Response characteristics of lithologic logging of Zhiluo Formation in Ordos basin

For accurately classifying the strata lithology, identifying strata and interpreting ore beds of Zhiluo Formation, the parameters of four logging curves of Jurassic Zhiluo Formation in four major uranium ore accumulation areas in Ordos basin, including quantitative gamma, natural potential, trilateral resistivity and density, were comprehensively analyzed and classified, statistics and morphological analysis of logging curves were used. The results show that there was no significant difference in gamma radiation rate in Zhiluo Formation in different areas, the resistivity value in southeast margin was obviously higher than that in other areas, and the density value was characterized by being high in the south and low in the north; Vertically the gamma background value and resistivity of the upper section of Zhiluo Formation was are lower than that of the lower section, and the density value didn't not change much; Regionally from coarse sandstone to mudstone the gamma background value increased gradually; The density value increased slightly, and the abnormal amplitude of resistivity and natural potential changed from the high to the low. Based on the difference of logging parameters and facies of different types of rocks, the lithologic identification model of resistivity and density crossplot in the northeastern margin area and the logging facies characteristic of Zhiluo Formation in different ore accumulation areas were established. The granularity of sandstone sections with radioactive anomalies should be increased by 1-2 grades during lithological interpretation of coal logging.