地震约束下时频电磁法识别富有机质页岩层系研究

Research on identification of organic-rich shales using seismic constrained time-frequency electromagnetic method

湘西北试验区属于典型南方碳酸盐岩山区,富有机质页岩与围岩电性差异及流体极化效应明显,有利于应用大功率时频电磁法勘探.通过采集并测定试验区页岩和其他岩石标本,分析富有机质页岩的物性特征,研究富有机质页岩电磁特性和极化机理,总结了时频电磁法针对富有机质页岩层系的资料处理和异常提取方法.试验区在时频电磁法采集测线上又覆盖了二维地震工作,在地震约束下时频电磁法反演能更好地描述试验区页岩层系展布特征,预测TOC高值异常区.通过反演结果进行分析,结合前期富有机质页岩物性特征研究,时频电磁法具有圈定富有机质页岩层系的能力.

Northwestern Xiang test area belongs to the typical southern carbonate rock mountains, Rich organic shale and polarization effect obvious electric difference between surrounding rock and fluid,conducive to the application of high power frequency electromagnetic prospecting. Through the acquisition of shale and other rock samples,We study the rich organic shale electromagnetic characteristics and polarization mechanism and summarize the frequency electromagnetic method in view of data processing and anomaly extraction method for shale formation. Test area apply not only frequency electromagnetic method but also collect online measurement and covered the 2-D seismic work. Seismic constrained time-frequency electromagnetic inversion can better describe the test area of shale formation distribution characteristics and predict the TOC high value anomaly area. Through the analysis of inversion result and combining with the feature of early rich organic shale property research,Time and frequency electromagnetic method have the ability to delineate rich organic matter of shale formation.