This paper presents proposed requirements for qualifying composite reinforcement for the hoop and tensile reinforcement layers of unbonded flexible pipe, and progress towards meeting those requirements by one manufacturer.
Due to lighter weight and resistance to corrosion and fatigue, composite materials are being implemented for the hoop and tensile reinforcement in unbonded flexible pipe. By reducing the weight of the pipe up to 50% or more, riser system and installation top tensions are substantially reduced. The lower weight and tension reduces project CAPEX, installation cost and risk by enabling lighter weight capacity floating production systems and installation vessels.
Currently ISO 13628-2/API 17J Specification for Unbonded Flexible Pipe [1] does not apply to composite reinforcement, largely because of the limited operational experience with composite materials. Proposed requirements to be included in Annex H of API 17B Recommended Practice for Flexible Pipe [2] as guidelines for composite armour, are summarized in the paper. As operational experience is gained, it will be proposed to include these requirements and learnings in a future revision of ISO 13628-2/API 17J. The efforts of one manufacturer to develop and implement a design methodology and qualification program to meet the proposed requirements are presented.
Most flexible pipe manufacturers are in various stages of developing and commercializing unbonded flexible pipe with composite armour. Yet, there has not been agreement in the flexible pipe community on product requirements. Without industry concurrence on requirements, manufacturers can expend significant funds developing and qualifying a design methodology which does not meet target requirements. This paper describes the first effort to obtain industry consensus on target requirements for unbonded flexible pipe with composite armour.
