With subsea infrastructure getting into ever deeper waters, umbilicals have had to shoulder an expanding load. Jennifer Pallanich talks to five leading SURF sector players about how the industry's thermoplastic and steel tube umbilicals have evolved, challenging projects currently in the works, and new market opportunities they see opening up in the years ahead.
Once upon a time, the umbilicals that powered equipment on the seabed from the surface were mostly made of thermoplastic. As Matt Smith, Oceaneering's global product manager for umbilical solutions, explains: ‘Most were direct hydraulics. It was one hose for every valve on the tree.'
Concerns of thermoplastic umbilicals failing opened the door for steel tube umbilicals.
‘The metal was seen to be more reliable, more high-tech,' says Finn-Peter Gjerull, Aker Solutions' VP, umbilicals. ‘That has been important. The subsea developments are more significant: bigger investment, deeper water. Reliability is more important.' As the industry continues its march into ever deeper waters, so are the umbilicals growing in size and weight, Gjerull adds.
The industry ‘gradually stepped' from the water depths of the North Sea of 400m to 2300m, notes Ragnvald Graff, Nexans' sales & marketing director for submarine power cables and umbilicals. The move into deeper waters demanded new technologies, which the umbilical providers worked to deliver.
Aker acts
Aker Solutions, which only manufactures steel tube umbilicals, created a technology to improve the performance of umbilicals being deployed in certain types of deepwater applications. Gjerull notes armoring ‘starts to be a challenge' for umbilicals planned for use in 2000m of water or more. Carbon fiber rods ‘provide enhanced mechanical properties of the umbilical,' says Gjerull, who's been working in the field of umbilicals since 1987. Aker Solutions' patented carbon fiber rod technology, used in the Independence Hub project in 9500ft of water in the Gulf of Mexico (OE November 2007), replaces the armoring typically used to strengthen the umbilical. The carbon fiber rods add strength without increasing the umbilical's weight.
When installed, the Independence Hub umbilicals were the deepest use of the carbon fiber rod technology. Aker has manufactured carbon fiber rod umbilicals for the Petrobras-operated Cascade and Chinook development in 8200ft of water in the Gulf of Mexico. At Cascade-Chinook, which will be the first FPSO to operate in the US Gulf of Mexico, Aker Solutions was concerned about the hangoff of the power umbilicals, where currents and vessel movement could cause umbilicals fatigue.
By suspending the power cores under the bending zone using Aker Solutions' SoftClamp system, the cores are ‘free floating' in the bending zone, so in this critical section of the umbilical the power cores will only experience bending loads and negligible axial load, according to Aker. Additionally, when subjected to thermal expansion, the power cores will have unrestricted movement, and the forces upon the power cores become predictable, the company says.
Aker manufactured the control umbilicals for BP's Block 31 deepwater PSVM project offshore Angola. The order was for 48km of carbon fiber rod enhanced steel tube umbilicals, which Aker Solutions manufactured at the company's Moss site and delivered at the end of 2010.
Duco delivers
Duco, which manufactures both steel tube and thermoplastic umbilicals, has developed a different way to address the issue of weight for umbilicals destined for water depths exceeding 2000m. Alan Dobson, Duco's technology development manager, notes conventional umbilical components, like copper, can add a ‘serious' amount of weight, and copper isn't load-bearing.
The ideal strength element, Dobson says, adds strength without adding weight so it doesn't add to the overall load on the structure.
One of the patented technologies Duco has developed to address that, he says, is a high modulus strength member, ie, a high tensile rope, that incorporates into the umbilical. This rope is strong, flexible, easy to work with, and easy to manufacture, without adding a lot of weight to the umbilical, Dobson says. This solution, he believes, will help avoid situations where an umbilical, particularly those incorporating steel tubes, is too heavy to sustain its own weight in ultra deepwater.
The second patented technology Duco is working on came from its work for the subsea power industry, where a high tensile aluminum core is being used. This core offers improved mechanical properties at a lighter weight, Dobson says. For cases where conventional copper cable might be too heavy, he says, the high tensile aluminum – a highstrength metal that has been used in the aerospace industry – can be used. Duco has not yet used the core in an installed umbilical, he says.
‘Both technologies are en route to the market in 2011 after extensive qualification trials,' says Dobson, who joined Duco about a decade ago as a product development engineer.
