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Borehole Geophysical Surveys / +44 (0)1939 210 710

Gamma-Gamma Tool

This density tool has two detectors at different spacings from a source of gamma radiation. The logs from each detector indicate the apparent density of the material surrounding the tool at a radius of investigation related to the spacing.

The Long Spaced Density detector (LSD) has a spacing of 48cm and the greatest depth of investigation.

The High Resolution Density detector (HRD) has a spacing of 24cm, this detector gives the greatest resolution but is more affected by borehole features such as linings and mud-cake.


  • Size:
    2250 x 38mm
  • Weight:
  • Max. temperature:

Logging Conditions

  • 2 – 5m / min
  • Free running

Borehole Conditions

50 – 300mm*

  • Fluid filled or dry
  • Unlined or lined**

*For boreholes larger than 300mm this tool may be run sidewalled with multiple runs around different sides of the borehole.

**In lined or cased sections of boreholes these logs give qualitative information on the density of the borehole.

Example formation investigation using dual density and natural gamma Logs through cased boreholes into old coal workings.