From Oklahoma City, Associated Press, April 7, 2018
Sandstone bricks from the historic Pawnee County Bank litter the sidewalk after an early morning earthquake in Pawnee, Oka., on Sept. 3, 2016.
COVINGTON, Okla. — The Oklahoma Corporation Commission has directed a wastewater disposal well to reduce its volume of injection after more than a dozen earthquakes rattled part of northwest Oklahoma since Friday, April 6, 2018.
The U.S. Geological Survey recorded three quakes Monday, including one near Covington now rated magnitude 4.5 after a preliminary rating of 4.3. Magnitude 3.3 and 2.8 quakes were also recorded Monday in the area about 55 miles north of Oklahoma City.
Garfield County Emergency Management Director Mike Honigsberg says there are no reports of injury or severe damage. Damage typically begins with magnitude 4.0 or stronger earthquakes, but Honigsberg notes that the area is very rural.
Many of the thousands of earthquakes in Oklahoma in recent years have been linked to wastewater injection by oil and natural gas producers.
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Parts of Oklahoma now have the same earthquake risk as California — and a new study found a scarily direct link to fracking
From an Article by Erin Brodwin, Business Insider, February 2, 2018
Oklahoma is being pummeled by earthquakes, a phenomenon scientists have strongly tied to wastewater injection and the practice of fracking.
A new study highlights just how strong that connection is. According to the US Geological Survey, the earthquake threat level in some parts of the state may now be approaching the level for some parts of California.
Over the course of a few days in August, Oklahoma was pummeled by seven earthquakes. The wave started on a Tuesday night, when five quakes struck the central part of the state in less than 28 hours. The shaking continued extended into the early hours of Thursday as two more hit.
Although none of those quakes was severe enough to cause significant damage, scientists are increasingly concerned about their cause. Rather than emanating from natural tectonic shifts deep inside the Earth, these temblors appear to be the result of human activity.
Hydraulic fracturing, more commonly known as fracking, involves jamming water deep into the Earth’s layers of rocks to force open crevices and extract the oil or gas buried inside. For several years, researchers have shown a link between wastewater injection, a process that’s used to dispose of waste fluids from a number of industrial activities and is similar to fracking, and the incidence of earthquakes in a region, but a new study highlights just how strong that connection is.
The authors of the latest paper, published this week in the journal Science, found that they could use the depth of the wastewater injection sites to roughly predict how big the earthquake they caused would be.
In other words, the deeper the injection site, the stronger the quake.
The researchers were confident enough in their assertions to make a recommendation:”Reducing the depth of injections could significantly reduce the likelihood of larger, damaging earthquakes,” Thomas Gernon, an associate professor of earth science at the University of Southampton, wrote in an article for The Conversation.
Oklahoma’s earthquake threat level is now predicted to be roughly the same as California
Until recently, earthquakes in Oklahoma were few and far between. In 2010, the state experienced just 41 tremors. By comparison, Southern California has about 10,000 earthquakes each year.
But that disparity may be shrinking. According to a forecast from the US Geological Survey, the risk of a significant and damaging earthquake in some parts of Oklahoma is now roughly the same as the risk in parts of California.
“The chance of having Modified Mercalli Intensity VI or greater (damaging earthquake shaking) is 5-12% per year in north-central Oklahoma and southern Kansas, similar to the chance of damage caused by natural earthquakes at sites in parts of California,” the forecast reads.
Over the past few years, Oklahoma has weathered hundreds of significant quakes— more than 900 in 2015 alone, according to The Conversation — as have parts of several other Midwestern states. The region is replete with eons-old fault lines that went quiet long ago, but wastewater operations appear to be re-awakening some of those faults.
Much (but not all) of that wastewater injection is associated with the fracking boom, which has led the practice to become more common in recent years, especially in Oklahoma.
“Our study is just the first step,” Gernon said. “We need the support of researchers, operators and regulators, to ensure this approach has a lasting impact on reducing man-made earthquakes.”
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Oklahoma Orders Wastewater Disposal Curbs in Response to Multiple Quakes
By Richard Nemec, NGI Shale Daily, April 9, 2018
Citing “strong” earthquake activity, the Oklahoma Corporation Commission (OCC) on Monday ordered reductions for a wastewater disposal well in the Covington/Douglas area of Garfield County as reports since last Friday have identified more than a dozen temblors in the northwestern part of the state.
The U.S. Geological Survey (USGS) recorded an earthquake with a preliminary magnitude 4.3 at 5:22 a.m. Monday, nearly an hour after a magnitude 3.3 quake struck the area near Covington.
The OCC’s Oil and Gas Conservation Division (OGCC) directed a disposal well in the area to reduce volumes being injected into the Arbuckle formation from 17,000 b/d to 5,000 b/d, noting the situation was ongoing and further actions may follow.
An OCC spokesperson told NGI’s Shale Daily that there are other wells in the area injecting into the Arbuckle.
