Regulator defends finding that Alberta's largest earthquake was caused by oilpatch
Alberta's energy regulator has defended its finding that the province's largest recorded earthquake was caused by oilpatch activity, saying the pattern of temblors since last fall clearly points to a water disposal well even though there's no suggestion rules were flouted.
"The connection between the earthquake sequence and the disposal well injecting into the deeper Leduc Formation was clear," says a timeline of the research conducted by the Alberta Geological Survey, a branch of the Alberta Energy Regulator.
The release of the timeline comes three days after Obsidian Energy, a Calgary-based oil and gas producer, openly challenged the regulator's attribution of a 5.6 magnitude quake last November to operations of the company's deep disposal well near the town of Peace River.
"Since we have not seen any data or other evidence for the (regulator’s) conclusions, we cannot — and do not — agree with these conclusions," said Obsidian president Stephen Loukas in a release.
"We have requested data from the (regulator) and intend to engage independent third-party experts to help us better understand (its) reasoning."
But the timeline, obtained by The Canadian Press, shows the regulator's conclusion was based on months of study, analysis from outside experts and the evidence of multiple seismic shocks and aftershocks.
On Nov. 29, 2022, a magnitude 5.6 earthquake about 40 kilometres southeast of Peace River knocked people to their knees and rattled both windows and nerves.
Oilpatch techniques like disposal wells that inject wastewater kilometres underground can induce earthquakes. One area disposal well has pushed more than a million cubic metres of water underground.
But provincial geoscientists originally concluded the big quake was naturally caused.
It was too deep to be from energy activity, they said. Nor did it line up with company data on the timing of water disposal.
"However, further work was needed to characterize the event," the timeline says.
Scientists placed sensors around the earthquake site to capture data from aftershocks and outline underground strata. That data was given to a third party for analysis.
Still, the frequency and size of aftershocks near the main shock continued to decay, consistent with a natural earthquake.
Then another earthquake with magnitude of 3.2 happened on March 9 at a shallower depth. On March 16, a magnitude 5 earthquake took place near where the November temblor shook.
"The recurrence of large, felt seismicity, more typical of induced seismicity led the (survey) to more strongly suspect the events associated with this cluster were induced," says the timeline.
An environmental protection order was issued to Obsidian on March 23. The company must submit plans to reduce the frequency and magnitude of the events and increase monitoring.
The regulator's conclusions were backed up by an independent study by seismologists at Stanford University, the University of Alberta and Natural Resources Canada. The regulator did not see that study before releasing its finding.
Obsidian did not comment on the regulator's timeline. But in its March 27 release, it maintains it has followed the rules.
"The company’s water disposal well is both approved and licensed by the (regulator)," it said.
"Obsidian Energy ensures that all of our operations are in compliance with regulatory requirements and operates the water disposal well at pressures far below licensed rates. Obsidian Energy’s … well has operated safely for more than a decade, as have, to the best of the company’s knowledge, similar water disposal wells operated by other oil producers in the vicinity."
Ryan Schultz, one of the seismologists behind the university study, has said the induced seismicity could have implications for Alberta's plans for large-scale injection of carbon dioxide into similar wells to reduce greenhouse gas emissions.
“If carbon capture is going to be done at a scale that is going to combat climate change, then significant amounts of volume need to be put in the ground,” he said after his study's release. “You might expect then also getting these types of earthquakes the more volume that you store.”
Schultz said the events around Obsidian's well should cause governments to require much more extensive seismic monitoring around carbon capture and storage.
This report by The Canadian Press was first published March 30, 2023.
CTVNews.ca Top Stories
DEVELOPING Person on fire outside Trump's hush money trial rushed away on a stretcher
A person who was on fire in a park outside the New York courthouse where Donald Trump’s hush money trial is taking place has been rushed away on a stretcher.
Mandisa, Grammy award-winning 'American Idol' alum, dead at 47
Soulful gospel artist Mandisa, a Grammy-winning singer who got her start as a contestant on 'American Idol' in 2006, has died, according to a statement on her verified social media. She was 47.
She set out to find a husband in a year. Then she matched with a guy on a dating app on the other side of the world
Scottish comedian Samantha Hannah was working on a comedy show about finding a husband when Toby Hunter came into her life. What happened next surprised them both.
Senators reject field trip to African Lion Safari amid elephant bill study
The Senate legal affairs committee has rejected a motion calling for members to take a $50,000 field trip to the African Lion Safari in southern Ontario to see the zoo's elephant exhibit.
'It could be catastrophic': Woman says natural supplement contained hidden painkiller drug
A Manitoba woman thought she found a miracle natural supplement, but said a hidden ingredient wreaked havoc on her health.
Police in Paris detain a man wearing fake explosives vest at Iran's Consulate
A man wearing a fake explosive vest and making threats was detained Friday outside the Iranian Consulate in Paris after police locked down the area, authorities said. His motive was unclear.
DEVELOPING G7 warns of new sanctions against Iran as world reacts to apparent Israeli drone attack
Group of Seven foreign ministers warned of new sanctions against Iran on Friday for its drone and missile attack on Israel, and urged both sides to avoid an escalation of the conflict.
CFIA monitoring for avian flu in Canadian dairy cattle after U.S. discoveries
The Canadian Food Inspection Agency is encouraging veterinarians to keep an eye out for signs of avian influenza in dairy cattle following recent discoveries of cases of the disease in U.S. cow herds.
After hearing thousands of last words, this hospital chaplain has advice for the living
Hospital chaplain J.S. Park opens up about death, grief and hearing thousands of last words, and shares his advice for the living.