After the recent quakes near fracking wells in Poland, why can’t we say that fracking causes earthquakes?
First of all, there has been no official link established between the seismic events and Hilcorp’s wells. The Ohio Department of Natural Resources is conducting a thorough investigation and reviewing all of Hilcorp’s logs, but it is simply too soon to make that determination.
Additionally, the link between the act of fracking and seismic disturbance is tenuous at best.
Earthquakes are known to be connected to deep injection wells, such as the one in Youngstown that caused as many as 109 quakes in 2011 and 2012. Those wells dispose of fracking wastewater, sand and chemicals deep underground. The industry refers to it as the safest and most efficient way of disposing of waste, but the practice has been scientifically linked to earthquakes.
The instances have been particularly high in the Barnett Shale play, around Dallas-Fort Worth, and the quakes are growing in both number and size.
In the case of the Youngstown injection well, owned by D&L Energy, the well was drilled too deep and penetrated the Precambrian formation, an ancient rock formation between 9,000 and 9,600 feet below the ground in this area. Since the rock is older, preexisting faults are under more stress and are more susceptible to being disturbed when lubricated with liquid.
That kind of connection between quakes and injection wells does not exist with fracking, though. There are only three instances where the U.S. Geological Survey can definitively say that fracking caused quakes.
Only one case happened in the United States—in Oklahoma, which has seen a dramatic rise in quakes between 2009 and 2013. The other two events occurred in British Columbia and England. That, certainly, is not enough evidence to say the practice of fracking, itself, triggers seismic activity.
What can be said, however, is that the underlying geology of certain areas may not be conducive to fracking, raising the probability that quakes will occur. That was the case in Oklahoma, and it may be the case in Poland, as well.
But if it does turn out that fracking was the trigger for the Poland tremors, it would be the exception, not the rule. According to FracTracker, there have been 1.1 million wells drilled in this country, and even more abroad. So the instances are extremely low.
For now, much remains unknown about what happened in Poland. We don’t have much information about what the geology is there, and ODNR continues to use a network of seismic monitors to better understand what happened there.
There have been calls for ODNR to move portable monitors to the site, but there has been no movement on that so far, and ODNR believes it has enough solid data at the moment to monitor the region as it continues its investigation. There has been outside interest from USGS and Lamont-Doherty Earth Observatory to move similar devises into the area, but they have not taken any action yet, likely as a professional courtesy to ODNR.
The picture will remain somewhat hazy until the investigation is complete. But for now, it is safe to say that fracking is not a definitive trigger for earthquakes, but if the geology of a certain drilling area is not right, tremors could occur.
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