Oklahoma Earthquake Blamed on Underground Injection Wells at Oil Drilling SiteMar 27, 2013
A 2011 earthquake that shook the Oklahoma area is being blamed on nearby oil drilling operations disposing of wastewater via a technique also common to the hydraulic fracturing (fracking) process.
According to an Associated Press (AP) report, federal scientists published a study in the journal Ecology this week that blames the 5.6-magnitude earthquake recorded on Nov. 6, 2011, in Prague, Okla., on the underground injection of wastewater generated by nearby oil drilling operations.
The study notes that the injection wells were not used to dispose of drilling fluids used in a fracking operation. Additionally – as we've also reported – small and sometimes frequent earthquakes can strike in locations near underground injection wells used for the disposal of fracking wastewater.
The earthquake was one of the largest ever to rumble in the Oklahoma area, damaging 14 homes and injuring two people, AP reports. Fourteen states felt the quake that day.
The study was conducted by researchers at the University of Oklahoma, Columbia University and the U.S. Geological Survey (USGS). The results are being contested by Oklahoma state officials who believe the quake was caused naturally. The study adds that a smaller earthquake was noted the prior day, and an aftershock hit a day after the major earthquake. The epicenters of the quakes were in an old oil well used to dispose of drilling wastewater, AP reports.
This area of Oklahoma began disposing drilling waste into underground injection wells in 1993; the process is similar to the one used in some fracking operations.
Our previous reports show that disposing of fracking wastewater into underground injection wells creates pressure that, when combined with the briny consistency of the fluids, can be enough to cause earthquakes – typically smaller ones, but sometimes large enough to damage property.
One Columbia University researcher included in the study suggested there is not enough evidence to conclusively blame the 2011 earthquake on wastewater disposal, AP reports.
The USGS notes that well pressure at the site of the earthquake began to increase in 2006.
Earthquakes are just one of the many drawbacks noted by opponents of fracking drilling, even though this incident wasn't caused by that specific type of drilling. Our previous reports also show that opponents of fracking believe the drilling process can adversely impact the environment and public health by releasing dangerous chemicals and toxins into underground fractures where they can contaminate groundwater and poison the air surrounding active well sites.