Originally posted by Denny
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Not all faults are super deep, and there are faults all over the place that are not on major tectonic plate boundaries.
It's been shown that injection can cause mini-quakes, but it is certainly not a guaranteed outcome.
Nov. 4, 2013 — A new study correlates a series of small earthquakes near Snyder, Texas between 2006 and 2011 with the underground injection of large volumes of gas, primarily carbon dioxide (CO2) -- a finding that is relevant to the process of capturing and storing CO2 underground.
Although the study suggests that underground injection of gas triggered the Snyder earthquakes, it also points out that similar rates of injections have not triggered comparable quakes in other fields, bolstering the idea that underground gas injection does not cause significant seismic events in many geologic settings.
The study represents the first time underground gas injection has been correlated with earthquakes greater than magnitude 3.
Map showing 2009–2011 earthquakes located in this study (red circles), gas injection wells active since 2004 (yellow squares), and focal mechanisms for regional events (beach balls). A series of small quakes occurred in the same region in 1979 and 1980 (green circles) and may have been related to injection of water for enhanced oil recovery.
Although the study suggests that underground injection of gas triggered the Snyder earthquakes, it also points out that similar rates of injections have not triggered comparable quakes in other fields, bolstering the idea that underground gas injection does not cause significant seismic events in many geologic settings.
The study represents the first time underground gas injection has been correlated with earthquakes greater than magnitude 3.
Map showing 2009–2011 earthquakes located in this study (red circles), gas injection wells active since 2004 (yellow squares), and focal mechanisms for regional events (beach balls). A series of small quakes occurred in the same region in 1979 and 1980 (green circles) and may have been related to injection of water for enhanced oil recovery.
There's more data coming in every day, but like I said, O&G recovery is not necessarily to blame... but it could be a factor when combined with other things like local faults.
Using a high-resolution temporary network of seismometers, Gan and Frohlich identified 93 earthquakes in the Cogdell area from March 2009 to December 2010, three of which were greater than magnitude 3. An even larger earthquake, with magnitude 4.4, occurred in Cogdell in September 2011. Using data on injections and extractions of fluids and gases, they concluded that the earthquakes were correlated with the increase in CO2 EOR in Cogdell.
"What's interesting is we have an example in Cogdell field, but there are other fields nearby that have experienced similar CO2 flooding without triggering earthquakes," said Frohlich, associate director of the Institute for Geophysics, a research unit in the Jackson School of Geosciences. "So the question is: Why does it happen in one area and not others?"
"What's interesting is we have an example in Cogdell field, but there are other fields nearby that have experienced similar CO2 flooding without triggering earthquakes," said Frohlich, associate director of the Institute for Geophysics, a research unit in the Jackson School of Geosciences. "So the question is: Why does it happen in one area and not others?"
There's other evidence of these smaller quakes at injection sites here being set off by larger more distant seismic activity
Distant Earthquakes Trigger Tremors at U.S. Waste-Injection Sites, Says Study
July 11, 2013 — Large earthquakes from distant parts of the globe are setting off tremors around waste-fluid injection wells in the central United States, says a new study. Furthermore, such triggering of minor quakes by distant events could be precursors to larger events at sites where pressure from waste injection has pushed faults close to failure, say researchers.
The 2010 Chile earthquake set off tremors near waste-injection sites in central Oklahoma and southern Colorado, says a new study in Science.
Among the sites covered: a set of injection wells near Prague, Okla., where the study says a huge earthquake in Chile on Feb. 27, 2010 triggered a mid-size quake less than a day later, followed by months of smaller tremors. This culminated in probably the largest quake yet associated with waste injection, a magnitude 5.7 event which shook Prague on Nov. 6, 2011. Earthquakes off Japan in 2011, and Sumatra in 2012, similarly set off mid-size tremors around injection wells in western Texas and southern Colorado, says the study. The paper appears this week in the leading journal Science, along with a series of other articles on how humans may be influencing earthquakes.
