Slimline Magnetic Susceptibility Sonde


Provides a quantitative measurement of the magnetic properties of the formation intersected by the borehole


  • Detection of magnetic anomalies
  • Heavy mineral prospecting
  • Cross-borehole correlation
  • Determination of magnetite content in iron-ore deposits
  • Grade control in iron ore
  • Indication of altered zones within ferromagnetic units
  • Horizon detection
  • Identification of mineralized zones
  • Water-well monitoring for salinity

Features and Benefits

  • Like all other Slimline equipment, the Slimline magnetic susceptibility sonde (MGSUS) is designed for logging without a rig, which reduces use of expensive rig time.
  • The sensitivity is scalable to make appropriate measurements for specific applications.
  • The small, lightweight tool can be easily transported in challenging environments, which enables logging of holes otherwise inaccessible to logging equipment.
  • The MGSUS is temperature-compensated to reduce the effects of thermal drift, thereby improving the accuracy of the gathered data.
  • The MGSUS can be run in dry holes and measures effectively through polyvinylchloride casing, which enables the capture of important data in difficult conditions.

Tool Description

The Weatherford Slimline magnetic susceptibility sonde (MGSUS) is sensitive to the presence of magnetic materials and is intended for use in magnetic-mineral prospection and stratigraphic correlation. It is engineered to avoid interference from rock conductivities, and the circuitry is temperature-compensated to minimize thermally induced drift.

The MGSUS is comprised of a transmitter coil and a balanced receiver coil. The coils are set up so that the direct coupling signal from the transmitter is cancelled when the tool is in a homogeneous environment.

The MGSUS responds to signals in phase (R-signals) and out of phase (X-signals) with the transmitter. The X-signals are more sensitive to the presence of magnetic materials. Some variants of the MGSUS record the X-signals only.

The MGSUS is commonly used in banded-iron formations to identify the sequence and quantify the grade. In massive sulphide deposits, it is typically used to identify resource boundaries. 

Depending on the specific type of MGSUS chosen for the application, it is calibrated in centimeter–gram–second (cgs) units or conductivity units (millisiemens per meter).