New composite contenders eye flexpipe ranks

Technip was the trailblazer, but GE and NOV Flexibles have also been investing heavily since their respective acquisitions of Wellstream and NKT. All three companies have invested in expanded capacity and are engaged in a pre-salt qualification process with Petrobras.

Dimensions are also increasing. Some of the recent Petrobras orders call for installation vessels with a traction pull bordering 650 tonnes.

Technip says its new $275 million plant at Acu will have the capacity to fabricate pipe up to 22-inch external diameter and have spools handling as much as 500 tonnes.

NOV Flexibles — part of National Oilwell Varco, following its acquisition of Denmark’s NKT Flexibles — will open a new $105 million factory at the Acu industrial port in the first quarter of 2014 and start delivering to Petrobras under an existing frame agreement.

According to Cristina Pinho, executive manager for E&P services with Petrobras, NOV Flexibles is engaged in a dialogue with Petrobras over a possible development contract for testing, qualification and application of flexible risers in pre-salt conditions.

GE’s Wellstream is also expanding capacity at its factory near Rio de Janeiro, and is similarly engaged in the pre-salt qualification process.

In the pre-salt, where internal and external pressures on pipe can reach 20,000 psi, there is a growing belief that flexibles will not be able to compete without significant advances on conventional technologies, especially in those sections under most stress, such as top sections and connectors.

Qualification work for flexible pipe has been extremely challenging at diameters of more than eight inches. Beyond this, the pipe gets ever bulkier in order to support its own weight.

This view is supported at the highest level. “At higher diameters there comes a point where you have to ask whether the armour on steel-reinforced pipe results in something that can really be described as flexible,” says Tommy Bjornsen, DNV’s director of operations in South America.

Petrobras and pre-salt partners such as BG Group are beginning to lean this way. “As the subsea systems go deeper and get heavier, you get to the stage where the top section can absorb very little movement. It is actually very rigid, so the industry has little choice but to move to new materials, and it seems clear that these will be composite rather than exotic steels,” says Pinho.

“There are big investments in qualification and capacity, but there is also a role for new materials. It is good for us when there is life across the market,” she added.

Technip’s own research into non-steel sour service materials has focused on the use of carbon fibre in the armouring of the critical top section. This will be combined with the company’s trademarked Teta design to resist internal pressures and cater for a 500-tonne traction load.

Technip sources say this development is probably two or three years away, but the company believes this hybrid solution will increase the scope for using smaller and cheaper installation vessels.

Technip has carried out tests in the pre-salt conditions and is in talks with Petrobras about field application of a prototype. “Ours is a revolution based on established products and is much closer to finalisation than are others,” comments Paulo Veronesi, until recently Technip’s commercial manager in Brazil, but now in Paris.

Other big flexible suppliers do not intend to be left behind. NOV Flexibles is close to starting commercial production at its state-of-the-art factory at Acu. These investments were founded upon a recent four-year frame agreement to supply Petrobras with flexible pipe for “post-salt” oilfields in the Campos basin.

The plant will have capacity for up to 16-inch diameter, but the big push into pre-salt qualification is starting with pipes ranging from four inch to 9 1/8 inch in diameter. This covers much of the demand in the first phase of the Santos basin pre-salt development.

NOV Flexibles is also working on composite materials to incorporate in the company’s flexible pipe products without abandoning basic principles. “There is a delicate relationship between strength and weight,” says Michael Hjorth, the company’s global managing director.

He adds that the driver for these newer materials is, for the time being at least, technical, rather than lower costs.

Some newer competitors are closing in on this emerging market, boosted by a growing interest among industry bodies in setting qualification standards.

DeepFlex, a Houston-based manufacturer of unbonded flexible pipe, is developing “breakthrough technology” for the engineering, qualification and fabrication of flexible pipes for ultra-deepwater applications such as risers and flowlines. It has had a qualification programme in place with Petrobras since 2011, covering ultra-deepwater applications, including the pre-salt.

The company uses composite materials for hoop and tensile reinforcement, reducing the weight of the pipe by 30% to 60% compared with conventional steel-armoured flexible pipe, according to Mark Kalman, principal technical adviser with DeepFlex.

