Sharp increase in central Oklahoma seismicity since 2008 induced by massive wastewater injection by K. M. Keranen, M. Weingarten, G. A. Abers, B. A. Bekins, and S. Ge, Received for publication 8 May 2014, Accepted for publication 24 June 2014, Science
Unconventional oil and gas production provides a rapidly growing energy source; however, high-production states in the United States, such as Oklahoma, face sharply rising numbers of earthquakes. Subsurface pressure data required to unequivocally link earthquakes to injection are rarely accessible. Here we use seismicity and hydrogeological models to show that fluid migration from high-rate disposal wells in Oklahoma is potentially responsible for the largest swarm. Earthquake hypocenters occur within disposal formations and upper-basement, between 2-5 km depth. The modeled fluid pressure perturbation propagates throughout the same depth range and tracks earthquakes to distances of 35 km, with a triggering threshold of ~0.07 MPa. Although thousands of disposal wells operate aseismically, four of the highest-rate wells are capable of inducing 20% of 2008-2013 central US seismicity.
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Injection wells blamed in Oklahoma earthquakes by Eric Hand, July 4, 2014, Science
Oklahoma now has more earthquakes because of fracking by Mary Noble, July 5, 2014, Politix
Oklahoma has seen dramatically more earthquakes in 2014 than California, and many of them have been caused by fracking, according to a new study published in Science.
The prairie state’s earthquake surge is startling, given that historically, California is way more prone to seismic upheavals. By June 2014, Oklahoma had seen 190 earthquakes of magnitude 3 or more, whereas California saw only 71.
The problem is caused by just four high-volume disposal water wells used near Oklahoma City, which are used to get rid of the water injected into the ground by the fracking process. “Katie Keranen, a geophysicist at Cornell University, and colleagues found that the four wells are capable of triggering the earthquakes,” PBS reports. “An expanding underground wave of pressure from the wells…closely matched the places and times of the quakes in the swarm.” At least one Oklahoma state regulator has been paying close attention to these warnings, and recently ordered one well operator to inject less waste water into the ground. [Emphasis added]
Earthquakes triggered by fracking wastewater in Oklahoma, Many quakes much farther away from the wells than expected by The Associated Press, July 03, 2014, CBC News
A new study explains how just four wells forcing massive amounts of drilling wastewater into the ground are probably shaking up Oklahoma. Those wells seem to have triggered more than 100 small-to-medium earthquakes in the past five years, according to a study published Thursday by the journal Science. Many of the quakes were much farther away from the wells than expected. The wastewater is leftover from unconventional wells that drill for oil and gas with help of high pressure liquids — nicknamed fracking — and from the removal of water from diluted oil. These new methods mean much more wastewater has to be discarded.
Combined, the four wells in the study daily pour more than 19 million litres of water around two or three kilometres underground into rock formations, the study found. That buildup of fluid creates more pressure that “has to go somewhere,” said study lead author Cornell University seismologist Katie Keranen. Researchers originally figured the water diffused through underground rocks slowly. But instead, it is moving faster and farther and triggers quake fault lines that already were likely ready to move, she said. “You really don’t need to raise the pressure a great deal,” she added.
The study shows the likely way in which the pressure can trigger fault lines — which already existed yet were not too active— but researchers need more detail on the liquid injections themselves to absolutely prove the case, Keranen said. While there are about 8,000 deep injection wells in the region, the amount of water injected at the four wells — named Chambers, Deep Throat, Flower Power and Sweetheart — has more than doubled since the drilling boom started about a decade ago.
From 1976 to 2007, Oklahoma each year averaged about one quake of magnitude 3 or more — strong enough to feel locally but too weak to cause damage. But from 2008 to 2013, the state averaged 44 earthquakes of that size every year. So far this year there have been another 233, Keranen said, getting her earthquake figures from the U.S. Geological Survey database.
Push for restrictions
The rattling has led some Oklahomans to push for restrictions on the use of injection wells. While past research has shown more quakes in Oklahoma, Texas, Arkansas and Kansas and correlated it statistically to injection wells, this study used computer simulations to identify the mechanism of how massive amounts of water travel as much as 32 kilometres from the well. The pressure then triggers existing small faults — or previously unknown ones. In the past, scientists thought wells could only jump-start quakes within five kilometres) or so.
