Hitachi Energy has started testing on the world’s most powerful 24 MVA subsea transformer, which will be supplied to OneSubsea®, the subsea technologies, production, and processing systems business of Schlumberger.
The tests will involve submerging the 55-tonne subsea transformer into the harbor basin to monitor its thermal behavior and pressure compensation system, as well as ensure its reliability in subsea conditions.
Multiphase compression system
The transformers form part of a large contract awarded to Hitachi Energy for the supply of two subsea OceaniQ transformers, two input transformers, two step-up transformers, and a common step-down distribution transformer. Once tested the subsea transformers will be submerged off the Norwegian coast in waters to a depth of about 850 m and will power the OneSubsea multiphase compression system for the Shell Ormen Lange field in the Norwegian Sea.
ABB is supplying its INSUBSEA® Long Step-out solution to deliver power to the OneSubsea compressors
Hitachi Energy has collaborated closely with ABB on the project. ABB is supplying its INSUBSEA® Long Step-out solution to deliver power to the OneSubsea compressors and has overall system responsibility for the power scope of the project that includes delivering drives for seabed compressors that sit away from topside infrastructure.
Strong underwater currents
The OneSubsea compression system will be powered and controlled from the Nyhamna onshore gas processing plant, which is 120 km from the subsea location. This power step out distance sets a world record for transmitting variable frequency power from an onshore facility to equipment on the seabed. The system will lower back pressure on the reservoir, helping increase recovery and extend the life of the field.
"We are delighted to be collaborating with ABB and OneSubsea on this important project,” said Bruno Melles, Head of the Transformer Business at Hitachi Energy. “A subsea transformer is an advanced technology due to its ability to operate in waters at a depth of up to 3,000 m and in extremely demanding conditions, including high pressure, corrosion, subzero temperatures, and strong underwater currents.”
Highest quality standards
Hitachi Energy is a key partner for ABB on this ground-breaking subsea project"
“Hitachi Energy´s OceaniQ subsea transformer technology is also ideally suited for the connection of floating offshore wind farms to the grid. This feature is another example of our company's ability to develop state-of-the-art power systems that meet the highest quality standards."
“Hitachi Energy is a key partner for ABB on this ground-breaking subsea project. Together our long offshore industry experience and power distribution expertise make for an unbeatable solution. We are proud to be contributing to life extension and boosting efficiency at Ormen Lange,” said Gunnar Lie, Head of Operations, Subsea and New Energy, Energy Industries at ABB Norway. Ormen Lange Phase 3 is a fully subsea-to-shore processing system fed by hydroelectric power from the Norwegian grid. Ormen Lange Phase 3 is one of the lowest carbon-intensive and most energy-efficient recovery improvement projects in the industry.
Powerful subsea transformers
Hitachi Energy is the pioneer and the manufacturer of subsea transformers. The development of the technology started in Finland already in the 1980s and the first subsea transformer was commissioned in 2000. In total, the company has supplied more than 40 subsea transformers. Earlier the world's most powerful subsea transformers have been a 20 MVA transformer for a pilot project at the Nyhamna gas field in Norway and two 19 MVA subsea transformers that are in production at the Åsgard field in Norway.
The Ormen Lange deep-water project off the Norwegian coast will produce natural gas from deep in the Norwegian Sea and bring it onshore to a refinery in Nyhamna. The plant supplies around 20% of the UK's total gas consumption. Hitachi Energy will deliver the subsea transformers by the end of 2022.
