Downhole Acoustic Logging Tool Attenuator Design
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Solution Overview
Problem
Conventional sonic logging tools face challenges in obtaining high-quality acoustic measurements in difficult logging conditions such as slow formations and large boreholes, requiring increased energy and struggling with quadrupole Airy phase at lower frequencies.
Innovation Solution
The acoustic measurement tools employ multiple transmitters and receivers with optimized configurations, including attenuators and stabilizers, to produce the necessary energy and frequencies for quality sonic measurements, such as monopole, Stoneley, and quadrupole modes, using piezoelectric materials like lead titanate and lead zirconate titanate, and featuring adjustable transmitter-to-receiver spacings and extended blocks for improved signal propagation and damping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sonic logging tools are used in slow formations and large boreholes, then measurement capability is maintained, but energy requirements increase and measurement quality deteriorates
Solution Approach 1:
The tool divides the acoustic measurement function into multiple specialized transmitters (monopole and quadrupole sources) and multiple receiver arrays, each optimized for specific measurement modes. This segmentation allows efficient energy utilization for each measurement type rather than requiring excessive energy for all measurements simultaneously.
Solution Approach 2:
The patent implements local quality optimization by positioning transmitters and receivers at specific locations and orientations within the tool assembly. The monopole and quadrupole sources are strategically placed to maximize acoustic energy coupling with the formation in slow formations and large boreholes, improving measurement quality without proportionally increasing energy consumption.
2Measurement precision
If multiple transmitters and receivers are added to improve measurement quality, then acoustic measurement capability improves, but device complexity increases
Solution Approach 1:
The tool assembly is designed with multi-functional transmitters and receivers that can operate in multiple modes. The same physical components can generate and detect different acoustic wave types (compressional, shear, Stoneley waves), reducing the need for separate dedicated components for each measurement type and thereby managing complexity.
Solution Approach 2:
The patent utilizes azimuthal arrangement of receivers around the tool body, adding a spatial dimension to the measurement capability. This azimuthal configuration allows the system to capture directional information and differentiate between various wave modes without requiring additional axial length or radial components, managing complexity through spatial optimization.
3Measurement precision
If transmitter-to-receiver spacing is increased to reduce interference, then signal quality improves, but measurement coverage decreases
Solution Approach 1:
The receiver system is segmented into multiple arrays positioned at different axial locations and azimuthal angles. This segmentation allows the tool to process signals from multiple spacing configurations simultaneously, maintaining signal quality through optimal spacing while preserving measurement coverage through the distributed array geometry.
Solution Approach 2:
By arranging receivers in multiple azimuthal directions and axial positions, the system transforms a one-dimensional spacing problem into a multi-dimensional configuration. This allows optimal transmitter-to-receiver spacing to be achieved in the radial direction while maintaining comprehensive formation coverage through the extended axial and azimuthal receiver distribution.
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
These tools enable accurate and high-quality sonic measurements in challenging conditions by optimizing transmitter configurations, reducing energy requirements, and minimizing unwanted signal interference, thereby enhancing measurement precision and accuracy.
Implementation Method 1
using piezoelectric materials like lead titanate and lead zirconate titanate
Implementation Method 2
produce the necessary energy and frequencies for quality sonic measurements, such as monopole, Stoneley, and quadrupole modes
Data Source
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AI summary
Apparatus for acoustic measurement in a downhole environment to enable high quality measurements to be obtained in difficult logging conditions are disclosed. An example apparatus includes a downhole tool having a body with a plurality of transmitters located on the body. A receiver is located on the body a distance from the transmitters and an attenuator section is integrally formed on the body between at least one transmitter and the receiver.