Pipeline Pig Flow Cavity for Speed Control and Obstruction Clearing

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Solution Overview

Problem

Pipeline pigs often become stuck due to debris and obstructions, which restricts pipeline flow and requires costly contingency measures like cutting the pipeline, as existing flow channels reduce the maximum fluid force and can prevent the pig from moving forward.

Innovation Solution

The pipeline pig features selectively openable relief channels and a bypass channel with pressure-activated valves that regulate fluid flow, allowing for increased force to clear obstructions and diverting fluid when necessary to maintain pipeline production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If flow channels are provided through the pipeline pig to regulate speed, then the speed of the pipeline pig is controlled, but the maximum fluid force available to drive the pig through obstructions is reduced

Engineering Contradiction:
Improvespeed of pipeline pigVSAvoidfluid force available to clear obstructions
Core Design Contradiction:
SpeedVSForce

Solution Approach 1:

The patent implements dynamic control of flow channels through pressure-activated valves that automatically open or close based on real-time pressure differential conditions. When pressure differential is high (indicating obstruction), the valves close to maximize driving force; when pressure differential is low (normal operation), the valves open to regulate speed. This dynamic adaptation resolves the contradiction by making the flow channel configuration variable rather than fixed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the flow resistance parameter of the flow channels by using valves that can transition between open and closed states based on pressure differential thresholds. This parameter change allows the system to optimize between two opposing requirements: maintaining speed control during normal operation while maximizing force during obstruction clearing operations.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the pipeline pig encounters debris or obstructions, then the pipeline pig may become stuck, but flow of the pipeline fluid is restricted or impeded

Engineering Contradiction:
Improveability to clear obstructionsVSAvoidpipeline flow continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent employs a feedback mechanism where pressure differential sensors monitor the force required to move the pig, and this information feeds back to the control system which adjusts valve positions accordingly. When high pressure differential indicates an obstruction, the system responds by closing flow channels to maximize force; when normal flow is detected, the system opens channels to maintain speed control. This closed-loop feedback ensures the pig can clear obstructions while minimizing impact on pipeline productivity.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The pressure-activated valves operate autonomously based on pressure differential conditions without requiring external control. The system self-adjusts its flow channel configuration in response to encountered conditions, enabling the pig to automatically optimize its performance for either speed control or obstruction clearing based on real-time operational needs.

Inventive Principle:
Principle #25Self-service

3Speed

If flow channels are used to regulate pig speed, then speed control is achieved, but the likelihood of the pig becoming stuck increases

Engineering Contradiction:
Improvespeed regulation of pipeline pigVSAvoidlikelihood of becoming stuck
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent transforms static flow channels into dynamic, adjustable pathways using pressure-activated valves. The valves automatically adjust the degree of opening based on pressure differential, allowing the system to maintain speed regulation during normal operation while preventing complete blockage that would cause the pig to become stuck. The dynamic nature of the flow channels adapts to operational conditions in real-time.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent modifies the flow resistance parameter of the channels through valve actuation, changing from a fixed parameter to a variable one. By adjusting the valve opening degree based on pressure differential thresholds, the system optimizes the balance between speed regulation and preventing complete blockage, thereby reducing the likelihood of becoming stuck while maintaining speed control capability.

Inventive Principle:
Principle #35Parameter changes

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 solution enables the pipeline pig to effectively clear obstructions by adjusting fluid force and flow direction, reducing the likelihood of getting stuck and minimizing downtime by ensuring continued pipeline operation.

Implementation Method 1

propelled by the pressure of a pipeline fluid flowing through a pipeline

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Implementation Method 2

relief channels and a bypass channel with pressure-activated valves that regulate fluid flow

Methodology Applied
Scientific EffectPressure-activated valve operation: Pressure Gradient

Data Source

PatentEP3110573B1Variable speed pipeline pig with internal flow cavity
Publication Date: 2021.04.14 SAUDI ARABIAN OIL CO
  • EP3110573B1 patent drawingFigure 1A~1B
  • EP3110573B1 patent drawingFigure 2A~2C
  • EP3110573B1 patent drawingFigure 3A~3B

AI summary

A pipeline pig (10) includes a plurality of relief channels (34) and a bypass channel (32) extending therethrough. To regulate a speed of the pipeline pig, relief valves within the relief channels open when a differential pressure between upstream and downstream ends of the pipeline pig reaches a pre-selected minimum relief pressure, If the differential pressure reaches a pre-selected maximum relief pressure, such as when the pipeline pig encounters an obstruction, the relief valves close to allow the differential pressure to further increase to clear the obstruction, If the further increase in differential pressure is insufficient to clear the obstruction and the differential pressure reaches a pre-selected minimum bypass pressure, a bypass valve opens to permit fluid flow through the bypass channel while the relief valves are closed. Flow through the bypass channel operates to reduce turbulence and permit production through the pipeline if the pipeline pig becomes stuck and obstructs the pipeline.