Multi-Layer Pipe Insulation for High-Temperature Reeling Flexibility
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Solution Overview
Problem
Existing high-temperature polymers used for insulating subsea oil and gas pipelines are costly and lack flexibility, which can lead to failure during the reeling process due to stress and delamination.
Innovation Solution
A molding system that applies two or more layers of insulation to a pipe, where a high-temperature polymer is used in a thin layer on the pipe surface, and additional layers are formed from a lower-temperature, more flexible polymer, allowing for enhanced flexibility and reduced cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a high-temperature polymer is used for insulating subsea oil and gas pipelines, then the maximum operating temperature is increased, but the flexibility is reduced and cost increases
Solution Approach 1:
The insulation system is segmented into multiple layers: an inner layer of high-temperature polymer (up to 12 inches thick) and an outer layer of flexible polymer (up to 6 inches thick). This segmentation allows each layer to perform its specialized function - the inner layer withstands high temperatures while the outer layer provides flexibility for reeling operations.
Solution Approach 2:
The patent employs a composite insulation structure combining two different polymer materials with complementary properties. The high-temperature polymer (e.g., polyimide, PBI, or PTFE) provides thermal resistance, while the flexible polymer (e.g., cross-linked polyolefin or thermoplastic elastomer) provides mechanical flexibility. This composite approach resolves the contradiction between temperature resistance and flexibility.
2Temperature
If a high-temperature polymer is used for insulating subsea oil and gas pipelines, then the maximum operating temperature is increased, but the cost increases
Solution Approach 1:
The expensive high-temperature polymer is applied locally only where it is most needed - in the inner layer directly contact with the hot pipeline. The outer layer uses a more cost-effective flexible polymer. This local quality approach optimizes cost by concentrating the expensive material where it provides maximum thermal protection value.
Solution Approach 2:
The composite structure allows the system to achieve high-temperature capability without using expensive high-temperature polymer throughout the entire insulation thickness. The combination of materials provides cost-effective high-temperature insulation by using each material where it provides the best value.
3Temperature
If a thick layer of high-temperature polymer is applied, then the maximum operating temperature is increased, but the flexibility is reduced leading to failure during reeling
Solution Approach 1:
The insulation is segmented into two functional layers with the flexible polymer outer layer specifically designed to accommodate reeling operations. This segmentation protects the brittle high-temperature polymer from mechanical stress during reeling while maintaining thermal protection, thereby reducing failure risk.
Solution Approach 2:
The patent changes the material parameter (flexibility) of the outer insulation layer to be suitable for reeling operations. By selecting flexible polymers with specific properties (elongation at break ≥50%, tensile strength ≥1000 psi) for the outer layer, the system maintains reliability during reeling while the inner layer maintains temperature resistance.
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 system effectively increases the maximum operating temperature of insulated pipes while reducing costs and improving flexibility, minimizing the risk of failure during reeling operations.
Implementation Method 1
One or more injectors are configured to inject a first polymer into the first mold cavity for forming a first layer of insulation on the pipe
Data Source
AI summary
A pipe has first and second exterior layers of insulation. The first layer of insulation has a higher temperature rating than the second. The second layer can be thicker than the first. In a system and method for forming the insulated pipe, a first mold having a first inner diameter is used for the first layer of insulation and a second mold having a second inner diameter greater than the first inner diameter is used for the second layer of insulation. The first layer of insulation is formed from a first polymer and the second is formed over the first layer from a second polymer. Multiple insulated pipes can be joined together at field joints and field joint insulation can be formed from first and second layers of field joint insulation corresponding in material and thickness to the first and second layers of pipe insulation.