Capacitively Coupled Resistivity

DMT has over 20 years’ experience managing and interpreting airborne geophysical surveys. Applications for airborne geophysical surveys include: groundwater exploration and investigation, oil and gas exploration, mining exploration, aggregate exploration and geotechnical engineering investigations.

DMT has extensive experience using the OhmMapper system for:

  • Sand and gravel exploration including frac sand
  • Environmental surveys for contamination – Volume analysis can be made from 3D presentation of OhmMapper data
  • Geotechnical investigations such as void detection
  • Groundwater and shallow bitumen exploration
  • Permafrost mapping
  • Other engineering, oil and gas and mining applications

The OhmMapper system is a capacitively coupled resistivity meter consisting of a coaxial-cable array with transmitter and receiver sections. When expertly used, the result is a resistivity section or 3D volume similar to that acquired by ground resistivity (i.e., electrical resistivity tomography or ERT). OhmMapper has advantages over electromagnetic (EM) and direct current (DC) resistivity surveys:

  • The measurements can be made much quicker and less expensively than by ground DC electrical methods by towing the system.
  • Geometric control of investigation depth allows better volume estimates than can be made from EM surveys.
  • Performs in areas where contact resistance problems would reduce ERT data quality.
  • There are limitations to the OhmMapper system such as a shallow depth of exploration and performance in some types of terrain. The planning, execution and processing of the OhmMapper survey benefits from the vast experience of DMT in a variety of geological terrains and applications. Please call DMT for more information.