Apparent resistivity curves of the transient method in a medium with cylindrical interfaces

Apparent Resistivity Curves of the Transient Method in a Medium with Cylindrical Interfaces 

We will present results of calculations of the field, dB /dt, on the borehole axis through apparent resistivity. It can be introduced in several ways, some of which have advantages within a certain range of time. We will use the following approach  

One of the features of the method of introducing the apparent resistivity is the independence of the probe coefficient from the resistivity of a medium. 

Examples of apparent resistivity curves are given in Figs. 9.8-9.22. Two-layer curves, when the invasion zone is absent, are given in Figs. 9.8-9.11. The index of the set of curves is the ratio p jp, while every curve is characterized by parameter a = L/a. The set of curves for a three-layer medium, Figs. 9.12-9.22, has as index  

The parameter of every curve is again the ratio of the probe length, L, to the borehole radius, a = L/aj. The ratio Ti/ai is plotted along the axis of the abscissa. 

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