World-class welding technologies - Subsea 7

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02 In-depth technology news More than ever before, Subsea 7 continues to commit to the development and commercialisation of new technology, vessels and equipment that deliver technical and cost-effective solutions to our clients in their increasingly challenging environments and operational scenarios. Many of our most effective technologies are developed in active collaboration with key suppliers from our supply chain. Our development partners play an important role in the emergence of effective new ideas and solutions for our clients, and they cover a unique range of technologies which reflect our global expertise and capability. We are proud to have received recent industry recognition of one of our pipeline technologies from the Pipeline Industries Guild. One of the industry’s foremost bodies, the Guild presented Subsea 7 with the prestigious “Subsea Pipeline Technology Award” at their annual dinner in London in March for our development work on the installation of mechanically lined pipe using the reel–lay method, (see page 8 for details of current development work). In this latest issue of deep7, you can read about our latest applied technology advances in disciplines ranging from pipeline welding to geotechnics, and from advanced vessel design to the installation of ground-breaking subsea infrastructure. To find out more about any of the technologies featured in this issue contact John Mair, Technology Development Director at john.mair@subsea7.com or email communications@subsea7.com DEEP7 May 2012 Welding enhancements in the pipeline Subsea 7 is developing and implementing leading-edge pipeline welding technologies to satisfy evolving market demand - both in terms of technical specifications and volume - and to meet increasingly stringent pipeline fabrication codes and operator specifications. Underpinning this technology development are three important strategic investments by the company: • entering into a technical partnership with CRC-Evans Pipeline International (CRC), one of the world’s leading designers and manufacturers of automatic welding systems for pipeline construction • committing to an extensive welding R&D programme to meet future industry demands • the opening in 2013 of a new Global Welding Development Centre in Glasgow, managed by Subsea 7’s Pipeline Production Group (PPG). Pipeline performance is currently being challenged on a number of fronts – not only by high demands on the performance of pipeline welding processes and the assurance of the integrity of girth welds, but also by the increasing usage of higher strength steels, clad/lined and solid corrosion-resistant alloy (CRA) pipe. Subsea 7 is implementing a welding methodology which meets the following criteria: • Adoption of a common approach to welding processes and equipment across all fabrication sites • Use of welding processes which allow the heat input to be controlled precisely to optimise weld mechanical and corrosion properties whilst ensuring weld soundness • Use of mechanised welding whenever practical in order to minimise welder intervention. Subsea 7’s reeled pipeline production facility at Vigra in Norway, accommodates the latest mechanised welding technology, and
demonstrates how careful assessment of project requirements and production factors can deliver cost-effective welding solutions. The new technology is about to be deployed in Brazil, and will thereafter be rolled out to Subsea 7’s other fabrication sites worldwide. In the case of larger-diameter carbon steel pipelines, the use of the mechanised Pulsed Gas Metal Arc Welding (PGMAW) process is now established as the welding method of choice for both riser and flowline applications. The process utilises low-heat input which results in excellent mechanical properties in the girth welds. The process can be deployed using either single torch, or in the case of larger diameter pipe, dual torch welding in order to improve productivity. This system is highly mechanised so that the role of the welding operator is simply to supervise the process with minimal intervention required. Since the current welding system was introduced to Vigra in early 2011, about 400km of carbon steel pipeline have been fabricated, with productivity and quality exceeding targets. The overall weld repair rate, which is a key quality indicator, is less than 0.5%. Subsea 7 has further developed the PGMAW process for use in the fabrication of metallurgically clad pipe. Welding of clad pipe requires the use of dissimilar welding filler material, i.e. Alloy 625. Subsea 7 has carried out extensive welding trials to optimise pulsed welding parameters and shielding gas composition. The qualified PGMAW solution makes use of the Controlled Metal Transfer (CMT) process for root welding, an advanced PGMAW technique which allows the weld root to be deposited very precisely, giving good control of the root bead quality and profile. These features are essential to maintain the corrosion 03 performance of the clad pipeline. During production, an internal camera and laser profiling device is utilised to perform an assessment of the quality of the root bead. The developed welding solution will be implemented in production this year for a number of pipeline projects, which will involve over 70km of metallurgically clad and mechanically lined pipe risers. For smaller diameter pipes (4-inches and below) a mechanised welding system has been developed by Subsea 7 and implemented at Vigra. A key benefit of this system is to provide a more precise control of the heat input in order to maintain the optimum mechanical and corrosion performance. This solution, initially deployed on a 2-inch duplex stainless steel service line, was based on the use of the orbital Gas Tungsten Arc Welding (GTAW) process using the Polysoude welding system. Production welding has been in progress since November 2011 with weld quality and productivity meeting expectations, and has confirmed that this technology can be successfully deployed on a global basis. The 2-inch duplex line was also a Vigra “first” for the use of an automatic arc monitoring system on the firing line to capture and record the essential welding parameters. Operations will begin in 2013 at Subsea 7’s new Global Welding Development Centre in Glasgow, which will incorporate 18 welding bays including facilities for J-lay and S-lay pipeline welding, and will act as a central technical authority for the development and qualification of all welding procedures for all Subsea 7 pipeline fabrication bases around the world. This major initiative by Subsea 7 will give clients the assurance of quality and delivery of pipeline welding performance at a competitive cost. For further information contact eric.law@subsea7.com seabed-to-surface
Page 1: Technology news from Subsea 7 - May
Page 5 and 6: Planning and precision combine on P
Page 7 and 8: Cutting-edge simulation Subsea 7 ha
Page 9 and 10: Swaged end connection for reel-lay
Page 11 and 12: Seven Viking Due for launch in late

World-class welding technologies - Subsea 7

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