CSAMT多偶极子源特征与张量测量研究

发布时间：2018-04-20 07:20

本文选题：张量 + CSAMT　；参考：《成都理工大学》2015年硕士论文

【摘要】：可控源音频大地电磁法是一种频率域电磁测深方法。其原理是采用人工源发射交变电流产生交变电磁场,通过观测电磁响应来计算波阻抗及视电阻率。频率域可控源大地电磁法沿用了AMT的测量方式,人工场源主要采用电性源,因为电性源建场方式简便、电磁场覆盖面积大、探测深度较大,多用于煤田探测,地热,油气和固体矿产深部找矿等。传统测量方式都是采用单一场源测量,近年来多源的张量CSAMT测量逐渐得到重视,由于张量测量需要多个源的发射,本文做了多偶极源的特征和张量测量的初步研究。论文首先基于麦克斯韦方程组,推导了水平电偶极源在层状大地地表的电磁场响应,编程实现了CSAMT一维正演,能够开展地表的场值分布特征的计算。同时,基于矢量叠加原理,得到了两个电偶极子的叠加场源分布特征;再通过电磁场的对称性,实现了张量CSAMT一维正演,分析了不同类型地电断面下的阻抗张量元素和磁传输函数的特征。其次,通过对张量CSAMT测量的分析,研究了张量CSAMT测量的勘探深度、最低工作频率、收发距等参数,特别是对不同的发射源的适宜观测区域做了一定的研究,主要分析了目前国内外试验研究的十字型源、L型源及旋转偶极发射装置的适宜观测区域,研究工作对张量CSAMT的实际测量有一定的参考价值。论文基于张量CSAMT数据的特点,本文初步研究了张量CSAMT数据处理的一般步骤,主要包括频谱信息的提取、主抗张量元素的求取和主轴方位的求取,然后求取主轴方向上的视电阻率值并进行反演研究。最后,论文采用CSAMT自适应的正则化方法实现一维全资料段的反演,反演结果能够较好地反映地电断面类型。
[Abstract]:Controlled source audio magnetotelluric method is a frequency domain electromagnetic sounding method. The principle is that the alternating electromagnetic field is generated by the alternating current emitted by artificial source, and the wave impedance and apparent resistivity are calculated by observing the electromagnetic response. The frequency domain controllable source magnetotelluric method adopts the method of AMT measurement, and the artificial field source mainly adopts electric source, because the electric source is simple in establishing the field, the electromagnetic field covers a large area, the detection depth is large, and most of them are used for coalfield exploration and geothermal. Deep prospecting of oil, gas and solid minerals. In recent years, Zhang Liang CSAMT measurement with multiple sources has been paid more and more attention. Due to the need for the emission of multiple sources, this paper makes a preliminary study of the characteristics of multi-dipole sources and Zhang Liang measurements. Based on Maxwell's equations, the electromagnetic response of the horizontal electric dipole source on the layered earth surface is deduced, and the CSAMT one-dimensional forward modeling is programmed to calculate the distribution characteristics of the field value on the surface. At the same time, based on the principle of vector superposition, the superposition field distribution characteristics of two electric dipoles are obtained, and the one-dimensional forward modeling of Zhang Liang CSAMT is realized through the symmetry of electromagnetic field. The characteristics of impedance Zhang Liang element and magnetic transfer function under different geoelectric sections are analyzed. Secondly, through the analysis of Zhang Liang CSAMT survey, the exploration depth, the lowest working frequency, the transceiver distance and other parameters, especially the suitable observation area of different emitter sources, are studied, such as the exploration depth, the lowest working frequency, the transceiver distance and so on. This paper mainly analyzes the suitable observation area of cross type source L source and rotating dipole emitter which has been tested and studied at home and abroad. The research work has certain reference value for Zhang Liang CSAMT actual measurement. Based on the characteristics of Zhang Liang CSAMT data, this paper preliminarily studies the general steps of Zhang Liang CSAMT data processing, including the extraction of spectrum information, the extraction of the main anti- element and the direction of the principal axis. Then the apparent resistivity in the principal axis is obtained and the inversion is carried out. Finally, CSAMT adaptive regularization method is used to realize the inversion of one-dimensional full data. The inversion results can well reflect the type of geoelectric section.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P631.325

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