Pipeline Defect Correction via Laser-MFL Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current non-destructive inspection methods for pipelines and storage tanks, such as Magnetic Flux Leakage (MFL), often result in systematic errors that lead to conservative mitigation plans and unnecessary costs due to insecurity about failure pressure, necessitating a more accurate defect pattern correction method.
Innovation Solution
A method involving dual non-destructive inspections using MFL and laser profilometry, where the second inspection corrects the systematic errors of the first by comparing defect patterns over overlapping areas, allowing for more precise defect dimension and position corrections, and classifying defects into categories for targeted corrections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If MFL inspection is used to inspect the pipeline surface, then large area coverage is achieved, but systematic errors occur in defect pattern measurements
Solution Approach 1:
The patent uses laser profilometry as an intermediary measurement tool to correct systematic errors from MFL inspections. The laser profilometer provides high-precision reference measurements on overlapping inspection zones, serving as a mediator to calibrate and correct the MFL defect patterns, thereby resolving the contradiction between large area coverage and measurement accuracy.
Solution Approach 2:
The patent changes the measurement parameters by combining two different inspection methods with different error characteristics. By adjusting the weighting and correction factors between MFL and laser profilometry measurements, the system optimizes the balance between coverage area and measurement precision, correcting systematic errors while maintaining broad inspection coverage.
2Reliability
If conservative mitigation plans are adopted due to measurement insecurity, then pipeline safety is improved, but maintenance costs and unnecessary repairs increase
Solution Approach 1:
The patent implements a feedback mechanism where laser profilometry measurements are used to verify and correct MFL inspection results. This feedback loop provides confidence in the accuracy of defect measurements, allowing mitigation plans to be based on corrected rather than conservative estimates, thereby reducing unnecessary maintenance costs while maintaining pipeline safety.
Solution Approach 2:
The patent performs preliminary correction of defect patterns using laser profilometry data before finalizing mitigation plans. By预先 correcting systematic errors in defect dimension and position measurements, the system enables more accurate risk assessment and optimization of maintenance schedules, avoiding both over-maintenance and under-maintenance scenarios.
3Measurement precision
If second inspection with smaller systematic error is performed on overlapping area, then measurement accuracy is improved, but inspection time and cost increase
Solution Approach 1:
The patent applies partial action by using laser profilometry only on overlapping inspection zones rather than the entire pipeline surface. This selective application of the second inspection method provides sufficient reference data for correcting MFL systematic errors while minimizing the additional time and cost required, avoiding the need for complete re-inspection.
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 reduces the conservatism in maintenance decisions, improves the prediction of corrosion growth rates and failure pressure, and optimizes maintenance schedules, while minimizing costs and errors, especially beneficial for buried or subsea pipelines where repairs are costly.
Implementation Method 1
for example based on Magnetic Flux Leakage (MFL)
Implementation Method 2
the first way of non-destructive inspection includes using Magnetic Flux Leakage measurements
Implementation Method 3
the second way of non-destructive inspection includes inspection by means of a laser, preferably laser profilometry
Implementation Method 4
laser profilometry. This method can yield a relatively accurate measurement
Data Source
AI summary
Method for non-destructive inspection of defects in a surface of a pipeline or storage tank. The method includes carrying out a first way of non-destructive inspection for determining a first defect pattern and carrying out a second way of non-destructive inspection for determining a second defect pattern. The method includes identifying at least one defect of the first defect pattern and at least one defect of the second defect pattern which represent one and the same defect, and comparing the dimensions and optionally also the positions of the identified defects so as to obtain a difference in dimensions and optionally also in the positions. The method also includes obtaining a plurality of such differences and obtaining at least one parameter representing said differences, and correcting the dimensions and optionally also the positions of defects of the first defect pattern by using the at least one parameter.