Closer Look at the Transocean Deepwater Horizon BOP

Blowout preventers (BOP) are standard safety equipment on any drilling rig, and consist of a series of valves that can be closed to shut-off the flow of oil if the underground pressure of the oil threatens to overstress the rig.

Transocean’s Deepwater Horizon, built in 2001, was using a Cameron Type TL double preventer, weighing approximately 450-tons (See Specs). For some reason the BOP has not responded to efforts to trigger the shut-off valve. There are often several ways that a BOP can close a well, including plugging a pipe or even crushing it horizontally to stop the flow.

In the case of Transocean’s Deepwater Horizon, it remains unclear why the companies involved (BP, Transocean, and Cameron International / Cooper Cameron) are unable to activate the BOP. Usually, the blowout preventer can be closed using hydraulic equipment on the oil rig itself, but there are also “Dead Man” switches that close the BOP automatically if communications are lost with the rig.

There is another back-up safety measure that can be used to activate the BOP remotely, but Deepwater Horizon lacked this equipment. A radio, or acoustic, controlled remote shut-off switch for the BOP was not present on Deepwater Horizon, even though they are commonly used in other major offshore drilling countries.

U.S. government tried to require this third line of defense, but the drilling companies lobbied against it – claiming the radio controlled shut-off was costly and unnecessary. As the Transocean Deepwater Horizon explosion investigation takes shape, attention will most certainly focus on the rig’s BOP, testing and maintenance schedule, and the effectiveness of the emergency response plans. We may never know whether the added safeguard of an acoustic remote shut-off switch could have contained this disaster.