EM Logging Tool Shielded Wire Tube for Low-Frequency Noise Mitigation
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Solution Overview
Problem
Electromagnetic noise interference between electrical conductors and receiving antennas in EM logging tools, particularly at low frequencies, reduces the signal-to-noise ratio and measurement range, complicating deep reading EM measurements.
Innovation Solution
Deploying an electrically conductive tube coaxially with the tool body to house the electrical conductor, reducing electromagnetic coupling by providing a low resistance path and shielding, thereby improving the signal-to-noise ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If electrical conductors are routed through the tool collar for power and data transmission, then the tool can perform logging operations, but electromagnetic noise couples between the conductors and receiving antennas, reducing signal-to-noise ratio
Solution Approach 1:
A non-conductive tube is introduced as an intermediary barrier between the electrical conductor and the receiving antenna. This tube physically separates the two components, blocking the electromagnetic coupling path while still allowing the conductor to transmit power and data through the tool collar structure.
Solution Approach 2:
The electrical conductor is extracted from direct proximity to the receiving antenna by routing it through a separate non-conductive tube. This separation removes the harmful electromagnetic interaction while preserving the conductor's functional role in power and data transmission.
2Length of stationary object
If low frequency measurements are used for deep reading EM measurements, then measurement depth is increased, but sensitivity to electromagnetic noise increases, reducing measurement range
Solution Approach 1:
The non-conductive tube serves as a mediator that specifically addresses the noise sensitivity issue in low frequency measurements by providing electromagnetic isolation between the conductor and antenna, enabling deeper measurements without excessive noise interference.
Solution Approach 2:
The non-conductive tube converts the potentially harmful electromagnetic coupling into a beneficial isolated transmission path, allowing low frequency deep reading measurements to proceed with reduced noise sensitivity while maintaining measurement depth capability.
3Device complexity
If electrical conductor is placed close to receiving antenna for compact tool design, then device complexity is reduced, but electromagnetic coupling between conductor and antenna increases
Solution Approach 1:
The electrical conductor is nested within the non-conductive tube, which is itself positioned within the tool collar structure. This nested arrangement maintains a compact overall tool design while introducing the necessary electromagnetic isolation between the conductor and receiving antenna.
Solution Approach 2:
The non-conductive tube acts as an intermediary element that preserves the compact nested structure of the tool while simultaneously reducing electromagnetic coupling between the conductor and antenna, achieving both simplicity and noise reduction.
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
Enhances measurement accuracy and precision of deep reading electromagnetic measurements by minimizing electromagnetic coupling, especially at low frequencies.
Implementation Method 1
an electrically conductive tube deployed in the tool body and within an inner diameter of the at least one receiving antenna such that a longitudinal axis of the tube is coincident with a longitudinal axis of the tool body
Implementation Method 2
electromagnetic coupling between the receiver antenna and alternating currents in power and/or communication wires in the EM tool
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
An electromagnetic logging tool includes at least one electromagnetic receiving antenna deployed on a logging while drilling tool body. The receiving antenna is configured to receive a complex voltage signal and thereby make electromagnetic logging measurements. An electrically conductive tube is deployed in the tool body and within an inner diameter of the receiving antenna such that a longitudinal axis of the tube is coincident with a longitudinal axis of the tool body. An insulated electrical conductor is deployed in the tube and is configured to transmit electronic data and/or electrical power from one axial end of the tool body to an opposing axial end of the tool body.