Composite materials technology moves flexible pipe into the 21st century

By Michael Rogers

Flexible Pipe combines the strength and durability of steel pipe with the ability to handle wave and wind induced motion (illustration: Baker Hughes)
Flexible Pipe combines the strength and durability of steel pipe with the ability to handle wave and wind induced motion (illustration: Baker Hughes)

Conventional flexible pipe – designed for use in applications such as floating production systems – consists of multiple layers of polymer tubes and wound steel helices.

A part of the Baker Hughes’ wider Subsea Connect initiative, the accelerated technology development of the company’s flexible pipe offering incorporates new composite materials that increase pipe durability and safety, while reducing weight.

To find out more about how Baker Hughes is applying the Subsea Connect philosophy to its flexible pipe development, Energy Northern Perspective spoke with Rogerio Mendonca, Vice President Flexible Pipe Systems, Oilfield Equipment.

Baker Hughes has been developing the composite products for almost 3 years now. How has that progressed?

“In the industry, flexible pipes have been around for almost 50 years now, since the early 1970s. As the complexity of the industry evolved, new technologies were required, so there have been technological developments over time. And in the last couple of years where were some particular requirements that have driven where we are today.”

“The composite is part of a family of what we call the ‘new materials’, for the flexible pipe. The traditional construction of a flexible pipe is a composition of a series of metallic and polymeric layers. What we do with these new materials – specifically the carbon fibre composite materials – is to replace the pressure armour layer with a much lighter material.”

The “spoolable” nature of the of flexible pipe can bring significant savings to the total installed cost of both flowlines and risers (photo: Baker Hughes)
The “spoolable” nature of the of flexible pipe can bring significant savings to the total installed cost of both flowlines and risers (photo: Baker Hughes)

“It started with making lighter pipes, and being lighter, those pipes would be easier to install, they would require less equipment to be installed. Being lighter they would also allow a type of configuration – instead of having a lazy wave configuration, where you need a number of buoyancies and ancillaries to hold the structure, you could do a free hanging catenary all the way from the FPSO or the platform to the bottom of the sea. And those aspects combined reduced a lot of the overall cost of the installed pipe.”

“We started the concept of the composite carbon fibre pipe two years ago, but in the meantime, other challenges became relevant to the industry. One is the world’s harsh environments, with a high content of CO2, H2S, where corrosion becomes a big challenge. And the carbon fibre composite pipe, as well as other composite materials – the non-metallic composite materials – have a very good application for these challenges.”

If I understand this correctly, you’ve reduced the weight of the pipe by some 30%? Is that consistent with all the sizes of the pipe or is that at the extreme?

“It is an average. If you say 1 kilometre of pipe, made with the traditional metallic materials and 1 kilometre of pipe made with the new composite materials, the new composite pipe will weigh around 30% less. So, this would apply to almost any configuration.”

“But I think there is a very relevant aspect of that as we started the development of the particular carbon fibre composite pipe, we’ve uncovered a whole family of new, non-metallic materials that would be applied to different applications. When we talk about this pipe specifically but also the family of pipes which other polymers – other non-metallic materials – could be applied to generate similar benefits.”

So, this is something for the future as well – you can see this evolving even further?

“We have a parallel product development on the technology side. Last year, we incorporated into the family a company that builds fully non-metallic onshore flexible pipes – so the same type of pipes for onshore oil, gas, and other fluids applications. So, the technology is already there, and we could potentially merge it with the existing offshore technology to create more non-metallic applications. But the technology is not only for the future – I would say it’s already a part of the existing portfolio.”

Has the qualification for the pipes in 2019 been completed?

“It has evolved – we still have steps to complete. We built the first sample of the carbon fibre composite pipe, and we put it in a test rig. We ran one million cycles according to the API qualification requirements – temperature cycles, bending cycles, etc. Completing these was a very important milestone. We are currently running a number of qualification tests for different elements of the family of these pipes in parallel, and these will continue.”

“We are developing partnerships to accelerate the development, both with the supply chain and with installers. One of our partners is a materials supplier, and we signed a technology cooperation agreement to accelerate materials qualification. In Brazil, we’ve also signed an agreement with an installation company to simulate the installation of the new pipe to determine how the lighter weight pipe will behave in the installation. Running the different elements of qualification in parallel should get a fully qualified economic scale pipe in the water very soon.”

And how are the operators responding?

“They are responding very well. Actually, we have a very close relationship through the development. Since this is a new technology, we are working in parallel with our customers, and they are helping us in the specification of the pipe, the operational requirements, in the testing and safety requirements for the pipe.”

