Trelleborg has launched a revolutionary new SealWelding technology which allows seals to be welded in-situ on an FPSO platform, eliminating the need for it to disconnect and return to shore.
Manufactured from Trelleborg’s already well-established seal material, this new technology will massively reduce the downtime and associated costs that come from maintaining an FPSO swivel stack. Currently, swivel stack maintenance requires a vessel to travel back to shore so that components can be completely disassembled and seals replaced.
“The offshore oil and gas sector has been going strong since the late 1940s, however, as the industry continues to move toward even more demanding offshore applications in order to drill deeper and reach further, the use of floating production, storage and offloading vessels have become particularly popular in recent years. While these offshore facilities have opened the potential of oil and gas exploration and production, maintaining them can often prove difficult and time consuming, especially as environments become more challenging,” commented Henk-Willem Sanders, Technical Manager Europe, Trelleborg Sealing Solutions.
“This is because with a number of component failures able to easily lead an FPSO to a shutdown that requires onshore maintenance, the cost and travelling time required to return an FPSO to shore can very quickly add up. In fact, when maintaining the swivel stack, a critical element onboard any facility, typically the FPSO would be down for between six and 12 weeks and the cost of that could rise to 100s of millions of dollars.
In situ maintenance
“With seals playing a vital role when it comes to ensuring the continued efficient and safe operation of an FPSO swivel stack, the industry has been looking for a way to solve the issue of onshore maintenance by developing a practice which would allow operators to remove and replace the seal in situ on the FPSO offshore – and I am pleased to announce that with our new technology, we have more than met the challenge.”
By optimizing billet welding, Trelleborg’s new technology is able to weld the original seal material in-situ. In a controlled manufacturing area, Trelleborg starts the process by producing a seal which has been cut in one place using a specially designed tool. The product is then packed so that it is well protected and avoids any damage in transit.
Offshore, onboard the FPSO, the seal is unpacked and installed onto the swivel by highly trained personnel from Trelleborg’s service team; the skilled engineer installs it in the Weld Head Enclosure (part of the welding machine) which, certified to ATEX zone 1, is then pressurized so that the welding can take place. Fully enclosed, production on other swivel stacks can continue without risk.
A Control Cabinet, which is purged and will also be certified to ATEX zone 1, ensures the smooth running of the process, as well as monitoring and logging all data. After the process is finished, the seal is safely removed from the Weld Head Enclosure before being polished and checked. If the values from the recorded data are satisfactory, the seal will be released for installation.
Henk-Willem continued: “We are confident that our new fully tested and portable system is not only set to make life for the offshore operator safer and easier, but also dramatically improve the bottom line for the oil company.”