Through-Bit Logging

Borehole geophysical logging tools are widely accepted as an aid to formation and resource evaluation. Nowadays, more often than not, the logging of drilled boreholes has become a mandatory requirement be it in exploration, reconnaissance drilling, groundwater or geotechnics. However, for a borehole to be logged, it needs to be accessible to the logging sondes and carry a minimal risk to their recovery. Accessibility can be an issue for example in highly deviated boreholes or in boreholes that are prone to collapse, blocking access or trapping sondes. In boreholes that present such access difficulties, a conventional wireline logging operation becomes either risky, difficult to perform or simply unpracticable. In these instances, suitable tooling and equipment can be deployed to allow for Through -Bit Logging (TBL) while tripping out pipe. The Geovista TBL technique has proved to be both viable and easy to implement. Crucially, the same probes can be used for both TBL and WL deployment techniques