宣达地区中、下三叠统含杂卤石蒸发岩测井响应及岩性识别

钾盐主要用于农业中钾肥的生产，中国是钾盐消费和进口大国，但中国钾资源少、产量低，因此钾盐勘探对中国粮食安全有重要意义。四川盆地是中国找钾的重要区域，文章运用岩芯样品、测井等资料，通过X射线粉晶衍射、元素含量测试等实验对宣达地区中、下三叠统嘉陵江组-雷口坡组含盐系典型矿物特征及岩石测井响应特征进行分析，并基于测井解释方法原理对杂卤石进行识别。结果表明，研究区钾盐矿物包括氯化盐矿物、硫酸盐矿物、碳酸盐矿物3类，固态钾盐矿物主要为杂卤石，常与石盐、硬石膏共存，具有高电阻率、高密度、高伽马、高K的特征，主要分布于T₁j^4-2、T₁j^5-2层段。

Logging response and lithologic identification of Middle-Lower Triassic polyhalite evaporites in Xuanda area

Potash salts are mainly used in the production of potassium fertilizer in agriculture. China is a major consumption and import country of potash salts, but potassium resources of China are insufficient and output is low. Therefore, potash salts exploration is of great significance to food security of China. Sichuan basin is an important area in search for potassium. In this paper, core and logging data were used to analyze characteristics of typical minerals and logging response characteristics of rocks of salt-bearing system from Jialingjiang layer to Leikoupo layer of Middle-Lower Triassic strata in Xuanda area by XRD, element content testing and other experiments, and the polyhalite was identified based on the principle of logging interpretation method. The results show that the solid potassium salt minerals in the study area include chloride minerals, sulfate minerals and carbonate minerals with polyhalite being dominant, which often coexist with halite and anhydrite, and have the characteristics of high resistivity, density, GR and high content of potassium. The polyhalite is mainly distributed in T₁j^4-2 and T₁j^5-2 layers.