Study: Hydraulic fracturing creating earthquakes
Researchers in Canada have determined that hydraulic fracturing (HF) is creating earthquakes. More specifically, a recent study discovered that the injection of stimulation fluids (fracking fluids) under high pressure create fractures in the impervious rock, and, ultimately, earthquakes.
— Water Canada (@CanadianWater) March 31, 2016
Canada is ranked second in the world in development of shale oil and gas, behind only the United States. It was previously thought that earthquakes in the Western Canadian Sedimentary Basin (WCSB) were a result of several factors, including stress changes in hydrocarbon production and wastewater disposal, as with the United States.
Proximity of HF wells is a factor
After selecting the WCSB as the source for the study, largely because of increasing earthquakes in the area, researchers began studying the correlation between the HF wells being drilled and the occurrences of earthquakes.
Researchers discovered that earthquakes were directly related to the increased number of HF wells being drilled, especially those in close proximity to one another.
According to the report, studies conducted in the United States have already shown that the injection of flow back fluid (waste water containing a cocktail of toxic and non-toxic chemicals) into the ground can trigger earthquakes.
Now, both the fracking procedure and the injection of fracking waste fluid into the ground has been linked to the occurrence of earthquakes.
HF wells increasingly concentrated
Since 2010, development of HF wells in the area has increased exponentially, mainly from recent technological advances in horizontal well drilling, resulting in multistage hydraulic fracturing.
Findings from the report revealed that this recent increase in concentrated drilling directly correlates to the advent of increased seismological activity.
Concerns regarding infrastructure
Although researchers admit that while the percentage of earthquakes that currently result is low (approximately 0.3 percent), they expressed concern over increased seismic activity if the current pace continues and wells are increasingly fracked in close proximity to one another.
The authors note that: "considering that thousands of such wells are drilled every year in the WCSB, the implications for hazard are nevertheless significant particularly if multiple operations are located in close proximity to critical infrastructure."
Time frames affect mitigation strategies
Researchers also expressed concern over the timing of the quakes, noting that quakes have "the potential to occur weeks or months after a treatment program has finished," thus requiring the re-examination of current mitigation strategies.
Reevaluation of studies in U.S. likely needed
Citing current and frequent 'frackquakes' in Oklahoma, and the high concentration of HF wells in the area, the authors also suggested that current wastewater events there may be masking quakes that are instead actually caused by the HF drilling process. Because of this, they suggested further examination an evaluation of the findings and to best determine the accurate causes.