The umbilicals in the oil and gas industry are the lifelines of deepwater O&G fields, connecting wells to the offshore platform. The use of carbon fiber rods to replace some of the steel sheathing is an interesting development for use in deepwater umbilicals.
Since the 1990s, subsea production systems have become increasingly important, specifically for deepwater plays. Some wells or well systems are located as far as 100 km from the production rig and may be up to 3,000 meters deep. As a result, umbilicals composed of steel tube conduit, thermoplastic hose, or a combination of the both, are critical for power, control, communication, and fluid injection to keep deepwater wells working efficiently and producing continuously.
Deepwater dynamic umbilicals represent a breakthrough for deepwater developments and static umbilicals are also used in subsea systems. Steel tubes are still the norm as internal umbilical sheathing but the introduction of carbon fiber rods to replace some of the steel tubes presents various advantages for deepwater umbilical systems.
The use of steel tubes combined with carbon fiber rods is revolutionizing deepwater umbilical design. Aker Solutions is at the forefront of this new design template and have patented the carbon fiber rod technology. The carbon fibre rods enhance stiffness without adding extra weight to the umbilical. This reduces the global elongation and keeps stress at a low level even in ultra deep waters. By adding carbon fibre rods, the umbilical's stiffness can be tuned to meet any maximum strain requirement at any water depth. As a result, this technology offers significant cost savings both at product and total system levels.
The first deepwater umbilical was installed by Aker Solutions at the end of 2006 in the Mississippi Canyon M-C920 project at 2,900 m. First gas was achieved in July 2007. Some of the advantages of deepwater dynamic umbilical are low weight, high strength, no need for buoyancy elements for deepwater applications (which alone simplifies operations and reduces cost), and finally eliminates any water depth limitations.
This new technology will undoubtedly be attractive for deepwater drilling companies and O&G operators working the Brazilian deepwater and deepwater pre-salt plays, which rely heavily on subsea systems and extensively use static and dynamic umbilicals to remotely control the various elements that compose subsea systems, such as well heads, manifolds, separation systems, valves etc...
Photo courtesy of Aker Solutions