Tyra project will safeguard Esbjerg jobs

The Tyra field redevelopment is a fascinating project that will not only have a major financial impact, but also capture the imagination of schoolchildren with engineering dreams.

Having produced natural gas since 1984, the ageing Tyra field, located 225 kilometres off the coast of Esbjerg, will now be redeveloped. The production of gas from the underground has caused subsidence of the chalk reservoir, which means the platforms are now about five metres closer to the water than they were originally. As a result, a gigantic wave could hit the platform deck. To eliminate that risk, the existing Tyra East and Tyra West platforms will now be dismantled and replaced by a new state-of-the-art processing plant and a new accommodation platform.

First, the old topsides will be lifted off. About 13 metres of new well pipes will then be added and new topsides  installed on top. That will extend the gap from platform deck to sea level sufficiently to allow the platforms to operate safely for the coming decades. One of the platforms, the combined processing and accommodation platform at Tyra East, weighs 15,000 tonnes, the same as 10,000 ordinary passenger cars. Due to the enormous weight involved, planning the work and mobilising vessels and cranes capable of lifting and transporting the components is a huge job. In addition, Maersk Oil expects to use about 1.5 million offshore man-hours to prepare the existing platforms for dismantling and to make the new ones ready for production before oil will again flow from the redeveloped field in 2022. 

For a long time, it was unclear whether Maersk Oil and the partners of Dansk Undergrunds Consortium (DUC) would be willing to make the necessary multibillion-kroner investment to redevelop Tyra. The reason it now looks like it will happen is the agreement the Danish government reached in March with Maersk Oil acting on behalf of DUC to enable future oil and gas investment in the Danish part of the North Sea.

“No final decision has been made yet. We still need to determine the cost of building new platforms, for example, but I’m optimistic”, says Morten Hesselager Pedersen, the man in charge of the redevelopment.

Re-establishing Tyra has huge implications: initially for Esbjerg, but in the longer term, naturally, for all of Denmark as well.

“We believe that the new facilities will safeguard several thousand jobs, most of them definitely in Esbjerg,” explains Mr Petersen.

Gigantic task

Building new platforms and replacing topsides that weigh anywhere from 3,000 to 15,000 tonnes is a huge project in itself. The fact that it will take place 225 kilometres offshore clearly only makes it even more complex, especially in terms of logistics and the performance of marine-based operations.

That does not worry Mr Petersen, however.

“We’ve been in the North Sea for 50 years, and we have extensive experience in most aspects of the project,” he says confidently.

One part of the process will be a first, however: the decommissioning of production platforms, i.e. removal of the existing facilities.

“That is something we haven’t attempted before, and the fact that the facilities have been modified in recent decades due to new needs and requirements won’t make the task any easier. Basically, the platforms were designed more with installation and operations in mind than dismantling,” says Mr Petersen, “and that will add to the complexity of the operation.”

For example, accommodation rigs will be needed for the crews employed to  dismantle the old platforms and ready the new ones. It will also require a number of ships, including crane vessels, transport vessels and vessels for general security surveillance. In Esbjerg, this will create more traffic and more activity in the port.

“There is a lot of work involved in just getting the platforms ready to be lifted off. Detailed engineering work has to be done before the crane vessel arrives to take the platforms off, and their structure has to be reinforced in places so they don’t collapse during the lifting process,” explains Mr Petersen.

Greater security of supply

But why go to all that trouble?

According to Mr Petersen, both Maersk Oil and the Danish government see potential in redeveloping the facilities. Denmark gets more than 90 per cent of its natural gas from the Tyra field, so closing it would have quite serious implications for the country and its energy supply.

With the Tyra field remaining in operation, Denmark will still be self-sufficient in gas for many years to come and will not have to source gas from mainland Europe.

“However, we also believe that the field can be developed further and that we can create more value,” adds Mr Petersen, emphasising that it will also mean tax revenue streams for Denmark going forward. 

The project will also make a big difference to Esbjerg. Local companies have already been involved in the early planning stages, and they are expected to play a part during the next couple of years as the dismantling and redevelopment work is performed offshore.

Maersk Oil expects to invest about DKK 500 million annually in operating the new Tyra field after 2022.

“We will need local labour, from our own people but definitely also from our suppliers, to operate the new facilities,” Mr Petersen says.

FACTS

Timeline:

End of 2017

Final decision on redevelopment expected. Maersk Oil has three partners on the project – the North Sea Fund, Shell and Chevron – and each of them must as DUC partners confirm their support for the investment.

2017-2019

Preparing the platforms for shutting down production and being moved by the crane vessels: a huge engineering and construction project.

Fourth quarter 2019

Shutting down production at Tyra completely. Shutdown will begin as early as the start of 2019 and progress gradually. Security and operational efficiency will be key.

2020

Finishing the six new topsides for the wellhead and riser platforms and shipping them to the Tyra field. The first topside will be lifted off and placed on a transport vessel, while the new topside is installed on the existing jacket with its extended wells. This process will be repeated until all six topsides have been replaced.

2021

Installation of the new processing facility and the new accommodation platform. For safety reasons, the accommodation facilities will be located 100 metres from the oil and gas installations. Today, the processing and accommodation facilities at both Tyra East and Tyra West are joined together in a single module.

2021-2022

Dismantling of the existing processing and accommodation facilities and disposing of them in accordance with existing regulations. The Tyra East platform weighs 15,000 tonnes.

2022

Inauguration of the new Tyra field and resumption of gas production. Before that happens, the facilities will have been prepared and extensive training programmes will be run so the crew will be able to apply the new technology and operate the facilities safely and efficiently.

About Tyra

225 kilometres west of Esbjerg

Operations began in 1984

90 production wells

Reservoir depth: 2,000 metres

Field area: 615.6 km2

Water depth: 42-46 metres

Denmark’s largest gas field

Ninety per cent of the natural gas produced in Denmark is processed at the Tyra field.

Operated by Maersk Oil on behalf of DUC, a partnership between A.P. Moller - Maersk (31.2%), Shell (36.8%), the North Sea Fund (20%) and Chevron (12.0%).