Low-volume fracking found still dangerous by Jonathan Sher, February 8, 2018, The London Free Press
Companies that frack less aggressively for oil can lessen the number of earthquakes but not necessarily their magnitude, a London researcher has found.
Gail Atkinson, a professor in Western University’s faculty of science, has found oil companies that reduce the volume of liquids they use to displace oil lack the evidence needed to show they won’t trigger a major earthquake, a finding that regulators may need to consider when deciding whether to allow fracking closer to population centres.
“This is an important finding because some previously held theories propose that there is a relationship between the largest magnitude of the earthquake and the injected volume, but what we have found is that the maximum magnitude isn’t what’s being controlled by the volume,” said Atkinson, the nanometrics industrial research chair in hazards from induced seismicity.
The use of fracking has grown in the past decade because it allows oil companies to drill a single vertical shaft until it reaches a bed of oil, then drill a horizontal shaft to extract that oil less expensively than the traditional method of drilling multiple vertical shafts, Atkinson said.
But when companies pump liquids through horizontal shafts, the pressure triggers earthquakes, previous research has found.
The newest research by Atkinson, published in a leading journal, Science, tapped into more detailed data on how liquids are used to frack near Fox Creek in central Alberta that holds Canada’s largest marketable reserves of oil.
“Industry needs to be aware that controlling the volume doesn’t provide a guarantee on the maximum magnitude,” says Atkinson, who teamed with researchers at the Alberta Geological Survey, the University of Alberta, the University of Calgary and Natural Resources Canada. “There is still a possibility for larger events, so industry still needs to be very careful where they conduct hydraulic fracturing operations. They have to stay away from critical infrastructure to prevent a damaging event.”
[Is a home critical infrastructure? A farm? A drinking water aquifer? A community drinking water reservoir? A citizen water well? Companies frac where ever they want. If anyone dares raise concerns or ask questions, in swoops the Nazi-Synergiesters like SPOG and Synergy Alberta, AER & CAPP, and often the local church, to silence the offensive reasonable citizens wanting to protect their loved ones, water, lands, homes, businesses, and communities]
When the number of earthquakes increases because fracking, while the vast majority will be small in scope, the greater their number, the greater the chance that one could be substantial, she said.
“There is some indication that industry is getting better at limiting induced earthquakes as the number of induced events has gone down in a number of jurisdictions, like Alberta and Oklahoma, over the past year,” says Atkinson. “For a while, every year, the largest event that was induced was the largest to date and we haven’t seen anything bigger this year than we have before. That may be a sign that industry is figuring some of these things out.” [How much damage underground, to buildings, homes, bridges, water supplies, etc in the meantime, how many gas migration pathways created, including in deadly sour gas zones under and or near towns like Fox Creek, Alberta? Emphasis added]
Fracking in shale plays could trigger earthquakes in deeper faults: study by Kathiann M. Kowalski, February 7, 2018
Miami University researchers analyzed three years worth of seismic events in an Ohio county and concluded fracking in shale plays can affect deeper faults.
Ohio oil and gas drillers could trigger noticeable earthquakes even if fracking activity doesn’t miss targets or directly contact deeper faults in the basement rock.
That’s the conclusion of new research from Miami University that looked at how pumping fluids underground can affect faults much deeper underground.
“With the results from our study, we can better advise environmental regulators and natural gas companies about what to expect when attempting hydraulic fracturing,” [DAMAGE!] said geologist Michael Brudzinski at Miami University in Oxford, Ohio, a co-author of the report published Monday in the Proceedings of the National Academy of Sciences (PNAS).
The study could lead to more regulatory scrutiny of shale gas drilling in Ohio and elsewhere, but it doesn’t give a quick yes-or-no answer on where drilling should or shouldn’t take place. As one Facebook status option says, it’s complicated.
What did the researchers find?
The study team found fracking can lead to two types of earthquakes, based on an analysis of the largest seismic events in Harrison County, Ohio, from 2013 to 2015. What happens depends on the local tectonics— geologic conditions linked to movements of parts of the earth’s crust over very long periods of time.
Larger earthquakes of magnitude 3 or more generally involve older faults in deeper layers, reported geologist Maria Kozlowska, who worked on the project as a post-doctoral researcher at Miami University. Fracking fluids don’t necessarily have to enter those faults or deeper layers in order to trigger earthquakes, Brudzinski said.
How old are those more mature faults, and how would fracking affect them?
Those older faults are in deep layers that date back to hundreds of millions of years ago when plates collided into eastern North America and built up the Appalachian Mountains. When things settled down, the fault movements slowed to nearly a stop. “We think that the injection has woken them up by allowing stored energy from long ago to finally be released,” Brudzinski said.
How deep are we talking?
In east-central Ohio, the Utica shale play is generally more than 6,000 feet below the surface, with the Marcellus Shale layer between 3,000 and 3,500 feet, according to a profile from the Ohio Department of Natural Resources. The Precambrian basement layer is generally more than 8,800 feet deep.
Should people worry about those earthquakes above magnitude 3?
As of now, no. The seismic hazard level for Ohio is not high, even in the state’s shale areas, Kozlowska said. “However, there is a potential risk of magnitude 4 events,” she added. “They may be felt but [are] not dangerous.” [Really? Tell that to the citizens, businesses and communities in sour gas country and the thousands of families with damaged homes]
Do fracking fluids have to enter those ancient faults in order to trigger earthquakes?
Maybe not. “Our results provide some new evidence that the stresses from fracturing the shale rocks may be enough to trigger the deeper older faults to move without having a direct connection,” Brudzinski said. Among other things, the timing didn’t quite match up between when operators pumped millions of gallons of fluids down under pressure and when the team might have expected to see seismic activity if the fluids had connected up with a fault.
However, the team couldn’t rule out a connection through a “flower structure,” where a fault from the older, deeper basement layer has gradually extended upwards and branched out into shallower layers.
Prior research also shows that fracking fluids don’t necessarily stay in the layers where they’re injected.
How will the research affect the future of fracking?
“With the results from our study, we can better advise environmental regulators and natural gas companies about what to expect when attempting hydraulic fracturing,” Brudzinski said. That might lead to more earthquakes being linked to fracking activity, which might preclude further work at some sites.
But seismic events are rare relative to the number of wells drilled in Ohio. And companies drilling for shale gas in Ohio must already do extensive seismic monitoring. If a magnitude 1.0 event happens, “you’ve got to shut down, and you’ve got to figure out” what’s happening, said Mike Chadsey, public relations director for the Ohio Oil & Gas Association.
[Compare to insane Alberta and BC, where companies can keep frac’ing even when it causes hundreds of quakes between magnitude 1.0 and 4.0!]
[Refer also to:
2015 02 20: Quakes in Gas Fields Ignored for Years, Dutch Safety Agency’s report a relevant read for any fracking zone; Fox Creek frac quakes make AER play deregulation with you and your loved ones: “Red Light = Green Light”
The fears of residents have not been assuaged by comments from Chiel Seinen, the spokesman for the Nederlandse Aardolie Maatschappij (NAM), a gas consortium including Royal Dutch Shell Plc and Exxon Mobil Corp, who conceded that people’s lives might be in danger. “You can never exclude anything if people are in the wrong place at the wrong time,” he told the BBC last month.]