The QL40-IND Dual Focused Induction probe provides two simultaneous conductivity logs, corresponding to “Medium” and “Deep” radii of investigation into the borehole. The two depths of penetration are useful in porous, permeable formations where displacement of formation fluids by drilling mud creates an invasion zone with different electrical properties.

High stability and exceptionally wide dynamic range allow the user to carry out precise measurements of conductivity in formations with sand-clay layers and mineralized, water-soaked sands. In contrast to electrical tools, this induction tool can be used in dry and non-metallic cased holes.

The QL40-IND tool is stackable within the Quick Link (QL) product line or it can be run as a standalone tool.


  • Indicator of permeable zones and porosity
  • Formation water salinity
  • Long term well monitoring
  • Ore Identification and quality correlation
  • Indication of Hydrocarbons

Operating Conditions

Borehole Fluid
[X] Water
[X] Mud
[X] Dry

[X] Uncased
[X] PVC Borehole
[_] Steel

[_] Required
[X] Not Necessary

Features & Benefits

  • Two depths of investigation for detailed formation characterization
  • More temperature stabilization than other tools on the market
  • Easy to calibrate for specific borehole conductivity ranges
  • Operates on any standard wireline (Mono, 4, 7 conductor, or Coax)
  • Slim, 45 mm diameter. One-person operation.
  • Can be combined with other logging tools of the QL product line or operated as a standalone tool.

Specifications – Metric/English

Specification Metric Imperial
Diameter 45 mm 1.77″
Length 1.925 m 75.78″
Weight 7 Kg 15.4 lbs.
Max. Temp. 70ºC 158ºF
Max. Pressure 200 bar 2900 psi


Intercoil Spacing: 50 cm and 80 cm
Operating Frequency: ~100 kHz
Accuracy: < 3% F.S.
Stability: < 0.5 mS/ 10 ºC
Conductivity Range: 1-3000 mS/m

QL Stack Possibilities

  • QL40IND + QL40GR (Gamma): Lithology tool in Dry and Non-Magnetic cased holes
  • QL40IND + QL40IP (Induced Polarization) : Hydrothermal Vein location, Graphite location
  • QL40IND + QL40IP (Induced Polarization) + QL40GR (Gamma): Uranium Exploration
  • QL40IND + QL40IP (Induced Polarization) + QL40MGS (Mag. Sus.): Mining Exploration Tool, Mineral and Ore body Identification


Data Sheet
User Guide

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