisation. I hereby congratulate Heerema with a successful performance of the Valemon jacket and wellhead module, delivered on schedule.”
Subsea World News Staff , May 29, 2012; Image: HFG