过套管电阻率测井仪器的径向探测特性

为研究过套管电阻率测井仪器的径向探测特性，本文给出了反映地层径向介质变化的几何因子.利用过套管电阻率测井的传输线方程实现了电阻率测井几何因子的数值计算，针对Schlumberger公司的CHFR测井仪和俄罗斯的ЭКОС-31-7测井仪分别计算了几何因子响应曲线，通过曲线分析发现：两种测井仪对低侵剖面（有低阻流体侵入）均有较大的探测半径，但随侵入流体电阻的增大（高侵剖面）仪器的径向探测半径在减小，本文的研究为地层电阻率测井解释和仪器径向探测特性分析提供了理论依据.

The detecting characteristics of resistivity log tool through casing

In order to study the radial detecting characteristics of resistivity log tool through casing,this paper gives the geometric factor which can image the radial change of stratal medium.The geometric factor of resistivity log tool has been calculated by the transmission line equation for resistivity logging through casing.Aimed at the CHFR tool of Schlumberger Corporation and the зKOC-31-7 tool of Russia we have given the response curves of the geometric factor,and found that two kinds of tools all have large radial detecting radius for the low invasion profile(invasion of low resistance fluid),but the radial detecting radii of tools decrease with the increase of invasion fluid resistance(high invasion profile).This research provides the theoretic foundation for the logging interpretation and the analysis of radial detecting characteristics of tools.