页岩有机碳含量测井评价方法及其应用

根据页岩气的定义,高有机质丰度既是成烃的物质基础,也是页岩气吸附的重要载体.利用页岩纵向高分辨率测井资料估算地层的有机碳含量,克服了因取心不足和受实验分析费用限制而造成的评价页岩的困难.依据页岩在不同测井曲线上的测井响应特征,利用电阻率、声波时差、自然伽马能谱等测井信息,采用△LgR法以及自然伽马能谱法回归计算页岩有机碳含量.最后以四川盆地2口井的页岩层有机碳含量计算为例,对TOC实测数据进行误差分析和检验,结果表明对于陆相页岩层段△LgR与U(铀)曲线叠合法较为适用,对于海相页岩层段这2种方法都取得了较好的效果.

Logging Evaluation Method and Its Application for Measuring the Total Organic Carbon Content in Shale Gas

Based on the definition of shale gas,the high abundance of organic matter is the material basis for hydrocarbon generation as well as the important carrier of adsorbed shale gas.This method estimated the organic carbon content of strata with the high-resolution vertical logging curves in shale strata and overcame the difficulty of evaluating shale gas which was caused by the shortage of core sample and the cost limitation of experimental analysis.Based on the logging response feature of the different logging curves and the logging information such as resistivity,acoustic slowness and natural gamma-ray spectrometry,this paper regressively calculated the organic carbon content with the methods of ΔLgR and natural gamma-ray spectrometer.Taking the calculation of shale organic carbon content of two wells in Sichuan Basin for example,the core data of TOC was subjected to error analysis and tested.The results showed that the congruent of ΔLgR and U curve was more applicable for continental facies shale,while good results have been achieved by both methods for marine facies shale.