Operations at a four-well Hilcorp Energy Co. pad in Western Pennsylvania remained idle on Wednesday, more than a week after a 1.9-magnitude earthquake was recorded near the drilling site.
The state's seismic monitoring network detected the earthquake in Lawrence County's Mahoning Township early on April 25 (see Shale Daily, April 27). The epicenter in Mahoning -- about 60 miles northwest of Pittsburgh -- was near Hilcorp’s four-well pad operated by subsidiary North Beaver NC Development.
U.S. Geological Survey records now show that five micro-earthquakes, which could not be felt by people in the area, were recorded between 12:05 a.m. and 10:10 p.m. EDT in Mahoning. They ranged in size from 1.7- to 1.9-magnitude.
Pennsylvania Department of Environmental Protection (DEP) spokeswoman Melanie Williams said Hilcorp was not ordered by the agency to stop its operations, but instead voluntarily suspended them so the DEP and the state Department of Conservation and Natural Resources could begin an investigation. Hilcorp had fractured two of the wells on the pad on March 30 and they're complete, but DEP said the company was stimulating the other two wells when the early earthquakes were detected.
Williams said the company has not restarted stimulation and added that the other two completed wells are not producing. Hilcorp, one of the nation's largest privately owned producers, has not commented about the incident. DEP is expected to meet with the company to review the geologic data it collected before and during drilling and completion at the site.
It's unclear how long the pad might be offline. "At this point, there isn't a timeframe for the investigation to be completed," Williams said.
Hilcorp is one of the most active operators in Northeast Ohio and Northwest Pennsylvania, where it has both Marcellus and Utica shale wells. It has been issued more than 150 unconventional drilling permits in Lawrence County alone, according to state records. The Mahoning site is about six miles west of another Hilcorp pad in Ohio that state regulators linked to a series of earthquakes in 2014 (see Shale Daily, April 11, 2014; March 11, 2014).