Qualification of Flexible Fiber-Reinforced Pipe for 10,000-Foot Water Depths
Authors: Jha Vineet , Latto James , Dodds Neville , Anderson Todd A , Finch David , Vermilyea Mark 
Published: May 2013

The combination of ultra-deepwater applications and large pipe diameter requirements presents severe engineering challenges for rigid pipe technology and remains outside current flexible pipe qualification scope. To address those needs, General Electric, with the support of Research Partnership to Secure Energy for America (RPSEA), has recently embarked on a development program to qualify flexible pipe with an internal diameter of greater than seven inches for ultra-deepwater applications. The program is based on a novel hybrid flexible riser technology that will be developed and qualified by a combination of design, analysis of performance, material and subcomponent testing, and finally a field trial.

The concept consists of an optimally engineered combination of metallic and composite reinforcing layer technologies. This design approach allows the pipe system properties to be tailored to yield the optimal result for any application conditions. The approach offers performance advantages including reduced risk on critical end fitting technology, reduction of sheath leakage by fusing together the reinforcement and liner, superior matrix chemical resistance by using proven thermoplastic materials, and a reduced layer count leading to easier inspection. This paper will review the conceptual design of the flexible pipe and end terminations, and an overview of the plan for pipe qualification will be discussed.

Introduction

The relatively recent ultra-deepwater (&gt; 1500 m) discoveries in the Gulf of Mexico, as well as off the coasts of Brazil and Angola, present an enormous opportunity and technical challenge. Specifically, the combination of ultra deepwater and relatively large pipe diameter is outside current flexible pipe qualification scope and imposes severe engineering challenges to both rigid and flexible pipe technologies. For a flexible pipe solution, the combination of greater than 2000 m operation depth and high design pressures (&gt;10,000 psi) will require technical innovations in current flexible pipe technology and rigorous testing to prove to customers that these new technologies are robust and durable.

To address those needs, General Electric, with the support of RPSEA, has recently embarked on a development program to qualify flexible pipe with an internal diameter of greater than seven inches for ultra-deepwater applications. The program is based on a novel hybrid flexible riser technology that will be developed and qualified by a combination of design, analysis of performance, material and subcomponent testing and finally, a field trial.

The concept consists of an optimally engineered combination of well-understood and mature metallic and composite reinforcing layer technologies. This design approach allows the pipe system properties to be tailored to yield the optimal result for any application conditions. The approach offers potential performance advantages including reduced risk on critical end fitting technology, reduction of sheath leakage by fusing together the reinforcement and liner, superior matrix chemical resistance by using proven thermoplastic materials, and a reduced layer count leading to easier inspection.

This paper will review the conceptual design of the flexible pipe and end terminations and an overview of the plan for pipe qualification will be discussed. To begin, an overview of the requirements and conventional pipe technology will be presented. A discussion of the proposed conceptual design will follow with some design and analysis predictions from the first few months of the program.