自然伽马能谱测井在四川盆地矿产资源勘探中的应用

Application of Natural Gamma Spectrometry Logging in Mineral Resources Exploration in Sichuan Basin

针对四川盆地高放射性储层不易识别、测井评价困难等问题,结合地质背景、能谱测井特征以及岩心资料等,总结梳理了储层高放射性的成因。利用能谱测井数据中的铀、钍、钾曲线组合特征以及交会图分析方法,有效解决了高放射性陆相致密砂岩气层、海相碳酸盐岩气层、页岩气储层及杂卤石固体矿产勘探中岩性及储层识别、泥质含量计算、烃源岩品质评价等相关研究和分析工作。该研究对盆地内及其他类似地质条件下工区的高放射性矿产资源勘探具有一定的借鉴意义。

In view of the difficulties in identification and logging evaluation of highly radioactive reservoirs in Sichuan Basin,the causes of high radioactivity in the reservoirs were summarized and sorted out in combination with geological background,energy-spectrum logging characteristics and core data.The combined characteristics of the uranium,thorium and potassium curves in the spectrometry logging data and the cross plot analysis method were adopted in the effective research and analysis related to lithology,reservoir identification,mud content calculation and hydrocarbon source rock quality evaluation in the exploration of highly radioactive terrestrial dense sandstone gas reservoir,marine carbonate gas reservoir,shale gas reservoir and miscellaneous halite solid minerals.There is much for reference of the study to the exploration of highly radioactive mineral resources in the basin and other work areas with similar geological conditions。