大回线源瞬变电磁场响应特性  

Characters of response of large-loop transient electro-magnetic field

作　　者：薛国强[1] 李貅[2] 郭文波[3] 底青云[4] 

机构地区：[1]北京市中国科学院地质与地球物理研究所,100029 [2]长安大学地质工程与测绘工程学院 [3]西安交通大学电子与信息工程学院 [4]中国科学院地质与地球物理研究所

出　　处：《石油地球物理勘探》2007年第5期586-590,共5页Oil Geophysical Prospecting

基　　金：中国科学院王宽诚博士后奖励基金资助;中国博士后基金资助(编号:2005038388)。

摘　　要：对不同偏移距情况下的大回线源瞬变电磁响应进行了理论分析与数据计算,并给出回线框内外各测点磁场分布平面图。数值计算结果表明,在回线中心地带60%范围内,垂直磁场分量分布相对稳定,适合进行快速扫面测量,但水平磁场相对较弱,在回线内不宜观测水平磁场分量。通过对倾斜地层情况下的回线源的响应进行等效面积计算可知,当地层较平时,磁场垂直分量能量较大,当地层较陡时,垂直分量能量较小,并给出了不同倾角情况下的磁场幅值误差表。The theoretical analysis and data computation are carried out for large-loop transient electro-magnetic response in a condition of different offsets, givng distribution map of magnetic field in different surveyed points inside and outside the loop frame. The numeric computation showed within 60% range of loop central zone,the vertical component distribution of magnetic field is relatively stable, which is suitable to carry out fast scanning survey, but horizontal magnetic field is relatively weak, which is unsuitable to survey horizontal component of magnetic field within loop. It is known by equivalent area computation of response of loop in a condition of tilted beds that the energy of vertical component of magnetic field is larger when the beds are slightly flat, and smaller when the beds are steeper. The paper also gave the error table of amplitude of magnetic field in a situation of different dips.

关 键 词：大回线源 瞬变电磁 非零偏 响应 倾斜地层 

分 类 号：P3[天文地球—地球物理学]