Rotatable Transmitter Cement Evaluation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing well logging technologies face challenges in accurately evaluating cement bonding conditions in wellbores due to the difficulty in physically rotating dipole transmitters and receivers to specific azimuthal directions, which affects the measurement sensitivity and accuracy of acoustic signals at the cement-casing interface.
Innovation Solution
The implementation of a rotatable unipole transmitter and an array of azimuthal receivers that computationally rotate the dipole response to align with any desired azimuthal direction, allowing for equivalent signal transmission and reception without physical rotation of the tool, thereby improving measurement sensitivity and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a dipole transmitter and receiver are used to obtain dipole response at specific azimuthal directions, then measurement precision of cement bonding is improved, but device complexity and ease of operation deteriorate due to the need for physical rotation
Solution Approach 1:
The dipole transmitter is segmented into two orthogonal unipole transmitters (X-dipole and Y-dipole) that can be independently activated. By measuring responses from both unipole transmitters and computationally combining them, the system achieves dipole response measurements at any azimuthal direction without requiring physical rotation of the tool, thus improving measurement precision while avoiding device complexity
Solution Approach 2:
Instead of physically rotating the dipole transmitter to different azimuthal directions, the invention creates computational copies of dipole responses by measuring unipole responses at fixed tool orientation and mathematically synthesizing the equivalent dipole responses for any desired azimuthal direction, thereby eliminating the need for mechanical rotation mechanisms
2Measurement precision
If a dipole transmitter and receiver are physically rotated to specific azimuthal directions, then measurement precision is improved, but ease of operation deteriorates
Solution Approach 1:
The invention replaces the mechanical rotation system with a computational approach. Instead of physically rotating the dipole transmitter to align with specific azimuthal directions, the system uses two fixed orthogonal unipole transmitters and computationally synthesizes dipole responses for any desired direction, significantly improving ease of operation while maintaining measurement precision
Solution Approach 2:
The invention introduces dynamic computational processing to achieve what would otherwise require static mechanical repositioning. By dynamically calculating and combining responses from orthogonal unipole transmitters, the system can obtain dipole responses at any azimuthal direction without mechanical movement, making the operation simpler and more flexible
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 measurement sensitivity and accuracy of cement bonding evaluations by enabling precise acoustic signal analysis at the cement-casing interface, overcoming the limitations of physical rotation and improving the reliability of cement bonding assessments.
Implementation Method 1
emitting the acoustic transmission outward toward the subsurface formation
Implementation Method 2
detecting, by the receiver array and without rotation of the downhole tool beyond a rotation threshold, an acoustic response
Data Source
AI summary
In some embodiments, a method includes conveying a downhole tool in a tubing, positioned in a casing which forms an annulus between the casing and a wellbore formed in a subsurface formation, the downhole tool having a rotatable transmitter and a receiver array. The method includes performing the following until an acoustic transmission has been emitted for each of a number of defined azimuthal positions: rotating the rotatable transmitter to one of the number of defined azimuthal positions, emitting the acoustic transmission, and detecting, by the receiver array and without rotation of the downhole tool beyond a rotation threshold, an acoustic response of a number of acoustic responses that is derived from the acoustic transmission. The method further includes computationally rotating, by a processor and after detecting, data of each of the number of acoustic responses in a pre-determined direction to generate a computationally rotated multipole response.