By Karl Henkel
The small earthquake that shook Youngstown on Christmas Eve had a depth shallower than originally reported, prompting the Ohio Department of Natural Resources on Friday to order D&L Energy Inc. to cease operations at a nearby brine-injection well.
The magnitude 2.5 earthquake, officially the 10th since March 17 to occur within two miles of the brine-injection well on Ohio Works Drive, had a depth of 11,000 feet, said Andy Ware, deputy director at ODNR. It was the shallowest depth of any of the quakes.
That is only about 2,000 feet below the bottom of the D&L injection well, which ceased operations as of 5 p.m. Friday.
“They want us to [backplug] it now,” said Ben Lupo, owner and CEO of D&L.
Injection wells accept brine water from well drilling, including fracking, a process in which water, chemicals and sand are blasted into rocks thousands of feet below the ground to unlock oil and natural gas.
The state first told The Vindicator on Nov. 24 that D&L eventually would have to halt operations at the Youngstown well site to backplug the bottom 250 feet of the well.
The state suspects that brine has entered the nearly impermeable Precambrian formation underground. That formation is more than 9,000 feet below the ground.
Brine should be entering the Mount Simon formation, a permeable formation directly above the Precambrian.
ODNR, however, had told D&L it could wait until one of its other brine-injection wells began operations.
D&L has or soon will have wells in Girard, Campbell, Coitsville, Hubbard, Springfield, and in Columbiana County in East Liverpool, Fairfield Township and Elk Run Township.
ODNR told The Vindicator earlier this month that it had entrusted Columbia University’s Lamont-Doherty Earth Observatory to install four seismographs around D&L well.
A seismograph is an instrument used to detect and record earthquake data.
One of the key data points in proving or disproving an injection well-earthquake correlation is the depth of a seismic event.
Before the installation of the four seismographs, the Youngstown area had just one — which is located at Youngstown State University.
The YSU seismograph targeted the depth of the first nine earthquakes at approximately 5 kilometers, or 7,500 feet below the bottom of the D&L brine-injection well.
But using data from all five seismographs, Columbia University determined a much shallower depth for the early-morning Dec. 24 earthquake.
At 11,000 feet, the earthquake’s focus was less than 2,000 feet below the bottom of the D&L well, which, according to ODNR records, is about 9,300 feet.
ODNR still hasn’t said there is a definitive correlation between the well and the earthquakes.
“Based on that info with the depth, we thought it was best to reach out to the company,” Ware said. “We believe it’s the prudent thing to do at this time.”
Brine-injection wells have been known to cause earthquakes, including at Colorado’s Rangely Oil Fields in the 1960s.
The D&L well has operated for about a year-and-a-half now but didn’t receive much attention until a series of earthquakes, all with epicenters near the well, began March 17.
Lupo told The Vindicator he expects the testing and plugging process to last about 10 days and says it will cost the company about $160,000 in business.