Examples of two large projects Duco has supplied over the past couple of years are Shell's Perdido development in the ultra-deepwater Gulf of Mexico and Total's Pazflor development offshore Angola in 1200m of water.
At the time, the Perdido umbilical was the deepest umbilical in the water, with a 3000m design depth. ‘The challenges there were numerous,' Dobson says. It was, he adds, ‘A long umbilical, a lot of weight.' There were concerns not just about installation issues such as radial compression but also the dynamic motions associated with the spar it was to be attached to. ‘The umbilical was the most analyzed umbilical we'd made to date,' Dobson says. It was designed for high tensile fatigue loading.
For Pazflor, Duco is supplying 80km of dynamic and static umbilicals manufactured at the Houston and Angola facilities. The final delivery under the $130 million contract award was slated for this month.
Shallow water also demands cutting-edge technology for the thermoplastic umbilicals installed there. Dobson says Duco has developed an electric cable with a barrier to prevent the potential problem of hydrogen in the seawater from migrating into the cable, resulting in integrity and safety concerns. ‘We developed a gas-blocking cable with a double barrier. It cuts out the problem altogether.'
Duco's solution uses bonded copper tape to reduce the absorption of hydrogen paired with a gel loaded with hydrogen scavengers that will absorb the rest of the hydrogen. Eni selected this solution for its Kitan project in the Timor Sea in 450m of water. The umbilical, manufactured in Newcastle, is due for delivery this quarter.
Nexans knowhow
Another move the industry has seen is the change from a static umbilical lying on the seabed to umbilicals that connect to a floating platform. ‘We have been pioneering that application by being the first ones to use steel tube umbilicals in general and in dynamic applications specifically,' Graff says about the 1996 project in 904m of water, which saw the first dynamic steel tube umbilicals.
Nexans also counts among its umbilical firsts the delivery of the first center tube umbilical in a dynamic application for Statoil's Norne field in 380m of water. ‘We have supplied umbilicals with 3in tubes in the center with the other umbilical elements around it. The operators use that, for example, for injection of methanol . . . to prevent waxing or icing in the pipeline,' Graff says.
Nexans supplied power umbilicals for BP's King project in the deepwater Gulf of Mexico in 2007. The power goes from the Marlim TLP to the seabed to drive the injection pumps. ‘That's the demand at the moment, to place more weight, more elements on the seabed so you don't need to have that on a platform,' Graff says. ‘So we have installed quite a few power umbilicals.
Recently, Nexans supplied the 145km umbilical for Snøhvit in 250m-345m of water and the two 125km umbilicals for the Ormen Lange project in 800m to 1100m of water. The company is now working on another 145km umbilical set for 2012 delivery to the Laggan-Tormore project in the North Sea. The firm is also delivering the umbilicals for the Usan project offshore Nigeria in 2460ft of water.
Nexans' first umbilical project using steel tubes in a dynamic application was in 1996 for Shell's Mars development in 904m of water in the Gulf of Mexico. The umbilical was 1700m long. The company's first umbilical project using large center tube umbilical was for Statoil's Norne development, also in 1996. This umbilical, with a center tube ID of 1.2in was 9100ft long and deployed in 380m of water.
Oceaneering offerings
Known for years in the umbilicals world as Multiflex, Oceaneering in December 2010 changed the name of its Multiflex business unit to Oceaneering Umbilical Solutions.
‘The challenges facing our industry are tremendous. Deeper water. Longer step outs. Higher pressure,' says Chuck Davison, Oceaneering's VP for umbilical solutions, as well as increased power requirements and more engineering analysis. The longer and larger umbilicals pose their own issues, such as the logistics question of how to move the umbilical to the installation site. ‘Logistics is a significant cost driver,' he says.
Oceaneering provided the umbilicals for phase one of Shell's BC-10 project offshore Brazil in 2008, and has received an order to provide the umbilicals for phase two. Oceaneering expects to begin manufacturing the 30km of umbilicals under that order this quarter.
Davison describes the BC-10 umbilical as ‘one of the most complicated' the company has ever manufactured. While the phase one project lasted two years, Oceaneering dedicated the first year to building prototypes and doing qualification work for the over 50km of umbilicals delivered.
The BC-10 umbilical has three separate three-phase circuits with each circuit cabled together before being incorporated into the umbilical. Because of the size of the cables, the design, Smith says, was complex to manufacture, requiring an in-line splice every 3km in each circuit. On the other hand, the design offers better electrical transmission than individually laid conductors, he says, so the improved transmission should translate into longer life for the subsea pumps.
