Time‐lapse electrical resistivity monitoring of salt‐affected soil and groundwater

Summary Time-lapse electrical geophysics is used to monitor the remediation of oilfield brines in soil and groundwater. Challenges with comparing geophysical surveys done during different seasons at different temperatures were overcome through temperature monitoring and geophysical processing techniques. The background electrical conductivity structure captured by the geophysics compared well with push tool conductivity logs collected and had strong correlation with salt samples taken. However the changes in electrical conductivity observed in the timelapse geophysics provided information about the remediation effectiveness that was not available from the logs and point measurements. From the observed changes in the geophysics we interpret that depression focused recharge has a large impact on remediation effectiveness. This research indicates that time-lapse electrical geophysics is an effective and low cost remediation monitoring method at appropriate sites.

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