The fires at a pair of Chevron gas wells in Dunkard, Greene County, ignited by an explosion last week, stopped burning Saturday afternoon, the company said Sunday.
A statement Sunday evening from a Chevron spokeswoman said the fires at the wells in Dunkard stopped burning more than 24 hours before, at 3 p.m. Saturday.
"It is premature to speculate on what caused the flames to go out. However, we do know that at this time, there is not enough fuel being emitted to sustain combustion, and with the cooling of the crane, the ignition source has been removed," the spokeswoman, Lee Ann Wainwright, wrote.
Ms. Wainwright said in an email that the fire on the 6H well had been "intermittently going out and reigniting" over the past several days and the company wanted to make sure the same would not happen with the 7H well before it made an announcement.
There was no immediate word on the status or identity of a contract worker who has been missing and presumed dead since the Tuesday morning explosion. Another worker was injured, though his injuries were described as minor.
"At this time, we cannot comment on the status of the unaccounted-for colleague," Ms. Wainwright said. "This is a subject of an ongoing Pennsylvania State Police investigation and out of respect for their jurisdiction, all questions regarding the missing person will be handled by them."
State police at the Waynesburg barracks said Sunday that there was no new information on the missing worker and Greene County Coroner Gregory P. Rohanna said his office had not been contacted about the missing man. .
The missing worker worked for Houston-based Cameron International's surface systems division, which could not be reached Sunday night.
Chevron and its well fire specialist, Wild Well Control of Houston, Texas, had been working to clear damaged equipment from the site, including a large crane super-heated by the fires, so workers can install equipment to divert the gas coming out of the wells away from the wellhead.
The crane, which has been severely damaged, must be removed before the work can start and special equipment has been brought in to get it out of the way, Ms. Wainwright said.
"One of our top priorities continues to be staging water near the site to prepare for well-intervention work and for fire prevention and suppression, if necessary," the statement says. "Ten water-storage tanks were delivered and installed on Friday and one tank was installed on Saturday.
"Additional tanks were able to be installed Sunday as well. Our focus will soon shift to connecting all of the tanks together and then filling them with fresh water."
The water will be used to cool the site and equipment so workers can safely access the wells.
The state Department of Environmental Protection has granted Chevron a temporary emergency permit to withdraw up to 1.15 million gallons of water a day from nearby Dunkard Creek, though.
Scott Perry, deputy secretary in the DEP's Office of Oil and Gas Management, said Wild Well Control says it will need only about 410,000 gallons a day.
Though gas is still leaking, the three wells at the site are not expected to reignite and officials are monitoring gas levels in the area, he said.
"If the well does not reignite, they won't need to utilize any of that water," he said.
Next, the company will have to remove two damaged wellheads and replace them to ensure the wells are secure.
Whether the wells, which were drilled in March 2012, will be returned to production remains to be seen.
"There's going to have to be some investigation into the overall integrity of the well itself. DEP's obviously going to be involved in that process," Mr. Perry said.
The explosion happened just before 7 a.m. Tuesday as workers were readying the well for production. They were preparing to install production tubing, narrower diameter pipe that goes inside the well to facilitate the production of gas and the simultaneous removal of fluid, Mr. Perry said.
"The best information we have is that they had not even touched the wellhead when the event occurred," Mr. Perry said. "They were having a safety briefing when some of the workers detected a malfunction at the wellhead and there was some independent ignition source and the fire occurred."
The DEP will conduct its own investigation.
"We just really don't have enough information at this juncture to understand why the leak occurred and also what was the ignition source," Mr. Perry said. "That's the question that needs to be answered is how did this event occur in the first place?"
He couldn't say how long the investigation might take, noting that it could require metallurgical evaluations, discussions with the manufacturer of the wellheads and interviews with workers on site.
"An operator has a duty to maintain control of their wells at all times," Mr. Perry said. "The culpability of the operator is certainly something we consider when assessing any penalty. That's going to be an important part of our investigation as to whether this was purely an accident or whether this was a preventable accident."
Robert Zullo: email@example.com or 412-263-3909. First Published February 16, 2014 7:00 PM