Geophysical prospection & camera inspection

Borehole logging: the accurate solution to characterize borehole profiles

AGT owns geophysical sensors of Robertson Geologging Ltd, which are  specifically designed for groundwater-related applications. The sensors
are extra slim to fit in small diameter boreholes and piezometer tubes, down to a depth of 500 m. With the Dual Induction probe (~EM39), existing piezometers can also be logged. The following probes can be immediately deployed:

  • 3-arm Caliper: borehole diameter;
  • Electric logging (SN, LN, SP and SPR): lithology and groundwater salinity;
  • Natural gamma-radiation: clay layers;
  • Dual induction: lithology and groundwater salinity, also in piezometers;
  • Camera inspection: of existing wells or piezometers.

Figure: camera inspection of well filter in white PVC.

Near-surface geophysics: mapping the underground from the surface

  • Applications:
    • Determination of optimal drilling locations;
    • Mapping of water-bearing layers for fresh water supply;
    • Detection of underground utilities or object (gaz tanks, foundations...);
    • Identification of fractures and cavities (karst);
    • Monitoring of fresh water-salt water interface.
  • Techniques:
    • Electrical resistivity tomography (ERT);
    • Electromagnetic induction (EM);
    • Ground penetrating radar (GPR);
    • Seismic refraction;
    • Magnetometry.

Figure: depth mapping of sweet-salt groundwater interface with EM34-measurements.