Composites are recognized as an enabling technology in deepwater drilling scenarios, because the materials are able to stand up to the harsh subsea environment while delivering lower overall system weight. Recently, the focus has been on piping. Market research firm Lucintel (Dallas, TX, US) reported in March 2014 that the oil & gas and chemical segments, together, accounted for more than 55% of the fiber-reinforced plastic (FRP) pipe market in the U.S.
One area where composite solutions are enabling applications is in ultra-deep oil and gas extraction, at depths greater than 1,500m. Top tensioning and flotation systems, installation expenses and deployment time, and longevity of asset life are all areas where high-performance composites can outperform traditional technologies in riser, jumper, intervention line, cable and umbilical applications. There has been progress in each of these areas.
Downlines were “hot” in 2014. Saipem SA (Milan, Italy), for example, recently completed pre-commissioning for two pipelines in the Guara & Lula NE gas-line project in Brazil, using a flexible 72.6-mm inside-diameter (ID) TCP downline. Deployed more than 30 times, the downline reached a depth of 2,130m — a record for a fully composite pipe — and reportedly reduced top tension by 90% compared to a steel-reinforced flexible tubular. Its lighter construction enabled downline operations from a smaller construction-support vessel than otherwise would have been possible. In addition, the TCP downline was deployed to the seabed in less than 2.5 hours. Conventional flexibles, which require the deployment of additional buoyancy support, would typically require 12 hours or more for a similar deployment.
Fiber-reinforced polyvinylidene difluoride (PVDF) pipe systems also are under development for applications at higher temperature. At relatively low pressures, E-glass fiber offers the best commercial value, but structural high-strength-glass (S-glass) is better for high-pressure applications where spoolability is key. For applications that require maximum strength-to-weight ratio and stiffness, carbon fiber is used. Fiber angles can be varied for each layer to optimize pipe design. Flowlines, for example, demand optimized flexibility, internal pressure containment and external pressure capabilities, but a relatively low tensile strength. By contrast, composite risers, downlines and coiled tubing require optimized tension and pressure containment, both internal and external. The pipes are manufactured in a continuous lengths that are limited only by the size of the carousels that can be handled in the factory and during transport. Read more about composites in oil & gas applications by clicking on “Fossil and mineral resources: Composites expand,” under “Editor’s Picks,” at top right.)
Magma Global Ltd. (Portsmouth, U.K.) also offers flexible monolithic composite pipe of carbon fiber-reinforced polymer (CFRP), Magma’s trademarked m-pipe was developed for use in ultra-deep risers, jumpers and flowlines. Magma uses a proprietary process to produce m-pipe from T700 carbon fiber (Toray Industries, Tokyo, Japan) and polyetheretherketone (PEEK) resin from Victrex Polymer Solutions (Cleveleys, Lancashire, UK). The pipe is available with IDs that range from 51 mm to 610 mm. Recently, Magma introduced s-pipe, which offers the fundamental qualities of m-pipe in smaller diameters (up to 76.2 mm) in versions with pressure rating to as high as 138 MPa. Designed for intervention and work-over applications that require ultrahigh pressure, high temperatures, sour service and fatigue resistance, s-pipe features Victrex PEEK reinforced with a combination of high-strain fibers.
Meanwhile, hydraulic fracturing is fueling an energy boom, especially in the US. According to the Society of Petroleum Engineers, 60 percent of all new oil and gas wells globally are being “frac’ed” and 2.5 million fracs have occurred since 2012, with more than 1 million in the US. The U.S. Energy Information Admin. forecasted an increase in domestic oil production from 6.89 million barrels/day in 2012 to 8.15 million bbl/d in 2014. Hydraulic fracturing has created new opportunities for composites (to read more, click on “Composites boon from hydraulic fracturing?” under “Editor’s Picks,” at top right.)