Tuesday, March 3, 2015

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.




MARCH 3, 2015

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."
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. 
"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."

"Worker safety is paramount" she said. "We learn from all incidents that may occur in our operations and thoughtfully implement necessary mitigation measures to ensure the safety of workers, the environment and the communities."

Questions directed to Trinidad asking for comment were not returned as of press time.

The well was "sweet," meaning that it did not contain poisonous hydrogen sulphide, which can be found in some natural gas fracking operations. 


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BC OIL &  GAS COMMISSION ISSUES ADVISORY FOLLOWING INCIDENT INVESTIGATION

FEBRUARY 17, 2015

The BC Oil and Gas Commission (Commission) is reminding operators Division 2 of the Drilling and Production Regulation contains regulatory requirements related to well control equipment, procedures, training and competency. Permit holders must ensure that reliably operating well control equipment is installed at all times and that site personnel have adequate training and competency to safely carry out well operations.

This follows an investigation into a March 2014 incident where approximately 9,400 cubic metres of sweet natural gas leaked from a well over five days, most of which was diverted to a flare stack before the leak was successfully repaired. The incident occurred following cementing operations on a natural gas well targeting the Montney formation. Drilling operations were complete, and production casing was installed in the well and cemented with nitrogen foam cement. The well is located in a remote area approximately 200 kilometres north of Fort St. John and there were no significant offsite or environmental impacts.

Approximately two-and-a-half hours after cementing was complete, the rig crew proceeded to partially unbolt the flange that secures the BOP (blowout prevention) stack to the well. Approximately three-and- a-half hours later, the well was de-pressurized at surface. Approximately 12 hours after cementing was complete, the well was found to be leaking gas. A hose was attached to the BOP stack in an attempt to de-pressurize the well and allow the leak to be repaired. The hose was not properly restrained when flow was diverted, and one worker was injured. Medical aid was provided at the scene and at the Fort St. John hospital.

The planned cement job included the pumping of nitrogen foam cement with a “cap” cement. The cap cement is a rapid-setting cement capable of providing pressure containment at surface while the foam cement cures. On arrival at the site, it was determined the cementing company did not have sufficient additives for the cap cement, so the decision was made to only pump the foam cement. Due to the job scope change, the cement setting time increased from six hours to 24 hours.

Key findings of the investigation are as follows:
·         Removal of some of the BOP flange bolts while the well was pressurized allowed a leak path to develop.  The bolts were removed prior to cement setting time elapsing.
·         Depressurizing the well prior to the cement setting time elapsing compromised the cement integrity, allowing a natural gas leak to develop.
·         The cementing job scope change was not adequately communicated to on-site personnel.
·         Adequate assessment and control of hazards were not completed during initial attempts to control the natural gas leak.