偏镭矿段对伽马测井解释和铀镭平衡修正结果的影响OA

Gamma logging is the fundamental method for quantitatively determining uranium content of mineralized intervals in boreholes.The U-Ra equilibrium in a certain sandstone-hosted uranium depos-it has been severely disrupted.To investigate the impact of Ra-rich sections(mineralized intervals where the equivalent uranium grade derived from radium is ≥0.010 0％but the uranium grade is＜0.010 0％)on log interpretation and U-Ra equilibrium correction results,the uranium and radium content analysis results of permeable ore samples were systematically studied.The results show that:for samples with a uranium grade≥0.010 0％,the weighted average uranium grade is 0.042 7％,the weighted average U-Ra equilibrium coefficient is 0.615,and the coefficient of variation is 1.041;for samples with an equivalent uranium grade derived from radium≥0.010 0％,the weighted average ura-nium grade is 0.029 5％,the weighted average U-Ra equilibrium coefficient is 0.890,and the coeffi-cient of variation is 3.785.Ra-rich sections will significantly increase the deposit's U-Ra equilibrium coefficient,increase the orebody thickness,and decrease the deposit's uranium grade.Gamma logging cannot identify and remove Ra-rich sections.Consequently,neither the log interpretation results nor the U-Ra equilibrium correction results objectively reflect the orebody's spatial position,grade and thickness.The estimated resource quantity is also inaccurate.