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
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.
Lim designs, produces and commercializes measuring instruments and solutions dedicated to drilling.