Progress in the Development of Test Methods and Flexible Composite Risers for 3000 m Water Depths

摘要

The primary aim of the present development program is to enhance access to deepwater fields in the Gulfrnof Mexico, Brazil, and West Africa by reducing system, transportation and installation costs for flexiblernproduction pipe technology. To accomplish that goal composite materials are being incorporated in hybridrnunbonded flexible pipe structures to enhance their overall system performance and expand the operationalrndesign envelope. The use of composite materials enables significant improvements in operating pressuresrnat larger pipe diameters, reduced weight and top tension, and the enhanced resistance to CO_2 and H2Srndrives further improvements in the structural sour service performance and lifespan.rnGE Global Research and GE Oil & Gas, with the support of Research Partnership to Secure Energy forrnAmerica (RPSEA), embarked on a development program to qualify flexible pipe with an internal diameterrnof greater than seven inches for ultra-deepwater applications. The concept consists of an optimallyrnengineered combination of metallic and composite reinforcing layer technologies. This hybrid designrnapproach allows the pipe system properties to be tailored to yield the optimal result for any applicationrnconditions. The approach offers performance advantages including reduced risk on critical end fittingrntechnology, continuous reinforcement of the liner eliminating discontinuities and local strains by fusingrntogether the reinforcement and liner, superior matrix chemical resistance by using industry provenrnthermoplastic materials, and a reduced layer count leading to easier inspection.rnThis paper will provide an overview of the progress made during the collaborative RPSEA programrnand specifically, will highlight the bespoke testing capabilities developed for the new composite pipernlayer. Although there are several individual standards, specifications and Joint Industry Projects (JIP) inrnrelation to composite pipes that address some of the required tests, there remains a general lack ofrnconsensus with regard to specific testing standards and understanding of the long term performance,rnespecially considering the variety of composite pipe technologies being developed by the industry. Thisrnpaper will highlight the results from mid-scale burst testing along with analysis validation, and a bespokernrotating bending fatigue test rig used to assess the bending fatigue of the composite pipe structure. Lastly,rnprogress toward the use of sub-scale tests allied with analysis to more rapidly assess the fatigue life willrnbe discussed.