时间域激电测深不同装置数据去耦分析

为消除激电测深中的电磁耦合干扰,根据频率域和时间域可相互转换的理论,采用静态IP和cole-cole参数的全波形IP、延时反演去耦方法,实现了快速去耦,最大限度地保留了激电信息。以山东沂南金矿金场矿区等为例,对时间域激电测深数据进行了去耦前反演与去耦后反演,结果表明:对称四极装置和非常规电极排列的电磁耦合效应随电极距的增大而增强,电磁耦合的影响深度大部分在时间域激电测深反演断面150m以浅;非常规电极排列采用三极+四极+偶极混合共线装置,其产生的电磁耦合干扰明显大于对称四极装置和单极—偶极装置;非共线单极—偶极装置的时间域激电测深电磁耦合影响较小。

A data decoupling analysis of different devices in time-domain IP sounding

This study aims to eliminate the electromagnetic coupling interference in IP sounding. Based on the theory that frequency-and time-domain data can be mutually converted, this study achieved rapid decoupling while retaining the IP information to the greatest extent by using decoupling methods including static IP inversion, the full waveform IP inversion of Cole-Cole parameters, and delay inversion. This study investigated a gold deposit in Yinan County, Shandong Province and conducted the inversion of time-domain IP sounding data before and after decoupling. The results are as follows. The electromagnetic coupling effect of symmetrical quadrupole devices and unconventional electrode array increases with an increase in the distance between adjacent electrodes, and its influencing depth is mostly less than 150 m in the inversion results of time-domain IP sounding; the electromagnetic coupling interference produced by the unconventional electrode array that adopts a collinear device of dislocation multipoles (tripoles, quadrupoles, and dipoles) is apparently greater than that of symmetrical quadrupole devices and monopole-dipole devices; noncollinear monopole-dipole devices generate slight electromagnetic coupling effect in the process of time-domain IP sounding.