Magnetotelluric Monitoring of Unconventional Energy Resource Development: Disruptive Technology or Damp Squib?

Abstract

A significant scientific and engineering challenge for the energy resources industry is to monitor injected or produced fluid at depths of hundreds or thousands of metres, and over time-scales of hours to years. A new approach using surface magnetotelluric (MT) methods has been developed over the last five years to map deep-fluid pathways by virtue of their electrical resistivity changes, both spatially and temporally. This is a cheap technology as it uses natural electromagnetic source-fields and does not require drilling. However, is this method really effective for industry for economic reasons and for social and environmental compliance? In other words, is it a disruptive technology or a damp squib?

This paper reviews the physics of the approach, and demonstrates the feasibility of the MT method for monitoring unconventional energy resource development. A number of case studies will be shown, including shallow coal seam gas de-pressurisation, deep hydraulic stimulation of a shale gas reservoir, and enhanced geothermal system development.