WEO COMPLETION SAFETY BULLETIN

Location of Incident: 10-2-71-13-W6M Incident Date: December 10, 2007

Superintendent: Larry Malekoff Manager: Frank Barlow

Grease Injector: two check valves failed

Incident Description:

While pulling out of hole with 118mm gauge ring, grease injection at surface, the check valve on the grease injection hose failed. The check vavle on the oil storage tank also failed. Gas returned to the e-line truck through the hose to the injection tank. Tank not rated for 11,500kPa pressure (on the well) and tank split spilling oil on the ground with sweet natural gas.

The operator had pulled his tool string up into the lubricator, closed the master valve and was then starting to bleed off the pressure in the lubricator. He had also turned the grease injection pressure to the grease head down to about 14 MPa. This action led to under pressure on the grease head to keep a seal and let pressure back through the one-way check valve on the grease head back to the truck and through the one-way check valve in the system on the truck and into the grease tank itself bulging it and blowing all the grease out. The crew packed-off the saber head above the grease head to gain control of what pressure there was still in the lubricator and bled it off. The grease tank had bulged enough to make holes in it where it was mounted on the truck. The crew cleaned up the oil on the ground and were released as the truck could not do another pressure run into the hole.

One check valve had the ball missing completely and the other check valve had a piece of plastic from the pail holding the ball off the seat.

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Contributing Factors

·  Decreasing the grease pressure contributed most directly as it let more pressure develop on the other side of the check valve. Even with the check valves not working if the grease pressure was high enough this would not have happened.

·  Inadequate inspections of check valves, practice, procedures and employee training. No JSA’s or review of critical task when expected pressure changed.

·  Improper communication to field personnel from Wireline management to ensure proper procedures and inspection of pressure equipment and visual inspection of surface pressures by the personnel running the pressure equipment. Lack of enforcement by management to ensure that critical Job Safety Analyses are performed, and reviewed when jobs tasks and conditions change.

Corrective Action Plan (CAP)

·  Further training on proper grease-pressure procedures. A 300 hour line truck service to include inspection of all check valves, and all check valves on all trucks and portable grease injector to be replaced with brand new valves, if less that 100%.

·  JSA's on all critical task must be used, and review with all involved in the process. When a job function changes, or an unplanned/unexpected issue arises then the JSA must be updated and reviewed with all.

·  Ask Service provider to check there Check valves on grease head and at the tank and make sure there is clear communication about the pressure on the well.

Investigation Team : Dennis Lester / Keith Jerram / Larry Malekoff