Antero Resources must cease operations at its north-central West Virginia gas well pad where eight workers suffered injuries including five treated for burns after an explosion last Sunday.
The West Virginia Department of Environmental Protection’s (DEP) Office of Oil and Gas said Friday the cause of Sunday’s fire at the Hinterer hydraulic fracturing operation near New Milton in Doddridge County remains under investigation.
Denver-based Antero must submit a report to the DEP by July 31 explaining what caused the accident and how it plans to safely resume operations.
The report must also include preventive measures the company plans to avoid similar incidents.
Antero said methane gas ignited as the crew was completing the well.
The DEP said the blast ruptured two tanks containing flow back water, but the secondary containment system captured the fluid as designed.
Five workers ended up transferred to United Hospital Center in Bridgeport and then flown to West Penn Burn Center in Pittsburgh.
The five workers flown to West Penn Burn Center did not work for Antero, but worked for three different contractors, said Kevin Kilstrom, an executive with Antero Resources. Kilstrom would not release the names of the contractors.
Pat Heaster, the Doddridge County director of emergency services, said he saw Nabors Industries trucks on the scene, indicating they were one of the contractors.
The explosion happened just before 4 a.m. Sunday at the Hinterer 2H well on the Ruddy Alt pad on Brushy Fork in New Milton, Kilstrom said. Kilstrom said there are three wells on the pad.
The explosion did not happen at the drilling rig itself, which did not suffer damage, but at a nearby operation, Heaster said.
“They were fracking a well and something exploded, either in the pump or around the pump,” Heaster said.
Heaster said they were pumping water down a well, part of the hydraulic fracturing process for recovering gas trapped in shale rock. He said the tanks that recover the water and other materials after they return to the surface are what exploded.
“The holding tanks that they were pumping into, that’s what exploded,” Heaster said. “It was a supplementary operation to the drilling process, the wellhead was not involved.”
Trent said that the fire was about 50 yards from the wellhead.
“Once we were on the scene the flames were never more than six to eight feet high,” Trent said.
Antero Resources owns at least 399 wells in Doddridge, Harrison, Ritchie, Tyler and Upshur Counties, according to a 2012 DEP database. The database lists 141 of those wells as being active, although, because the database is incomplete, that number is likely higher.