Single Coil Antenna Eddy Current Pipe Inspection
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Solution Overview
Problem
Current wellbore pipe inspection methods are limited in their ability to accurately monitor the structural integrity of multiple concentric pipes, particularly the outermost pipes, due to azimuthal sensitivity and depth limitations, and struggle with effectively detecting corrosion and defects in harsh environments.
Innovation Solution
The use of a pipe inspection tool with a single coil antenna featuring multiple excitation and measurement points, combined with a segmented ferrite core, allows for variable depth investigation and independent measurements, enabling detection of defects such as corrosion and metal loss through electromagnetic inspection methods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If acoustic wave pulse reflection methods are used for pipe inspection, then defects can be detected, but the method is limited to shallow depth and azimuthal sensitivity
Solution Approach 1:
The patent replaces acoustic wave pulse methods with electromagnetic eddy current methods. The electromagnetic sensor generates eddy currents in the pipe walls and measures the resulting impedance changes, enabling depth investigation beyond acoustic limitations while maintaining defect detection precision through multiple measurement points along the pipe length
Solution Approach 2:
The patent transitions from one-dimensional acoustic reflection measurement to multi-dimensional electromagnetic measurement by placing multiple measurement points at different axial positions along the pipe. This enables simultaneous measurement at multiple depths and locations, overcoming the single-depth limitation of acoustic methods
2Adaptability or versatility
If electromagnetic inspection methods are used to sense beyond the first pipe, then measurements from outer pipes can be obtained, but azimuthal sensitivity limits the effectiveness
Solution Approach 1:
The patent divides the electromagnetic sensor into multiple independent measurement points positioned at different axial locations along the pipe. Each measurement point can independently measure electromagnetic properties at different depths, allowing selective measurement of inner or outer pipes by choosing appropriate measurement points, thereby eliminating azimuthal sensitivity issues
Solution Approach 2:
The patent assigns different measurement functions to different axial positions of the sensor. By strategically placing measurement points at specific locations, the system optimizes local measurement quality for target pipes at different depths, with each position tuned to provide optimal measurement for its specific depth range
3Adaptability or versatility
If multiple coil antennas are used to achieve different depths of investigation, then variable depth measurement is possible, but device complexity increases
Solution Approach 1:
The patent makes a single coil antenna perform multiple measurement functions by placing multiple measurement points along its length. The same physical antenna structure serves multiple measurement purposes at different axial positions, eliminating the need for multiple separate coil antennas while achieving variable depth investigation capability
Solution Approach 2:
The patent combines multiple measurement functions into a single integrated sensor assembly. Instead of using separate coil antennas for different depths, the system merges all measurement points into one unified sensor that can simultaneously or sequentially perform measurements at multiple depths through its distributed measurement points
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 provides accurate and selective depth investigation, allowing for the detection of pipe characteristics like thickness, magnetic permeability, and conductivity, effectively monitoring the integrity of all pipes, including those with multiple concentric layers, and minimizes cross-coupling while maintaining signal strength.
Implementation Method 1
transmitting an excitation signal between a first terminal and a second terminal of the coil antenna
Implementation Method 2
Multiple-depth eddy current pipe inspection with a single coil antenna
Implementation Method 3
measuring a first response signal between a third terminal and a fourth terminal of the coil antenna
Data Source
AI summary
A method includes introducing a pipe inspection tool into a first pipe positioned within a wellbore and further positioned within at least a second pipe. The pipe inspection tool includes an electromagnetic sensor having a coil antenna that includes a coil winding extending axially along at least a portion of the electromagnetic sensor. An excitation signal is transmitted between a first terminal and a second terminal of the coil antenna. A first response signal is measured between a third terminal and a fourth terminal of the coil antenna, wherein at least one of the third and fourth terminals is different from the first and second terminals. The first response signal is then processed to determine a characteristic of the first pipe.