The technology promises higher strength-to-weight ratios and immunity from the corrosive effects of harsh environment service compared with steel-reinforced flexpipe, he says.

DeepFlex has its roots in the materials side of the industry, with intellectual property rights and trade secrets on a broad range of composite materials. The company uses a patented system of thin laminated composite tapes formed into helical stacks.

The move to fibre-reinforced materials is gaining traction within major oil companies and backers believe they will soon be competitive against other high-temperature/high- pressure products, particularly if the volume of sales starts to increase.

The company has a product it dubs “flexible hybrid reinforced pipe” that is being developed for high-pressure/high-temperature production applications. Two of the six-inch variations planned for qualification are targeted for pre-salt applications in up to 2500 metres water depth.

“The unbonded flexible pipe can be spooled on reels and is also more fatigue-resistant than bonded pipe,” says Kalman, adding that this technology can allow the use of a free-hanging or a simple lazy wave catenary riser system in the pre-salt, possibly with some ballast.

A fundamental aim of such products is to offer lower costs compared with alternatives such as hybrid riser towers. The technology may permit the use of cheaper installation vessels than would otherwise be the case. Low tension loads can be achieved with little or no need for added buoyancy.

DeepFlex’s qualification process with Petrobras is ongoing, and it is in discussions with other operators in Brazil. The company received a vote of confidence earlier this year in the form of private equity investment from backers, including Brazilian investors. The cash will fund a new manufacturing and development facility in the US, due to become operational in 2014, as well as implementation of a manufacturing and development facility in Brazil.

DeepFlex is also one of the partner companies selected in a US government-sponsored RPSEA project, along with Total, Statoil, Shell and BG Group. This project covers a high- temperature/high-pressure riser project for water depths up to 3000 metres.

The developers of unbonded pipe designs such as Technip, DeepFlex and others face competition from suppliers of bonded composite pipe. These newcomers are taking the composite concept to the point of replacing the established unbonded approach — a series of layers that can move relative to each other — with a solid wall from inner bore to outer surface.

UK-based newcomer Magma Global has used the Gulf of Mexico and West Africa as a starting point for qualifying its products.

Magma has developed a low-permeation, high-end polymer-based product called m-pipe to cope with sour service agents and motion fatigue and to reduce the payload hanging off installation vessels. “In Brazil, where developments require a large riser count, this can be an important advantage,” says commercial director Steve Hatton.

This pipe combines polyether ether ketone and carbon fibre to achieve its high strength. Wall thickness is similar to an equivalent steel pipe — say 20 millimetres for a six-inch pipe — but the weight of m-pipe in water is about 10% of the weight of conventional solid steel or flexpipe, and it has 10 times the flexibility of steel pipe, Hatton says.

It is so light it can need weight coating or ballast chains in some cases. However, as Magma points out, putting weight back is easier and cheaper than adding buoyancy, and also provides a means to control the shape and dynamic response of the riser. And such pipe has the added benefit of a small drag diameter that reduces hydrodynamic loading.

“We are not copying the logic of steel but starting from a new viewpoint about how to get the best out of composite performance,” Hatton says.

Magma is developing a manufacturing facility at its Portsmouth, England, base, with production of six-inch pipe expected to start in the first quarter of 2014, and with capacity for pipe up to 10 inch. Long-term plans envisage an overseas factory, as well, probably in Brazil.

“So far we have been focussing on discrete lengths for things like kill and choke lines and jumper spools, where you need maybe only 20 to 50 metres of pipe,” says Hatton. “That allows us to get a good track record and good experience. But now we are setting up to be able to do spooled product, which means thousands of metres long and moves us into a different ballgame.”

Dutch company Airborne Oil & Gas is walking a similar path of development for fully bonded thermoplastic composite risers, developing cheaper polymers and glass fibre materials.

The company has applied its technology to deliver composite downlines for water depths up to 2200 metres and has put its thermoplastic pipe technology to the test in a production riser scenario through a joint industry project backed by six majors, including Petrobras, BG and Shell, and also SBM Offshore.