CeBr3 Scintillator Logging for Dual Gamma-Ray Spectroscopy
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Solution Overview
Problem
Conventional well logging tools require separate passes or runs to measure neutron-induced gamma rays and natural gamma rays due to limitations of gamma-ray detectors, making dual applications infeasible and increasing operational complexity and time.
Innovation Solution
Employing cerium bromide (CeBr3) as a scintillator in a pulsed neutron logging tool to simultaneously detect both neutron-induced and natural gamma rays, enabling dual-purpose spectroscopy in a single run.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional gamma-ray detectors are used, then measurement capability is limited to single-purpose applications, but device complexity increases when multiple separate tools are required
Solution Approach 1:
The patent applies universality by designing a single logging tool that can perform both neutron-induced gamma-ray spectroscopy and natural gamma-ray spectroscopy. The tool includes a pulsed neutron generator and a gamma-ray detector that can operate in two distinct modes: during neutron pulsing to detect neutron-induced gamma rays, and during non-pulsing periods to detect natural gamma rays. This multi-functional design eliminates the need for separate tools for each measurement type, directly resolving the contradiction by achieving dual-purpose capability without proportionally increasing device complexity.
Solution Approach 2:
The patent utilizes periodic action through the pulsed neutron generator that operates in alternating on/off cycles. During the pulsed intervals, the detector measures neutron-induced gamma rays; during the non-pulsed intervals, it measures natural gamma rays. This periodic operation allows a single detector to sequentially perform both measurement functions, enabling dual-purpose capability while maintaining relatively simple detector architecture by time-multiplexing the measurement modes.
2Measurement precision
If separate logging runs are performed for neutron-induced and natural gamma-ray measurements, then measurement precision is maintained, but loss of time increases due to multiple passes
Solution Approach 1:
The patent implements continuity of useful action by performing both neutron-induced and natural gamma-ray measurements during a single continuous logging run. The pulsed neutron generator enables the system to alternately acquire data for both measurement types without removing the tool from the wellbore or stopping drilling operations. This continuous operation maintains measurement precision through systematic data collection while eliminating the time loss associated with multiple separate passes or runs.
Solution Approach 2:
The periodic pulsing of the neutron generator creates alternating measurement opportunities within a single logging run. During pulsed intervals, neutron-induced gamma rays are measured; during non-pulsed intervals, natural gamma rays are measured. This periodic action enables both measurements to be obtained continuously during one logging operation, maintaining measurement precision while significantly reducing the time loss compared to requiring separate logging runs for each measurement type.
3Productivity
If conventional detectors are used, then device complexity remains manageable, but productivity decreases due to requiring multiple runs
Solution Approach 1:
The patent achieves improved productivity by designing a universal logging tool that consolidates both neutron-induced and natural gamma-ray measurement capabilities into a single device. This multi-functional tool eliminates the need for multiple separate logging runs, thereby increasing productivity and reducing operational time. The design manages device complexity by using a single gamma-ray detector that can operate in different modes, rather than requiring multiple specialized detectors, thus achieving higher productivity without proportionally excessive complexity.
Solution Approach 2:
The patent merges the functionality of two separate logging operations (neutron-induced gamma-ray spectroscopy and natural gamma-ray spectroscopy) into a single integrated tool. By combining the pulsed neutron generator and gamma-ray detector into one unified system that can perform both measurement types during a single run, the patent increases productivity by eliminating the need for multiple runs. The merging is achieved in a way that manages device complexity by sharing common components and using time-multiplexed measurement modes.
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
Facilitates accurate, high-resolution gamma-ray measurements with low background noise, reducing the need for multiple runs and enhancing operational efficiency in well logging operations.
Implementation Method 1
a gamma ray scintillator detector having a scintillator including CeBr3
Data Source
AI summary
A variety of methods and apparatus are disclosed, including, in one embodiment, a pulsed neutron logging tool for a borehole in a subterranean formation, including: a pulsed neutron generator to broadcast neutrons into the subterranean formation; and a gamma ray scintillator detector comprising cerium bromide (CeBr3), wherein the pulsed neutron logging tool (e.g., as lowered into the borehole) is configured to detect neutron-induced gamma rays from the subterranean formation and natural gamma rays from the subterranean formation.