This investigation report refers to an accident that took place during an attempt to weld the casing head of a slip-on wellhead, gas flow was noticed coming from the +10 valve. Later, unsuccessful attempts were made to stop the flow, which was then coming from the drive pipe/surface casing annular region. The gas flow eventually ignited and caused extensive damage to the platform. The well bridged over and kill operations were completed successfully and fortunately there were no injuries.
Officer of the Watch 