Nuclear Logging Tool Dual-Function Detectors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing nuclear logging tools require multiple radiation sources and detectors, leading to high costs, low reliability, and large size, limiting their effectiveness in measuring formation parameters in oil and gas exploration.
Innovation Solution
The development of nuclear logging tools with dual-function detectors capable of detecting both neutrons and gamma rays, combined with a reduced number of neutron sources, enables more accurate and precise formation parameter measurements by using scintillator materials like Cs2LiYCl6 and Cs2LiLaBr6, and innovative detector configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple radiation sources and detectors are used to measure formation parameters, then measurement capability is improved, but device complexity and size increase
Solution Approach 1:
The patent employs dual-function detectors that can detect both neutrons and gamma rays simultaneously. This allows a single detector to perform multiple measurement functions, eliminating the need for separate neutron detectors and gamma ray detectors, thereby reducing device complexity while maintaining comprehensive measurement capability
Solution Approach 2:
The patent combines multiple detection functions into unified detector assemblies. The dual-function detectors integrate neutron detection and gamma ray detection capabilities, merging what were previously separate detection systems into a single integrated unit, reducing overall device complexity and size
2Adaptability or versatility
If multiple radiation sources and detectors are used to measure formation parameters, then measurement capability is improved, but tool size increases
Solution Approach 1:
Dual-function detectors perform both neutron and gamma ray detection in a single device, eliminating the need for separate detector units and reducing the overall tool volume required to accommodate all necessary detection components
Solution Approach 2:
By merging neutron detection and gamma ray detection into unified detector assemblies, the patent reduces the total space required for detection components, thereby decreasing overall tool size while maintaining full measurement capability
3Adaptability or versatility
If multiple radiation sources and detectors are used to measure formation parameters, then measurement capability is improved, but cost increases
Solution Approach 1:
Dual-function detectors eliminate the need to purchase and install separate neutron detectors and gamma ray detectors, reducing the total quantity of expensive detection components required while maintaining comprehensive measurement capability
Solution Approach 2:
By combining multiple detection functions into fewer integrated detector units, the patent reduces the total number of components that need to be manufactured, sourced, and installed, thereby reducing overall tool cost while preserving full measurement functionality
4Adaptability or versatility
If multiple radiation sources and detectors are used to measure formation parameters, then measurement capability is improved, but reliability decreases
Solution Approach 1:
Dual-function detectors reduce the total number of radiation sources and detectors required in the tool, and each radiation source needs fewer corresponding detectors, thereby reducing the number of potential failure points and improving overall system reliability
Solution Approach 2:
By integrating multiple detection functions into unified detector assemblies, the patent reduces the total component count and interconnections required, thereby reducing potential failure points and improving system reliability while maintaining comprehensive measurement capability
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 reduces the complexity and size of logging tools while enhancing the accuracy of formation parameter measurements, such as density, porosity, and saturation, improving the reliability and efficiency of nuclear logging in both wireline and LWD environments.
Implementation Method 1
a variety of scintillation detectors, e.g., NaI, CsI, BGO, GSO, LaBr3, YAP scintillators and photomultiplier tubes (PMTs), are employed to detect gamma rays. These scintillators change the deposited energy of gamma rays into scintillation lights.
Implementation Method 2
The PMT converts the scintillation lights into electrons and amplifies them to form electronic signals.
Implementation Method 3
neutron porosity logging tools investigate the formation porosity by measuring the ratio of neutron count rates from a near detector to that of a far detector after fast neutrons from an isotope neutron source have been slowed down by tool surroundings and scattered back to the detectors
Implementation Method 4
Formation density is obtained by measuring back-scattered gamma rays from a gamma radiation source received at two detectors placed at different distances from the gamma ray source
Implementation Method 5
The energy spectrum of neutron-induced gamma rays from each element is unique. Therefore, by measuring the energy spectrum of gamma rays from inelastic scatting and/or from neutron capture reactions, one may identify elements
Implementation Method 6
The energy spectrum of neutron-induced gamma rays from each element is unique. Therefore, by measuring the energy spectrum of gamma rays from inelastic scatting and/or from neutron capture reactions
Implementation Method 7
by measuring thermal neutron time-decay curve or capture gamma ray time-decay curve after a neutron pulse or several neutron pulses, one may obtain the macro thermal neutron absorption cross section
Data Source
AI summary
A nuclear logging tool has a housing, one or more neutron sources, one or more shields, and two or more detectors disposed about the housing. Each of the one or more neutron sources is configured to generate neutrons in pulses or continuously and each of the two or more detectors is operable to detect neutrons and gamma rays. The two or more detectors include a first detector disposed at a first distance from a first neutron source and a second detector disposed at a second distance from the first neutron source. The first distance is shorter than the second distance. The first distance and the second distance is measured in the longitudinal direction of the housing. Each shield is operable to absorb neutrons and gamma rays and is disposed inside the housing between one of the one or more neutron source and one of the one or more detectors.