Gamma ray detectors having azimuthal sensitivity
AssigneeBaker Hughes Incorporated
InventorsAnton Nikitin, Alexandr A. Vinokurov, Richard R. Pemper
Life of this patent
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Abstract
An instrument for performing measurements downhole includes: at least one gamma-ray detector with azimuthal sensitivity equipped for discriminating energy of incident gamma-rays. This instrument is equipped with or without a neutron or gamma-ray source. A method and computer program product providing the azimuthal sensitivity of the instrument is provided.
Claims15
A radiation detector for performing measurements downhole in a wellbore, the detector comprising:
- a plurality of radiation scintillators, each scintillator in the plurality comprising a shape that is configured to provide azimuthal sensitivity relative to the wellbore for detection of radiation downhole, wherein each scintillator in the plurality comprises an optical coupling to a respective photodetector that receives a pulse signal due to detection of a gamma ray in the respective scintillator;
- and
- a processor configured to receive pulse signals from each respective photodetector and to provide anticoincidence counting that excludes redundant pulse signals received due to the same gamma ray being detected in two or more scintillators in the plurality.
A method for fabricating a radiation detector for performing a measurement downhole in a wellbore, the detector comprising:
- selecting a radiation scintillator material for shaping as a radiation detector having a plurality of radiation scintillators;
- determining an optimal shape of each radiation scintillator in the plurality that is configured to provide azimuthal sensitivity relative to the wellbore for detection of radiation downhole;
- shaping the material to the optimal shape for each scintillator in the plurality to provide the azimuthal sensitivity relative to the wellbore for detection of radiation downhole;
- optically coupling each scintillator in the plurality to a respective photodetector that receives a pulse signal due to detection of a gamma ray in the respective scintillator;
- and
- coupling a processor to each respective photodetector, the processor being configured to provide anticoincidence counting that excludes redundant pulse signals received due to the same gamma ray being detected in two or more scintillators in the plurality.
A non-transitory computer readable medium comprising computer executable instructions for evaluating signals from a plurality of radiation detectors, the instructions implementing a method comprising:
- receiving a plurality of detection events from each scintillator of a radiation detector comprising a plurality of radiation scintillators, each scintillator comprising a shape that is configured for the radiation detector to provide azimuthal sensitivity relative to the wellbore for detection of radiation downhole;
- at least one of excluding and combining selected ones of the radiation detection events from an output to provide an adjusted output;
- and
- providing the adjusted output to a user;
- wherein the excluding comprises performing an anticoincidence analysis.
Dependencies are inferred from the claim text.