Jeff Gu, a University of Alberta geophysicist, says the scientific community needs to better understand what’s triggering earthquakes near fracking operations. Ryan Jackson / Ryan Jackson/Edmonton Journal
Early in the new year, a tremor shook the area near Fox Creek in northwest Alberta.
It wasn’t the region’s first earthquake, but it was the largest — rattling pictures on walls, but not causing injuries or damage.
However, it did more than simply unnerve local residents.
It reverberated into the Alberta government, which ordered the province’s energy regulator to speed up its examination into the links between hydraulic fracturing and seismic activity.
The tremor that struck just west of Fox Creek on Jan. 12 registered as a 4.8-magnitude event, classified as a moderate quake.
Three months later — and after 23 more seismic events in the area — the province has just received a draft report on the issue from the Alberta Energy Regulator, with a final version expected this fall.
No one is saying what’s in the preliminary version.
But it’s logical to expect the AER will recommend more education, and possibly more monitoring, as more fracking by energy companies takes place.
Hopefully, it will call for more science to understand why this particular area has felt so many tremors, with more than 420 seismic events recorded near Fox Creek since the start of 2015.
The review comes as a new survey published this week by a team of researchers indicates a link between oilpatch hydraulic fracturing in Western Canada and quakes in the region.
The group reviewed data from 12,289 oil and gas wells drilled across the Western Canadian Sedimentary Basin (WCSB) since 1985.
In 39 cases, it found a correlation with earthquakes that registered at a magnitude of 3 or more.
Between 2010 and 2015, more than half of all induced earthquakes of such scale occurred “in close proximity to hydraulic fracturing operations, in both time and space.”
“There’s a scientific consensus that some areas — particularly in the Fox Creek area and parts of the Montney trend of British Columbia — there’s a clear association between hydraulic fracturing and induced earthquakes,” says David Eaton, a geophysicist at the University of Calgary who worked on the report.
Before the fault-line of public opinion splits apart in Alberta, it’s important to put this issue into context.
According to the Alberta Geological Survey, any seismic event of a magnitude under 4 is categorized as being “small, minor or micro,” while under 6 is deemed “moderate.”
Provincial data indicates only four earthquakes near Fox Creek since 2015 have been categorized at a magnitude of 4 or higher.
The industry drills thousands of wells each year. Last year, the AER approved almost 2,000 wells completed by fracturing.
Yet, the study found significant seismic activity occurred in only a tiny fraction of fractured wells, about 0.3 per cent of such cases.
The AER points out induced seismic activity has not caused any injuries or damage. But that doesn’t mean we should ignore the issue, either.
“Considering that thousands of such wells are drilled every year in the WCSB, the implications for hazard are nonetheless significant … particularly if multiple operations are located in close proximity to critical infrastructure,” the report cautions.
In other words, Alberta only needs one significant man-made seismic headache for the fallout to shake everyone to their core.
Jeff Gu, a University of Alberta geophysicist involved in the study, notes the report uncovers several other findings.
Unlike induced earthquakes in United States, which appear to be tied to underground wastewater disposal, the main source of induced earthquakes in Canada is associated with hydraulic fracturing.
But he believes the scientific community needs to better understand what’s triggering these quakes, why they’re clustered in specific areas — such as the Duvernay formation around Fox Creek — and how the risk can be reduced.
“It’s definitely worth looking into because we don’t know exactly how big these events are or can be, and where the next one will happen,” Gu says.
Canada trails only the United States in developing its shale oil and gas resources, and fracking has allowed the industry to unlock massive petroleum reserves underground.
The method usually involves high-pressure injection of fluids along horizontally drilled wells, often at two or three kilometres deep, to create or open cracks in rock underground to access the resource.
The NDP government took a cautious stance to the new survey this week, saying it’s working with the regulator and industry to better understand the relationship between fracking and seismic activity.
From industry’s perspective, the Canadian Association of Petroleum Producers noted the report reinforces a link between hydraulic fracturing and seismicity established in recent studies in British Columbia — but it also shows the vast majority of seismic events in the basin are minor and localized.
In the regulator’s realm, the AER issued new rules for operators near Fox Creek following an earlier quake in 2015. It requires companies fracking in the area to monitor seismic activity within five kilometres of their wells.
The AER also introduced a traffic light system: if companies record anything above a magnitude 2 event while fracking, they hit a yellow light and must inform the regulator. Anything above a 4-magnitude quake means full stop.
This go-slow approach makes sense. A moratorium, such as in New Brunswick, doesn’t seem like the answer.
And hopefully, the AER examination will get to the bottom of what’s causing the tremors near Fox Creek.
“We have to weigh the economic development against the risks on both sides. There’s a danger in going too far in either direction,” says Eaton.
In other words, proceed with caution.
Chris Varcoe is a Calgary Herald columnist
Source: Varcoe: Alberta seeks answers on links between earthquakes and fracking | Calgary Herald
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