How to avoid accidental activation of marine breakaway couplings in FPSO hose reel applications

According to a report published this month by Global Data, more than 60 planned and announced FPSOs are expected to start operating by 2025[MOU1] . Six of these were ordered from global shipbuilders in 2017, and a further 11 were announced last year[MOU2] – significant figures, given that in 2015 and 2016, no new orders were made. Indeed, in the face of the new normal, where finding cost efficiencies means the difference between thriving and just surviving, operators are now turning to FPSOs more than ever before, leveraging the economical and efficiency benefits of floating production that storage and offloading vessels can deliver. New design concepts, fabrication and integration innovations at global shipyards, creative financing options, and industry partnerships, according to Rystad, are all contributing to an upswing in orders.

But as the global FPSO pipeline continues to grow, so too does the need for companies to invest in safe practices - particularly with regards to offloading operations – to guarantee the successful and reliable performance of the cargo transfer.

There are a number of inherent safety risks that operators of FPSOs must mitigate. For offloading transfers, these include a collision between the FPSO and the tanker vessel, tanker drift-off, unexpected pressure surges, and transfer failure. All of these can result in asset damage, injury to operational personnel, and product spill. To mitigate these risks, operators often use a marine breakaway coupling (MBC) or an emergency release coupling (ERC).

While superficially similar, there are some fundamental differences of which operators should be aware. At Trelleborg, we would advocate the use of an MBC for a number of reasons. Firstly, unlike the ERC, the MBC requires no manual activation from personnel, eliminating the potential for possible operator failures. At the same time, the MBC is superior in mitigating the risk of surge pressure, and offers greater overall protection of the offloading hose in the event of tanker drift-off.

However, despite its advantages, it is well known within the industry that there are a number of major challenges when using MBCs in combination with a hose reel – specifically the un-intended parting of the MBC during the reeling operation. This often happens when an operator uses a standard double carcass nipple hose that, when an MBC is added, has a stiff section that is longer than 1.7m. When the hose is stored on the reeling application, the stress placed upon the stiff section becomes too great, resulting in the unexpected release of the MBC.

To overcome this challenge, Trelleborg Oil and Marine has developed a solution specifically for reeling applications on FSPOs. Using Trelleborg’s unique nippleless design, our REELINE dual carcass hoses contain reinforced compact flanges and integrated bending stiffeners – which means more flexibility, higher resistance to tension and collapse, and no stress concentration in the flange area. Even when operating in challenging sea conditions, our REELINE offloading solution has an unparalleled track record in long service life, making offloading operations safer and more reliable.

Our REELINE hoses allow perfect integration of an MBC in the submarine or floating string, and thanks to its flexible and robust design, substantially reduce the risk of accidental activation during reeling/unreeling operations. The results speak for themselves: Since 1997 we have installed more than 60 REELINE offloading lines globally – 14 of which have featured an integrated MBC. Of these, we haven’t received a single incident report regarding accidental activation.

The combination of Trelleborg’s REELINE hose and an MBC offers far greater protection during operation, and mitigates the risk of oil incidents or damage to equipment, particularly when compared to the use of a manually activated ERC. At the same time, the amount of maintenance required is significantly reduced, as are overall operating costs.

If you would like to find out more about our REELINE portfolio, feel free to drop me an email on [email protected] or send me a direct message on LinkedIn.