PEKK Pipe Barrier Layers for Low CO2 and H2S Permeability
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Solution Overview
Problem
Current materials used in pipes for transporting petroleum fluids, such as poly(etheretherketone) (PEEK) and vinylidene fluoride copolymers, lack sufficient gas barrier properties against CO2 and H2S, especially under extreme conditions of high temperature and pressure, leading to corrosion and reduced pipe lifetime.
Innovation Solution
The use of poly(etherketoneketone) (PEKK) with a degree of crystallinity greater than 5% and a specific ratio of T:I units, providing superior gas barrier properties by reducing CO2 and H2S permeability to less than 10−8 cm3 per second per bar for a 1 cm2 surface area at 130° C., measured by GC, in pipes and coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polymers like PEEK or vinylidene fluoride copolymers are used in pipes for transporting petroleum fluids, then the pipes can withstand high temperature and pressure conditions, but the gas barrier properties against CO2 and H2S are insufficient, leading to corrosion and reduced pipe lifetime
Solution Approach 1:
The patent changes the chemical composition parameter of the polymer material from conventional PEEK or vinylidene fluoride copolymers to PEKK (poly(etherketoneketone)), which has inherently lower gas permeability. This material parameter change provides superior barrier properties against CO2 and H2S while maintaining the required mechanical strength and temperature resistance, thereby extending pipe lifetime without compromising structural integrity
Solution Approach 2:
The patent employs PEKK as a composite or alternative material solution that combines multiple desirable properties: low gas permeability, high temperature resistance, and adequate mechanical strength. This material substitution effectively addresses the corrosion issue caused by gas permeability while maintaining compatibility with high temperature and pressure operating conditions
2Object-affected harmful factors
If the thickness of the barrier layer is increased to reduce gas permeability, then the corrosion protection improves, but the pipe weight and manufacturing complexity increase
Solution Approach 1:
By changing the material parameter from conventional polymers to PEKK, the patent achieves superior gas barrier properties with inherently lower permeability coefficients. This allows for a thinner barrier layer to provide the same level of corrosion protection, thereby reducing pipe weight while maintaining adequate corrosion resistance
Solution Approach 2:
The patent uses a material with such superior barrier properties that a thinner layer provides equivalent protection, effectively creating a more efficient, lighter-weight solution that replaces the need for thick, heavy barrier layers
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
PEKK significantly enhances the gas barrier performance of pipes, reducing corrosion and extending their lifespan by maintaining low permeability to CO2 and H2S even under severe conditions, allowing for potential reduction in pipe thickness and weight.
Implementation Method 1
PEKK exhibits very advantageous gas barrier properties, especially in relation to CO2 and H2S, these properties, more particularly, being markedly superior to those of poly(etheretherketone) (PEEK)... reducing the CO2 and H2S permeability of a part
Implementation Method 2
The phenomena of migration and corrosion are exacerbated at high temperature... reducing the residual stress therein, by carrying out slower and therefore more uniform crystallization of the polymer
Data Source
AI summary
The use of PEKK for lowering the CO2 and H2S permeability of a part intended to enter into contact with a petroleum effluent. Also, a pipe for transporting a petroleum effluent, including a layer intended to be in contact with the petroleum effluent, wherein the layer intended to be in contact with the petroleum effluent comprises PEKK and has a CO2 permeability at 130° C. of less than 10−8 cm3, for a thickness of 1 cm and a surface area of 1 cm2 and per second and bar of CO2 pressure and/or an H2S permeability at 130° C. of less than 10−8 cm3 for a thickness of 1 cm and a surface area of 1 cm2 and per second and bar of H2S pressure, the amount of CO2 and H2S being measured by GC, respectively. Lastly, a number of methods for manufacturing such a pipe.