X-Ray Cement And Casing Imaging In Multi-Casing Wellbores
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Solution Overview
Problem
Current methods for evaluating cement integrity and annular anomalies in wellbores are limited by the inability to accurately determine the radial and azimuthal position of anomalies within the annular region, leading to potential fluid migration paths and compromised zonal isolation, and lack the capability to simultaneously measure casing integrity without physical contact.
Innovation Solution
An x-ray based cement evaluation tool using a non-padded, concentrically-located borehole logging tool with actuated collimators and multi-pixel imaging detectors to analyze the density and integrity of annular materials, providing azimuthal and radial anomaly detection without direct contact with the casing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ultrasonic tools are used to evaluate cement bond, then cement bonding information can be obtained, but measurement accuracy deteriorates due to dependence on casing quality and annular material properties
Solution Approach 1:
The patent replaces ultrasonic measurement methods with x-ray imaging technology. Instead of using acoustic waves that depend on material properties and bonding quality, the invention uses x-ray attenuation measurements to directly image the annular region, eliminating dependence on casing-formation bond quality and annular material mechanical properties for measurement accuracy.
Solution Approach 2:
The invention changes the physical parameter used for measurement from acoustic impedance (ultrasonic) to x-ray attenuation coefficient. This parameter change allows direct imaging of density variations in the annular region without being affected by the mechanical bonding conditions that limit ultrasonic method reliability.
2Measurement precision
If mechanical calipers are used to measure casing integrity, then geometric measurements can be obtained, but the ability to detect radial and azimuthal anomaly positions is lost
Solution Approach 1:
The patent transitions from one-dimensional mechanical caliper measurements (inner diameter only) to two-dimensional x-ray imaging that captures radial and azimuthal positions of anomalies. The x-ray detector array records attenuation data from multiple angles, enabling reconstruction of anomaly locations in both radial distance and azimuthal angle, thus adding dimensional information that mechanical calipers cannot provide.
Solution Approach 2:
The invention replaces mechanical contact measurement (calipers) with non-contact x-ray imaging. This substitution enables detection of anomalies at various radial positions and azimuthal angles without physical contact, providing comprehensive spatial information about casing integrity while maintaining geometric measurement capabilities through image analysis.
3Measurement precision
If padded tools with source and detector assemblies in contact with casing are used, then direct casing imaging is possible, but adaptability to multiple-casing environments and non-contact operation is reduced
Solution Approach 1:
The patent designs an x-ray imaging system that can operate in multiple-casing environments without requiring physical contact with the casing. The centralized (non-padded) tool configuration with rotatable collimators and detector arrays provides universal applicability across single-casing, dual-casing, and multiple-casing wellbore environments, maintaining measurement capability through x-ray penetration and attenuation imaging of all casing strings simultaneously.
Solution Approach 2:
The invention uses x-ray photons as an intermediary to obtain casing images without direct contact. The x-ray source emits photons that penetrate through the annular materials and casing walls to reach detectors, providing imaging information through this electromagnetic intermediary rather than requiring mechanical contact between the tool and casing surfaces.
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 accurate detection of anomalies and measurement of casing integrity in multi-casing environments, ensuring zonal isolation and well integrity by providing detailed, non-contact imaging of the annular region.
Implementation Method 1
measuring an x-ray attenuation signal generated by the formation surrounding the borehole
Implementation Method 2
an x-ray based cement evaluation tool uses x-rays to illuminate a formation surrounding a borehole
Implementation Method 3
actuated collimators and multi-pixel imaging detectors to analyze the density and integrity of annular materials
Data Source
AI summary
An x-ray based cement evaluation tool for measurement of the density of material volumes within single, dual and multiple-casing wellbore environments is provided, wherein the tool uses x-rays to illuminate the formation surrounding a borehole, and a plurality of detectors are used to directly measure the density of the cement annuli and any variations in density within The tool uses x-rays to illuminate the casing surrounding a borehole and a plurality of multi-pixel imaging detectors directly measure the thickness of the casing The tool includes an internal length having a sonde section, wherein the sonde section further includes an x-ray source; a radiation shield for radiation measuring detectors; sonde-dependent electronics; and a plurality of tool logic electronics and PSUs. Other systems and subsystems appropriate for carrying out the foregoing are also disclosed, as are a plurality of example methods of use therefor.