Alert 99 – 31 High Pressure Release of Trapped Nitrogen
Alert 99 – 31 High Pressure Release of Trapped Nitrogen
WHAT HAPPENED:
Following the foam cementation of 20″ (50 cm) casing in deepwater from a semi-submersible rig, the inner cementing string was found to be plugged during its recovery. When breaking out the final joints of cement stinger using chain tongs, a high-pressure release of trapped nitrogen gas blew cement particles into the face of a floorman.