【摘要】 电性源短偏移距瞬变电磁法(SOTEM)具有探测深度大、分辨率高、施工方便等特点,在第二深度空间(500～2000 m)金属矿勘探中发挥了重要作用.实际测量中,当遇到具有激发极化效应的岩矿石时,SOTEM观测曲线会出现畸变和负值响应(符号反转)的现象.SOTEM激电效应的研究对金属矿勘探具有重要意义,为此,本文对SOTEM多分量激电响应特性进行分析.通过基于Cole-Cole模型的SOTEM一维正演计算,分析了不同装置参数(收发距,极化体埋深)和极化参数(极化体电阻率、极化率,频率相关系数以及时间常数)对常用的E_x、H_z和dH_z/dt电磁场的影响规律,研究结果表明水平电场分量受激电效应的影响最大,垂直磁场分量和垂直磁场分量的时间导数受到的影响要小得多,研究结果将有助于指导野外实际生产.更多还原

【Abstract】 The Short-Offset Grounded-Wire Transient Electromagnetic(SOTEM) method can realize large-depth detection easily with high resolution. It plays an important role in the exploration of deep-seated metal ores in the second depth space. In practical measurement, rocks with induced polarization effects will cause distortion and negative values in the observed SOTEM curves. In this paper, multi-component EM responses with the IP effects are analyzed. We analyze the IP effect with different device parameters(source-receiver separation, depth of the polarized body) and polarization parameters(the resistivity of polarized body, polarizability, the frequency correlation coefficient and time constant) on the E_x, H_z and dH_z/dt using the 1 D forward routine based on Cole-Cole model. It is concluded that the horizontal electric field is seriously affected while the vertical magnetic field component and its time derivative are less affected, which is a good guide to the SOTEM field work.更多还原