Polyamide Sealing Layer Copper Stabilizer Offshore Pipes
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Solution Overview
Problem
Current polyamide compositions used in offshore oil and gas pipelines face limitations in thermal resistance, hydrolysis lifespan, and extrudability, with high costs associated with hydrogenated nitrile butadiene rubber (H-NBR) elastomers and high polymolecularity indices leading to high solution viscosities.
Innovation Solution
A composition comprising 70-91% semi-crystalline polyamide, 5-25% functionalized polyolefin with epoxy or anhydride functions, and 3-20% plasticizer, along with 0.05-5% copper complex stabilizer, free of alkali metal halides and oligo- or poly-carbodiimides, is used as a sealing layer in pipes to enhance thermal resistance and hydrolysis resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If polyamide is used as sealing layer for temperatures above 40°C, then thermal resistance is improved, but hydrolysis lifespan deteriorates due to quick aging
Solution Approach 1:
The patent modifies the chemical composition parameters of the polyamide by incorporating specific additives (copper-based stabilizers, hydrolysis inhibitors, antioxidants) to change the material's resistance parameters without changing its fundamental polyamide structure, enabling both high temperature service and extended hydrolysis lifespan
Solution Approach 2:
The patent creates a composite sealing layer material by combining polyamide with multiple functional additives including copper-based stabilizers, hydrolysis inhibitors, and antioxidants, forming a composite material that simultaneously achieves thermal resistance and hydrolysis resistance
2Reliability
If H-NBR elastomer is added to improve resistance to aging, then durability is improved, but manufacturing cost increases due to high material cost and additional grinding step
Solution Approach 1:
The patent replaces expensive H-NBR elastomer with a more economical combination of polyamide and cost-effective stabilizers/additives, achieving similar or comparable aging resistance without the high material cost and additional grinding processing requirements
Solution Approach 2:
The patent introduces copper-based stabilizers and hydrolysis inhibitors as intermediary substances that mediate between the polyamide matrix and the aging/hydrolysis environment, providing protection without requiring expensive elastomer additions
3Strength
If chain extenders are used to improve mechanical properties, then strength is improved, but viscosity in molten state increases making extrusion difficult
Solution Approach 1:
The patent optimizes the molecular weight and structural parameters of the polyamide and carefully controls the type and amount of additives to achieve the desired mechanical strength while maintaining molten state viscosity within extrusion processable ranges
Solution Approach 2:
The patent applies different functional additives at specific concentrations and distributions within the polyamide matrix, providing localized reinforcement and protection while maintaining overall processability
4Temperature
If polyamide composition is optimized for thermal resistance, then service temperature is extended, but flexibility deteriorates
Solution Approach 1:
The patent creates a composite formulation combining polyamide with flexible additives and plasticizers that maintain material flexibility at extended service temperatures, preventing the typical trade-off between thermal resistance and flexibility
Solution Approach 2:
The patent adjusts the glass transition temperature and crystallinity parameters of the polyamide composition through additive selection and concentration optimization, enabling the material to maintain flexibility at higher service temperatures than conventional polyamides
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
The solution provides improved extrusion properties, thermal resistance, and extended service temperature, reducing the need for chain extenders and maintaining flexibility while inhibiting viscosity rise in the molten state, thus enhancing the durability and performance of offshore pipeline materials.
Implementation Method 1
at least one stabilizer based on a copper complex... improved resistance to aging... limiting the weight content of plasticizer
Implementation Method 2
matrix comprising at least one catalyzed thermoplastic polymer
Implementation Method 3
at least one polyolefin comprising an epoxy function, anhydride or acid, introduced by grafting or by copolymerization
Data Source
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AI summary
The present invention relates to the use of a composition comprising: 70 to 91 % by weight of at least one semi-crystalline polyamide, 5 to 25 % by weight of at least one polyolefin having an epoxy, anhydride or acid function introduced by grafting or copolymerisation, 3 to 20% by weight of at least one plasticizer, 0.05 to 5% by weight of at least one stabilizer on the basis of a copper complex, and at least one catalyst, said composition being free from alkaline metal halide and oligo- or polycarbodiimide, as sealing layer in a pipe containing oil or gas, the pipe being used in the exploitation of offshore oil or gas reservoirs.