REGINA – SaskEnergy says the cause of a massive natural gas fire at a storage facility south of Prud’homme, Sask. will not be known until spring at the earliest.
Flames approximately 100 feet high and escaping gas were finally stopped by Alberta-based company Safety Boss on the evening of Oct.17.
“Safety Boss used fire retardant to put out the fire then installed the wellhead through the blowing gas and used the wellhead to stop the gas from coming up from the cavern,” said Dave Burdeniuk, SaskEnergy/TransGas spokesman.
There were 730 terajoules (TJ) of gas in the underground cavern when it was full prior to its ignition on Oct. 11.
“They could have put out the fire at any time but you can’t stop the gas from blowing and Safety Boss said they would prefer to address this as a fire rather than as invisible blowing gas coming out under pressure,” said Burdeniuk.
“The gas is lighter than air but if it’s burning it’s all going up in the one place, if it’s just blowing out you could have the wind carrying portions of it, you don’t want it temporarily accumulating near the surface and then it could ignite in a flash somewhere else.”
There were no injuries during the entire ordeal. The facility was automated at the time of ignition.
Once the new wellhead was installed, SaskEnergy was able to do pressure tests and determined about 90 per cent of the gas was burnt up over the seven-day period.
“It probably could have burned for a few more days but what we wanted to preserve as much of the gas in there as possibly,” said Burdeniuk.
About 665 TJ or $2 million worth of gas was lost.
A total bill for the damage is estimated in the five to 10 million dollar range.
“We have an insurance policy that covers gas and storage it also covers any damage to equipment or to facilities at the surface and that also includes the fire-fighting costs,” said Burdeniuk.
SaskEnergy has a $500,000 deductible and says it has an aggressive efficiency and productivity program.
“Over the last five years we’ve achieved $27 million worth of savings,” said Burdeniuk.
“We have $6 million of efficiencies targeted in 2015 and that deductable for the Prud’homme fire will be paid out of efficiencies in 2015, which is why we are saying no rate impact to SaskEnergy customers from any of the costs.”
Natural gas to replace what was lost has already purchased by the Crown Corporation. This cost will be reimbursed through insurance.
SaskEnergy plans to do a full assessment to find the cause of the blaze.
“We need to look inside that well, the casing of the cavern … the casing pipe that leads from the surface all the way three quarters of a mile down to the cavern itself,” said Burdeniuk.
There’s still 10 per cent of the gas left inside the cavern that needs to be transferred to the other six caverns on site, which are full. The earliest SaskEnergy will be able to take a look inside is May 2015.
The damaged wellhead is currently being analyzed by independent industry experts in Calgary.
The four families evacuated during the incident were allowed back into their homes on Oct. 19 after the wellhead was thoroughly tested.
Air quality testing was done within the two-kilometre perimeter and found no containments were present.