The Magazine for Underwater Professionals
Subsea friction welding with ROVs and divers
The SUT evening meeting ‘Subsea Friction Welding with ROVs and Divers’ was conducted by Dave Gibson, technical authority for friction welding at Proserv, and Stuart Harvey, product champion for friction welding, also at Proserv. The presentation gave an overview of subsea welding processes, and focused primarily on the advantages, applications and capability of Proserv in relation to subsea friction welding with ROVs and divers.
The presentation began with an overview of Proserv as a company and a brief company history. This was followed by an overview of subsea welding processes, specifically wet welding, hyperbaric habitat welding and friction welding.
We learnt that subsea friction welding involves the rotation of a stud at high speed, using ROV or diver tooling and applying an axial force to complete the attachment to the target surface. The stud is generally attached to a large tubular or flat surface subsea, such as a vessel hull. The generation of heat by the rotating stud against the surface results in the tip of the stud flowing plastically to form the weld. The presentation included a short video demonstrating the process, which was described as being analogous to forge welding by a blacksmith.
The many benefits of friction welding were described. The ROV process is virtually unlimited by water depth and as the weld process is solid phase, the weld is free of slag and porosity. Unlike electric arc welding, where high residual stresses can be present at the weld pool, the residual stresses with friction welding are compressive, resulting in good fatigue strength. Fatigue testing had shown good results in the as-welded condition without post-weld heat treatment and tensile testing had shown that failures do not occur at the weld.
The presentation continued by outlining a number of projects where the friction welding technique was used by Proserv, as well as an overview of the tooling involved. The examples that were shown included an anode attachment to a vessel hull, where a short video of a post-installation ROV survey showed some of the 450-pound (204-kilogram) anodes that were attached by ROV.
Another project showed that the technique was useful in anode retrofit to subsea structures by means of a stud and cable attachment.
Other projects included subsea friction plug welding for valve repair, welding of studs to live equipment and cofferdam attachment to a vessel using the friction stud welding technique.
It was clear from the presentation that subsea friction welding with ROVs and divers is an effective and robust method of stud attachment that can be used in various applications. After the presentation, several questions were asked by the inquisitive audience and samples of welded studs were passed around for inspection. The Proserv team answered the questions knowledgeably, after which we departed for the usual cheese and wine.
The Society for Underwater Technology Texas A&M University (TAMU) Student Chapter hosted its annual Welcome Dinner for more than 100 of its student members in the Memorial Student Center with invited industry representatives from SUT Houston.
Colleges from every aspect of the university, including geosciences, engineering, archeology and business, were represented that evening, demonstrating the multidisciplinary nature and uniqueness of SUT TAMU.
To begin the evening, the three 2015 Student Paper Contest winners were acknowledged and awarded US$1500 from SUT London. The winning papers were selected by SUT Houston volunteers from many high-quality papers submitted in the areas of engineering, science and technology. The 2015 Student Paper Contest winners were Ahmad Abdullah (engineering), Lindsay Martin (science) and Kewei Chen (technology). Dr Medina Cetina, associate professor of Civil Engineering and SUT TAMU academic advisor, read a message from Dr Bob Allwood, SUT’s chief executive officer, congratulating the Student Paper Contest winners and recognising the achievements of SUT TAMU.
Christopher Curran, BP advisor and HIPPs and subsea controls engineer for deepwater facilities, then gave a keynote presentation on the current underwater technology and procedures related to deep-sea drilling with two case studies in the northern Atlantic Ocean. Following the presentation, students discussed the current and future opportunities of underwater technology as well as personal experiences with the many emerging and established industry representatives from SUT Houston.
SUT TAMU is a multidisciplinary student organisation that works towards building a bridge between students and industry experts in the field of underwater technology, providing education and professional opportunities to its members. The TAMU Student Chapter was the first of its kind within the United States and, with the support of the SUT London and Houston branches, continues to gain momentum within the university as student membership grows.
SUT TAMU is thankful for the volunteers who came and talked with students about their careers and provided advice to the next generation of subsea engineers and industry members. Specifically, a warm thank you is given to John Allen, president of Intecsea, Roger Osborne, senior consultant for Ocean Flow International, Mark Siegmund, subsea systems engineer and wells reliability advisor for BP, Logan Brant, project geotechnical engineer for Geosyntec, Nicole Otten, FMC Technologies Design Center manager, Neil Manning, chief executive officer of SLAM Group, Eric Sears, technical supervisor at the College Station Design Centre for FMC Technologies, and Alan Foley, president of Svitzer Surveys.
The 2015 Welcome Dinner was a major success and the perfect introduction to a year full of engaging events and seminars spanning from tailgates and field trips to climate change and job-hunting strategies. SUT TAMU is always looking for more members and sponsorship from companies for events.
The Aberdeen Branch SUT+ group has provided some fantastic events throughout 2015.
In May, the group visited the KCA Deutag drilling simulator (DART) at the Robert Gordon University (RGU). The DART facility at RGU utilises a state-of-the-art drilling simulator incorporating cyber chairs, touch screens, a ‘doghouse’ environment and a cinema-style projection of an offshore drilling facility. It is used to train and assess drill crews, specialising recently in scenario, situational and behavioural aspects of well control situations. KCA Deutag Group head of operation, Geoff Monson, gave the group an introduction to the world of drilling on the night.
The group was also lucky to have the chance to undertake a taster workshop on project management, delivered by Jacqui Smith of Pro-fection. This proved to be a very useful and worthwhile session giving attendees a fast-track overview of the standard APMP qualification course.
In June, Subsea 7 opened the doors to its North Sea spoolbase in Leith, Edinburgh, where attendees were given a tour of the pipeline fabrication process – in action!
Activity did not stop over the usual SUT summer break. In July, SUT+ welcomed Wood Group chief executive Bob Keiller to give an informal talk at the inaugural ‘An Evening With…’ event. This will be followed up with presentations from more industry leaders very soon.
This was followed up by two site visits – to Wild Well Control at Smith Quay, Peterhead, to see the company’s capping stack equipment and to Wärtsilä to see its workshop and manufacturing facilities.
In August, a second visit to the National Hyperbaic Centre was provided where attendees learned about diving, hyperbaric medicine and hyperbaric testing of subsea equipment. The group will continue to provide visits to the NHC as they are proving to be very popular.