GUIP38: Focused Electric

The defining element of the GUIP38 probe, the use of a pair of equipotential “guard” electrodes, ensures a reliable formation resistivity measurement by focussing the injected current in a way that maximises vertical resolution and penetration into the formations while avoiding dissipation in the borehole fluid.

As well as providing high-resolution and full-range focussed resistivity measurements, an onboard processor calculates formation conductivity (in mmho/m) and capacitance (µF) values.

Due to focussing of the injection current, this method allows a resolution of thinner layers compared to a log of the traditional “normal” type. The other advantage of this method lies in the fact that it is suitable for difficult hole conditions (salt mud). This type of log is most often used for formation evaluation (lithology / porosity) and groundwater quality studies.