Pipeline Inspection Gauge Tracking Using Fiber Bragg Grating Sensors

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Solution Overview

Problem

It is challenging to determine the position and speed of a Pipeline Inspection Gauge (PIG) within a pipeline, especially when it is stuck, as existing methods lack accurate tracking and removal techniques.

Innovation Solution

The method involves using sensors, such as optical fibers with fiber Bragg gratings, to detect signals and generate movement data by extracting parameters like strain and frequency ratios, which are then processed to determine the PIG's position and speed, allowing for real-time tracking and potential removal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional methods are used to track PIG movement, then the system is simple, but the measurement precision of PIG position and speed is insufficient

Engineering Contradiction:

ImprovePIG position and speed measurement precisionVSAvoidtracking system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical tracking systems with optical sensing technology. Optical fibers with Fiber Bragg Gratings (FBGs) are used to detect strain signals caused by PIG movement, converting mechanical detection into optical measurement. This substitution enables precise measurement of PIG position and speed through optical signal processing rather than mechanical means.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces optical fibers as intermediary elements between the PIG and the detection system. The optical fibers act as sensors that translate PIG movement into detectable optical signals. By using optical fibers with FBGs as intermediaries, the system achieves indirect but highly precise measurement of PIG position and speed without direct mechanical contact.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of information

If no tracking system is used, then the device complexity is low, but the ability to determine PIG exit time and locate stuck PIG is lost

Engineering Contradiction:

Improveinformation about PIG position and speedVSAvoidtracking system complexity

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The patent implements a feedback mechanism where optical sensors continuously monitor PIG movement and provide real-time position and speed information. This feedback enables operators to determine when the PIG will exit the pipeline and to locate stuck PIGs promptly. The system processes optical signals to generate actionable information about PIG status and position.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If optical fibers with FBGs are used to detect PIG movement, then the measurement precision improves, but the device complexity and cost increase

Engineering Contradiction:

ImprovePIG movement detection precisionVSAvoidsensor system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the optical fiber system multi-functional by using the same optical fibers with FBGs for both strain detection and position tracking. The optical sensing network serves multiple purposes: detecting PIG movement, determining position, measuring speed, and monitoring pipeline conditions. This multi-functionality reduces the need for separate specialized devices.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent utilizes changes in optical parameters (wavelength, intensity, phase) of light reflected from FBGs to detect PIG movement. By monitoring shifts in these optical parameters in response to strain, the system achieves precise measurement of PIG position and speed. The FBGs convert mechanical strain into measurable optical parameter changes.

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 approach enables precise tracking of the PIG's movement and position within the pipeline, facilitating timely exit prediction and efficient removal, even in low-visibility zones, thereby improving maintenance efficiency.

Implementation Method 1

Detecting the one or more signals may comprise interrogating the one or more lengths of optical fiber using an optical fiber interrogator configured to transmit one or more light pulses along the one or more lengths of optical fiber and to detect reflections of the one or more light pulses

Methodology Applied

Scientific EffectStrain: Deformation

Implementation Method 2

Methodology Applied

Scientific EffectReflection: Reflection

Data Source

PatentUS20230102764A1Methods and systems for tracking a pipeline inspection gauge

Publication Date: 2023.03.30 HIFI ENGINEERING INC

AI summary

There is described a method of determining a position of a pipeline inspection gauge (PIG) in a fluid conduit. While the PIG is moving through the fluid conduit, one or more sensors positioned along the fluid conduit are used to detect one or more signals. Parameter data is extracted from the detected one or more signals. The parameter data includes one or more parameters of the detected one or more signals as a function of time and position along the fluid conduit. PIG movement data indicative of a position of the PIG in the fluid conduit as a function of time is generated using the parameter data.