地—井瞬变电磁响应特征研究  

Research on response of ground-borehole TEM

作　　者：易洪春 YI Hong-Chun(Chongqing Research Institute of China Coal Technology and Engineering Group,Chongqing 400037,China)

机构地区：[1]中煤科工集团重庆研究院有限公司,重庆400037

出　　处：《物探与化探》2018年第5期970-976,共7页Geophysical and Geochemical Exploration

基　　金：国家十三五重大专项"井下致裂效果范围测定技术与装备"(2016ZX05045004-007)

摘　　要：地—井瞬变电磁法作为瞬变电磁法的一种装置形式,由于其接收探头在钻孔或井下巷道中,靠近目标异常体,具有电磁干扰小、有用信号强等优点,越来越多地被国内外学者所研究。本文采用时域有限差分法(FDTD),以回线源为激发源,建立含板状体和矩形低阻体的地质模型,从地面—井筒观测方式和地面—巷道观测方式的角度,计算矩形回线源在半空间中产生的地—井瞬变电磁场响应,并对其响应的特征及规律进行研究,研究结果表明当有多个异常体同时存在时,地—井瞬变电磁能够区分出不同的异常体存在,并且能够对不同异常体的埋深和横向位置准确定位,为地—井瞬变电磁法定量解释异常体埋深和位置提供参考依据。As a device form of transient electromagnetic method,the ground-borehole TEM is being studied by more and more experts both in China and abroad. It has such advantages as small electromagnetic interference,strong signal for its receiving probe in the drilling or downhole tunnel,and closeness to the target anomaly. In this paper,the author used loop source as the excitation source,and established the geological model using finite-difference time-domain method（ FDTD） with plate-like body and rectangular low-resistance body. The author calculated the transient response of the rectangular loop source ground-borehole TEM in the half space,and studied its characteristics and laws from the perspective of ground-borehole observation and ground-tunnel observation. The results show that,when multiple anomalies exist simultaneously,the ground-borehole TEM can distinguish different anomalies from the anomalous body and can accurately locate the depth and the horizontal position of different anomalies. The results can provide reference for the quantitative explanation of the depth and location of the anomaly with ground-borehole TEM.

关 键 词：地—井瞬变电磁法 响应特征 数值模拟 定量 

分 类 号：P631[天文地球—地质矿产勘探]