‘There was a lot of testing to come up with that solution,' Pete Moles, Oceaneering's chief technology manager for Umbilical Solutions, says, noting the company looked at several ways to arrange the conductors.
Smith, who's been with Oceaneering since 1995, notes the umbilical system has copper and steel shielding to limit crosstalk from the power circuits to the signal cables. The backup signal is fiber optic, which also receives no interference from the electrical supply. Smith describes connecting fiber optics subsea as tricky because of the wetmate process. Moles elaborates: ‘You're trying to align 9 microns with 9 microns. That's how small the size is.' Smith jumps in: ‘Trying to get that to line up in 3000m of water with high pressure and be wetmatable, well, that's tricky.'
Oceaneering also supplied umbilicals for ExxonMobil's Kizomba project offshore Angola and is working with OGX to deliver umbilicals for that company's projects in the shallow waters offshore Brazil.
Smith says he's seen increased subsea pumping requirements of 1MW to 1.5MW of power that must be delivered from the host platform to the seabed. ‘It's an order of magnitude more complicated to design an umbilical with that kind of delivery capacity,' he explains. One issue is the amount of heat that capacity generates, and the power can also interfere with the signal cables. ‘You can get crosstalk between the signal and power components,' he adds.
JDR's journey
‘The industry's arguably going more electric,' says JDR Cable Systems' executive vice president Paul Gahm. ‘That's a clear focus for JDR.' The company makes umbilicals with large electric power cores.
For now, JDR is providing subsea power umbilicals with medium voltage, ie 35kVA, adds Gahm, who has been involved in the umbilicals business since the early 1970s.
Looking forward, Gahm sees JDR focusing on heavier, longer subsea stepout umbilicals with medium voltage cables. ‘We don't see umbilicals going away, but we see more electric cables being used,' he adds.
JDR supplied the umbilicals for OMV's Maari field in 102m of water offshore New Zealand last year. That order called for a 2.4km, 3 x 500mm2 8.7/15 (17.5)kV power, optical and injection link.
‘There are three things about that project that made it challenging,' notes Gahm. First, the wells produce to a floater. JDR had to put lead on the umbilicals to give them the weight necessary to behave as desired in the dynamic environment. Second, the umbilicals had to have an automatic disconnect system. Third, the required umbilicals supplied a medium level of power in a 90°C environment. JDR carried out thermal modeling to confirm the umbilicals would work at those temperatures.
Monitoring motions
Duco has been focusing on actively monitoring umbilicals. ‘After you've done the predictive analysis, you expect the structure to last its design life,' Dobson says. But in 2005 several powerful storms hit in a single season in the Gulf of Mexico. It is unlikely installed umbilicals would have been designed to handle multiple storms in a short period, he notes. Thus, he adds, it's important to be able to monitor the impact of unexpected events in terms of the umbilical's fatigue life as it ages. Variables of interest include real-time temperatures, displacement, and tension, among others, he says.
Duco is now qualifying two types of instruments that can monitor umbilicals, one for new projects and one to be used as a retrofit. The first is fiber optic and is built into the umbilical to monitor strain, temperature and so forth. The second is a retrofitted monitoring pod that can be attached outside the umbilical to communicate with the host vessel through a radio frequency link to record the motion of the umbilical and look at fatigue damage and high strain events, he says. The technology has ‘generated a lot of interest from some major operators,' Dobson says.
Nexans, working with the University of Trondheim in Norway, developed a computer program to simulate the operation of the umbilical in the sea conditions at the site where the umbilical would be used, in addition to simulating the movement of the platform. Nexans engineers run umbilical designs through the resulting program, U-FLEX, before creating a prototype for testing. ‘We have built several generations of dynamic test rigs in our factory that simulates the lifetime of that umbilical in that specific application in that field,' Graff explains.
In one test for a power cable destined for use the North Sea, he adds, Nexans ran 24 million cycles to simulate a quarter-century lifetime. ‘I think we had to replace parts of the test machine twice, but the cable was okay.'
Fast forward
The umbilical providers have been investing in facilities, R&D, and good-old human know-how. They've been considering the markets they compete in. For instance, JDR doesn't compete in the Brazilian thermoplastic market, where there are three local players. ‘We're real niche focused. We don't go where there's a lot of competition,' Gahm says. ‘I'm real conscious of where we are in the food chain.'
