New Study Links Hydraulic Fracturing Operations to Earthquakes in Western Canada
A newly-released study links hydraulic fracturing operations to injection-induced earthquakes in Western Canada. Geoscientists at the University of Calgary studied all wells completed from December 2014 to March 2015 within the Devonian Duvernay Formation, finding both spatial and temporal correlations between hydraulic fracturing operations and seismic activity in the area. The largest observed seismic event during this time measured magnitude 3.9. Nonetheless, a prior study found that induced seismic events of magnitude 3 or greater are associated with only about 0.3% of hydraulically fractured wells in western Canada.
The new study also found important differences in how different portions of the underlying fault system responded seismically; the east fault strand was primarily active during hydraulic fracturing operations, whereas the west fault strand remained activated for several months afterwards. The authors conclude that “the elastic response of the rockmass to hydraulic fracturing” is one of several different mechanisms that can trigger fault activation, leading to seismic activity. Indeed, the study acknowledges that the recent increase in induced seismic activity in North America “is primarily associated with” a different mechanism—the “high-rate injection of large volumes of saltwater into porous rock formations” that occurs in underground wastewater disposal operations. However, the authors also cite to two earlier studies that found links between hydraulic fracturing operations and earthquakes in Oklahoma and Poland, Ohio.
Speaking with the New York Times, one of the study’s authors acknowledged that different geographic areas respond differently to hydraulic fracturing activity, and that additional research should be conducted to “understand the origin of the differences.” Read the study in full