时频电磁技术及其在中国西部地区的应用

摘要

The time-frequency electromagnetic (TFEM) method combines frequency-domain sounding with time-domain sounding to form a comprehensive system so that it is possible to select different frequencies and induce waves according to the objective depth to be explored.During processing not only resistivity but also polarization information can be provided so we can study resistivity as well as predict oil-bearing characteristics simultaneously. Time-domain resistivity information is obtained by pseudo-2D resistivity inversion and frequency-domain IP information is obtained using the Cole-Cole model. Some successful applications in western China show that it provides unique results in an overthrust zone, deep igneous rock investigation, and hydrocarbon prediction.%本文介绍了近几年来推广应用的时频电磁法技术及其在勘探逆掩构造带和深部火山岩体,以及油气预测方面的应用效果.时频电磁技术将频率域测深与时间域测深联合在一个系统中,可针对勘探目标的深度选择不同频率和不同类型的激发波形,不但能提供电阻率信息,还能提供激发极化信息,因而在研究电性构造的同时又能检测其含油气性.时间域测深处理采用拟二维电阻率反演获得电阻率信息,频率域测深处理引入Cole-Cole 模型提取激发极化信息.文中以中国西部地区特殊勘探目标为实例表明,时频电磁法在逆掩构造带勘探、深部火山岩体探测,以及油气预测方面的有其独特的应用效果.