The West Virginia Department of Environmental Protection (WVDEP) has issued a cease operations order to Antero Resources Corp. after an incident that occurred on Sept. 24 in northern West Virginia, when the company inadvertently breached a producing well while drilling another on the same pad.

The incident, which occurred at the five-well Primm Pad in Doddridge County, near West Union — 120 miles northeast of the state capital, Charleston — was reported by Antero. WVDEP spokeswoman Kelly Gillenwater said that while drilling the Stella 1H, Antero’s drill collided with the Callie 2H, which was producing. Four wells are already completed at that pad, Gillenwater said, and the incident led to two notices of violation (NOV) in addition to the cease operations order that halted production at the Callie 2H and a separate producing well at a different pad in the area.

“The WVDEP sent inspectors to the site and upon further investigation, it was determined that two other area wells — one still in production and another well that is abandoned — were likely affected and that one or both of those two wells was providing an avenue for the methane from the Callie well to flow elsewhere,” Gillenwater told NGI’s Shale Daily.

There are 12 private water wells in the area and Gillenwater said WVDEP personnel are taking samples to see if the supply has been impacted. As a precaution, the three water wells closest to the Primm pad have been disconnected from homes to ensure no gas gets inside. All of the affected homeowners are being supplied drinking water by Antero.

The agency’s NOVs require Antero to act on the situation by Wednesday. All of the regulatory documents were signed and dated on Monday. They require the company to determine the cause of the collision and conduct necessary repairs to the Callie 2H’s production casing, among other things.

“The agency is still evaluating whether additional enforcement action — such as the levying of fines — is warranted,” Gillenwater said. “Right now, the priority is to make sure all the wells are secure and that there is no threat to nearby residents or the environment. The WVDEP is working with Antero, which is cooperating in the investigation and the response, to accomplish that goal.”

Antero is one of the Appalachian Basin’s most active operators. It is currently running 15 rigs in West Virginia, where, combined with leasehold in southwest Pennsylvania, it has more than 378,000 net acres in the Marcellus Shale. Nearly all of its 9.1 Tcfe of proved reserves, or about 94%, are located in the Marcellus (see Shale Daily, July 18; July 16).

In 2012, the company disturbed an aquifer while attempting to dislodge a stuck drill bit in West Virginia’s Harrison County, causing blowouts at four abandoned private water wells and prompting the WVDEP to respond (see Shale Daily, June 8, 2012). The agency said Antero was cooperative in that instance as well.