On the other hand, Oceaneering expects the Brazilian market to be one of the places to be. While the demand for umbilicals offshore Brazil is now about 600km/year, it's expected to reach 1000km/ year by 2014, notes Davison. Oceaneering has focused on beefing up its Brazilian capabilities by investing $14 million under a five-phase strategy aimed at increasing productivity and capacity as well as the ability to offer steel tube umbilicals in the traditionally thermoplastic Brazilian market, Smith said.
And Oceaneering is hoping to see more operators more involved in the umbilicals choice. ‘A lot of customers are trying to commoditize umbilicals, and they're not a commodity,' Davison says. ‘There's a lot to these.' Smith has noticed more operators are now buying the umbilicals directly, rather than buying the umbilicals as part of an EPIC package and transferring the risk to the installers.
All the companies want to ensure their umbilicals perform as expected, and they're spending plenty of time in analysis to help make sure that happens. After all, Gahm says, ‘We all want everybody's umbilicals to work. We just want ours to work better.' OE
Aker Solutions manufactures steel tube umbilicals at its Mobile, Alabama, and Moss, Norway, facilities. The Mobile facility, opened in 2003, is handling the 330km of umbilicals for Noble Energy's Tamar field offshore Israel in 5500ft of water, with delivery slated for 3Q 2011. The Moss facility has the order for 264km of umbilicals for Chevron's Gorgon project offshore Australia in 4300ft of water, with final deliveries slated for 2Q 2012. Opened in 1993, the Moss facility saw nearly NKr70 million in upgrades in 2010, including upgrade and expansion of the production hall, a new 2500t carousel and new testing equipment. This year will see further upgrades to the production line, allowing the company to produce longer cables more efficiently.
Duco put down its roots supplying thermoplastic umbilicals from the Newcastle, UK, manufacturing facility, primarily to the North Sea, as Dunlop Umbilicals. Coflexip bought Dunlop in 1995 and took the ‘Du' from Dunlop and the ‘Co' from Coflexip to create Duco. In 1996, the company opened a steel tube manufacturing facility near Houston to meet growing demand in the Gulf of Mexico market. In 2004, following the 2001 Technip purchase of Coflexip, Duco opened another steel tube facility, this time in Angola. Last year, Technip opened the Asiaflex Products facility in Malaysia dedicated to manufacturing flexible pipe and thermoplastic umbilicals.
Nexans' manufacturing facility in Halden, Norway, specializes in umbilicals and submarine power cables. The facility has two lay-up machines, two large armoring machines, and large capacity turntables to store umbilicals, and it duplicates other large manufacturing equipment. In addition, insulated power cores for inclusion in power umbilicals are manufactured in the Halden plant. In the Rognan facility, Nexans specialize in submarine fibre optic cables and ROV-umbilicals. It also manufactures electrical elements and fibre optic cables for use in the subsea umbilicals. Nexans draws on many of the company's capacities to manufacture both thermoplastic and steel tube umbilicals, making its own electric cables and fiber optic elements. ‘We make our own insulated power cords. We do our own welding on the steel tubes. We have more control over each element in the umbilical than each of the competitors,' says Ragnvald Graff.
Direct loadout of an umbilical to Oceaneering project installation vessel Intervention II from the company's Panama City, Florida, manufacturing facility. Oceaneering has three plants and can supply armored, unarmored, thermoplastic and steel tube umbilicals from any of its three locations. The Panama City facility has two 250ft-diameter carousels that can manufacture 480km/yr. The Rosyth facility in the UK can manufacture 360km/yr while the facility in Niteroi, Brazil – operational since 1999 – will be able to manufacture 400km/yr once a major expansion now under way is complete.
JDR, which manufactures thermoplastic hose umbilicals and subsea power cables, has facilities in Littleport and Hartlepool in the UK and another in Sattahip, Thailand. The company came into being 17 years ago following the merger of two established offshore cable suppliers, Jacques in the UK and De Regt in the Netherlands. Early in its history, the landlocked Littleport facility's 100t weight limit prompted the company to focus on dynamic applications involving floaters and harsh environments. At its state-of-the-art Hartlepool facility commissioned just two years ago (OE September 2009), JDR is adding an additional vertical laying machine to enable the factory to make longer, heavier products.
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