METHOD OF CALIBRATING DOWNHOLE SPECTROMETERS Russian patent published in 2011 - IPC G01V5/04 

FIELD: physics.

SUBSTANCE: natural or induced gamma radiation is detected. Spectral flux density is determined. The null reading of the spectrometer is corrected. The first channel is that channel in which non-zero spectrum intensity was detected. The current spectrum is compared with spectrum of Compton scattering of the gamma radiation and the observed spectrum is transformed through normalisation thereof to an analytically approximated spectrum of Compton radiation using a given formula. The peak of the maximum amplitude i_a and the peak with the highest number in are then selected from significant peaks. One of these peaks is then matched with the reference line of known energy E₀ present in the detected radiation, and energy E of the detected radiation is then calculated using the formula E = k·i, where k=E₀/i_n, (or k=E₀/i_a), E is radiation energy, MeV, i is the number of channels.

EFFECT: high measurement accuracy, easy calibration of downhole equipment and less time spent on implementing the method.

2 dwg