Pipeline Pigging Incident Dave Shepherd Aug 2005 Chevron

Pipeline Pigging Incident Dave Shepherd Aug, 2005 © Chevron 2005 DOC ID

What is a Pipeline Pig? Used to clean or inspect pipelines that are in service. Commonly used for: n Paraffin removal n Corrosion Inhibition n Pipeline Suspension © Chevron 2005 DOC ID 2

Background n Two workers were attempting to remove a pig from a line that was launched the previous day. n Found pig was stuck in reducer section but cleared block valve so valve could be closed. n After depressuring pig receiver and opening it to atmosphere, both workers believed energy had been removed. Pig had to be pulled into pig receiver through the reducer to remove so they fashioned a hook from some ss tubing. Open to Atmosphere Receiver © Chevron 2005 DOC ID Reducer Ball Valve 3

Incident n When worker hooked onto pig, the pig shot out and struck him in the nose resulting in major facial injuries. n Apparently, part of the pig created a seal with a weld in the reducer section, which created a pressure trap behind the pig. © Chevron 2005 DOC ID 4

Injured Worker July 27, 2005 © Chevron 2005 DOC ID August 1, 2005 5

Facial Reconstruction n 8 hour procedure n 7 plates (Titanium and Stainless Steel) used to reconstruct nose, eye sockets, and cheekbones. n Held together with 39 screws. n Jaw wired shut 2 – 4 weeks. n Expected to make full recovery. © Chevron 2005 DOC ID 6

Other Factors n Safety glasses were not damaged but covered in oil and water. Likely prevented any chemical damage to eyes. n Trapped pressure was just high enough to create a seal but too low to move pig on its own. If pressure was lower or higher, incident would not have occurred. n Root cause was in hazard recognition. Neither worker considered any pressure existed since the pipe was open to atmosphere. © Chevron 2005 DOC ID 7