Austin Holland, a seismologist at the Oklahoma Geological Survey said Keranen’s study confirms what he is seeing in the field and will help better understand what’s happening in Oklahoma. “It’s a study that needed to be done,” said U.S. Geological Survey seismologist Elizabeth Cochran. “That changes how we might look at the hazard for a particular well.” [Emphasis added]
Oklahoma earthquake surge tied to energy industry activity – study by Carey Gillam, July 3, 2014, Reuters
A dramatic jump in the number of earthquakes in Oklahoma to a rate never seen there by scientists before, appears to be caused by a small number of wells where wastewater associated with oil and gas production is injected into the ground, a study released on Thursday said. Just a few of these so-called disposal wells, operating at very high volumes, “create substantial anthropogenic seismic hazard,” according to findings from Cornell University researchers published in the journal Science.
Earthquake activity in Oklahoma has skyrocketed in recent years, and the U.S. Geological Survey recently warned that the state faces increasing risk of more potentially damaging earth-shaking activity.
Through the end of June, the number of potentially damaging earthquakes – magnitude 3.0 or larger – was up more than 120 percent compared to all of last year, according to state officials.
“There is an awful lot of smoke here,” said Matt Skinner, spokesman for the Oklahoma Corporations Commission, which oversees oil and gas activities in the state. “We are examining the study very, very carefully. If this is an issue, this is a risk we will manage properly.” The worries come in a state where the local economy is closely tied to the oil and gas industry, and where officials have dubbed one of its cities, Tulsa, the “oil capital of the world.”
And while most earthquakes occur naturally, some scientists openly worry that pressurized injections of wastewater from natural gas and petroleum production deep into wells can trigger earthquakes. Oklahoma has 4,597 such disposal wells. The Oklahoma Independent Petroleum Association said because oil and gas activity is so prevalent in the state, seismic activity is likely to occur near industry operations, but that does not prove a correlation. Other states lacking significant oil and gas work also see increased seismic activity, OIPA President Mike Terry said. “A rush to judgment based on one researcher’s findings provides no clear understanding of the causes,” he said.
Cornell’s team reported that they found earthquakes can be induced nearly 30 km, or nearly 19 miles, away from a disposal well, beyond the current range of about 5 km, or 3 miles, currently used to diagnose induced earthquakes. Additionally, four of the highest-volume disposal wells in Oklahoma were capable of triggering 20 percent of recent earthquakes in the region, the researchers said. Overall, Oklahoma earthquakes in areas of high industry waste water disposal constituted nearly half of all central and eastern U.S. seismicity from 2008 to 2013, they added.
For the first half of 2014, Oklahoma recorded 241 earthquakes of 3.0 or greater, up from 109 of that level in 2013, and nearly at the five-year total of 278 recorded from 2008-2013, according to state data. From 1978 to 2008, the state on average recorded only two earthquakes of magnitude 3.0 or larger a year.
In 2011, Oklahoma suffered its biggest recorded quake, a 5.6 magnitude event that damaged more than a dozen homes and several businesses.
[Refer also to:
August 2012: Investigation of Observed Seismicity in the Horn River Basin
Horn River Basin seismicity events, from 2009 to late 2011, were caused by fluid injection during hydraulic fracturing. All events occurred during or between hydraulic fracturing stage operations. [Emphasis added]
Slide from Ernst presentations
Well integrity could potentially be affected by seismic activity – either activity induced by the hydraulic fracturing process, or other seismic events. … As reported by Broderick et al (2011 NPR), one study indicated a maximum induced magnitude of around 3, for that location, which was considered insufficient to cause surface structural damage but to potentially damage the wellbore itself. [Emphasis added]
Large earthquakes around the world have been found to trigger tremors at US sites where wastewater from gas drilling operations is injected into the ground, a US study said Thursday. For instance, the massive 9.0 magnitude earthquake in Japan in 2011 set off a swarm of earthquakes in the western Texas town of Snyder near the Cogdell oil field, culminating in a 4.5 magnitude quake there about six months later, said the research in the journal Science.
