Root Causes of the Deepwater Horizon Oil Spill: An Investigative Analysis

The Accident
On the night of April 20, 2010, the deepwater drilling rig Deepwater Horizon suffered a catastrophic explosion and subsequent sinking in the Gulf of Mexico. This tragic event resulted in the death of 11 workers and has since been recognized as the largest marine oil spill in the history of offshore drilling operations.

etration Was Human Error

The primary cause of the Deepwater Horizon oil spill was not corporate greed, as some might suggest, but rather a series of human errors and a critical failure to adhere to stringent safety protocols and regulations. These errors were made by numerous low-level management personnel on the rig, not by the company as a whole.

Normalization of Risk

One of the key concepts behind the Deepwater Horizon disaster was normalization. This refers to the phenomenon where individuals continue to engage in risky behavior because they believe that such behavior is non-harmful based on a series of past experiences. In the case of the Deepwater Horizon, it was a critical series of errors that ultimately led to the explosion.

Nature of the Incident

Shortly before the explosion, a surge of natural gas blasted through a recently installed concrete core, designed by Halliburton, intended to seal the well. Due to the extreme depth of the sea and the pressure conditions in the well, it was exceptionally challenging to seal the well properly. The accumulation of human errors exacerbated this critical situation.

“Swiss Cheese” Model of Failure

A thorough investigation revealed that numerous factors had to fail simultaneously for the disaster to occur. The ‘swiss cheese’ model of failure, which visually depicts a series of systemic and equipment failures, highlights the complexity involved. In reality, the number of failures and the depth of the systems involved are even higher. For instance, under the “Mechanical Barriers” category, up to six different failure points had to be present.

Contributors to the Accident

Bad luck also played a role. One of the critical failures was the malfunctioning of the Blind Shear Rams (BSR). The BSR, designed to cut through the drill pipe, failed because the collars of the drill pipe were situated precisely where the shear ram was supposed to act, rendering the BSR ineffective. While the chances of this happening are low, it contributed significantly to the disaster.

Root Cause Analysis

The core issue was human judgment and action on the rig. Despite multiple visible signs of potential blowout, the team on the Deepwater Horizon disregarded these warnings, focusing on data from the kill lines over the drill pipe pressure. This decision to ignore evident signs of danger and rely on less direct measurements reflects a systemic failure in decision-making processes.

Management Failures

While management on shore should have intervened, their failure to do so was a manifestation of a broader problem. The real root cause, however, lies in the actions and decisions made directly on the rig. The rig manager’s decision to unload mud and save a few hours of rig time during a critical test highlights a lack of adherence to established safety protocols.

Conclusion

The Deepwater Horizon oil spill was not a single event but a complex series of failures. These included not only equipment and system malfunctions but also critical human errors and a fundamental disregard for safety by individuals and management on the rig. A deeper investigation into these factors is crucial for preventing similar disasters in the future.

Moderators and safety professionals should take heed of the lessons learned from the Deepwater Horizon incident to ensure that decision-making processes on rigs and platforms prioritize safety and compliance with regulations.