Gas release from 1st stage separator during flushing

During the flushing operations, the hose became detached at the instantaneous coupling connection point. The sudden depressurisation of vessel caused gas break out from the fluids, oily water, released to the atmosphere and activated multiple gas heads with the area.

The gas heads cleared almost instantaneously however their activation resulted in GPA and a level two surface process shutdown.

Investigations identified that the instantaneous coupling was not correctly engaged as the lugs on instantaneous coupling clashed with the bolts which were in place to secure the flanged connection point for the hose on top of the vessel and/or the fact lugs on instantaneous coupling female section were stiff to locate securely onto the male section as no formal inspection or maintenance was carried out on hose.