Multi-mode Acoustic Tool for Downhole Formation Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing downhole acoustic tools are typically designed to optimize a single mode of excitation, limiting their ability to effectively image and analyze formation properties in multiple modes, especially in complex formations like transversely isotropic formations.
Innovation Solution
A downhole acoustic tool with a transmitter section and a receiver section, each comprising multiple transmitters and receivers aligned orthogonally, capable of exciting and detecting multi-mode waveforms, including monopole, dipole, quadrupole, and hexapole modes, to interpret formation characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a tool is designed to optimize a single mode of excitation, then the transmission and receipt of that specific mode is optimized, but the tool cannot effectively image and analyze formation properties in multiple modes
Solution Approach 1:
The transmitter section is designed with multiple transmitters (at least four) that can be selectively activated to generate different excitation modes (monopole, dipole, quadrupole, hexapole). The receiver section similarly includes multiple receivers that can detect all these modes. This universal design allows a single tool to perform multiple measurement functions that would otherwise require separate specialized tools.
Solution Approach 2:
The tool is divided into distinct transmitter and receiver sections, each with multiple independently controllable elements. The transmitters are spaced at different positions along the tool body and can be activated in specific patterns to generate different modes. This segmentation allows flexible configuration to achieve various excitation modes while maintaining a manageable structural complexity.
2Measurement precision
If multiple transmitters and receivers are added to enable multi-mode waveforms, then formation property analysis capability is improved, but the device complexity and manufacturing difficulty increase
Solution Approach 1:
The transmitters and receivers are positioned at specific locations along the tool body with precise spacing relationships. The transmitters are located at different positions to enable generation of various modes, and the receivers are similarly positioned to detect these modes. This localized positioning strategy achieves the required measurement precision while maintaining a systematic manufacturing approach.
Solution Approach 2:
The transmitter and receiver sections are designed with asymmetric positioning and spacing arrangements that are optimized for generating and detecting multiple excitation modes. The specific spacing and positioning of transmitters and receivers creates the necessary asymmetric field patterns for dipole, quadrupole, and hexapole modes while maintaining manufacturing feasibility.
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
Enables robust data acquisition and analysis of formation properties, including anisotropy and shear slowness, by efficiently exciting and receiving multiple modes of acoustic signals, improving the accuracy and reliability of oil field logging tools.
Implementation Method 1
a transmitter section located along the acoustic tool body, the transmitter section including four or more transmitters to be driven so as to excite multi-mode waveforms
Implementation Method 2
a receiver section located along the acoustic tool body, the receiver section including a receiver sub-section comprising four or more receivers axially aligned with the four or more transmitters
Data Source
AI summary
A downhole acoustic tool and method of use are provided. The acoustic tool includes an acoustic tool body. In addition, a transmitter section located along the acoustic tool body, including four or more transmitters to be driven so as to excite multi-mode waveforms. The acoustic tool further includes an array receiver section located along the acoustic tool body, containing a receiver sub-section comprising four or more receivers axially aligned with the four or more transmitters and spaced axially apart from the transmitter section. The acoustic tool also includes a processor configured to drive the transmitter section to excite multi-mode waveforms and to extract the multi-mode waveforms detected by the receiver section for interpretation of formation properties. A method for measuring a formation using the described acoustic tool is also provided.