“All of our actions in relation to these events have been reductions and/or shut-ins,” the spokesperson said. “All of those options are on the table in this case, and there are other Arbuckle disposal wells in the area.”
Over the past three years, state officials have shut in scores of wells and ordered reductions in response to swarms of low intensity seismic activity linked to the disposal wells.
The seismic activity has been linked to stepped up drilling activity in Oklahoma’s myriad reservoirs, including the STACK and the SCOOP, aka the Sooner Trend of the Anadarko Basin, mostly in Canadian and Kingfisher counties, and the South Central Oklahoma Oil Province.
Last week, there was a reported easing of small induced quakes in Oklahoma linked to oil and gas activity, while the risks from seismic events remained high, according to a study by the USGS.
http://www.naturalgasintel.com/articles/113965-oklahoma-orders-wastewater-disposal-curbs-in-response-to-multiple-quakes
Earthquakes rattle northwest Oklahoma
From CBS/AP (KOTV), Oklahoma City, OK
COVINGTON, Okla. — Earthquakes are rattling part of northwest Oklahoma where more than a dozen temblors have struck since Friday. The U.S. Geological Survey recorded an earthquake of magnitude 4.5 at 5:22 a.m. Monday, nearly an hour after a magnitude 3.3 quake struck the area near Covington, about 55 miles north of Oklahoma City.
Garfield County Emergency Management Director Mike Honigsberg says there are no reports of injury or severe damage from any of the quakes, which have ranged in magnitude from 2.4 to 4.6. The magnitude 4.6 earthquake that shook Oklahoma on Saturday was also felt in neighboring Kansas and Missouri, according to the USGS.
There have been 4 earthquakes with magnitudes ranging from 2.6 to 4.5 between Covington and Perry in northern Oklahoma in the past 24 hour. #okquake
Thousands of earthquakes have been recorded in Oklahoma in recent years, with many linked to the underground injection of wastewater from oil and natural gas production. State regulators have directed several oil and gas producers in the state to close injection wells or reduce volumes.
The strongest earthquake on record in Oklahoma was a magnitude 5.8 recorded near Pawnee on September 3, 2016, CBS affiliate KOTV reports.
https://earthquake.usgs.gov/earthquakes/map/ …
South Korea’s Most Damaging Earthquake Linked to Geothermal Fracking
From Lorraine Chow, EcoWarch.com, April 27, 2018
PHOTO: A Hyundai damaged from an earthquake in Pohang, South Korea on Nov. 15, 2017.
One of South Korea’s largest earthquakes was likely triggered by hydraulic fracturing associated with geothermal energy production, according to two studies published Thursday in the journal Science.
The 5.5-magnitude temblor that struck the city of Pohang on Nov. 15, 2017 was the second most powerful on record and its most damaging, leaving the infrastructure in ruins, injuring dozens of people and leaving about 1,500 homeless.
Hydraulic fracturing, aka fracking, works by injecting high-pressure fluid underground to fracture rock in order to achieve increased rates of flow. Fracking is often associated with unlocking oil and natural gas deposits, but in this case, the intention was to enable circulation to produce geothermal energy.
Using geological and geophysical data, South Korean researchers from one of the studies suggested that the Pohang earthquake was induced by fluid from an enhanced geothermal system site that was injected directly into a near-critically-stressed subsurface fault zone.
Kwanghee Kim, a seismologist at Pusan National University and lead author of the study, explained that the well’s high-pressure water lubricated an unknown fault in the rock, causing it to slip and trigger the quake.
In the second study, researchers from the University of Glasgow, ETH-Zurich in Switzerland, and GFZ-Potsdam in Germany found that the mainshock and its largest aftershocks occurred within 2 kilometers or less of the geothermal site, where many thousands of cubic meters of water were injected under pressure into boreholes.
They also determined that the mainshock and the 46 aftershocks detected between Nov. 15-30 all occurred at depths of 3 to 7 kilometers, which is unusually shallow compared to previous quakes in the area.
“It would be a very remarkable coincidence if this earthquake were to be unrelated to the activity at the site, given that it occurred so close to it,” Robert Westaway, a senior research fellow at Glasgow university’s school of engineering, and one of the paper’s co-authors, told The Guardian. “My own personal view is that it is highly likely there is a connection.”
Other research has linked fracking for oil and gas to anthropogenic, or man-made, earthquakes, including a 4.8-magnitude earthquake in 2016 in northern Alberta. The alarming swarm of quakes currently rocking Oklahoma has been connected to the disposal of large volumes of wastewater from oil and gas production into underground wells.
Geothermal energy is often touted as a source of clean power, but previous studies have also found that drilling deep into Earth to tap its natural heat could cause seismic activity, thus raising questions about the long-term risks of this energy source.
“If the Pohang earthquake proves to be human-caused, it would be the largest known associated with deep geothermal energy, and this would certainly impact future projects,” team member Stefan Wiemer of the Swiss Seismological Service told New Scientist.
https://www.ecowatch.com/south-korea-earthquake-fracking-2563846110.html/