Downhole Logging System Azimuthal Radial Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional downhole logging systems lack high azimuthal and radial sensitivity for detecting backscattered photons, leading to inefficiencies in material density measurement due to multiple scattering and other shortcomings.
Innovation Solution
A downhole logging system with a photon source, position-sensitive photon detectors, and a collimator design that includes concentric frustoconical radial collimators and blade-shaped azimuthal collimators to restrict backscatter angles, allowing for improved detection of material density anomalies with enhanced azimuthal and radial resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional downhole logging systems are used, then material density measurement is performed, but azimuthal and radial sensitivity is insufficient leading to measurement imprecision
Solution Approach 1:
The detector is divided into multiple detector pixels arranged in a two-dimensional array, with each pixel independently detecting photons from specific azimuthal and radial directions. This segmentation enables precise angular resolution and eliminates information loss from multiple scattering by tracking individual photon paths.
Solution Approach 2:
Each detector pixel is equipped with dedicated collimators (radial and azimuthal) that provide localized directional sensitivity. This local quality enhancement ensures that each pixel detects photons only from its specific angular sector, improving measurement precision while preventing contamination from scattered photons.
2Productivity
If conventional photon detection is used, then backscattered photons are detected, but operational time is excessive due to noise from unwanted photons
Solution Approach 1:
The collimator system extracts and removes unwanted photons from the detection path by allowing only photons within specific angular ranges to reach the detector pixels. This extraction of harmful photons reduces noise and enables faster, more accurate measurements.
Solution Approach 2:
The collimators serve as intermediary elements between the photon source and detector, filtering photons based on their angular trajectories. This intermediary structure eliminates noise from unwanted photons while preserving signal photons, thereby reducing operational time.
3Measurement precision
If simple collimator geometry is used, then device complexity is low, but azimuthal and radial resolution is insufficient
Solution Approach 1:
The collimator system transitions from simple one-dimensional geometry to a two-dimensional configuration with both radial and azimuthal collimating members. This dimensional enhancement provides superior azimuthal and radial resolution by controlling photon trajectories in multiple angular directions simultaneously.
4Measurement precision
If conventional detector arrangement is used, then device complexity is low, but material density mapping accuracy is insufficient
Solution Approach 1:
The detector is segmented into multiple pixels arranged in a two-dimensional array, with each pixel independently contributing to the material density map. This segmentation enables accurate spatial mapping of density variations by maintaining precise angular and radial information for each detector element.
Solution Approach 2:
The detector arrangement transitions from a simple linear or single-point configuration to a two-dimensional pixel array. This dimensional enhancement provides comprehensive angular coverage and improves material density mapping accuracy by capturing photons from multiple discrete directions simultaneously.
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
The system achieves improved azimuthal and radial sensitivity, enabling more accurate material density mapping and anomaly detection, reducing operational time and noise from unwanted photons, and providing a 2-D density map of the target object.
Implementation Method 1
One type of downhole logging system makes use of a physical phenomenon known as Compton scattering. Generally, in Compton scattering, the number of backscattered photons from an object in front of a photon source is a function of photon energy and backscattering angle.
Implementation Method 2
The backscattering angle of the photons that the tool is sensitive to may be determined by the design of the detector collimator geometry.
Data Source
AI summary
Embodiments of the invention provide a downhole tool that includes a photon source, a photon detector having a plurality of detector pixels in a cylindrical row and column arrangement, and a radial collimator having at least two concentric frustoconical collimators circumferentially arranged about the photon detector and at least two azimuthal collimating members radially arranged with respect to the photon detector, wherein one of the azimuthal collimating members is on a first side of a detector pixel and a second azimuthal collimator is on a second side of a detector pixel opposite the first side.