电性源瞬变电磁激电效应的正反演方法技术研究
[Abstract]:When the polarizer exists underground, the induced polarization effect is included in the transient electromagnetic response, and the negative electromagnetic response may occur in the measurement. This IP effect has been studied and proved in practice. As the "long offset" method of artificial source is essentially the same as the natural field source method, it is observed in the "far field", and electromagnetic induction is the absolute predominance. It is very difficult to extract the weak and weak IP anomaly which is "submerged" by the strong electromagnetic effect anomaly, and its prospect is not optimistic. Compared with frequency domain electromagnetic method, time domain electromagnetic method can detect short offset or zero offset. Compared with the loop source, the electric source has a greater detection depth and can be observed both in magnetic field and in electric field. Therefore, it is helpful to study the characteristics and rules of the transient electromagnetic response of electric source and the method of extracting the information of induced electromagnetism, which is helpful to solve the ore-bearing information of deep large deposits (reservoirs). In this paper, the origin of Cole-Cole model is briefly introduced. Through the one-dimensional forward calculation of electric source transient electromagnetic based on Cole-Cole model, the influence of polarization resistivity and device transceiver distance on the induced electric effect is analyzed. The effects of parameters of Cole-Cole model on the components of transient electromagnetic field (xHyE and,? tHt z) are analyzed by the uniform half-space model. It is found that the polarizability parameters have the greatest influence on the electromagnetic field response, and the frequency correlation coefficient is the second. The influence of time constant is minimal. The three layer geoelectric model is simulated and calculated. The results show that different geoelectric models are affected by the induced electric effect to different extent, and the polarization layer is the relatively low resistivity layer, which is the most affected by the induced electric effect. By comparing the characteristics of CSAMT method and electric source transient electromagnetic method under the influence of induced electric effect, it is found that it is more promising to extract the IP information by using the electric source transient electromagnetic method. In this paper, the whole area apparent resistivity is defined by magnetic field intensity and inductive electric type, and the influence of induced electric effect on the two apparent resistivity curves is discussed. In this paper, the modified damped least square method is used to invert the whole parameters of the model (resistivity, thickness, polarizability, frequency correlation coefficient and time constant). When the initial model is suitable, the inversion results are satisfactory. But the full parameter inversion model has too many parameters, and the inversion result is greatly affected by the initial model. If the initial model is not suitable, there is no reasonable result. In this paper, the time derivative based on the horizontal magnetic field component has little effect on the induced electric effect, and the main parameter affected by the induced electric effect is polarizability. By using the fixed frequency correlation coefficient and the time constant, the results of the other three parameters are retrieved as the initial model. Using the time derivative of the vertical magnetic field component to carry out the full parameter inversion, the ideal results can be obtained. The feasible direction is added to the inversion, which to some extent inhibits the multi-solvability of the inversion. The theoretical results show that the TEM induced effect of the electrical source is significant and can be extracted, and the inversion results are in good agreement with the actual parameters.
【学位授予单位】:长安大学
【学位级别】:硕士
【学位授予年份】:2015
【分类号】:P631.325
【参考文献】
相关期刊论文 前10条
1 罗延钟,张胜业,熊彬;天然场源激电法的可行性[J];地球物理学报;2003年01期
2 白登海,Maxwell A Meju,卢健,王立凤,何兆海;时间域瞬变电磁法中心方式全程视电阻率的数值计算[J];地球物理学报;2003年05期
3 殷长春,,刘斌;瞬变电磁法三维问题正演及激电效应特征研究[J];地球物理学报;1994年S2期
4 严良俊,胡文宝,陈清礼,胡家华;长偏移距瞬变电磁测深法在碳酸盐岩覆盖区落实局部构造的应用效果[J];地震地质;2001年02期
5 翁爱华,王雪秋;长偏移距瞬变电磁测深甚晚期响应及视电阻率的数值计算[J];地震地质;2003年04期
6 刘磊;昌彦君;曹中林;;可极化大地上CSAMT激发极化效应的研究[J];工程地球物理学报;2008年06期
7 余传涛;刘鸿福;张新军;杨德义;李白红;;从瞬变电磁响应中提取IP信息的研究(英文)[J];Applied Geophysics;2013年01期
8 陈明生,解海军;电偶源瞬变电磁测深研究(三)——大地表面瞬变电磁场[J];煤田地质与勘探;1999年03期
9 陈明生,田小波;电偶源瞬变电磁测深研究(四)——瞬变电磁测深视电阻率[J];煤田地质与勘探;1999年04期
10 孙鸿雁;磁性源瞬变电磁测量中激电效应作用规律的探讨[J];物探与化探;1998年01期
相关硕士学位论文 前2条
1 邱宁;瞬变电磁信号的预处理和激电效应识别研究[D];中国地质大学;2007年
2 黄磊;CSAMT中的IP效应提取[D];中南大学;2009年
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