Brine and Wastewater Spills
Brine and Wastewater Spills can be an unfortunate side effect of oil and gas extraction operations. Large volumes of wastewater are associated with oil and gas wells, from the water required in the ‘hydraulic fracking’ process to the constant stream of ‘produced water’. This water is typically contaminated when it returns to the surface, and needs to be properly stored, treated, and disposed of. Since the water can be very salty, and contain radioactive elements and toxic metals like arsenic, the effect to the environment can be devastating if spills occur. Brine and wastewater spills can occur from pipeline or injection well failures, leaking impoundment and storage ponds, or accidents during transportation.
Geophysical surveys are well suited for providing a fast and efficient characterization tool for brine and wastewater spills.
HGI has several decades of experience deploying geophysical tools to map brine and wastewater spills and monitor cleanup and remediation efforts in the oil and gas industry, as well as other sectors. Based on the high salt content, the majority of spills are electrically conductive making the electrical resistivity and electromagnetic methods ideally suited to delineating the extent of contamination in the subsurface.
The example below shows the results from an electrical resistivity survey in response to a brine spill from a salt-water disposal well. The data, presented as a color contoured slice of high and low resistivity values, display the plumes associated with salt-water contaminated groundwater as cooler colors.
Geophycsical surveys are also deployed in operational impoundments and ponds to test the integrity of the geotextile liner or pinpoint leak locations for repair.
Geophysical surveys can be used as a cost efficient reconnaissance tool, mapping out the extent of spills to “fill in the blanks” between wells and reduce drilling costs. Geophysical methods can also be used to survey areas where drill rig access is restricted and to improve understanding in complex geological areas. In addition, these surveys can be repeated over time to monitor contaminant movement, direct remediation efforts, and monitor the effectiveness of remediation efforts.