鄂尔多斯盆地延长组页岩有机碳测井解释方法与应用

富有机质页岩中有机质含量是资源潜力评价的重要参数。为了获取研究区未取心井富有机质页岩有机碳含量，试图通过测井解释方法，建立研究区目的层位关于有机碳含量（TOC）的数学模型。通过对研究区20口井延长组岩心TOC测试结果与相应测井参数相关性分析，发现岩心实测TOC值与自然伽马和电阻率的对数呈现较好的正相关性，但与声波时差相关性不明显。据此，利用多元统计方法，建立研究区关于自然伽马和电阻率的对数解释延长组富有机质页岩TOC含量的数学模型。根据柳评177井TOC测井解释结果与实测TOC误差分析结果，该测井解释模型误差均值为5.35%。利用上述数学模型，对研究区46口未取心井延长组富有机质页岩TOC进行计算，并结合20口取心井的测试结果，分析研究区延长组富有机质页岩TOC空间分布特征。上述TOC分布结果与沉积微相的变化趋势具有良好的吻合性，从侧面表明文中建立的有机碳测井解释模型的可靠性和有效性。

TOC logging interpretation method and its application to Yanchang Formation shales,the Ordos Basin

Total organic content(TOC)of organic rich shale is an important parameter in resource assessment.In order to predict the TOC of shales in the non-cored wells in the study area,this paper established a mathematical model of TOC for the target layer through logging interpretation.Based on an analysis of the relationship between the measured TOC of cores sampled from the Yanchang Fm in 20 wells and the corresponding logging parameters,we found that the measured TOC values are positively correlated with the logarithm of Rt and GR,but not insignificantly correlated with AC.Multivariate analysis method was used to establishe a mathematical model for predicting TOC of the Yanchang organic-rich shale with the logarithm of Rt and GR.Its application in the cored Liuping-177 well gave a mean error of 5.35% between the logging interpreted TOC and the measured TOC.The mathematical model was used in calculation of TOC of the Yanchang organic-rich shale in 46 non-cored wells.The spatial distribution of TOC of the Yanchang organic-rich shale in the study area was mapped based on these calculation results and the measured TOC of additional 20 cored wells.The TOC distribution is consistent with the distribution of sedimentary microfacies,verifying the reliability and effectiveness of this method.