Tyra II nears completion after 10 years

The seventh of eight platforms has been installed at Denmark’s Tyra II gas field after the initial Tyra plant was temporarily closed in 2019.

Since 2013, operators TotalEnergies and the Danish Underground Consortium have been working to decommission Tyra, which due to natural subsidence in the chalk reservoir below had sunk by about five metres.

When the project is completed in 2023, 95% of the eight platforms and all associated materials, cables, pipelines and so on will have been recycled and used to build the new Tyra II.

The seventh platform, a seven-storey, 35m high structure weighing 5,400 tonnes, is the residential quarters of the crew, consisting of walls, rooms, furniture, hospital, fitness area, control rooms and a helideck on top.

It was towed from Italy, where it was built, on Heerema Marine Contractors’ 122m Barge H-408, arriving at the site around 10 days ago after a 5.800km voyage.

On arrival on April 12, Heerema’s crane vessel Sleipnir, said by field operator TotalEnergies to be the largest in the world, was used to hoist the platform 30 metres in the air until crane operators could place the platform accurately on its legs.

Just one platform, the processing platform, remains to be installed. It is currently being built in Indonesia, Total says, and is the heaviest of the eight platforms at almost 17,000 tonnes and 47 metres in height.

95% recycled materials

“Among other things, a big focus has been put on recycling and reusing more than 95% of the old Tyra,” says Total. “As such, local companies disassembled old parts, renovated them, installed new technology and reassembled it, giving them a new life on Tyra II.”

The project has been run by a partnership of TotalEnergies (43.3%) and the Danish Underground Consortium, which consists of Noreco (36.8%) and Nordsøfonden (20%).

Tyra is Denmark’s largest natural gas field, producing 90% of Denmark’s gas until it was closed, when gas then had to be imported. It also has oil reserves of 60,000 barrels per day.

“With a total weight of over 35,000 tonnes and up to 54 metres in height, Tyra II will become a small high-rise town on pillars in the North Sea225 km from the west coast of Jutland,” says TotalEnergies. “There are great forces of nature at stake here, and every detail of the crew’s safety has been thought of.

“Between 2021 and 2023, our hook-up and commissioning crew will have spent more than 1.3 million man hours in the Tyra field, connecting cables and pipes, testing equipment, integrating reservoirs, wells, compressors and pumps, and reconnecting Tyra II with the Danish gas supply and distribution network onshore,” says Total.