Gulf oil spill: The mile deep challenge

Safety Device Questioned in '04

Excerpt:

The shear rams are an integral part of the giant blowout preventer, which sits on the sea floor, 5,000 feet below the surface. R. Scott Amann, a spokesman for the sheer ram manufacturer, Cameron International Corp., said he did not know exactly what happened.

"We remind you that our devices have never been involved in an accident like this," he said.

The cause of the oil well blow-out remains unclear. Petroleum engineers say it was probably related to the cementing process, which is supposed to secure the well and prevent oil and natural gas from escaping by filling in the space around the pipe and plugging the well.

But once workers lost control of the well, which was spewing a flammable mixture of crude oil and natural gas, the blowout preventer became the only option for stopping the flow.

Investigators are expected to focus on whether the blowout preventer received a signal from workers on the rig. The Deepwater Horizon wasn't equipped with a backup remote trigger that is a common drill-rig requirement in other oil-producing nations, but not the U.S.

If the blowout preventer did receive the signal, experts say, a critical question is why the rams didn't seal off the well.

Some newer rigs have blowout preventers with two separate pairs of shear rams—providing an added safeguard in case one shear malfunctions or hits an obstruction in the pipe. The Deepwater Horizon had a single pair of shear rams.

Comment: The WSJ article has a helpful graphic. Click through to view! A detailed drawing of a blowout preventer is here.