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Composites to cut subsea costs

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Ramin Moslemian Ramin Moslemian
Principal Specialist

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thermoplastic composite pipe
Oil and gas companies will soon view thermoplastic composite pipe as a proven technology, says Airborne Oil & Gas, maker of a spoolable version (pictured) (Photo: Airborne Oil & Gas)
Thermoplastic composite pipe can change the economics of subsea production say two of the first manufacturers. An industry project aims to pave the way for more cost efficient qualification of such components

Industrial use of composites in which plastics are combined with other materials for added strength, flexibility, fatigue resistance or other desired properties is relatively mature in sectors such as aerospace. The Boeing 787 Dreamliner aircraft is a complete composite structure, for example.

In oil and gas, the past decade has seen a rapid advance in the qualification and application of thermoplastic composite pipe (TCP) to counter inherent drawbacks of steel: corrosion, fatigue and weight.

Of respondents to a DNV GL survey of industry leaders, 57% see a need for cheaper, more effective pipeline material in general, while the average cost of installing and maintaining a pipeline accounts for around 35% of a typical subsea tie-back project.

In today’s cost control climate, the industry now views TCP as a viable alternative to steel across project lifecycles. A growing variety of applications offshore include flowlines, risers, jumpers, expansion spools, and lines for uses such as access, chemical injection, choke and kill, commissioning and intervention.

Confidence in composites

The TCP can change the economics of subsea production, according to Charles Tavner, COO of Magma Global. The UK company makes m-pipe®, a high-quality, high-strength, low-weight carbon and Victrex PEEK (polyether ether ketone) pipe. It is 10 times lighter than equivalent steel pipe.

“You can see direct capital expenditure saving and then, as the installed base starts to increase, there are some very large operational expenditure benefits,” explains Tavner. “Once it has been in use for many years, there are also attractive decommissioning attributes.”

Magma is working with operator BP and service company Subsea 7 on a GBP 10 million (USD12.5m) joint development agreement to extend the qualification of m-pipe® for more demanding subsea conditions. The aim is to develop lighter and more cost-efficient jumpers and riser systems.

“A lightweight, fatigue-resistant product has very broad applications and this programme of activity will take us to 6-inch, 10,000 to 15,000 pounds per square inch (psi) products, at higher performance than that at which even a flexible pipe can perform,” says Tavner.

“This will help reduce the cost of deepwater field developments and pipelines required to handle sour service and corrosive fluids. The logical next step is into risers and that is where it will go next.”

Magma’s has completed its test and qualification programme for m-pipe® as a 3” dynamic downline product. This was performed in accordance with DNV GL’s Recommended Practice DNVGL-RP-F119 Thermoplastic composite pipes (2015), to assure performance, reliability and safety during the product’s lifetime. Magma chose DNV GL to provide the 3rd party verification throughout the qualification process.

mPipe
Magma Global’s m-pipe®

Tavner says: “We have seen a shift in the last few years where people broadly accept that this technology is here to stay and are starting to both use it and routinely request it in bids. We want to deliver the most reliable products and DNV GL helps us do that.”

Major operator commitment to composites

Saudi Aramco Energy Ventures (SAEV) demonstrated belief in the future of composites in the industry through its October 2016 investment of EUR10m (USD11m) in Dutch company Airborne Oil & Gas, the first manufacturer of fully-bonded TCP.

Airborne Oil & Gas’s TCP product is solid wall-pipe with glass or carbon fibre reinforcements completely embedded within a thermoplastic material. This creates a robust spoolable pipe, 80% lighter than metallic equivalents, and adapted to customer-specific requirements.

Airborne CEO Eric van der Meer reports that rising confidence in the technology was underlined at a recent conference1 where, he says, more than 80% of those at a pipelines and risers session agreed that TCP is the must-have solution to cut costs in the future.

“In the decade since we started producing, we have fought an uphill battle in terms of perceptions, qualifications and issues, so such a positive response was a fantastic moment,” he enthuses.

The benefits of TCP are so large, and there is now so much evidence in terms of qualification and track record that you could argue that the risk is far lower than five years ago. In another couple of years, it will no longer be considered a new technology but a proven technology.”

Airborne Oil & Gas has received a Technology Certificate for its general design methodology2 and production process in accordance with DNVGL-RP-F119.

The company has provided a 12,500psi methanol injection spool for permanent service on Chevron’s Alder field, offshore UK. This first-ever TCP installation for a permanent jumper application subsea overcame high qualification requirements and competition from traditional flexible options.

Van der Meer says: “For more than 35 years, Alder was extremely difficult to develop and needed several new technologies. Our TCP spool is on the seabed locked in at well flowing pressure and will be there for the life of field. It is the first high-pressure, hydrocarbon-containing TCP system – monumental progress.”

The company is looking to deploy a similar system in the South China Sea in 2017. It is also working with Shell on qualification for a TCP jumper spool for depths below 2,000 metres and pressures exceeding 10,000psi. Its first application is anticipated for Shell’s Perdido field in the Gulf of Mexico.

Cheaper qualification in sight

One drag on the uptake of composites is that their design and technical qualification is costly and lengthy, especially for documenting long-term performance.

An ongoing DNV GL-led joint industry project (JIP) aims to change this by cutting the cost of qualifying composite components for subsea use by reducing the need for large-scale tests with ‘certification by simulation’.

One current difficulty in real-life testing is that it is for a specific set of operating conditions; a specific temperature range or a sweet service environment, for example. Tests must be repeated if the component is used at a different operating temperature range or for a different application, such as in a sour service environment.

“This has been an obstacle for composites in the oil and gas industry,” confirms Ramin Moslemian, project manager, DNV GL – Oil & Gas. “Through the JIP, we aim to create models simulating variable conditions and applications. We hope to increase simulation and modeling’s share of total qualification cost from around two per cent now to 10-20%.”

The JIP has so far documented full-cycle qualification costs for a carbon-reinforced TCP subsea jumper pipe for different levels of qualification performed according to DNV GL Offshore Standard DNV-OS-C501 and Recommended Practice DNVGL-RP-F119 for composite components.

DNV GL hopes to generate a publicly-available initial document for a Recommended Practice describing how the new models can be used, and what a new qualification scheme will look like.

Airborne Oil & Gas is participating in the Affordable Composites JIP alongside GE, Mitsui, Nexans, NOV, Petrobras, Petronas, Statoil and Technip. “The model-based qualification approach can get end results so much quicker,” van der Meer says. “It is a massive cost and time saving, and we are convinced it will work.”

With the JIP expected to finish in mid-2019, there is still room and time for new participants to join, Moslemian says: “We are interested to recruit companies from across the value chain, such as material suppliers, service companies and more operators.”


References

1 MCE Deepwater Development conference, Amsterdam, Netherlands, April 2017

2 A technology certificate for a general design methodology affirms that the general design method can be used. A product certificate however, covers a specific design, manufacturing and the assembly of a product.

Disclaimer:
DNV GL prides itself on providing accurate information but makes no claims or guarantees about the accuracy, completeness or adequacy of contents in this publication, and disclaims liability for any errors or omissions. The authors’ views here do not necessarily reflect DNV GL’s views.