瞬变电磁法观测数据超格效应原理及消除方法  

Principle of supergrid effect of TEM observation data and its elimination method

作　　者：隆季原 李文尧[1] Long Jiyuan;Li Wenyao(School of Land and Resources Engineering,Kunming University of Science and Technology,Kunming Yunnan 650093,China)

机构地区：[1]昆明理工大学国土资源工程学院,云南昆明650093

出　　处：《化工矿物与加工》2021年第9期25-28,共4页Industrial Minerals & Processing

基　　金：国家重点研发计划(2018YFC0603903-03)。

摘　　要：在用瞬变电磁法探测地下矿体的过程中,会出现仪器观测数据超格效应,这部分超格数据因无法进行电阻率计算而严重制约瞬变电磁法的探测能力。基于此,对超格效应的原理、盲区深度计算理论进行了分析,并开展了探测实验,结果表明:观测数据超格效应造成的探测盲区与匹配电阻和均匀半空间电阻率有关;匹配电阻过大会导致观测数据出现超格或震荡且超格现象,影响的盲区深度范围可从数十米至数百米;减小匹配电阻,可以有效消除仪器观测数据超格效应带来的不利影响。In the course of detecting underground ore body with transient electromagnetic method(TEM),the supergrid effect of instrumental observation data may be observed.This part of supergrid data will seriously restrain the capability of TEM for detecting underground ore body due to the failure in calculating the resistivity.Because of this,the principle of supergrid effect and the theory of calculating blind area depth were analyzed,in addition,the detection experiments were carried out.The results show that the detecting blind zone caused by supergrid effect of instrument observation data is dependent on the matching resistance and well-distributed half-space resistivity.Oversized matching resistance leads to supergrid or vibration with supergrid of instrumental observation data,and the blind zone depth affected ranges from tens of meters to hundreds of meters.Reduction of the matching resistance is likely to effectively eliminate the adverse effects caused by the supergrid of instrumental observation data.

关 键 词：瞬变电磁法 超格效应 检测盲区 匹配电阻 时间窗口 消除方法 电阻率 

分 类 号：P631.3[天文地球—地质矿产勘探]