Acoustic Logging Receiver Array for Mud-Resistant Cement Evaluation
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Solution Overview
Problem
Current cement evaluation methods in well installations, such as Cement Bond Log (CBL) and Pulse Echo, face challenges in accurately determining cement bond quality due to borehole mud interference, leading to reduced resolution and increased costs and inefficiencies, especially in deep downhole measurements.
Innovation Solution
Implementing a receiver array with different radial depths for the Pitch Catch method, combined with Pulse Echo, to simultaneously measure both annulus and borehole mud properties, reducing the need for additional tools and improving measurement accuracy by processing waveforms from both in-line and shifted receiver positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If an aligned array of receivers is used for Pitch Catch method, then the influence from borehole mud is reduced, but the accuracy decreases when borehole mud is attenuative
Solution Approach 1:
The receiver array is divided into multiple groups with different radial positions (some aligned with the transmitter, some offset). Each group measures different aspects of the acoustic wave, allowing separate analysis of cement properties and mud properties to eliminate mutual interference.
Solution Approach 2:
Different receivers are positioned at different radial locations to capture localized wave characteristics. Receivers at specific positions are optimized for measuring specific parameters (cement bond vs. mud attenuation), allowing each measurement to be optimized for its target while minimizing interference from other media.
2Measurement precision
If a mud cell is implemented to measure borehole mud properties, then mud measurement accuracy is improved, but logging time and cost increase due to multiple logging runs required
Solution Approach 1:
The cement evaluation tool and mud measurement capabilities are merged into a single integrated tool. The same receiver array used for Pitch Catch cement evaluation also captures borehole mud attenuation and velocity data, eliminating the need for separate mud cell logging runs and reducing total logging time.
Solution Approach 2:
The acoustic logging tool is designed with multi-functionality, capable of performing both cement bond evaluation and borehole mud characterization using the same hardware platform. This universal tool replaces the need for specialized single-function tools, improving productivity while maintaining measurement accuracy.
3Productivity
If a single tool setup is used for both cement evaluation and mud measurement, then logging efficiency is improved, but measurement accuracy may be compromised
Solution Approach 1:
The receiver array is segmented into multiple functional groups positioned at different radial locations. This segmentation allows simultaneous measurement of multiple parameters (cement attenuation, cement velocity, mud attenuation, mud velocity) with dedicated measurement pathways for each parameter, maintaining high accuracy while using a single integrated tool.
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 of cement and borehole mud measurements, lowers hardware costs, and increases logging efficiency by utilizing a single tool setup, providing reliable cement evaluation and borehole mud information.
Implementation Method 1
transmit one or more acoustic waves into the borehole with one or more transmitters
Implementation Method 2
receive one or more waveforms from the borehole or surrounding casing with an array of receivers
Implementation Method 3
Pitch Catch gives a more reliable solution in such conditions. But to measure flexural mode attenuation, Pitch Catch utilizes an aligned array of receivers for reducing the influence from borehole mud
Implementation Method 4
Another way is to apply ultra sonic tools which use methods such as Pulse Echo. Pulse Echo is sensitive to debonding cement layer
Data Source
AI summary
A method or system comprising: disposing an acoustic logging tool into a borehole, wherein the acoustic logging tool is configured to: transmit one or more acoustic waves into the borehole with one or more transmitters; and receive one or more waveforms from the borehole or surrounding casing with an array of receivers. In addition, the method ay also comprise an information handling system configured to predict one or more waveforms at a shifted position with two waveforms recorded at an in-line position to form one or more predicted waveforms at a shifted position; and compare the one or more predicted waveforms at a shifted position with at least one or more waveforms recorded at a shifted position to yield a borehole mud attenuation and/or velocity.