海洋TEM中心回线装置一维正演及全时域视电阻率计算  

1D FORWARD OF TEM OF CENTRAL LOOP CONFIGURATION ON SEA FLOOR AND CALCULATION OF ALL-TIME APPARENT RESISTIVITY

作　　者：胡俊华[1] 昌彦君[1] 雷胜兰 孙卫斌 

机构地区：[1]中国地质大学地球物理与空间信息学院,湖北武汉430074 [2]东方地球物理公司,河北涿州072750

出　　处：《物探与化探》2013年第6期1137-1140,共4页Geophysical and Geochemical Exploration

基　　金：国际海域资源调查与开发"十二五"课题(DY125-11-R);大型油气田及煤层气开发科技重大专项(2011ZX05019-007);国土资源部公益项目(08Z11101)

摘　　要：首先对海洋中深海区中心回线装置的瞬变电磁响应进行了一维正演计算,频率域垂直磁场分量表达式中的汉克尔积分变换采用了124点滤波系数进行数值计算;时—频域转换使用了适应时间范围较宽的余弦变换算法;然后采用连分式算法求取了典型地电模型全时域视电阻率随深度变化的曲线。结果表明,曲线基本可以反映地下电性介质的相对大小变化;并且,根据极值点可以大致确定低阻或高阻层顶界面深度。这为海洋TEM实测资料的快速定性解释以及反演初始模型参数的选定打下了基础。1D forward of transient electromagnetic response of central loop configuration on sea floor was conducted first,in which the Hankle transform involved with the expression for vertical magnetic component in frequency domain was numerically calculated using filter coefficients of 124 points,and frequency-time domain transform was performed by using cosine transform method which could be adaptive within a wide range of time. And then,the algorithm of all-time apparent resistivity was employed,which is based on Continued Fractions expression. Several representative models were calculated and curves of apparent resistivity versus depth were drawn. The results show that these curves can generally describe the variation of resistivity under seabed,and the depth of conductivity / resistivity layers can be estimated according to the extreme points,thus providing a fast and efficient approach for the interpretation of marine TEM data and the assessment of original models.

关 键 词：海洋瞬变电磁法 中心回线装置 一维正演 连分式算法 全时域视电阻率 

分 类 号：P631.325[天文地球—地质矿产勘探]