Cement Failure Contributed to Deepwater Horizon Explosion

By ThinkReliability Staff

The investigation to determine the causes behind the April 20, 2010 explosion of the Deepwater Horizon oil rig and the resulting oil spill is still underway.  (A previous blog discussed the BP report and the initial findings from their investigation.)

The newest piece of information that has come to light is that cement used to seal the production casing wasn’t properly tested.  It was previously assumed that the cement must have failed or the hydrocarbons would not have been able to leak into the well and subsequently feed the massive explosion that destroyed the oil rig.  But more information is coming available that explains why the cement failed.

The well was cemented with nitrogen foam cement supplied by a contractor. Investigation by the presidential commission on the oil spill has revealed that the cement was not properly tested prior to use.  More significantly, the cement was found to be unstable when tested.

 The data indicates that the cement failure was a cause of the oil rig explosion, but was it the root cause?

It’s easy to see that the cement failure was not the only cause.  In addition to the failure of the cement, there were other things that had to occur for the accident to happen.  One of the most obvious is the failure of the blowout preventer.  Even if the cement failed and the hydrocarbons leaked into the well, a functioning blowout preventer would have blocked the leak path for the hydrocarbons and prevented this tragedy.

As with any incident of this magnitude, there is no single root cause, rather there are a number of causes that contributed to the incident.  Determining all the causes that contributed to the incident will allow better understanding of the incident, which will hopefully lead to development and implementation of better solutions to prevent similar accidents in the future.