As the number of coring cores is limited,the cores cannot reflect the continuous variation of organic carbon in the reservoir and seriously affect the accuracy of the core analysis method to evaluate the total organic carbon content.The using of logging methods to evaluate the organic carbon content of shale can reduce the heterogeneity of organic matter distribution and the representative of the rock samples to bring the indoor core analysis error.In order to further optimize the method for the evaluation of organic carbon content by logging data,this paper analyzes the logging response characteristics of organic-beating shale,and chooses the data of several wells in a shale gas reservoir in Sichuan Basin to analyze the total organic carbon content by logging evaluation method.The single factor calculation model of lithologic density logging,the single factor calculation model of natural gamma ray and the multi-factor calculation model of acoustic resistivity were used to evaluate the total organic carbon content respectively.The following conclusions can be drawn by comparing the results of three models.① The single factor method of density logging is easily affected by the hole enlargement in shale reservoir.② Due to the few factors considered,the accuracy of natural gamma single factor calculation model is low.③ It has a great subjectivity for acoustic resistivity multi-factor method when determining the shale " baseline" artificially,not proper to field applications.This paper provides a valuable method and method for calculating and evaluating the organic carbon content of other shales in China.%由于取芯数量有限,导致所获得的岩心不能反映储层内有机碳的连续变化情况,严重影响了岩心分析法评价总有机碳含量的精度.而采用测井方法评价页岩有机碳含量,可以减少因有机质分布的非均质性和岩样的代表性带来的室内岩心分析误差.为进一步优选利用测井数据评价有机碳含量分析的方法,本文在分析含有机质页岩的测井响应特征基础上,选取了四川盆地某页岩气藏区块多口井的数据,运用测井评价方法分析总有机碳含量.分别使用岩性密度测井单因素计算模型、自然伽马单因素计算模型和声波电阻率多因素计算模型的评价总有机碳含量,对比3种模型的评价结果,可以得出以下结论:①密度测井单因素法在页岩储层中容易受到扩径的影响;②自然伽马单因素计算模型由于考虑因素少导致准确度较低;③声波电阻率多因素法有这很大的主观性,因为人为确定页岩“基线”,不便于操作.本文提供了计算和评价页岩有机碳含量方法和思路.
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