Dual Laterolog Tool


Provides accurate formation resistivity in high-contrast borehole environments


  • Determine formation resistivity in conductive 
  • Determine water saturation (Sw)

Features and Benefits

  • Determines true formation resistivity (Rt) and flushed zone resistivity (Rxo)
  • Provides inputs required to calculate water saturation
  • Generates quantitative evaluation of invasion

Tool Description

The Weatherford dual laterolog (DLL) tool simultaneously measures formation resistivity at two depths of investigation and at ranges up to 40,000 ohm-m. The tool offers excellent resolution of thin beds down to 24 in. (61 cm).

The DLL tool contains an array of nine electrodes to focus current into the formation and produce two advanced laterolog measurements with different current paths and frequencies. The tool often is run in combination with the microspherically focused laterolog (MSFL) tool to obtain an extra-shallow resistivity measurement, which allows calculation of Rt and Rxo in invaded conditions.

The DLL tool continuously monitors current and voltage to the measurement electrode. This ensures that the tool’s drive power consistently provides a wide, dynamic range of measurement. Conductive fluids must be present in the borehole for the DLL tool to work.

The DLL is fully combinable with other tools in the service line.