Flexible Pipe

What is Flexible Pipe?

Unbonded flexible pipes consist of concentric layers of metallic wires, tapes and extruded polymers designed to form a structure that addresses the specific environmental requirements and characteristics of the transported fluids.

Flexible Pipe Construction

Flexible pipe is a technically challenging, multi-layer structure of helically wound metallic wires and tapes and extruded thermoplastics 

 Regarding Aplication

• Risers : Static or Dynamic Application
• Flowlines : Static Application 

Regarding the Internal Fluid 

• Smooth bore : Water Injection 
• Rough Bore : Oil and Gas 

Regarding H2S presence 

• Sweet service : with H2S 
• Sour service : without H2S 

Flexible Pipe Standards:

API 17J - Specification for Unbonded Flexible Pipe Petrobras NI-2409-A - Flexible Pipe Specification - 2003 

– Must be in compliance on all Petrobras Projects.

ISO 13628 - Petroleum natural gas industries - Drilling and production equipment - Design and operation of subsea system- Part 2: Flexible pipe systems for subsea and marine applications. 

Bureau Veritas NI 364 DTO ROO E - Non-bonded Flexible Steel Pipes used as Flowlines 

DNV Rules for Flexible Pipe 

Other oil company specifications 

–- ALL SUPERSEDED BY API 17J 

RP17B - Recommended Practice for Unbonded Flexible Pipe (sister document to API 17J) 

References : "Introduction to Unbonded Flexible Pipe Design and Manufacturing" www.lem.ep.usp.br/pef418/wellstream.pdf