By Daniel Canty
“22 March 2017 was a great day in the Danish Business Unit,” enthuses Patrick Gilly, the unit’s managing director. “It was
a long-awaited announcement and I am quite sure that we all had a smile on our face when the news finally broke.”
Maersk Oil, on behalf of its Danish Underground Consortium (DUC) partners, struck a deal of huge significance with the Danish government, making possible comprehensive future oil and gas investments in Maersk Oil’s North Sea heartland.
Future plans come into focus
This redevelopment opens the door to more near field opportunities in the future, so all decisions being taken now need to take those possibilities into account. Key decisions have already been made about which new facilities and technologies are needed to maximise the future value of the Tyra field and its surrounding satellites. The new processing and accommodation platforms have been designed to be able to cater for potential further field development beyond Tyra itself.
The project execution schedule is also in place (see timeline on page ten). It includes plans for decommissioning, redevelopment (brownfield) and entirly new development (greenfield). The complexity of the work means robust precision planning is absolutely essential.
Bids from engineering procurement and construction companies are expected to come in over the summer. These are the functions who will take the detailed front end design and actually build it. “The tender process represents a very significant part of the project and it is always a really critical step towards the final investment decision,” explains Morten Hesselager Pedersen, Head of Tyra Future Development.
Nailing down a final budget for the project can only
begin to take place after these bids for large packages of work are received. However, it’s clear that given the size and complexity of the project, we are talking about a truly significant budget, possibly in the billion dollar-plus range.
“Many of our colleagues had spent days, weeks and months maturing the project and many of us had followed the process with great interest, eagerly awaiting the good news,” says Patrick.
The final investment decision is due to be taken before the end of 2017, but a great swathe of work has already begun in earnest. “It’s obviously very satisfying to have a world-class project in our portfolio,” adds Patrick. “It will add many productive years to the life of the Danish North Sea oil and gas adventure and enable us to support the growth of the company for longer.”
Final Investment Decision and award of main contracts
Preparations for shut-in and
Pipeline installation, enabling oil export during the construction period
Ramp-down of production will start from Tyra East and West
All satellites will be ‘safed’ and production will cease
Shut-in of production from Tyra
Wellhead and riser platforms replaced
Installation of new processing centre and accommodation platform
Removal of existing process and accommodation platforms
First production from the new Tyra facilities
In March a historic agreement transformed the prospects for gas production in the Danish North Sea. Today, as detailed plans are laid for a massive redevelopment of Tyra, ‘Tyra Future’ is beginning to become a reality.
DANGER: extreme waves
The central reason the Tyra field needs redeveloping is that the seabed supporing it has been sinking. This is because the underlying chalk reservoir has shrunk as hydrocarbons have been extracted from it. In fact the Tyra platforms have sunk by around five metres over the last 30 years – bringing the surface of the sea ever closer to the platform decks.
The closer the sea gets, the more likely it is that an extreme wave could hit.
And that is why huge investment is needed if the Tyra complex is to continue producing safely and reliably over the next decade. Indeed, Tyra Future is being built to run until at least 2042, when the concession agreement ends, and possibly even further.
The big question is how to ensure that the same challenges which have driven us to rebuild Tyra are not repeated in 10 or 20 years.
Detailed forecasts based on historic data
“We have gained extensive knowledge about subsidence and wave impact on the facilities from our unique experience, particularly in recent years,” explains Morten. “This has been actively used in the planning of the redevelopment, so the new facilities will be safe to operate for a long time.”
Many years of historic data make it possible to forecast future subsidence. “The subsidence is expected to continue and so the analysis has been used to design the necessary ‘air gap’ to match the general 25-year design life of the new topsides,” says Morten.
Wherever possible, existing infrastructure and assets will be maintained. Most of the wells and pipelines will be maintained, as well as all the jackets on the six riser and wellhead platforms.
The jackets (or supporting frames) are in good shape structurally, so instead of replacing them, they will simply be extended upwards by a full 13 metres. At the same time the topsides – the upper strutures sitting on the jackets, including the accommodation blocks and processing facilities – will be replaced with entirely new units. These will have a much larger air gap between them and the sea. Meanwhile, the unmanned platforms will stay largely as they currently are.
Innovation at the core
The Tyra Future project is not only very complex, but is also a groundbreaking combination of decommissioning, brownfield and greenfield work. The full redevelopment plan presents a real opportunity to deploy new technology. One critical component will be so-called condition monitoring – real-time tracking of the performance of equipment right across the field.
“We will be continuously collecting data from all major equipment, and have experts available in onshore support centres, both locally and globally, with the ability to interpret the signals and translate these into future maintenance requirements“ says Morten.
“We call this ‘predictive maintenance’ because we will proactively and deliberately take equipment out of service before it breaks down. This approach essentially provides safer, more reliable operations at lower cost.”
At the same time, there will be a significant increase in the use of wireless technology, as there has been at Maersk Oil’s other major operated North Sea project, Culzean. Only the integrated control and safety system will use cabling for communications. This not only saves money during the building phase, it also reduces costs during operations and offers opportunities to run things in more reliable and safer ways.
For example, wireless technology means staff on the platforms can get instant access to information via hand held devices – freeing them from being stuck in offices looking at computer screens. “Allowing our supervisors and leaders to be on the deck rather than in the offices is really important element of safety leadership,” says Morten, “and certainly a critical enabler for taking the last steps towards truly Incident-Free operations.”
Although Maersk Oil has been operating in the Danish North Sea for around 50 years, this will be our first major decommissioning project here. What’s more, the two processing and accommodation platforms weigh around 22,000 tonnes – so this is no small task. Clearly a project of such scale takes a great deal of collaboration with suppliers and contractors and careful planning to allow safe and environmentally sustainable removal of the old facilities.
Maersk Oil - CEO, Gretchen Watkins announcing Tyra redevelopment
Tyra Future is a major project for Maersk Oil, but also one of strategic importance to Denmark. Tyra is where more than 90% of Denmark’s gas is processed and exported.
“This means two things,” explains Patrick Gilly. First, if we were to permanently shut-in the Tyra facilities we would also be closing down critical infrastructure, and that would limit further developments in the Northern fields. Second, by rebuilding this
infrastructure we give ourselves the opportunity to unlock further potential.
“We are looking at a variety of development projects in order to maximise the outcome for Maersk Oil, for the DUC and not least for Denmark. So,” Patrick concludes, “there are winners in every corner and we are confident that we are proceeding well and with purpose.”