Shear and Flexural Wave Attenuation for Cement State Differentiation
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Solution Overview
Problem
Current cement evaluation technologies in the oil and gas industry can only differentiate between a limited number of conditions behind the casing, such as solid/cement, gas, liquid, and micro-annulus, failing to accurately determine the specific state of cement or other materials, which is crucial for ensuring proper hydraulic isolation and casing protection.
Innovation Solution
The integration of shear and flexural ultrasonic acoustic waves to differentiate various conditions by measuring shear and flexural attenuation rates, allowing for the identification of up to nine distinct states, including different types of solids and fluids, through a logging tool that stimulates these waves and compares the measurements against specific division boundaries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional cement evaluation technologies are used, then the evaluation process is simple, but the differentiation capability between cement states is limited
Solution Approach 1:
The patent combines shear wave and flexural wave measurements into a unified evaluation methodology. By integrating two different wave types and their respective attenuation measurements, the system achieves enhanced differentiation capability (identifying up to nine distinct conditions) while managing the complexity through a systematic approach that correlates both measurements together.
Solution Approach 2:
The patent transitions from single-parameter evaluation to multi-dimensional evaluation by incorporating both shear attenuation rate and flexural attenuation rate as independent measurement dimensions. This two-dimensional measurement space allows for more sophisticated differentiation of cement conditions, where each condition occupies a unique region in the parameter space.
2Measurement precision
If multiple wave types are integrated for measurement, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The logging tool is designed with multi-functional capability to generate and measure both shear waves and flexural waves. This universal tool can perform multiple measurement functions (shear attenuation measurement, flexural attenuation measurement) using integrated transducers that can operate in different modes, thereby improving measurement precision without requiring separate dedicated tools for each wave type.
3Reliability
If detailed differentiation of cement conditions is achieved, then the reliability of hydraulic isolation assessment improves, but the difficulty of detecting and measuring increases
Solution Approach 1:
The methodology incorporates feedback through the systematic comparison of measured shear and flexural attenuation rates against established condition regions. The measurement process provides feedback about the cement condition by mapping the attenuation pair onto a diagnostic space where different regions correspond to different cement states, enabling reliable assessment through iterative measurement and comparison.
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 a more accurate and detailed differentiation of conditions, enabling better monitoring of cement quality and state, improving hydraulic isolation and casing protection, and extending the life of oil and gas wells by identifying problematic intervals for remedial cementing operations.
Implementation Method 1
stimulating shear waves and flexural waves in the casing
Implementation Method 2
stimulating shear waves and flexural waves in the casing
Implementation Method 3
shear and flexural ultrasonic acoustic waves
Implementation Method 4
obtaining a shear attenuation rate measurement and a flexural attenuation rate measurement within the casing responsive to the media on the exterior of the casing
Data Source
AI summary
Methods for determining properties of a media on an exterior of a casing in downhole systems are described. The methods include conveying a logging tool through a casing in a downhole formation, stimulating shear waves and flexural waves in the casing, obtaining a shear attenuation rate measurement and a flexural attenuation rate measurement within the casing responsive to the media on the exterior of the casing, comparing the measured shear attenuation rate and the measured flexural attenuation rate against a plurality of respective division boundary values, and determining one or more properties of the media on the exterior of the casing based on the comparison of the measured shear attenuation rate and the measured flexural attenuation rate against the plurality of respective interfaces.