Digital Spectrometer for Downhole Ionizing Radiation Measurement

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Solution Overview

Problem

Current borehole logging methods face challenges in accurately estimating parameters of interest in earth formations due to issues like pile-up phenomena and temperature-related performance degradation, especially in high-flux environments where gamma interference distorts recorded spectra.

Innovation Solution

A high-flux configurable digital spectrometer is introduced, featuring multiple radiation detectors and an ionizing radiation spectrometer with ADCs and processors to convert analog signals into digital pulses, allowing for reliable radiation count information and energy level resolution, while mitigating pile-up effects through digital processing and adaptive filter configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional analog spectrometers are used in high-flux environments, then device complexity is reduced, but measurement precision deteriorates due to pile-up phenomena and temperature-related performance degradation

Engineering Contradiction:
Improveradiation count information accuracyVSAvoidspectrometer structure
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional analog signal processing circuits with digital signal processing systems. ADCs convert analog detector signals to digital domain, where filtering, pile-up rejection, and spectral analysis are performed using digital algorithms rather than analog electronics, improving precision while managing complexity through software-based solutions

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements adaptive filtering where filter parameters (bandwidth, cutoff frequencies, time constants) are dynamically adjusted based on detected radiation flux levels and temperature conditions. This allows the system to maintain optimal measurement precision across varying environmental conditions without requiring complex hardware reconfiguration

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If digital signal processing is implemented to resolve pile-up effects, then measurement precision improves, but device complexity and processing time increase

Engineering Contradiction:
Improveenergy spectrum resolutionVSAvoidsignal processing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary digital filtering and pulse shape analysis immediately after ADC conversion, before full spectral processing. By pre-processing signals to identify and flag potential pile-up events early in the detection sequence, the system reduces computational burden for subsequent analysis and minimizes overall processing time

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent implements dynamic processing modes where the level of digital signal processing applied adapts based on radiation flux conditions. In high-flux conditions with significant pile-up, full digital spectral processing is applied. In low-flux conditions, simplified processing paths are used, reducing processing time when high precision is less critical

Inventive Principle:
Principle #15Dynamics

3Reliability

If multiple radiation detectors are used to improve measurement reliability, then measurement precision improves, but device complexity and quantity of components increase

Engineering Contradiction:
Improveradiation detection reliabilityVSAvoiddetector array configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines signals from multiple radiation detectors through digital summation and correlation analysis. By merging detector outputs in the digital domain and applying coincidence detection algorithms, the system improves measurement reliability and signal-to-noise ratio while avoiding the need for complex analog signal combining circuits

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent designs the detector array with universal signal processing channels that can handle inputs from any detector configuration. The same digital processing pipeline processes signals whether from one detector or multiple detectors, allowing the system to scale reliability by adding detectors without proportionally increasing processing complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Measurement precision

If adaptive filter configurations are used to mitigate pile-up effects, then measurement precision improves, but device complexity and computational requirements increase

Engineering Contradiction:
Improveradiation event resolutionVSAvoidfilter configuration system
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback mechanisms where the digital signal processing system continuously monitors detected radiation events for signs of pile-up (such as abnormal pulse height distributions or timing patterns). When pile-up conditions are detected, the system automatically adjusts filter parameters and processing algorithms to mitigate the effects, creating a self-regulating system that maintains precision without manual intervention

Inventive Principle:
Principle #23Feedback

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 solution enhances the reliability and flexibility of borehole logging by improving the accuracy of radiation count information and energy spectrum analysis, even in high-temperature downhole environments, enabling better estimation of radionuclide concentrations and other formation parameters.

Implementation Method 1

at least one radiation detector configured to generate an analog electrical signal responsive to a plurality of radiation events, wherein each radiation event of the plurality of radiation events comprises an absorption of incident ionizing radiation at a corresponding energy level

Methodology Applied
Scientific EffectPhotoelectric effect: Photoelectric Effect

Implementation Method 2

an ionizing radiation spectrometer configured to convert each analog electrical signal from the at least one radiation detector into a plurality of digital signal pulses corresponding to the radiation events

Methodology Applied
Scientific EffectAnalog-to-digital conversion:

Data Source

PatentEP3452696B1Digital spectrometer for measuring ionizing radiation downhole
Publication Date: 2021.06.02 BAKER HUGHES CO
  • EP3452696B1 patent drawingFigure 1A
  • EP3452696B1 patent drawingFigure 1B~1C
  • EP3452696B1 patent drawingFigure 2~3

AI summary

Systems, methods, and devices for evaluating an earth formation intersected by a borehole. Apparatus may include at least one radiation detector configured to generate an analog electrical signal responsive to a plurality of radiation events, comprising absorption of incident ionizing radiation at a corresponding energy level, and an ionizing radiation spectrometer configured to convert each analog electrical signal from the at least one radiation detector into a plurality of digital signal pulses corresponding to the radiation events and resolve the plurality of digital signal pulses into radiation count information representative of the radiation events. Spectrometers include an input channel for each detector of the at least one radiation detector comprising an analog-to-digital converter (ADC) and configured to convert the analog electrical signal for each detector into the plurality of digital signal pulses; and at least one processor configured to generate the radiation count information.