Determination of emanation correction in gamma-ray well logging

Abstract

As it is known, almost all gamma-radiation of equilibrium uranium series is accounted for by the radium part: short-lived radon decay products Ra (B + C). For the MS-type counters the gamma-radiation of the uranium part of the series is only 5.1%, and Ra (B + C) -94.9% of the total intensity. Removal of radon from the rock as a result of emanation leads to a corresponding decrease in the content of its decay products in the rock and, consequently, to a decrease in the intensity of gamma-radiation. The emanation factor of ores in the crushed state reaches several tens of percent. Although the emanation factor in natural conditions is usually lower, this fact requires mandatory study. The emanation correction α' must be taken into account in the interpretation of gamma-ray measurements.