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The Ohio Department of Natural Resources has suspended operations at a Youngstown Township fluid injection well after a 4.0 earthquake struck the area on New Year’s Eve, the 11th temblor in the area since March.
The earthquake at 3:05 p.m. was felt as far away as Michigan, Ontario, Pennsylvania and New York, reported Michael C. Hansen, state geologist and coordinator of the Ohio Seismic Network, part of the Ohio Department of Natural Resources’ Division of Geological Survey.
Scientists have determined that the likely cause was fracking – although not from drilling into deep shale or cracking it with pressurized water and chemicals to retrieve natural gas. Rather, they suspect the quakes are caused by disposal of waste water from the operations, done by pumping it back down into equally deep sandstone.
Hydraulic fracturing, or “fracking,” is the process of injecting water and proppant – a material such as sand or other particles that prevent the cracks from slamming shut when the injection is stopped – into a well under high pressure to fracture the rock layer underground and release any natural gas or oil that may be trapped inside.
While the research conducted to date does not establish a clear and direct correlation to drilling at the site and seismic activity, state officials believe that there is enough evidence to suspend operations pending further study.
To gather the evidence, the ODNR asked Columbia University’s Lamont-Doherty Earth Observatory to conduct field research on the problem. The university placed four seismometers in the area to gather data on the seismic activity. In 2011, the sensors recorded 11 events within 10 miles of the wells. It was the 11th quake to hit the area that caused state officials to stop the waste injection operations.
John Armbruster, a seismologist with Lamont-Doherty Earth Observatory, part of Columbia University, believes the waste from fracking in Ohio has led to the earthquakes there.
“Look at the evidence. Youngstown is an area which doesn’t have a history of earthquakes. This disposal well started operating in December of 2010. Three months later, the earthquakes began and the earthquakes are trickling along. From March to November, you have nine earthquakes, all of a similar size, 2.5, 2.1, and 2.7.”
On Christmas Eve, there was a 10th, magnitude 2.7 earthquake. The location of the quake, about half a mile from the bottom of the well, was sufficient evidence to conclude that there could be a link.
The 11th and largest quake occurred one week later, on New Year’s Eve.
By triangulating the arrival time of shock waves at the four stations, Armbruster and his team determined with 95 percent certainty that the epicenters of the two latest quakes were within 100 meters of each other, and within half a mile of the injection well. The team also determined that the quakes were caused by slippage along a fault line at about the same depth as the injection site, almost 2.8 miles down.
Environmentalists and lawmakers opposed to fracking and the disposal methods are seizing on the seismic activity in Youngstown to urge caution in the use of the fracking process as a way to produce natural gas.
The injection wells in Ohio are similar to ones used in Texas, where a 4.8 magnitude earthquake occurred near drilling sites in the Eagle Ford Shale formation in South Texas in October. The seismic activity in Texas, Ohio and elsewhere may indicate a link between fracking fluid disposal wells and earthquakes.
A University of Texas seismologist also believes that hydraulic fracturing by itself does not cause earthquakes. It is the disposal of the fracking fluids that is the cause of the problem. Once a well is fractured, the fracking fluid is pumped out of the well so that the gas or oil can escape to the surface and be collected. The waste fluid is then reinjected into a disposal well as a method of removal.
Originally, drilling company operators tried to recycle the fracking fluid. The state of Pennsylvania tried to mandate recycling the fluid, but found that wastewater treatment plants couldn’t get all of the toxic material out of fracking water, and the “cleaned up” water returned to rivers wasn’t clean enough. Well operators in the state then decided to ship wastewater to Ohio, where it has been going down into wells.
A 4.8 quake in the 1960s at the Rocky Mountain Arsenal in Colorado was also linked to a disposal well. Rocky Mountain Arsenal’s deep injection well was constructed in 1961 and was used to dispose of liquid waste. The Army discontinued use of the well in February 1966 because of the possibility that the fluid injection was triggering earthquakes in the area.
Arkansas residents have recently filed five class action cases against energy companies which jointly operate a number of hydraulic fracturing wells in Arkansas. The lawsuits allege that these injection wells have caused several minor earthquakes in the area as well. The plaintiffs in the case claim that since Sept. 10, 2010; the area has experienced 599 temblors in an area that is not known for any earthquake activity. The most significant was a 4.7 magnitude earthquake, which was supposedly the largest to hit the state in 35 years. In March 2011, the Arkansas Oil and Gas Commission ordered a temporary shutdown of the wells to allow time to investigate the cause of these earthquakes.
