基于近代天线理论的钻孔电磁波法正常场  

The Normal Field in Borehole Electromagnetic Wave Method Based on the Modern Antenna Theory

作　　者：孙建国[1] 

机构地区：[1]吉林大学国土资源部应用地球物理综合解释理论开放实验室,吉林长春130026

出　　处：《地球学报》2002年第6期567-571,共5页Acta Geoscientica Sinica

基　　金：国家自然科学基金项目"利用偶极天线探测地层电磁参数的基本理论"(40074029)资助。

摘　　要：钻孔电磁波法的正常场公式是进行各种钻孔电磁波探测理论研究和资料解释的基础,因此有必要将其建立在近代天线理论之上。通过对钻孔电磁波法中的基本电磁系统的分析讨论,证明了关于绝缘天线的广义传输线理论在钻孔电磁探测和电磁波测井中的可应用性,并给出了在一般条件下的基于广义传输线理论的钻孔电磁波法正常场公式。通过与经典的正常场公式的定性对比发现,基于广义传输线理论的正常场公式既包含了天线本身绝缘层的作用,又考虑了钻孔的影响。因此,本文提出的公式能提供更多的关于围岩和钻孔流体的电磁性质的信息,应能成为跨孔电磁成像和电磁波测井的现代理论基础。The normal field in borehole electromagnetic wave method is the basis for both the theoretical investigation and the data interpretation. Therefore, it is necessary to establish the theory of the normal field on the basis of the modern antenna theory. Through an analysis of the basic electromagnetic system in borehole electromagnetic method, it is shown that the generalized transmission line theory of the insulated antenna is applicable to both the cross ?hole electromagnetic exploration and electromagnetic wave logging. In comparison with the classical formulations of the normal filed, it is found that the formula based on the generalized transmission line theory considers the influences of the insulate layer of the antenna and that of the boreholes. As a result, the formulas presented here can provide more information on the electromagnetic parameters of the surrounding rocks and the borehole fluid. They should become the theoretical foundation of the cross - hole electromagnetic exploration and the electromagnetic wave logging.

关 键 词：钻孔电磁波法 正常场 广义传输线理论 磁导率 围岩 钻孔流体 

分 类 号：P631.325[天文地球—地质矿产勘探]