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Did brine well trigger 6 Mahoning Valley earthquakes?
By Karl Henkel
YOUNGSTOWN
The Mahoning Valley has experienced seven minor earthquakes since March — the only quakes ever recorded with epicenters in the Valley.
The sudden occurrences have experts now examining a brine- water injection well near Salt Springs Road and state Route 711. The Ohio Department of Natural Resources is looking into the correlation between the 18-month-old well and the earthquakes.
Injection wells are a back-end process in the hydraulic-fracking industry. In the fracking process, water, chemicals and sand are blasted through pipes into rocks thousands of feet below the ground to unlock natural gas and oil. That liquid is returned to the surface as brine wastewater, which ultimately is flushed underground by injection wells.
Some wells, such as the one in Youngstown, go 9,000 feet below the earth’s surface.
Of the seven earthquakes, six had epicenters near the injection well on Youngstown’s West Side, just off the Salt Springs Road exit and Ohio Works Drive.
“There’s definitely a coincidence,” said Jeffrey Dick, geology department chairman at Youngstown State University.
“But whether or not there’s a link, nobody has enough data quite yet.”
ODNR has oversight over the process, and Dick said ODNR has contacted him about geological mapping in response to the quakes.
But Heidi Hetzel-Evans, an ODNR spokeswoman, said the agency stands by its regulations that permit the well operations.
“(ODNR has) not seen any evidence that shows a correlation between localized seismic activity and deep-injection well disposal.”
The well, completed 10 months before the Valley’s first 2011 quake, is operated by D&L Energy Inc., an oil-and-gas exploration company.
“There’s no data linking the well to earthquakes,” said Nick Paparodis, vice president of land operations for Youngstown-based D&L.
“We’ve complied with all of [ODNR’s] recommendations.”
D&L’s Youngstown site has had a daily injection average of 2,000 barrels, or 84,000 gallons, of wastewater. That’s 504,000 gallons each week, based on the site’s six-day operation schedule. Through the first six months of 2011, it has injected 7.6 million gallons.
Those averages could grow, because in May, ODNR approved an increase in the daily load level. Six of the seven earthquakes occurred after the increase.
THE INJECTION PROCESS
In the deep injection process, wastewater passes through the Marcellus Shale, Clinton Sandstone and Utica Shale formations.
Wastewater pumped into the well isn’t as heavily pressurized as it is during the fracking process.
Instead, only the pressure exerted by gravity is used to flush the water into rock formations and cavities as far as 9,000 feet down.
“The weight of 8,500 feet of fluid from the surface down to the injection zone is what is going to force the water into the formations,” Dick said.
During the injection process, the water continuously increases in volume and becomes a part of the ecosystem. It is at that point the water can cause strain on a previously undiscovered fault line — which could possibly cause earthquakes, some hypothesize.
MORE WELLS PLANNED
D&L also is establishing at least two other injection wells in the Mahoning Valley and has permits from ODNR.
One is off U.S. Route 422 in Campbell behind Mc-Cartney Auto Sales. Another is in Girard, also on 422, near the V&M Star plant.
Both wells have been drilled but won’t accept wastewater for four to six more months, Paparodis said.
Yet another could be on its way to Hubbard, according to a letter sent by D&L acquired by The Vindicator.
The locations were selected based on proximity to Pennsylvania. Wastewater from Pennsylvania fracking makes up a majority of the Ohio Works Drive well’s business.
EARTHQUAKE CONNECTION?
The correlation between earthquakes and deep-well injections is not new.
Dick said in only one instance — in Colorado in the 1980s — has there been enough evidence to link injection wells to earthquakes.
But earlier this year in Arkansas, the state Oil and Gas Commission banned some injection wells near a fault line after the area experienced 1,100-plus small earthquakes similar in magnitude to those felt in the Mahoning Valley.
Other wells voluntarily ceased production.
Geologic experts are concerned — and convinced — injection wells are causing those earthquakes during the last couple years. In February, the area had its largest rumble — a magnitude-4.7 earthquake.
The quakes initially subsided, but have since started to pick back up, said David Johnston, earthquake geologist at the Arkansas Geological Survey.
“Most of them have been pretty small in a 1.5 to 3 range, and most of them you couldn’t feel,” he said. “We’re still kind of evaluating the whole situation, but we’re confident that there is some sort of correlation.”
There are a few distinct differences between Arkansas and the Mahoning Valley, most notably the number of brine wells.
Arkansas had as many as four injection wells near the switchboard of the earthquake; the Valley has only one.
Central Arkansas has had two other “earthquake swarms” — one in the early 2000s and the first in the 1980s, according to geologic records, both of which predate the drilling activities of the Fayetteville Shale.
“That’s what makes it hard to say whether the recent swarm is natural or possibly related to the frackwater disposal wells,” Johnston said.
The Mahoning Valley didn’t have an earthquake centered in the area until this year.
A DEFINITIVE ANSWER
One way to detect a correlation between earthquakes and well injections is by pinpointing the depth of an earthquake.
Michael Hansen of the Ohio Seismic Network said that earthquakes are detected at network stations, like the one at Youngstown State University. But one network alone cannot detect a precise depth.
Hansen said at least three are needed to pinpoint a depth.
Temporary seismic stations are a possibility, but not for ODNR. Hansen said the U.S. Geological Service has such devices, which cost about $5,000 and take about six months for delivery.
The stations must also be in a quiet, stable area.
A three-station system could prove the ties between the wells and shakes, but it could also debunk the theory, since the seven Valley earthquakes appear to be at depths of 16,000 feet, Hansen said.
“We’ve tried to look at this in various ways, indirectly to determine a depth,” he said. “Most of these events are shallow, right around that depth.”