The Use of Electrical Resistivity Imaging to Map Coal Seams

Subsurface Imaging, University of Adelaide and Geostudi Astier formed a collaborative team to investigate and develop the use of Electrical Resistivity Imaging techniques in the coal industry of Australia.

The objective of this project was to pave the way for resistivity imaging to fulfill a similar role by mapping out coal seams and surrounding geology, in three situations where seismic is not applicable:

• using surface resistivity for mapping shallower open cut coalmines;
• using crosshole resistivity to map out underground mining leases, in areas where surface conditions preclude the use of seismic;
• using crosshole resistivity for detailed mapping of complex structures

The work provided an initial assessment of the technique's capability in these situations, through two case studies at representative sites in Queensland and New South Wales. These case studies were underpinned by geological and geophysical calibration data as well as detailed computer simulations.

Success will be defined by the ability of resistivity imaging to map out economically significant changes in coal seam properties, to useful precision, and in a manner which is cost effective and logistically attractive.

A secondary aim is to identify ways to improve the technique within the coal mining environment and assess their relative merits.