Five people were injured after a Marcellus Shale gas well owned by Antero Resources exploded in Doddridge County, WV, on Sunday morning.
Alvyn Schopp, Antero vice president for accounting and administration, told NGI's Shale Daily that an explosion occurred at the company's Hinterer 1H well, near New Milton, at 4 a.m. EDT.
"We were landing production tubing," Schopp said Monday. "At this point we don't know if the source of gas was a flowback tank, or if it was the well itself. We're not sure of the ignition source, either."
Schopp said all operations at the site -- including three wells on a pad and storage tanks that primarily hold flowback water -- have been shut down, and inspectors from the Occupational Safety and Health Administration and the West Virginia Department of Environmental Protection (DEP) have been to the site. He said the company has also hired two private consulting firms to do an independent analysis to determine the cause of the explosion.
"Those investigations will be ongoing and the operations will not resume there until those are completed," Schopp said.
Schopp said he did not know how many people were at the site at the time of the explosion. He said the five people injured had varying levels of burns, and were transported to the West Penn Burn Center in Pittsburgh for treatment. Schopp did not know the condition of the victims.
According to Schopp, flowback stored at the tanks at the Hinterer pad is hauled away by truck.
DEP spokesman Tom Aluise told NGI's Shale Daily that Antero is permitted for five wells at the Hinterer pad, but only three have been drilled. He said the well involved in Sunday's incident has not been hydraulically fractured.
"Our initial observation is that they were in the stage of logging the well, when the pump they were using to pump the logging equipment through the horizontal leg of the well broke down," Aluise said Monday. "As they were trying to repair the pump, some type of ignition source impacted two of the storage tanks that were probably 30 feet away [from the victims]."
Aluise said four tanks, each with about 20,000 gallons of capacity, were at the site and appeared to have produced water in them at the time of the explosion. "They were using the production water in conjunction with the pump," Aluise said. "Apparently some vapors present in the tanks ignited and ruptured two of the tanks. The other two tanks were not ruptured but did catch on fire.
"We don't know how much water was in the tanks at the time, and we don't know how much escaped, but what water did escape was contained by secondary containment on the pad. There are also liners under the equipment which we feel prevented any type of groundwater contamination. From an environmental standpoint, we don't feel that there is an imminent threat."
Aluise said three of the victims were employees of Nabors Industries Ltd., a logging company, and one was a pump operator from a company named CNR. He said the fifth victim was an Antero consultant who was overseeing the project at the time of the incident.
Denver-based Antero holds about 320,000 net acres in the Marcellus -- in West Virginia and Pennsylvania -- and plans to have 15 drilling rigs deployed there for the remainder of the year (see Shale Daily, June 17). The company's net output for 1Q2013 was 114% higher from 1Q2012, and 21% above 4Q2012, mostly on gains in the Marcellus (see Shale Daily, May 14).
The privately held company, which is controlled by private equity firm Warburg Pincus LLC, plans to raise $1 billion through an initial public offering of some of its stock on the New York Stock Exchange (see Shale Daily, June 17).