July 11, 2013 — Large earthquakes from distant parts of the globe are setting off tremors around waste-fluid injection wells in the central United States, says a new study. Furthermore, such triggering of minor quakes by distant events could be precursors to larger events at sites where pressure from waste injection has pushed faults close to failure, say researchers.
The 2010 Chile earthquake set off tremors near waste-injection sites in central Oklahoma and southern Colorado, says a new study in Science.
Among the sites covered: a set of injection wells near Prague, Okla., where the study says a huge earthquake in Chile on Feb. 27, 2010 triggered a mid-size quake less than a day later, followed by months of smaller tremors. This culminated in probably the largest quake yet associated with waste injection, a magnitude 5.7 event which shook Prague on Nov. 6, 2011. Earthquakes off Japan in 2011, and Sumatra in 2012, similarly set off mid-size tremors around injection wells in western Texas and southern Colorado, says the study. The paper appears this week in the leading journal Science, along with a series of other articles on how humans may be influencing earthquakes.
The 2010 Chile quake also set off a swarm of earthquakes on the Colorado-New Mexico border, in Trinidad, near wells where wastewater used to extract methane from coal beds had been injected, the study says. The swarm was followed more than a year later, on Aug. 22 2011, by a magnitude 5.3 quake that damaged dozens of buildings. A steady series of earthquakes had already struck Trinidad in the past, including a magnitude 4.6 quake in 2001 that the U.S. Geological Survey (USGS) has investigated for links to wastewater injection.
The new study found also that Japan's devastating magnitude 9.0 earthquake on March 11, 2011 triggered a swarm of earthquakes in the west Texas town of Snyder, where injection of fluid to extract oil from the nearby Cogdell fields has been setting off earthquakes for years, according to a 1989 study in the Bulletin of the Seismological Society of America. About six months after the Japan quake, a magnitude 4.5 quake struck Snyder.
The new study found also that Japan's devastating magnitude 9.0 earthquake on March 11, 2011 triggered a swarm of earthquakes in the west Texas town of Snyder, where injection of fluid to extract oil from the nearby Cogdell fields has been setting off earthquakes for years, according to a 1989 study in the Bulletin of the Seismological Society of America. About six months after the Japan quake, a magnitude 4.5 quake struck Snyder.
"We've known for at least 20 years that shaking from large, distant earthquakes can trigger seismicity in places with naturally high fluid pressure, like hydrothermal fields," said study coauthor Geoffrey Abers, a seismologist at Lamont-Doherty. "We're now seeing earthquakes in places where humans are raising pore pressure."
Correlation doesn't equal causation, I get that, but don't write it off completely just yet.
- The risk of setting off earthquakes by injecting fluid underground has been known since at least the 1960s, when injection at the Rocky Mountain Arsenal near Denver was suspended after a quake estimated at magnitude 4.8 or greater struck nearby
- A series of similar incidents have emerged recently. University of Memphis seismologist Stephen Horton in a study last year linked a rise in earthquakes in north-central Arkansas to nearby injection wells.
- University of Texas, Austin, seismologist Cliff Frohlich in a 2011 study tied earthquake swarms at the Dallas-Fort Worth Airport to a brine disposal well a third of a mile away.
- In Ohio, Lamont-Doherty seismologists Won-Young Kim and John Armbruster traced a series of 2011 earthquakes near Youngstown to a nearby disposal well
We found that the onset of earthquakes and cessation were tied to the activity at the Northstar 1 deep injection well. The earthquakes were centered in subsurface faults near the injection well. These shocks were likely due to the increase in pressure from the deep waste water injection which caused the existing fault to slip," said Dr. Won-Young Kim. "Throughout 2011, the earthquakes migrated from east to west down the length of the fault away from the well -- indicative of the earthquakes being caused by expanding pressure front."
But it should also be noted that fracing is not being directly linked to the seismic activity. The volume of water used in those operations is not enough to cause what they're seeing... it's the waste waster disposal wells that are getting the attention.
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