The drilling companies who are defendants in the cases maintain that the earthquakes are coincidental and are not caused by operation of the wells. The companies also point out that in the week following the shutdown, earthquakes continued to occur, although not with the same frequency. Plaintiffs argue that earthquakes would continue to occur since the fluid injected into underground is still there, at high pressure, continuing to exert pressure on the rock formation.
The United States is not the only country that suspects there is a relationship between the fracking process and earthquakes.
In the 1960s, geologists theorized that gold mines in South Africa had created small earthquakes. Mine shafts dug thousands of feet into the earth collapsed, and the “pancake” effect of the collapsing mines caused earthquakes. One of the quakes was measured at 5.2 on the Richter scale, enough to cause major damage to the poorly constructed buildings in the nearby area.
In the United Kingdom, the Cameron government said it will consider “carefully” a report commissioned by the U.K. energy company Cuadrilla Resources that acknowledges recent earthquakes in the country were caused by hydraulic fracturing.
“We will look at Cuadrilla’s report carefully with the assistance of our independent experts and regulators before deciding whether hydraulic fracturing operations should resume,” said UK Energy Minister Charles Hendry. “The potential for unconventional gas is worth exploring because of the additional security of supply and economic benefits it could provide. But its development must be done in a way that carries public confidence.”
The Geomechanical Study of Bowland Shale Seismicity report, an independent study commissioned by Cuadrilla, had several conclusions:
- It is highly probable that the hydraulic fracturing did trigger a number of minor seismic events.
- The seismic events were due to an unusual combination of geology at the well site coupled with the pressure exerted by water injection as part of operations.
- If these factors were to combine again in the future, local geology limits seismic events to around magnitude 3 on the Richter scale as a “worst-case scenario.”
The report was conducted by a research team under the direction of Hans de Pater, professor of geotechnology at the Delft University of Technology in the Netherlands.
Few geologists are familiar with these induced or triggered quakes. The quakes are usually small and have not been extremely common. However, fracking is being conducted on thousands of wastewater wells, often in heavily populated areas that historically have not been seismically active. That means even small earthquakes that would have gone unnoticed before now draw attention.
The problem of fracking and earthquakes could have a major impact on the nation’s energy supply.
There are two areas in United States that are generating a lot of interest by energy companies for the energy resources they are thought to contain: the Bakken and the Marcellus formations. These formations contain oil and natural gas, but they are locked inside shale formations that need fracking technology to release the hydrocarbons locked inside.
The Bakken formation is an oil shale geologic structure that is estimated to occupy 200,000 square miles underlying parts of Montana, North Dakota and Saskatchewan. The entire formation is deep underground and fracking is thought to be the best method to recover significant producible reserves of oil held within the formation. An April 2008 USGS report estimated the amount of recoverable oil at 3 to 4.3 billion barrels. In 2008, fracking started to be employed in the formation, which caused a boom in production. By the end of 2010, oil production rates had grown so high that it was outstripping the pipeline capacity to ship oil out of the area, hence the need for the Keystone XL pipeline that the Obama administration is yet to approve. The fracking process has led a veteran industry insider to declare the USGS estimates are too low.
The Marcellus formation in extends throughout much of the Appalachian Mountain region in the eastern United States. Like the Bakken formation, the Marcellus formation contains largely untapped reserves, and its proximity to the populated areas of the East Coast makes it an attractive area for energy development.
A 2009 West Virginia University study estimated that the Marcellus formation contained up to 1,307 trillion cubic feet of technically recoverable natural gas. A Penn State University study estimates that the use of fracking could add a trillion dollars worth of energy resources to the nation’s shrinking energy reserves.
Terry Engelder, professor of geosciences at Penn State has said, “We can go back to wells that are already drilled and played out, and then drill horizontal from there. Reusing old wells has both economic and environmental value.”
However, the residual oil and gas left in depleted wells can only be recovered if enhanced recovery techniques, like fracking, are employed.
“If we want the energy, and I think we do, we have to figure out how to handle this,” says natural resources economist Michal Moore of Canada’s University of Calgary. The alternative is to send such wastewater to water-treatment plants not designed to handle industrial waste, he says.
“This earthquake is a cautionary tale at this point,” Moore says.