Synthesizing Pure TE TM Responses in Electromagnetic Logging Antennas
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Solution Overview
Problem
Current electromagnetic logging tools face limitations in achieving pure transverse electric (TE) or transverse magnetic (TM) radiation modes, leading to mixed mode responses that affect the accuracy of formation measurements, particularly in terms of vertical resolution and standoff immunity.
Innovation Solution
A method and apparatus for synthesizing pure TE and TM responses from the non-ideal mixed response of existing antennas by combining direct and derivative responses from multiple antenna arrays, allowing for more accurate determination of formation properties such as permittivity and conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional single antenna arrays (broadside or endfire) are used, then the signal strength or depth of investigation is improved, but the measurement accuracy deteriorates due to mixed mode responses
Solution Approach 1:
The patent combines multiple antenna arrays (broadside and endfire arrays) into a single logging tool system. By merging the capabilities of different antenna configurations, the system can simultaneously achieve strong signal strength from broadside arrays and deep investigation capability from endfire arrays, while using signal processing to synthesize pure TE or TM mode responses for accurate measurements.
Solution Approach 2:
The patent divides the antenna system into separate broadside and endfire antenna arrays, each optimized for specific functions. The broadside arrays provide strong signals with good vertical resolution, while endfire arrays provide deep investigation capability. By segmenting the system and processing signals from each segment separately, the patent eliminates mixed mode responses and achieves pure TE or TM mode measurements.
2Power
If broadside antenna arrays are used, then signal strength is improved, but vertical resolution deteriorates due to mixed mode responses
Solution Approach 1:
The patent uses signal processing techniques that analyze the responses from multiple antenna arrays and apply computational methods to synthesize pure TE or TM mode responses. This feedback-based signal processing corrects the mixed mode responses and enhances vertical resolution while preserving the strong signal characteristics of broadside arrays.
3Length of stationary object
If endfire antenna arrays are used, then depth of investigation is improved, but signal strength deteriorates due to mixed mode responses
Solution Approach 1:
The patent merges endfire and broadside antenna arrays in a single system, allowing the endfire arrays to provide deep investigation capability while the broadside arrays provide strong signals. The combined system processes signals from both array types to achieve both deep penetration and strong signal strength simultaneously, eliminating the trade-off present in single-array systems.
4Device complexity
If mixed mode antenna responses are used, then device complexity is reduced, but measurement reliability deteriorates due to sensitivity to standoff layers
Solution Approach 1:
The patent segments the antenna system into multiple independent arrays (broadside and endfire) that can be processed separately. By treating each array type independently and combining their responses through signal processing, the system achieves pure TE or TM mode measurements that are immune to standoff layer effects, while maintaining manageable device complexity through modular architecture.
Solution Approach 2:
The patent employs signal processing feedback mechanisms that analyze the mixed mode responses from multiple antenna arrays and computationally synthesize pure TE or TM mode responses. This feedback-based approach eliminates sensitivity to standoff layers and improves measurement reliability while keeping the physical antenna structure relatively simple.
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 enhances the accuracy and reliability of electromagnetic logging by providing improved vertical resolution and reduced sensitivity to standoff layers, effectively overcoming the limitations of existing antenna designs.
Implementation Method 1
transmitting a first electromagnetic energy into a formation from a first antenna array; receiving the first electromagnetic energy at two or more first antenna array receivers
Data Source
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AI summary
A method and apparatus are disclosed for synthesizing desired antenna responses from a combination of measured antenna responses, as well as antenna arrays particularly suited to provide the measurements. Those arrays may include cross dipole and double cross dipole antennas.