EM25: Slim Single Induction

The Slim Single Focused Induction EM25 sonde uses a three-coil focused electromagnetic array to provide a conductivity log. An oscillating high frequency magnetic field from a transmitter coil inside the probe induces an alternating electrical current within the surrounding conductive formation. This current, in turn, induces a voltage within receiver coils in the probe proportional to the formation conductivity. The transmitter-receiver spacings determine the depth of investigation of the measurements. Additional focusing coils minimize the contribution of the borehole signal. The sonde coil spacings are optimized to achieve high vertical resolution and a deep radius of investigation, with minimal borehole influence when logging in conductive-fluid-filled boreholes.

The Slim Single Focused Induction EM25 sonde main features are :

Formation conductivity measurement in dry or fluid-filled borehole or even in PVC casing
Phase detector discriminates between magnetic susceptibility and conductivity signals
Natural gamma measurement available for correlation