Rig Operations at time of Incident tripping in
Perforation Guns. String still above BOP at time of
event.
During tripping Operations Thruster 2 control power
supply suffered major failure when flash over
destroyed Main Line inverters.
On investigation it was noted that smoke was
billowing from Siplink cabinets. General alarm was
initiated and once full muster was confirmed teams
assembled to make area safe, The smoke from
Thruster Cabinets cascaded through machinery
spaces causing Thruster #6 to shut down on smoke
detection alarm. As smoke migrated through T#1
went into alarm and shut down. Station keeping
presented no issues and vessel remained stable with
minimal excursion.