Deepwater Horizon Preclass Analysis
Process and Equipment of Deepwater Drilling
Control is at the blowout preventer (BOP)
126 crew change shifts every 12 hours they changes
4 separate crews
Complex team
Difficult to access the subsurface
During hurricanes the BOP need to separate from the MLRP
Need to cut the pipe using the blind shear ram and block the pipe
Everything under the surface is done using remote controlled vehicles
Questionable Issues
Long string has one less degree of safety than the liner and tie-back method which is more costly
Lockdown sleeve - wasn’t installed at the stage of the accident
Negative pressure test - no standard procedure for the test
Results were not interpreted correctly
Conducted too soon after cementing
Issues Involved in the Accident
Cement job failed to seal off the producing reservoir, casing seal failed
Didn’t do the log, testing for the cement
Didn’t use 21 centralisers
Hydrocarbon inflow was not recognised and hydrocarbon entered the ris
Gas ignited on the rig, causing fire and loss of power
Fans were not designed to shut down automatically on gas detection
Set off alarms but needed someone to manually shut it down
BOP failed to seal the well
Emergency disconnect - button to shut it off
Automatic cut off
