POSSIBILITY OF SPECTROMETER GAMMA LOGGING WHEN SOLVING PROBLEMS OF OIL AND GAS GEOPHYSICS
There is considered the possibility of solving the problems of oil and gas geophysics according to gamma and spectrometer measurements of natural radioactivity of rocks caused by disintegration of uranium, thorium and potassium. There is given the characteristic of rocks at the level of natural radioactivity. There is shown the essence of gamma and spectrometer studies consisting in separate definition of uranium, thorium and potassium. It is shown that spectrometer modification of gamma logging reflects lithologic typification of rocks more contrastively. The differentiating ability of the selected gamma and spectral parameters changes depending on the type of layers. There is confirmed the informational content of using the concept «uranium equivalent» for assessing rocks shaliness. The integrated intensity of natural gamma radiation of clay minerals closely correlates with shaliness. For a number of terrigenous collectors using potassium – thorium radiation is the most preferable. It is shown that using natural gamma radiation in terms of the uranium equivalent for assessing shaliness is characterized by the best metrological characteristics.