Oil spillsNew Lessons from the Worst Oil Spill Disaster ever

By Nancy Bazilchuk

Published 1 July 2020

Ten years ago, the Deepwater Horizon accident in the Gulf of Mexico killed eleven men and resulted in the largest accidental oil spill in history. Years of investigations concluded that the drilling crew missed critical warning signals that would have stopped the problem. A new analysis suggests that wasn’t the case.

Ten years ago, the Deepwater Horizon accident in the Gulf of Mexico killed eleven men and resulted in the largest accidental oil spill in history. Years of investigations concluded that the drilling crew missed critical warning signals that would have stopped the problem. A new analysis suggests that wasn’t the case.

The magnitude of the Deepwater Horizon accident is almost impossible to fathom. On April 20, 2010, eleven men died when the drilling rig exploded. An estimated 507 million litres of oil spilled into the Gulf of Mexico over 87 days, coating nearly 1000 km of coastline with sticky black goo. Birds and marine life took a beating, and shrimpers who relied on the Gulf of Mexico were deeply affected when fishing grounds were closed.

Years of investigations and legal proceedings found many reasons for the accident, including that the crew itself had missed critical information which, had they noticed in time, would have allowed them to address the problem before it exploded.

But a new analysis of data from the drilling platform paints a very different picture of what has previously been found, said Dag Vavik, a Norwegian engineer with 30 years in the industry. Vavik recently defended his PhD on the accident at the Norwegian University of Science and Technology.

“In previous investigation reports… we have been told how the drilling crew failed to observe that the well was flowing during the last 20 minutes before the explosion,” Vavik said. “However, real time data and witnesses from the Deepwater Horizon tell a different story.”

Questioned Industry Standard
Vavik has nearly 25 years’ experience designing offshore floating drilling units, like the Deepwater Horizon, and was well aware of the problems these rigs could face.

His experience made him question an industry practice recommended in 2001 for separating natural gas from drilling mud. Vavik felt the recommendation could result in an uncontrolled release of mud and gas onto the rig.

The Deepwater Horizon’s mud gas separator system was based on this recommendation. The problem was that the system was designed to allow gas and mud to return from the well by being routed directly to the mud gas separator without any restrictions, Vavik said.