张量CSAMT方法及对比实验

发布时间：2018-05-17 06:07

本文选题：标量CSAMT + 张量CSAMT　；参考：《石油地球物理勘探》2017年04期

【摘要】：可控源音频大地电磁法(CSAMT)目前主要以标量测量为主,标量CSAMT只能在地下产生单一方向的电流矢量,只能求取标量阻抗,因此只适合一维构造及构造走向与测线垂直的二维情况。对于复杂的三维地电结构,CSAMT可采用张量测量。本文使用V8多功能电法仪进行张量CSAMT试验,发射端采用两个相互垂直的发射源,接收端采用五分量接收,数据处理采用阻抗张量分解技术,与标量CSAMT和音频大地电磁测深(AMT)结果对比,表明张量CSAMT远区数据与同测点AMT数据曲线整体形态趋势一致,重合性很好,只是天然场信号较弱,高频段AMT曲线不及张量CSAMT曲线圆滑;标量CSAMT数据与AMT数据相差很大,已经不能正确反映地下结构特征。因此,张量CSAMT可以弥补标量CSAMT适用范围的局限性和AMT信号弱、干扰大的问题。
[Abstract]:Controlled source audio magnetotelluric method (CSAMTs) is mainly based on scalar measurement. Scalar CSAMT can only produce a single direction current vector in the underground, and can only obtain scalar impedance, so it is only suitable for one-dimensional structure and two-dimensional case where the tectonic strike is perpendicular to the survey line. CSAMT can be measured by Zhang Liang for complex three dimensional geoelectric structure. In this paper, the Zhang Liang CSAMT test is carried out by using V8 multifunctional electric instrument. The transmitter adopts two vertical emitters, the receiver adopts five-component receiver, and the data processing adopts the technique of impedance Zhang Liang decomposition. Compared with the results of scalar CSAMT and Audio magnetotelluric sounding (CSAMT), the results show that the data of Zhang Liang CSAMT are consistent with the curve of AMT data at the same point, the coincidence is very good, but the natural field signal is weak. The AMT curve in the high frequency band is not as smooth as the Zhang Liang CSAMT curve, and the scalar CSAMT data differ greatly from the AMT data, which can no longer reflect the characteristics of underground structure correctly. Therefore, Zhang Liang CSAMT can make up for the limitation of scalar CSAMT and the problem of weak AMT signal and large interference.
【作者单位】：中国地质大学(武汉);国土资源部地球物理电磁法探测技术重点实验室;中国地质科学院地球物理地球化学勘查研究所;国家现代地质勘查工程技术研究中心;
【基金】：中央公益性基本科研项目“张量CSAMT三维电磁场值正演数值模拟研究”(AS2016J04);“张量CSAMT场源组合方式研究”(AS2016J03);“张量CSAMT方法技术研究与传感器研制”(12120113100800)联合资助
【分类号】：P631.325

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