Reel-Lay Pipe Spooling With Variable Pigs for Liner Wrinkle Control

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Solution Overview

Problem

Bimetallic pipes with mechanically lined sleeves face issues during spooling and unspooling, such as wrinkling and deformation, which can hinder fluid flow and reduce fatigue life, especially when bending, due to the difference in material strength between the outer and inner layers.

Innovation Solution

A method involving cyclic pressurization and the use of variable diameter pigs to manage the transition between pipelines of different diameters, ensuring the inner liner sleeve remains stable by maintaining internal pressure and preventing wrinkling during spooling onto a reel.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thin-walled liner sleeve is used to protect the outer pipe from corrosion, then corrosion resistance is improved, but the liner sleeve undergoes significant deformation and wrinkling under bending and external pressure

Engineering Contradiction:
Improvecorrosion resistanceVSAvoidliner sleeve deformation
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary anti-action by pressurizing the pipeline with fluid before spooling operations. This internal pressure creates a counteracting force that prevents the thin-walled liner sleeve from deforming and wrinkling under external bending loads and pressure during reel-lay operations. The pre-applied internal pressure essentially prepares the system to resist the anticipated external forces.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent changes the physical parameter of internal pressure to resolve the contradiction. By maintaining elevated internal pressure during spooling and unspooling operations, the liner sleeve remains structurally stable despite its thin walls. This parameter change transforms the liner from a vulnerable component to a stable structure that can withstand bending without wrinkling.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If the pipeline is pressurized to prevent liner deformation, then liner stability is improved, but the complexity of the spooling process increases

Engineering Contradiction:
Improveliner sleeve stabilityVSAvoidspooling process complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent implements continuity of useful action by maintaining pressurization throughout the entire spooling process rather than applying pressure only at critical moments. The pipeline remains pressurized during assembly, spooling, unspooling, and installation, eliminating the need for multiple pressure cycles and reducing process complexity. This continuous pressurization simplifies the overall procedure while ensuring liner stability.

Inventive Principle:
Principle #20Continuity of useful action

3Stability of the object's composition

If a clad pipe with metallurgically bonded liner is used, then liner stability during bending is improved, but the manufacturing cost increases significantly

Engineering Contradiction:
Improveliner stability during bendingVSAvoidmanufacturing cost
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent uses pneumatic and hydraulic principles by introducing fluid pressurization to stabilize the liner sleeve during bending operations. This alternative approach replaces the need for expensive metallurgically bonded clad pipes with a simpler mechanically lined pipe system that achieves equivalent stability through internal pressure, significantly reducing manufacturing costs.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent introduces fluid pressure as an intermediary element that mediates between the thin-walled liner sleeve and external bending forces. This intermediary pressurization system allows the use of economical mechanically lined pipes instead of expensive clad pipes, as the fluid pressure acts as a buffer that prevents liner deformation during spooling and installation operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

This method effectively minimizes wrinkling and deformation of the liner sleeve, ensuring smooth fluid flow and extended pipeline life by maintaining internal pressure and using adaptable pigs to manage diameter transitions during spooling.

Implementation Method 1

filling already-assembled pipe stalks with a pressurising liquid, elevating the pressure of the pressurising liquid and spooling the pipe stalks onto the reel while thereby pressurised internally

Methodology Applied
Scientific EffectInternal pressure: Pressure Increase

Implementation Method 2

the diameter of the first pig changes to match the inner diameter of the second pipeline

Methodology Applied
Scientific EffectVariable diameter expansion: Deformation

Data Source

PatentEP3887699B1Pipe spooling for reel-lay operations
Publication Date: 2022.11.23 SUBSEA 7 DO BRASIL SERVICOS LTDA
  • EP3887699B1 patent drawingFigure 1~3
  • EP3887699B1 patent drawingFigure 4~6
  • EP3887699B1 patent drawingFigure 7~10

AI summary

Lined pipelines (82) with different inner diameters are spooled successively onto a reel while their constituent pipe stalks are cyclically pressurised internally to combat wrinkling of the liner. A first, variable diameter pig (34) is advanced to a trailing end of a first pipeline. A transition joint (84) is attached to the trailing end of the first pipeline to effect a transition from the inner diameter of the first pipeline to the different inner diameter of a second pipeline. A leading end of the second pipeline, containing a second pig (80), is attached to the transition joint. The first pig is driven through the transition joint into the second pipeline. The diameter of the first pig changes to match the inner diameter of the second pipeline. The first and second pigs are then driven along the second pipeline when assembling the second pipeline from a succession of pipe stalks.