The Brazilian shuttle tanker market: the clock is ticking on both the existing fleet and regulatory requirements, the need to set tomorrow’s strategy today is pressing
Wärtsilä director of thrusters & propulsion control systems Lauri Tiainen opened the second Shuttle Tanker Tech & Ops webinar: Fleet renewal and future-proofing shuttle tanker operations offshore Brazil, with Norwegian classification society DNV the premier partner of the event, and sponsorship by technology group Wärtsilä.
Despite being one of the most recognisable (and most mis-pronounced) names in the shipping services and equipment provider sector, Wärtsilä’s thrusters division is somewhat obscured by the company’s engines, but powerful thrusters are absolutely vital for station keeping in the heavy swell encountered in the Brazilian portion of the Atlantic Ocean.
“Our history in offshore thrusters goes back 50 years, with Wärtsilä producing the first retractable thruster in the 1970s, and passing the 1,500-unit mark in 1990. We have experience, and are the leading player for these products,” said Mr Tiainen.
Mr Tiainen noted that the position of the thruster and its relationship with the underwater form of the shuttle tanker hull is often misunderstood. It is important to direct the thruster downwards, by 8°. “By tilting this unit downwards, you are also directing the thrust and the waterflow under your keel,” he said. This eliminates the thrust being directed at the hull, which can reduce the efficiency of the thruster by 20%. The efficiency is vital in the station keeping performance in the Atlantic waters, otherwise larger thrusters would be needed, taking up more space and energy. For Brazil, Wärtsilä thrusters are between 2,000 kW and 3,500 kW.
One question that comes up about thrusters, is controllable-pitch propellers or fixed-pitch? Mr Tiainen favoured the fixed-pitch propeller in conjunction with variable frequency drive. This, coupled with an electrified thruster steering and retraction system, maximises the use of energy and reduces the environmental risks of hydraulic oil leakage or spillage. “Using the same control platform for the whole propulsion plant is easy, safe and simple. Most importantly, this consumes less fuel, which is economical but also ecological, future proof,” he said.
The audience agreed, with 84% choosing a retractable thruster with 8° tilt.
In a poll question, when it comes to the thruster systems on your next shuttle tanker will you prioritise capex optimisation or opex optimisation? 90% of respondents chose capex optimisation.
OSM Europe managing director Geir Sekkesæter noted that the company is now the largest third-party shipmanager providing services to the shuttle tanker sector, and in an earlier guise, was the first shipmanager for shuttle tankers. The challenge for OSM Europe is clear. “We need to train people to handle LNG.”
LNG is the favoured fuel for shuttle tankers in the transition to decarbonising shipping – with 90% of those polled agreeing or strongly agreeing.
However, the Brazilian sector does not currently have the LNG infrastructure. In a poll, 78% agreed that LNG would become available as a marine fuel in Brazil within five years.
LNG was also the main pick (70%) as the fuel of choice for a vessel to be delivered within the next five years. Ethanol (a favoured fuel in Brazil) polled 11%, as did LPG. MGO was chosen by 5% and HFO was favoured by 2%.
LNG is widely regarded as a transition fuel, but when asked: What do you consider as main marine fuels 10 years from now in Brazil? 48% chose LNG. IMO-compliant fuel pooled 44% and LPG 2%.
Altera infrastructure shuttle and storage sustainability manager Christian Fjell was on hand to describe the company’s involvement in shuttle tankers. “Our asset base is 29 shuttle tankers, nine FPSO’s, four FSOs and 10 towage vessels. We operate worldwide, but for shuttle tankers, we work in the UK sector of the North Sea and the Norwegian continental shelf. We also operate in Newfoundland on the east coast of Canada and we have a presence in Brazil,” said Mr Fjell.
Altera has introduced state-of-the-art shuttle tankers in the North Sea. These are not yet available in the Brazilian sector, but could be if aligned with Petrobras’ requirements. To reduce emissions, the so called E-shuttle utilises LNG instead of MGO, which reduces the CO2 equivalent by 25%. In addition, there is no need for emissions reduction devices. Another large contributor to emissions are volatile organic compounds (VOC) released from the cargo. Without collecting VOC’s harmful gases, CO2 and methane are vented directly into the atmosphere. To reduce these emissions, the shuttle will be fitted with breakthrough technology that uses the light VOC gases to power gas turbines, and the heavier VOC is liquefied and stored on board.
By mixing VOC with LNG, the VOC is transformed from waste into valuable fuel for the engines. Up to 100 tonnes of recovered VOC can be collected on a single loading and voyage, which represents 30% to 40% of the fuel required for that voyage.
Equinor’s specialist, platform technology ship technology Frank Aksel Svanes summed up the impact of the E-shuttle tankers. “Each of the vessels reduces its emissions by approximately 25,000 tonnes compared to the last series of vessels we built for the North Sea. So for four of these vessels it is 100,000 tonnes of CO2. An average personal car in Norway emits around 1.7 to 1.8 tonnes of CO2 per year. That means the greenhouse gas reduction effect of these four vessels would be the same as replacing 60,000 cars with Teslas in Norway, and quite coincidentally, there are actually 60,000 Teslas running on the roads in Norway these days.”
Is the uncertainty of alternative fuel retrofit options delaying your second-hand purchase? Ask the experts at the Marine Propulsion Webinar Week (6-9 April 2021). Register for all Riviera events here.
The webinar panel, from left to right: Altera Infrastructure shuttle and storage sustainability manager Christian Fjell, Equinor platform technology ship technology specialist Frank Aksel Svanes, Wärtsilä director of thrusters and propulsion control systems Lauri Tiainen, and OSM Europe managing director Geir Sekkesæter