Geophysics as an integral part of the Aquifer Storage and Recovery (ASR) process

Purpose: Develop a rationale for electrical resistivity surveying as a means for mapping ASR (Aquifer Storage and Recovery) bubble morphology during an ASR injection/withdrawal cycle.

Background: Bubble morphology is often assumed to have radial symmetry when the ASR process is modeled. While density variation and its effect on cross-sectional shape is sometimes included, too little attention is given to radial asymmetry due to fracture-dominated permeability, lateral variations in limestone mineralogy, or regional groundwater flow. The net combination of these could influence bubble growth such that the 'real' bubble shape could depart significantly from radial symmetry. We propose that electrical resistivity surveying is a tenable means of mapping bubble morphology/growth characteristics from the ground surface without impacting the ASR process itself.