Supervisors erred in 2014 oilfield accident by William Stodalka, March 3, 2015, Alaska Highway News
A BC Oil and Gas Commission investigation has found that on-site supervisors had a role in a man’s injury during work to prevent a leak on a natural gas site last year.
The incident, which happened last March, involved workers for Trinidad Drilling Ltd., who were contracted by Progress Energy to perform drilling activities at a location about 200 kilometres north of Fort St. John.
Neither the OGC nor WorkSafeBC would say what the extent of the man’s injuries were, other than to say that he was taken to Fort St. John Hospital, and it was non-fatal.
About 9,400 cubic metres of sweet natural gas leaked over five days, but most was diverted to a flare stack, where it was burned off, and the OGC said there were “no significant offsite or environmental impacts” because of the leak.
The incident occurred northwest of Fort St. John, near the Alaska Highway.
The crew had finished cementing the well, which is part of a procedure to prevent leaks.
Workers had been told it would take six hours for the cement to set. But apparently a change in the type of cement used at the site meant that it would take 24 hours to set.
Around six hours later, the well was depressurized at the surface. (The difference between the pressures on the surface and underground allows gasses underground to rise to the surface.) The decision to depressurize the well before the cement had set allowed a natural gas leak to develop, the BC OGC said.
Around 12 hours after the cementing job was finished, the crew discovered that the pipe was leaking gas.
It took this long, said Alan Clay, a spokesman for the BC OGC, because “it took time for the natural gas to migrate to the surface where it could be detected.” [Is anyone monitoring groundwater to determine the level of gas and chemical contamination?]
Then, the crew attached a hose, called a blowout prevention stack, to depressurize the well and fix the problem.
The hose was not properly restrained, however, and it struck and injured one of the workers.
A BC OGC investigation found that the on-site supervisors did not do an adequate job of telling their workers about the change in the cement setting time. [Greed induced perhaps?]
“It is the responsibility of the on-site supervisors to ensure that changes to the nature of the job are reviewed with those employees involved with the work and that a hazard assessment is carried out beforehand and built into the work plan.”
The last time the OGC issued a safety advisory was in 2013.
Stacie Dley, a Progress spokesperson, said they are still concluding the matter with the OGC.
The injured worker has “recovered and is back at work.” [Emphasis added]
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