Flash fire at Questar facility causes minor injuries to 12 workers
Gobblers Knob Compressor Station on the Pinedale Anticline
by Dawn Ballou, Pinedale Online!
October 22, 2008
A flash fire at the Questar Gobblers Knob Compressor Station resulted in minor injuries to 12 contractors last weekend.
According to Diana Hoff, General Manager for the Questar’s Pinedale Division, the incident occurred around 6:50 PM on Saturday, October 18th at a compression station facility located in the southern portion of the Pinedale Anticline gas field on the Mesa, south of Pinedale and north of WYO 351.
"It was a flash fire of short duration and a loud bang," Hoff said in a telephone interview on Tuesday, October 21. "The noise was magnified by the size of the pipe they were working on."
Hoff said there was no natural gas going through the plant or the 20" pipe at the time. "Workers had purged the pipe with nitrogen," she explained. Nitrogen by itself isn’t combustible unless it is mixed with oxygen and there is an ignition source. There was not supposed to be oxygen in the line at the time, but somehow it got inadvertently introduced into the system from another source. "Workers heard the noise of the fire when it was about 100 feet away in the pipe and moved out of the area," she said. "There was a loud bang and an instant flash. The fire lasted just an instant."
Twelve people received medical treatment due to the explosion. Six were taken to the local clinic by ambulance, treated, and later released. Of those, one person received a minor dislocated shoulder and the others complained of hearing problems. Two people drove themselves to the clinic with hearing issues and were later released. Four others were also treated for hearing issues. All contractors are now back at work.
Hoff said safety inspectors and on-site welding crews were aware something was amiss and had time to move everyone to a safe area out of the way before the explosion.
"As far as we can tell from our initial visual inspection there was no damage to the equipment," she said. The Occupational Safety and Health Administration (OSHA) was notified and there were no spills. Crews are now doing more detailed inspection of the site to make sure nothing was missed with their naked eye visual inspections of the equipment.
"The good news is that injuries were relatively minor and folks on location were moved to a safe area quickly and impacts were minimized," Hoff said. She commended all the emergency response personnel for their quick response time to the site.