Composite riser pipe for offshore oil applications steps closer to implementation
By Staff | September 01, 2004
Source: Spenser Composites
C4PO, a division of Spencer Composites Corp. (Sacramento, Calif., U.S.A.), is producing a limited number of carbon fiber composite production riser pipe joints for the ConocoPhillips Magnolia tension leg platform (TLP) located in the Gulf of Mexico. Magnolia is moored in 1433m/4,700 ft of water, the greatest depth of any TLP in the world. The tubular joints will be incorporated at varying depths in the platform's steel production riser strings. According to published sources, delivery is scheduled for the end of this month.
The 3.2m/63-ft long risers are filament-wound over a steel liner and have an outer thermoplastic sheath for protection (see HPC July 2002, p. 40). Outer diameter (OD) is 34.3 cm/13.5 inches, inner diameter (ID) is 24.6 cm/9.69 inches and overall weight is one-half that of a steel riser joint. Flanged steel end fittings compatible with the platform's steel joints are overwrapped with the carbon/epoxy tows during winding to ensure a strong composite-to-metal interface. Sources say performance specs are 10,000 psi operating pressure and 21,000 psi minimum burst pressure, with axial load capacity of 1.14 million kg/2.5 million lb. Each joint consumes approximately 1,500 lb of carbon fiber. The fiber supplier is Grafil Inc. (Sacramento, Calif., U.S.A.). HPC will continue to monitor developments in this potentially huge market.
