Determination of Uranium, Thorium and Potassium Concentrations in Different Clay Types by Spectral Gamma Ray Log, in Hawaz Formation in Well O6i-NC115, Murzuq basin, SW Libya

Abstract

The paper discusses Uranium, Thorium and Potassium Concentrations in different clay types based on log data. The paper discusses uranium concentration in different clay types based on log data. This investigation is done within Hawaz sandstone formation in the well O6i-NC115 in Murzuq basin, SW of Libya. The study implemented a well log data of spectral gamma ray which has been performed throughout two hundred and six feet thick of Hawaz sandstone intervals. The Spectral gamma ray data includes uranium, thorium and potassium that logged from 5447 ft. to 5653 ft. depth of the well. The analysis includes values of uranium (U) and thorium (Th) in ppm, where potassium (K) is recorded in percentage. The values of potassium and thorium are plotted on (clay type diagram of Schlumberger). This shows different locations of data according to their content of potassium and thorium which reflect particular clay type. The analysis is being obtained from different types of sandstone beds in Hawaz formation namely H6, H7 and H8. These intervals contain distinctive type of clay content and in respect of this they have different values of uranium concentration. The H6 which has clay type Montmorillonite-Illite has lesser values of uranium concentration (average 1.48 ppm), whereas the intervals H7 and H8 have higher values of uranium (average 2.03 ppm and 2.04 respectively) which they cemented or interbedded by Montmorillonite clay. This work contributes to understanding the uranium concentration in sandstone facies as well as the relation between clay type and concentration of uranium within Murzuq basin, SW Libya.