摘要
时频电磁法是近年来发展起来的一种新型的电磁勘探方法,其发展前提是可控源音频大地电磁测深技术（CSAMT）和长偏移距瞬变电磁测深技术（LOTEM）,它一次采集即可同时获取频率域和时间域的电磁信号,目前已广泛应用于深部矿产资源的勘探以及油气勘探等领域。从麦克斯韦方程组出发,结合边界条件,推导出了时频电磁法所满足的一维层状介质情况下的时间域和频率域的水平电场方程,并利用正余弦变换进行数值模拟。以三层介质为例,探讨了随薄层电阻率大小变化的水平电场分量Ex对薄层的探测能力。数值模拟结果显示,时频电磁法测深对低阻薄层的分辨率很强,对高阻层的分辨能力比低阻薄层弱;频率域电磁法测深对高阻薄层的分辨能力要强于时间域电磁法测深,时间域电磁法测深对低阻薄层的分辨能力强于高阻层。
Time and frequency electromagnetic method（TFEM）is a new type of electromagnetic prospecting one developed in recent years,whose development premise is controlled source audio-frequency magnetotellurics（CSAMT） and long offset transient electromagnetic method（LOTEM）.Electromagnetic signal of frequency domain and time domain may be collected together.TFEM has been widely used in deep exploration of mineral re-sources and oil and gas exploration and other fields at present.Starting from Maxwell ′ s equations and boundary conditions,horizontal electric field equation of time domain and frequency domain was deduced under one-dimensional layered media met the demands of time and frequency electromagnetic method,and numerical simulation was done through cosine transform.Taking three-layer medium as an example,horizontal electric field component Exchanges with thin layer resistivity,and its detection ability on the thin layer was discussed.Numerical simulation result shows that the time and frequency electromagnetic sounding has stronger resolution on the low-resistivity thin layer than on the high-resistivity layer.Frequency domain electromagnetic sounding has stronger solution on the high-resistivity thin layer than time domain electromagnetic sounding,and the time domain electromagnetic sounding has stronger solution on the low-resistivity thin layer than that on the high-resistivity layer.
作者
王竞飞
Wang Jingfei(China University of Petroleum ,Qingdao Shandong 26658)
出处
《中外能源》
CAS
2018年第3期25-31,共7页
Sino-Global Energy
关键词
时频电磁法
电阻率
时间域
频率域
CSAMT
LOTEM
time and frequency electromagnetic method
resistivity
time domain
frequency domain
CSAMT
LOTEM
