The Ohio Department of Natural Resources is studying seismic data from wells near last month’s Poland Township earthquakes, but no such review occurred prior to drilling.
That’s because the agency responsible for regulating the state’s oil and gas industry does not require oil and gas companies to obtain or to submit seismic reflection data when applying for a permit to drill fracking wells. Fracking extracts natural gas from shale under pressure.
“An application to drill a horizontal well does not contain seismic requirements,” said ODNR spokesman Mark Bruce. “ODNR has and continues to work with partners to gather as much seismic information about the state as we can, and that general knowledge is used by our permitting staff when reviewing applications.”
But according to the state’s top geologist, seismic data is not necessarily easy to come by.
“Seismic reflection data are limited because the information is expensive to obtain,” Tom Serenko, chief of ODNR’s geological survey division, told The Vindicator last month in an email. “Many geophysical companies hold this as proprietary and sell it to oil companies who look for oil and gas.”
“There is no public seismic reflection information available for Mahoning County,” he wrote.
It was in Mahoning County last month that a series of earthquakes occurred close to seven wells, owned by Hilcorp Energy Co., at the Carbon Limestone Landfill. One well was actively producing, and at least one other well, on a separate pad, was being fracked at the time.
Tremors are familiar to the Valley. Three years ago, a Youngstown injection well — drilled too deep — triggered as many as 109 low-magnitude quakes.
Since then, ODNR has required companies to do seismic testing when drilling injection wells, but no such rule exists for fracking wells.
Instead, it is up to drilling companies to seek out their own data, and many do.
Seismic surveying has taken off in Ohio since companies began developing the Utica Shale play in 2011 and 2012, said Steven McCrossin, president of Precision Geophysical in Millersburg.
His staff has doubled as the company has grown to meet the needs of drillers large and small. Seismic surveying is a hot commodity in Eastern Ohio, drawing companies from other states, he said.
In the exploration phase, many drillers choose to contract with geophysical companies that specialize in acquiring and processing seismic data, and they use the data to better plan their operations.
The data come from seismic surveys, in which geophysical companies typically send a charge into the earth from a special truck. A series of geophones, set along a straight line, record the energy that is reflected back off rock layers. The information is then processed by a computer, and — depending on the type of testing — the company either has a two-or three-dimensional image of the geology.
Generally, drillers are looking for oil and gas and for the brittleness of the underlying rock. Additionally, they want to identify the orientation of any pre-existing fractures.
Drillers can either commission the survey, purchasing the rights to the data, or they could buy the data from a geophysical company that did an unsolicited speculation, or spec, shoot in the area of interest.
In the case of a spec shoot, the geophysical company maintains rights to the data and holds it as proprietary.
In either event, no mandate exists to turn the data over to ODNR.
Nor is there a requirement to continue seismic surveying after the initial exploration phase, said David R. Hill, a geologist and president of the Ohio Oil and Gas Association.
The imaging provides drillers a thorough understanding of both the Precambrian-basement formation and the overlying Cambrian rocks, he said.
With the average well costing anywhere from $8 million to $10 million to drill, companies want to be able to identify faults and avoid problem areas.
“It is in their financial interest not to drill there,” Hill said. “These people are acting out of an abundance of caution.”
But two slews of seismic activity here have raised questions about whether the geology of Mahoning County is suitable for fracking to occur.
“There seems to be something about the geology [in Mahoning County] that’s really throwing up a red flag,” Ray Beiersdorfer, a geology professor at Youngstown State University, said at a news conference last month.
“Now that we know we have this problem, maybe ODNR should demand [companies] to turn over their [seismic] data,” in order to obtain a permit to drill in Mahoning County, Beiersdorfer said last week.
Though that mandate may go too far across the state, companies should at least be required to notify ODNR of any faults they encounter in their testing, he said.
“It seems like that would be a reasonable request,’’ said Beiersdorfer.
The Poland Township quakes should be a “wake up call” for ODNR to start requiring seismic data as a part of the application process, said Brian Kunkemoeller, conservation program manager for the Ohio chapter of the Sierra Club.
“There has to be some better understanding of our underground geology before we move ahead with this type of thing,” he said. “There should be standards for geologic charting before you can drill.”
It is unclear exactly what kind of seismic surveying Hilcorp did before drilling its wells. But Bruce said the company is “fully complying” with an ODNR order to provide a “range of seismic data or analysis of seismic data,” including seismic reflection data, a magnetic anomaly survey, structural maps and well-completion logs.
While the connection between injection wells and earthquakes has been well-documented in recent years, a link between the fracking process and seismic events remains unclear.
Geologists point to only three instances where fracking was the cause of earthquakes. In Oklahoma, British Columbia and Great Britain, fracking has been linked to a series of low-magnitude tremors, registering from 2.0 to 3.0 on the Richter scale, according to the U.S. Geological Survey.
But the instances are exceedingly rare, given the number of hydraulically fracked wells in this country — 1.1 million, according to FracTracker — and abroad.
As of last week, Hilcorp’s six fracking wells in the development stages remained shuttered. The one producing well — on a separate pad — is still active.