Creating offshore power certainty for Bluestream
Bluestream is an offshore services company, providing a wide range of topside and subsea services to companies involved in wind energy, and the oil and gas industries. The subsea projects are carried out by both divers and remotely operated vehicles (ROV)– both of which relies on equipment which cannot be allowed to fail, even if there is a power cut. To head off this risk, most of Bluestream’s vessels are equipped with a specially adapted electrical generator by Bredenoord.
Sometimes the generator is the primary power source, at other times it functions as a backup. “It is always a challenge to fully guarantee a reliable power supply offshore,” says Bluestream’s senior technical advisor Frank Groot. “On shore we use earth leakage circuit breaker-based power supply security. On a vessel we don’t have this option so we work with an IT grounding system using a line insulation monitor (LIM). With an earth leakage error the power falls away, but with a LIM-error we receive a warning in advance. This enables us to disconnect the power in a controlled manner so that we can examine and fix the malfunction. In addition, the power supply on our vessels is not always stable. A strong voltage dip may result in our ROV’s being stranded at the bottom of the sea without power.”
For diving operations there must always be at least one redundant power supply available, but there aren’t many vessels with three redundant power units on board. A decision is taken on a vessel-by-vessel basis whether a generator will be required or if connecting to the on-board power supply will be sufficient. Bredenoord’s generators are well adapted to offshore work and have been equipped with special facilities such as a spark arrester and rig saver as well as LIM protection.
Our projects are running 24/7 and every minute of delay costs money. Everything we do depends on providing a fast and reliable service. Bredenoord works with us in finding the best solutions to help our clients achieve their goals
Special offshore frame
The exact requirements for an installation differ per operation and location. For most installations or maintenance work, the vessel’s own on board power supply will be sufficient. When a generator is required, ideally a 20ft container with twin generators is fastened to the deck. “We mostly work during calm weather,” explains Peter Prins, Bluestream’s senior project manager. “But in order to reach the work site we occasionally sail under variable weather conditions, so that we may arrive on site when the weather has improved.” The generator, however, is running continuously to ensure all equipment remains powered up. Occasionally the genset will be transferred to a rig or production platform. “We have to follow strict regulations to lift at sea,” says Groot. “The frame holding the generator must be DNV or LLOYDS certified. Bredenoord built this frame, partly at our request, so that we can safely lift generators of up to 70 KVA offshore.”
Another custom solution by Bredenoord is a specialist air filter system that prevents the ingress of seawater during vessel operations in all weather conditions. The filter made its debut on a Bluestream vessel in April 2020. “When we changed the setup of the vessel a few months ago, the container with the gensets was moved closer to the railing and it turned out that salt water was still able to get in,” says Prins. “This was an unexpected setback during a large project in UK waters. Our main aim is to solve our clients’ problems and Bredenoord takes a similar approach. They found a reliable solution in the UK very quickly and our client’s only problem was a conflict in scheduling. After this we sat down to discuss further improvements. This resulted in the new air filter system and a slightly different set-up on deck. We work together in a real partnership, and it is Bluestream and Bredenoord’s people who are making the difference.” “You know what it is,” Groot adds, “you can build the most fancy, new and high-quality systems possible, but one day it will break down. And, of course, according to Murphy’s law, that will always happen at the wrong place and the wrong time. Then it comes down to service, which Bredenoord always delivers, immediately and 24/7.”
Bluestream takes a similar approach to its clients. “The use of ROVs is increasing, because this is always safer than letting people dive, as well as being more efficient. The growth in offshore wind turbines has had a key role in this because in this industry margins are small. One kWh of electricity doesn’t generate as much profit as oil and gas do. We are trying to expand some of the solutions which we have developed for the wind industry so they can be applied to the oil and gas industries too. This can deliver considerable cost savings.” The fact that Bluestream combines three specializations under one roof (diving, ROV and rope access) generates additional efficiency. Bluestream is also developing unique equipment to help clients with maintenance, service and dismantling turbines and rigs. Groot: “We strive to be one step ahead of our clients with our innovations, so we can deliver the best service possible. And we value this in our work with Bredenoord. For example, we have noticed that the demand for power producing lower emissions is growing, and Bredenoord has already developed several options to address this challenge.”