Similarly, small to mid-sized quakes were observed near active injection wells in Prague, Oklahoma following an 8.8 magnitude quake in Chile in 2010. Uncommon seismic activity stirred that region 16 hours after the Chile quake with a 4.1 magnitude tremor, and it continued until a 5.7 magnitude quake in November 2011, said researchers at Columbia University’s Lamont-Doherty Earth Observatory. The 2010 Chile quake also led to heightened seismic activity in Trinidad, Colorado, including a 5.3 magnitude quake in August 2011, in an area where methane is extracted from the coal bed and wastewater is reinjected into the Earth. …
The study helps explain a surge in earthquakes in the central United States, which in recent years has seen a more than six-fold increase in earthquakes over 20th century levels.
An accompanying study in Science said there were 300 3.0-magnitude or higher earthquakes in the central United States from 2010 to 2012, after an average of 21 such quakes per year from 1967 to 2000. The change coincides with a growing natural gas boom that is based on using large amounts of fluids to crack open rocks for natural gas, known as hydro-fracturing or fracking.
… The US Department of the Interior last year also acknowledged an uptick in seismic activity — predominantly in Texas, Colorado, Arkansas, Oklahoma and Ohio — where disposal of wastewater through injection wells has “increased significantly,” it said. One of the earliest known cases of wastewater inducing earthquakes dates back to the Rocky Mountain Arsenal Well near Denver, Colorado, where large amounts of wastewater were injected from 1962 to 1966, leading to a series of earthquakes below magnitude 5.0, the DOI said. …
“These passing seismic waves are like a stress test,” said co-author Heather Savage, a physicist at Lamont-Doherty. “If the number of small earthquakes increases, it could indicate that faults are becoming critically stressed and might soon host a larger earthquake.” The largest so far has been the 5.7 magnitude quake on November 6, 2011 in Prague, Oklahoma, triggered by the Chilean quake a year earlier. The US quakes have been felt by many people but have caused minimal damage and no deaths, though researchers point out that elsewhere in the world, similarly strong quakes have resulted in massive damage and loss of life. Scientists have no way of predicting when a particular field has reached a dangerous point….
In an accompanying article in Science, William Ellsworth of the US Geological Survey framed the problem another way. “Ignorance of the things that we understand we should know but do not leaves us vulnerable to unintended consequences of our actions,” Ellsworth said. [Emphasis added]
Earthquakes from onshore gas drilling threaten a disaster, warn residents of Dutch city, Residents of Groningen are up in arms over onshore gas drilling that triggered earthquakes, damaging homes and sending property prices crashing
CLIENT ADVISORY New Technology Creates New Insurance Issues for Oil and Gas Lease Operators by Pascal Ray and the AmWINS Energy Specialty Practice
This shift to unconventional drilling and heavy multi-stage fracking has created new insurance issues for the industry:
• Increase in blowouts during the completion/fracking stage.
• Increase in blowouts involving communication between multiple wells.
• Increase in blowouts caused by casing/cementing failure.
• Increase in blowouts caused by surface events.
In addition to these blowout trends, we are seeing:
• An increase in blowouts involving producing wells.
• An increase in blowouts involving plugged and abandoned wells.
2012; Spanish earthquake in Lorca ‘triggered by groundwater extraction’, A major earthquake in Spain that killed nine people and destroyed hundreds of homes was triggered by groundwater extraction, a scientific study has found
The gas field was discovered in 1956 and production began in 1962. Over the next 14 years, roughly 600×106 m3 of water, or 106 ton per km2, were injected. … Beginning in 1976, a series of large earthquakes was recorded. The first significant earthquake occurred on April 8, 1976 at a distance of 20 km [12 miles] from the Gazli gasfield boundary. The earthquake magnitude measured 6.8. Just 39 days later, on May 17, 1976, another severe earthquake occurred 27 km [17 miles] to the west of the first one. The magnitude of the second earthquake was 7.3. Eight years later, on March 20, 1984, a third earthquake occurred 15 km [9miles] to the west of the second earthquake, with a magnitude of 7.2. … Aftershocks occurred in a volume surrounding the three hypocentres. These earthquakes are the strongest of all the known earthquakes in the plain of Central Asia. … The amassed data indicate that the Gazli earthquakes were triggered by the exploitation of the gas field.
In regions of high tectonic potential energy, hydrocarbon production can cause severe increases in seismic activity and trigger strong earthquakes, as in Gazli, Uzbekistan. In regions of lower tectonic stress, earthquakes of that magnitude are less likely, but relatively weak earthquakes could occur and damage surface structures. [Emphasis added]