Pipeline Pig Cathodic Protection for Debris-Free Water Pipelines

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Solution Overview

Problem

Pipeline pigs often get stuck due to debris and obstructions, leading to costly downtime and restricted pipeline flow, as existing cleaning methods are inefficient in maintaining a debris-free and corrosion-free pipeline.

Innovation Solution

A pipeline pig equipped with a cathodic protection system that includes a cleaning tool with guide discs, an anode, and an impressed current source, where the anode is encapsulated in a hydrophilic wax-repellent cementitious material to prevent corrosion and allow ion flow, ensuring efficient cleaning and protective coating deposition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pipeline pig is propelled through the pipeline to clean and inspect it, then the pipeline can be maintained, but the pig may get stuck due to debris and obstructions, causing downtime and restricted flow

Engineering Contradiction:
Improvepipeline maintenance effectivenessVSAvoidpipeline flow continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The cathodic protection system is activated before the pigging operation to pre-condition the pipeline interior surface by removing corrosion and deposits. This preliminary protective action ensures that when the pig travels through the pipeline, it encounters a cleaner surface with reduced friction and fewer obstructions, thereby maintaining reliability while minimizing disruptions to pipeline flow continuity

Inventive Principle:
Principle #10Preliminary action

2Speed

If flow channels are provided through the pipeline pig to regulate speed, then the pig speed can be controlled, but the maximum fluid force that can be applied to drive the pig is reduced, increasing the likelihood of getting stuck

Engineering Contradiction:
Improvepipeline pig speed controlVSAvoidfluid force on pipeline pig
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The cathodic protection system operates continuously during the pig's travel through the pipeline, maintaining a protective current that prevents corrosion and keeps the surface clean. This continuous action ensures that the pig consistently experiences reduced friction and maintains adequate driving force throughout its journey, allowing speed regulation through flow channels without increasing the risk of getting stuck

Inventive Principle:
Principle #20Continuity of useful action

3Ease of manufacture

If conventional cleaning methods are used, then the pipeline can be cleaned, but the pipeline pig still gets stuck due to remaining debris and obstructions

Engineering Contradiction:
Improvecleaning method implementationVSAvoiddebris-free pipeline maintenance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces purely mechanical cleaning methods with an electrochemical cathodic protection system. Instead of relying solely on mechanical scraping or brushing that may leave debris, the cathodic protection system uses electrochemical reactions to dissolve and remove corrosion and deposits at the molecular level, ensuring a truly debris-free surface that prevents the pig from getting stuck while remaining easy to implement

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 cathodic protection system effectively cleans the pipeline interior, prevents corrosion, and maintains a debris-free surface, reducing the likelihood of the pipeline pig getting stuck and enhancing operational efficiency by ensuring continuous pipeline flow.

Implementation Method 1

depositing a cathode layer on the interior of the pipeline

Methodology Applied
Scientific EffectElectrolysis: Electrolysis

Implementation Method 2

the encapsulant includes a hydrophilic wax repellant cementitious material that is sufficiently porous to allow ions to pass therethrough

Methodology Applied
Scientific EffectIon transport through porous material: Porosity

Implementation Method 3

the encapsulant includes a hydrophilic wax repellant cementitious material

Methodology Applied
Scientific EffectWax repulsion: Hydrophobe

Data Source

PatentEP3710177B1Apparatus and method for in-situ cathodic protection of piggable water pipelines
Publication Date: 2021.08.18 SAUDI ARABIAN OIL CO
  • EP3710177B1 patent drawingFigure 1A~1B
  • EP3710177B1 patent drawingFigure 2~3
  • EP3710177B1 patent drawingFigure 4A~4B

AI summary

Apparatus and method for cleaning the inner surface of a pipeline (P) from deposits and for forming a protective coating are disclosed. The apparatus includes a cleaning tool which is caused to move in the interior of the pipeline (P) by a flow of a fluid (F), the cleaning tool comprising a plurality of guide discs (18, 20) engaging the pipeline surface and mounted along a longitudinal axis (A) of the cleaning tool, an anode (118) positioned inside the cleaning tool, and an impressed current source electrically connected to the anode (118) and the interior of the pipeline (P), the interior of the pipeline (P) acting as a cathode when current is applied from the current source so that ions (114) flow from the anode (118), through the fluid (F), to the interior of the pipeline (P).