Spooling speed

Maersk Supply Service is finding new solutions to decommission oil and gas installations more efficiently while maintaining the safety focus. It is an important part of a strategy to deliver more integrated solutions to customers’ needs.

On board Maersk Achiever, recovering flexible flowlines from the seabed. Photo: Maersk Supply Service

One kilometre an hour may be slow for a car, a bike, or even walking.

When the anchor handling tug supply (AHTS) vessel Maersk Master reeled in 6.5 kilometres of piping in seven hours, working on the decommissioning of the Janice field in the North Sea, it was incredibly fast.

The new Maersk Supply Service vessel achieved this by spooling umbilicals and flow lines on to its winch, which was originally designed for anchor handling. Umbilicals are the cables that house wires, fibre optic cables and other communications, and flow lines transport the oil and gas produced.

It was a significant advance from the old technique of cutting into 12-metre sections, ready to be placed on a truck on arrival in port. Maersk Master then delivered the 6.5km of piping to the port in Lerwick, in the Shetlands, where the recycling facilities are at the quayside, so there was no need for further transport. 

“It’s a completely new and revolutionary method. Last year we did more than 900 cuts on smaller flexibles of up to 450m lengths, and now we took 6.5km in one piece,” says Jens Klit Thomsen, Head of Decommissioning Business Development for Maersk Supply Service.

“Maersk Master is new and has very large winch capacity and we have actually shown how we could use it in a completely new and smart way. Another advantage of this vessel is the hybrid diesel electric setup, which makes is very economical.”

Integrated solutions

Work on the decommissioning of Maersk Oil’s Janice installation in the North Sea is two-thirds complete, safely removing infrastructure that is 19 years old from the seabed. It is moving ahead as planned, without lost time incidents and on time and under budget.

In many cases the infrastructure has been designed and installed without too much consideration of how it will be recovered at the end of its operational life. Robust systems and processes are needed so Maersk Supply Service can adapt quickly on the job and manage change effectively, as well as be innovative in removing equipment safely and cost effectively.
It is an example of the integrated solutions the business can provide – with vessel services as the core business and bundling extra services and managing subcontractors to offer a more simplified and efficient operation.

“Building on our 50 years’ legacy and our strong assets and people skills, the expansion of Maersk Supply Service’s portfolio with Integrated Solution is taking form and showing its worth to customers,” says CEO Steen Karstensen.

For Jens Klit Thomsen, the key is that there is a lot of experience in the marine sector within Maersk Supply Service – he himself is a DUAL officer, so both Master Mariner and Marine Engineer - and they understand how the vessels work. This allows them to use technology in different ways to offer better solutions for customers.

In direct continuation of the work on Janice and using what it has learnt there, Maersk Supply Service will be spooling in 7.5km of piping in the decommissioning of Leadon, another Maersk Oil-operated North Sea field, building on the work done at Janice. The business has filed six patents related to how decommissioning can be done in an even smarter way.

“Maersk Oil is listening to us and we are an integrated project team, focused on the solution and end goal, with an open-minded approach to new ways of doing things which has enabled us to use the vessels to do things that no one thought possible before,” Thomsen says.

“We have been able to change the perspective on decommissioning and use the assets in a different way because of our maritime experience, combined with the right level of engineering.”