Try and try again


BP lowered a giant containment dome over one of the leaks, but low temperatures caused the device to clog up.

Domes and hats

The source of the leaking oil is below 5000 feet of water. That’s too deep for human divers—at that depth, the water is very cold, and the pressure is very high—so all the work at the mouth of the borehole has to done by remote-controlled submarines. These conditions have made stopping the rapid flow of oil from the broken drilling equipment extremely difficult, and as of the beginning of June 2010, all efforts to close the well or capture the oil have failed.

BP first tried to contain and capture the leaking oil with a giant dome attached by a pipe to a ship at the surface. The metal dome, which was several stories tall and weighed 125 tons, was placed over the largest of the leaks in the broken riser. Oil that flowed into the dome could be sucked up and contained until the leak was stopped. Unfortunately, the near-freezing water at the floor of the gulf combined with leaking gas from the well to form crystals called methane hydrate. The chunks of methane hydrate floated to the top of the dome, and blocked the pipe leading to the surface, rendering the dome useless.

Next, a much smaller dome, nicknamed a “top hat” was lowered to the leak. The top hat wouldn’t capture as much leaking oil as the larger containment dome, but it was fitted with features to keep it from being clogged with frozen materials. Once the top hat was lowered, however, BP set it aside from the leak while they tried yet another plan. Read on to learn more.