The work is taking place at the Baker Hughes facilities in Newcastle?

“Currently, for the flexible pipe business we have two major sites for the offshore business. We have one here in Newcastle and one in Brazil. A big part of the flexible pipe business is in Brazil, so that factory deals mostly with that part of the market. And in Newcastle, in addition to the manufacturing of the pipes, we also have the technology centre.”

“It’s very convenient to be here. We can ship directly from Newcastle to locations in the Middle East, in Asia – and particularly in Europe and across the North Sea – as well as the technology development that’s close to offshore production in the region.”

Outer sheath integrity – SPIRE monitors breach location, and location of annular water (photo: Baker Hughes)
Outer sheath integrity – SPIRE monitors breach location, and location of annular water (photo: Baker Hughes)

How much of the technology development has been happening in Newcastle?

“With material engineers and the product engineers based here Newcastle, we’ve had a lot of the technology development from the early stages. Fundamentally, we have what we call Module 1, which is the pilot machine that has been building pipe samples for qualification.”

“There is a significant effort in terms of technical development. We have developed strong partnerships with carbon fibre technology centres in the UK as well. The US and the Brazilian sites, are part of engineering that eventually contributes to the whole portfolio – but I would say most of the composite development has been happening around the Newcastle innovation centre and the Module 1.”

“The way we produce the composite today is to deploy carbon fibre tapes on top of the pipe structure. When we replace those layers and with these new materials, we can maintain most of the original characteristics of the conventional pipe, applying this new layer on the same structure.”

“And why is that relevant? Because if you look at the existing operators, some of the assumptions of our development is that they will be able to use the same installation vessels, they will be able to use the same type of connections and they want to have the rest of the structure of the pipe very similar to the conventional pipe. So, one of the challenges our customers have given us is to have the technology with all the value and advancements, but they wanted to maintain their installation logistics and the pipe installation operation as closely as possible to the existing processes, which has been achieved.”

So, there’s cost savings for the operators from the start when they don’t have to invest in equipment upgrades?

“It allows them to maintain a continuous operation, with a combination of some new technologies, new materials, and the traditional conventional pipes. When we look at the future, I think the strategy – with the input we’re getting from our customers – is to phase in our technology development and build a comprehensive portfolio of technologies. The conventional technologies will still exist – there are some great, valuable applications that will be there. The new materials composite carbon fibre technology is one of the elements and will come on top of that and complement the portfolio.”

MAPS® integrity management technology (photo: Baker Hughes)
MAPS® integrity management technology (photo: Baker Hughes)

“I mentioned the lighter weight of the pipe, allowing easier installation, utilisation of less buoyancy, fewer ancillaries. And it extends the life, particularly on the corrosive environments – high CO2 or H2S content environments – and that’s very important, because it’s not only a cost reduction in extending the life, but also a critical element of safety and reliability of the operation.”

The conventional pipe will continue to be an option?

“Conventional pipe continues to receive technology enhancements. There’s specifically one for our region here in the North Sea, where industry has been facing some challenges over time – ‘FLIP’ or flow induced pulsation. We have developed an upgrade; a new technology called FlexInsert™ that deals with the vibration challenge the industry has been facing for some time. It’s a structure that’s inserted into the flexible pipe carcass to make the surface much smoother so the gaps that create the pulsation are eliminated. Technology enhancements like FlexInsert for the FLIP application on gas exports in the North Sea will continue to drive and add value to the portfolio.”

How has the Subsea Connect digital focus been integrated into the new flexible pipe products?

“In combination with our product portfolio, we have a suite of what we call integrity management products. These are products help in maintaining the efficiency and the safety of the lifecycle of the pipe. For example, we have a range of products that deals with the monitoring of the pipes. We signed a recent contract and the product we call Spire will be part of that pipe. Spire is a system that allows the operator to monitor the pipe and identify if water has entered the annulus. Spire determines if the water coming in is a result of an immediate breech or a gradual increase of water, which suggests that the pipe has been impacted by potential corrosion.”

“We have another inspection tool that we call MAPS®, which works outside the pipe, inspecting the metallic layers of the pipe for their integrity. So, we’re talking about conventional technologies of pipe, and we’re talking about new materials, that being the carbon fibre composite, the star of the new materials.”

“I think that from a customer efficiency and reliability perspective, the combination of the conventional new technologies plus the digital aspects are fundamental elements.”