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US 10,209,378 B2Granted
Photopeak location systems and methods
AssigneeHalliburton Energy Services, Inc.
InventorsJames E. Galford, Weijun Guo
Life of this patent
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Abstract
A laser photopeak location system comprises a gamma-ray spectrometer and a processor. The processor computes a plurality of correlation coefficients based on a comparison of a pulse-height spectrum of the gamma-ray spectrometer with an array of values. The processor locates one or more photopeaks of the pulse-height spectrum based on at least one of the plurality of correlation coefficients. Additional apparatus, methods, and systems are disclosed.
Claims20
A method, comprising:
- positioning a well logging tool along a wellbore, the well logging tool including a gamma-ray spectrometer and a gamma-ray spectrometer calibration system,
- wherein the spectrometer calibration system includes a closed control loop comprising a stabilization multichannel analyzer, a stabilization processor, a current driver, at least one temperature sensor, and a preamplifier;
- directing output pulses from a photomultiplier tube through the preamplifier to the stabilization multichannel analyzer;
- scanning one or more channels of a pulse-height spectrum within a correlation window;
- determining a plurality of correlation coefficients based on a comparison of the pulse-height spectrum with an array of values;
- locating at least one photopeak in an energy spectrum measured by a gamma-ray spectrometer based on one or more of the plurality of correlation coefficients;
- and
- calibrating the gamma-ray spectrometer based on a location of at least one photopeak, wherein the calibrating comprises adjusting a voltage input to a photomultiplier and a laser.
5 more elements
A system, comprising:
- a well logging tool along a wellbore, the well logging tool including a gamma-ray spectrometer and a gamma-ray spectrometer calibration system,
- wherein the spectrometer calibration system includes a closed control loop comprising a stabilization multichannel analyzer, a stabilization processor, a current driver, at least one temperature sensor, and a preamplifier;
- output pulses from a photomultiplier tube through the preamplifier to the stabilization multichannel analyzer;
- and
- a processor to:
- compute a plurality of correlation coefficients based on a comparison of a pulse-height spectrum of the gamma-ray spectrometer with an array of values;
- locate one or more photopeaks of the pulse-height spectrum based on at least one of the plurality of correlation coefficients;
- and
- adjust an input voltage to a photomultiplier and a laser to calibrate the gamma-ray spectrometer based on the one or more photopeaks.
6 more elements
A method, comprising:
- positioning a well logging tool along a wellbore, the well logging tool including a gamma-ray spectrometer and a gamma-ray spectrometer calibration system,
- wherein the spectrometer calibration system includes a closed control loop comprising a stabilization multichannel analyzer, a stabilization processor, a current driver, at least one temperature sensor, and a preamplifier;
- directing output pulses from a photomultiplier tube through the preamplifier to the stabilization multichannel analyzer;
- performing a correlation evaluation of a pulse-height spectrum generated by a gamma-ray spectrometer to produce a plurality of correlation coefficients;
- identifying a selected correlation coefficient value of the plurality of correlation coefficients;
- determining a location of at least one photopeak of the pulse-height spectrum based on a value of the selected correlation coefficient;
- and
- calibrating a gamma-ray spectrometer based on the location of the at least one photopeak, wherein the calibrating comprises adjusting a voltage input to a photomultiplier and a laser.
5 more elements
Dependencies are inferred from the claim text.