System for measuring the natural gamma radiation of surface and subsurface formations

Patent · Tue Apr 01 04:00:00 EST 1986

OSTI ID:5848883

Dion, E P

A system is described for measuring natural gamma radiation consisting of: a. a sodium iodide scintillation type gamma ray detector for providing an output representative of the total natural gamma radiation spectrum for potassium, uranium and throium sources, the output of the detector being temperature sensitive, b. an artificial source of gamma radiation that is temperature insensitive for producing a stabilized energy peak under variable environmental conditions and does not interfere with the energy peaks from potassium uranium or thorium, the artificial source of gamma radiation being positioned so as to permit measurement of the artificial gamma radiation by the detector at the same time as the measurement of the natural gamma radiation, c. a multichannel analyzer for recording the full energy spectrum output from the detector and for gain stabilizing the full energy spectrum on the stabilized energy peak of the temperature insensitive artificial source of gamma radiation, d. means for performing a channel-by-channel least squares fit of the measured full energy spectrum from the multichannel analyzer to at least one standard full energy spectrum recorded from known amounts of potassium, uranium and thorium gamma radiation, and e. means for determining the separate potassium, uranium and thorium contents of the measured full energy spectrum from the channel-by-channel least squares fit.

• Assignee: Mobil Oil Corp., New York, NY
• Patent Number(s): US 4580048
• OSTI ID: 5848883
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
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Geology
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46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
47 OTHER INSTRUMENTATION
ACTINIDES
ALKALI METALS
AMPLIFICATION
DETECTION
ELECTRONIC EQUIPMENT
ELEMENTS
ENERGY SPECTRA
EQUIPMENT
GAIN
GAMMA DETECTION
GAMMA LOGGING
GEOLOGIC DEPOSITS
LEAST SQUARE FIT
MAXIMUM-LIKELIHOOD FIT
MEASURING INSTRUMENTS
METALS
MINERAL RESOURCES
MULTI-CHANNEL ANALYZERS
NAI DETECTORS
NATURAL RADIOACTIVITY
NUMERICAL SOLUTION
PETROLEUM DEPOSITS
POTASSIUM
PULSE ANALYZERS
RADIATION DETECTION
RADIATION DETECTORS
RADIOACTIVITY
RADIOACTIVITY LOGGING
RESOURCES
SCINTILLATION COUNTERS
SOLID SCINTILLATION DETECTORS
SPECTRA
STABILIZATION
TEMPERATURE EFFECTS
THORIUM
URANIUM
WELL LOGGING
WELL LOGGING EQUIPMENT