Segmented Insulating Insert for Bend-Resistant Pipeline Field Joints
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Solution Overview
Problem
Existing field joint coatings in subsea pipelines face challenges with cracking and prolonged curing times, leading to delays and increased operational costs, particularly during the reel-lay method where bending stresses and strains cause stress concentrations and potential corrosion.
Innovation Solution
A solid insulating insert with flexible links is positioned around the field joint, allowing for angular displacement and reducing stress concentrations, combined with a method of embedding the insert in a thermoplastic field joint coating to ensure continuity of thermal insulation and reduce production time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solid insulating insert is used in field joint coating, then thermal insulation continuity is improved, but the insert may crack under bending stresses and strains
Solution Approach 1:
The solid insulating insert is divided into multiple segments that can move relative to each other, allowing the insert to accommodate bending stresses and strains without cracking while maintaining thermal insulation continuity across the field joint
Solution Approach 2:
The insert segments are designed to be dynamically movable relative to each other, enabling the insert to adapt to differential stresses and strains during pipeline bending operations such as reel-lay installation
2Ease of manufacture
If traditional field joint coating methods are used, then application is simpler, but curing time is prolonged causing production delays
Solution Approach 1:
The insulating insert is pre-positioned around the field joint before the thermoplastic coating is applied, allowing the coating to be injected and cooled quickly without waiting for prolonged curing, thereby reducing production time while maintaining application simplicity
3Reliability
If the insert is rigid to maintain insulation, then thermal insulation is effective, but stress concentrations increase during pipeline bending
Solution Approach 1:
Dividing the rigid insulating insert into multiple segments that can move relative to each other reduces stress concentrations during pipeline bending while maintaining thermal insulation effectiveness through continuous coverage across the field joint
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 enhances resistance to cracking and reduces production time for field joint coatings, maintaining thermal insulation and preventing corrosion by accommodating differential stresses and strains during pipeline bending.
Implementation Method 1
The links are flexible relative to the segments to facilitate bending of the insert along its length by enabling relative angular displacement between adjacent segments of the series
Implementation Method 2
The insert comprises a longitudinal series of annular or part-annular segments of insulating material... maintaining thermal insulation... preventing corrosion by accommodating differential stresses and strains during pipeline bending
Data Source
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AI summary
An insulating insert is positioned around a field joint of a pipeline to insulate the field joint. The insert comprises a longitudinal series of annular or part-annular filler segments of insulating material, curved about a longitudinal axis, that are each joined to one or more adjacent segments of the series by at least one link. The links may be webs, rods or articulated links. The links are flexible relative to the segments to facilitate bending of the insert along its length by enabling relative angular displacement between adjacent segments of the series.