Multi-Directional Sonic Waveform Analysis for Cement Bond Logging
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Solution Overview
Problem
Current methods for evaluating cement bond quality in wellbores are subjective, prone to error, and provide incomplete information, especially in multi-string environments, where concentric casing strings interfere with sonic or ultrasonic waves, making it challenging to generate accurate and comprehensive cement bond logs.
Innovation Solution
A multi-directional cement bond logging tool that transmits and receives sonic or ultrasonic waves in a radial fashion, processing waveforms to determine amplitude values indicating cement bonding, and creating composite color-, grayscale-, or intensity-coded images to visualize the cement bonding status across the entire wellbore, including in multi-string environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional sonic or ultrasonic logging methods are used, then cement bond evaluation can be performed, but the results are subjective and prone to substantial error and variation among different interpreters
Solution Approach 1:
The patent replaces subjective human interpretation with automated computer-based processing of sonic and ultrasonic waveforms. The system uses algorithms to automatically analyze waveforms, identify cement bond characteristics, and generate quantitative evaluations, eliminating interpreter variability and subjectivity while maintaining measurement precision.
Solution Approach 2:
The system incorporates automated feedback mechanisms where the computer processing system continuously refines waveform analysis based on established criteria and patterns. The system provides objective feedback on cement bond quality through standardized metrics and visual displays, enabling consistent interpretation across different logging operations and eliminating human subjectivity.
2Loss of information
If conventional logging tools are used, then limited portions of the cement sheath can be evaluated, but the resulting logs provide an incomplete and often misleading picture of the true cement bonding status
Solution Approach 1:
The patent divides the cement sheath evaluation into multiple directional components using arrays of sonic and ultrasonic receivers positioned at different angles around the wellbore. By segmenting the measurement approach into multiple directional views and combining them through computer processing, the system achieves complete 360-degree coverage of the cement sheath, eliminating the limited coverage of conventional single-direction tools.
Solution Approach 2:
The system transitions from conventional single-direction waveform analysis to multi-dimensional evaluation by incorporating receivers positioned at multiple angles and depths. This dimensional expansion allows comprehensive mapping of the entire cement sheath circumference and length, providing complete information about cement bonding status throughout the wellbore.
3Measurement precision
If sonic or ultrasonic waves are transmitted in conventional single-direction methods, then processing is simpler, but accurate cement bond logs cannot be produced in wellbores with multiple concentric casing strings due to wave interference
Solution Approach 1:
The patent segments the wave transmission and reception into multiple directional beams using arrays of transducers and receivers positioned at different angles. This segmentation allows the system to isolate and analyze waves reflected from specific regions of the cement sheath, even in multi-string environments, by processing each directional component separately and combining them through computer algorithms.
Solution Approach 2:
The system uses computer processing algorithms as intermediaries to separate and identify wave reflections from different casing strings and cement sheath regions. The processing system acts as a mediator that filters out interference from concentric casings and isolates the relevant cement bond signals, enabling accurate evaluation even in complex multi-string configurations.
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 generates accurate, consistently reproducible cement bond logs that provide a 360-degree representation of cement bonding throughout the wellbore, facilitating the identification of poor bonds and offering a more complete picture of the cement sheath quality, even in complex environments.
Implementation Method 1
sonic or ultrasonic waves are transmitted from the logging tool in the wellbore
Implementation Method 2
sonic or ultrasonic waves are transmitted from the logging tool in the wellbore
Implementation Method 3
reflected waves from the casing, cement, and formation are received
Data Source
AI summary
A method for generating a cement bond log, in some embodiments, comprises transmitting sonic or ultra-sonic waves in multiple directions from a logging tool disposed in a wellbore, receiving reflected waves at the logging tool and recording waveforms based on the received waves, processing the waveforms to determine numerical values that indicate a degree of bonding associated with multiple portions of a cement sheath disposed in the wellbore, aggregating the numerical values, and generating a composite image based on the aggregated numerical values.