地-井瞬变电磁响应特征数值模拟分析  

Numerical simulation analysis of surface-hole TEM responses

作　　者：孟庆鑫[1] 潘和平[1] 

机构地区：[1]中国地质大学(武汉)地球物理与空间信息学院,武汉430074

出　　处：《地球物理学报》2012年第3期1046-1053,共8页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(41074086)资助

摘　　要：井中瞬变电磁法(Bore-hole transient electromagnetic method-BHTEM)是指接收线圈在钻井中观测瞬变场响应用以勘查深部矿产资源的勘探方法,其中以地-井(地面激发井中接收)组合方式研究最多、应用最广.本文应用时域有限差分法(FDTD),建立包含薄板导体的均匀半空间二维数学模型,采用线源为激发源,选用Mur吸收边界条件,对矩形回线源在半空间中产生的瞬变电磁场进行数值模拟,计算了低阻板状导体在均质半空间和有低阻覆盖层影响情况下的地-井瞬变电磁异常响应,并对响应的特征及规律进行研究分析,为研究地-井TEM提供参考.Bore-hole transient electromagnetic method（BHTEM） is a geophysical survey method of mineral resource which measures the transient electromagnetic field in a borehole by placing the receiving coils in the borehole.Therein,surface-to-borehole TEM measurement（transmitters are on the surface,receivers are in the borehole） is the most popular acquisition layout and used widely.Using a finite-difference time-domain（FDTD） method,we develop a 2D simulation program.At first,we simulate the response of a large rectangular loop source in a half-space using a line source and Mur absorbing boundary condition.Then we simulate a model of uniform half-space with a conductive plate and another model with a conductive overburden,respectively.The model responses provide useful information for the surface-to-borehole TEM research.

关 键 词：井中瞬变电磁 地-井瞬变电磁 均质半空间 导电薄板 时域有限差分 

分 类 号：P631[天文地球—地质矿产勘探]