伽马能谱测井在罗辛铀矿勘查中的应用研究  

Study on the application of spectral γ logging in Rössing uranium deposit

作　　者：焦仓文[1] 冯延强[1] 王恒 潘自强[1] JIAO Cangwen;FENG Yanqiang;WANG Heng;PAN Ziqiang(CNNC Key Laboratory of Uranium Resource Exploration and Evaluation Technology Beijing Research Institute of Uranium Geology,Beijing 100029,China)

机构地区：[1]核工业北京地质研究院中核集团铀资源勘查与评价技术重点实验室,北京100029

出　　处：《世界核地质科学》2024年第1期12-22,共11页World Nuclear Geoscience

基　　金：中核集团集中研发项目(编号:物SD03-02)资助。

摘　　要：纳米比亚罗辛铀矿床属于白岗岩铀-钍混合型矿床。在一定量矿心分析数据对比基础上,一直沿用γ测井解释结果作为铀资源储量估算的基础数据。针对该伽马测井结果,要经过各种校正,尤其是钍作为一种“干扰”的不可忽视的因素。大量(岩)矿心分析历史数据表明,罗辛铀矿床Th/U比随着矿体走向、倾向以及深度、蚀变、岩性的变化而变化;通过数理统计分析矿心Th/U比采用常数法或者函数拟合方法用于γ测井的钍修正。但利用伽马能谱测井方法可直接获取矿(化)段的铀、钍元素含量。从仪器、数据采集、误差分析、伽马能谱测井解释铀含量与钍修正后γ测井解释铀含量,以及与矿心分析元素含量对比等几方面进行论述,验证该方法的可靠性和可信度。结果表明,伽马能谱测井是一种快速、有效的测井方法,尤其适用于热液型铀矿勘查。Domestically,gross gamma-ray well log,coupled with certain amount of core assay validation,is used as the basic method for the uranium resource estimation for years,which needs a variety of correction,such as iron,mud as well as disequilibrium of uranium-radium.Thorium as an‘interference’to uranium measurement is mandatory to be deducted correctly from gross gamma.Rössing uranium deposit is a kind of leucogranite-type uranium deposit.Tons of history core assay results show that the Th/U ratio varies along with the ore body strike and dip,as well as with alteration and lithology.Either Th/U constant method or function fitting based on the statistics of core assay analysis is generally applied to deduct thorium from gross gamma log in Rössing deposit.However,spectral gamma-ray logging can be directly used to probe the concentration of radium and thorium of the mineralization section.This paper illustrated the spectral gamma-ray technique to be reliable and of credibility,in the aspects of instrument,field data probing,error analysis between uranium concentration of spectral gamma-ray logging and thorium-corrected uranium content of gross gamma-ray logging,and reconciliation between uranium concentration computed by spectral gamma-ray log and core assay.It was believed that the spectral gamma-ray well logging is more fast and effective than that of gross gamma-ray logging,particularly applicable to the hydrothermal hard-rock uranium prospecting.

关 键 词：铀矿勘查 铀-钍混合型矿床 伽马能谱测井 岩(矿)心分析 

分 类 号：P631[天文地球—地质矿产勘探] P619.14[天文地球—地质学]