Unsafe acts/conditions during routine tasks in platforms/offshore and how to avoid them.

Dear all. Most of us are working already or planning join to oil and gas industry as an engineer,so you will do routine jobs frequently. I would like to share incidents/accidents and near misses those happened in the rig where I work and explain reasons ,how to avoid them. I hope you will benefit from this information in you future career. 

TOPIC 1 

Uncontrolled
release of energy in the top drive

Target audience for this alert

 Drilling Supervisors

What happened

 Whilst running in hole with the 13
3/8” seal assembly, as the driller picked up the string to remove the slips,
there was an unplanned rotation of the pipehandler. This caused the elevators
to make contact with the dolly tracks and subsequently open, dropping the
string downhole.

 Well barrier was compromised with
8” DC lying across the BOP. Ability to close in using the Annular, but couldn’t
use the pipe rams or shear rams.

Why it happened

 String picked up whilst top drive
was still running.

 No visual checks were made on the
top drive or RPM gauge, decision based on torque gauge alone.

 Dual activities being performed in
the dog house with insufficient communications between the two parties (driller
and Toolpusher). At the time the Toolpusher was mentoring the driller, who was

new to the rig.

Lessons learned

 Though it was unknown at the time,
the internal plug in the PORRT Tool would have enabled an internal seal.

 As both Annular preventers are part
of the LMRP and not the BOP, it resulted in a compromised ability to disconnect
the BOP and further escalation risk to subsea assets.

Recommendations

 Well Control considerations for
every tubular and BHA need to be assessed prior to running.

 Specific risk assessments should be
performed for any fullbore tool or unshearable BHA.

 Reinforce the Red Zone policy.