Modeling and Inversion of Gamma-Ray Logs: Estimation of Radionuclide Concentrations

The natural radionuclide concentrations (U, Th and K) present in crustal rocks are usually estimated from rocks samples treated in labs. Investigations have assessed the rate of radiogenic heat production in the studied area. However, it is sometimes<br>impossible to have samples to assess them in laboratory. Here, we propose a methodology to estimate natural radionuclide concentrations (i.e, CU, CTh and CK) by inversion of gamma-ray logs. Below we present the methodology to achieve this goal by using a robust physical model for gamma-ray measurements in sedimentary basins. The result of the estimations of radionuclide concentrations was then applied in the radiogenic heat and gammaray equation and compared with the initial values proposed in a lithologic model. The methodology will be used in sedimentary basins real to know the radionuclide concentration, uranium, thorium and potassium elements.