UPDATE: BP officials elected to go with the “top hat” solution, and lowered a smaller containment box over the drilling site on Tuesday, May 11. Wednesday morning, they reported the box had reached the sea floor, but had not yet been placed over the leaking pipe. According to a report by the Associated Press, BP officials say they want to move slowly, to avoid a buildup of the icy material that caused the first, larger containment dome to fail. They say robots will position the new box over the leak by Thursday. A pipe connected to the box is expected to draw the leaking oil to the ocean surface, where it will be collected by boat.
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Oil industry experts and BP officials had hoped a 100-ton dome would contain the massive amounts of oil currently gushing into the Gulf of Mexico following the April 20 explosion of the Deepwater Horizon drilling platform. Since the platform sank on April 22, an estimated 5,000 barrels of oil per day have been leaking into the gulf. Over the weekend, BP lowered the containment dome over the primary leak site, almost a mile below the surface of the ocean. However, an icelike substance called methane hydrate clogged the box, which then had to be removed.
Workers trying to find a way to stem the leak are basically flying blind, as a situation like this one has never happened before, at such a depth. Pressure at the source of the leak, which is 5,000 feet below the ocean surface, is equal to more than 150 atmospheres, and water temperature is near freezing. BP officials had hoped the containment box would slow the flow of oil until they can implement a more permanent solution, drilling a second well at the site that will allow them to divert the flow of oil. However, that plan will take time, estimated at up to three months.
Meanwhile, oil is spreading throughout the Gulf of Mexico. It has already negatively affected the commercial fishing industry, as activity has been suspended in a large area around the spill site. It also threatens the tourism industry, as skittish vacationers cancel reservations. This weekend, tar balls were found onshore at Dauphin Island, Alabama. These are being examined to verify whether or not they come from the oil spill site, although it’s very likely. The economic and environmental impact of the spill is expected to be unprecedented.
So, what now? BP officials are looking at several options. Leading the list is the deployment of another, smaller containment box, which officials feel would have less chance of getting clogged. It also is the quickest option, as the box could be deployed by the middle of this week. This box is called a “top hat.” Other ideas that are being debated include:
- Cutting the riser pipe and placing another pipe over it to bring the oil up to a ship on the surface. This is a dangerous option because cutting the riser will most likely temporarily increase the flow of oil, and if BP is unsuccessful in threading the second pipe over the cut riser, they have a bigger problem on their hands.
- Plugging up the well with mud and concrete or shredded rubber, garbage, golf balls and other debris. These substances would be delivered into the blowout preventer, which was supposed to shut off the flow of oil in the event of an explosion, but which failed. This technique is known as a “top kill.” The process could take two or three weeks.
- Try again with the large containment box, after exploring a way to prevent the ice-like crystals from building up.
There has not been any announcement yet from BP officials about which option they plan to try next. In the meantime, the spill is being treated with chemical dispersants in an effort to break up the oil. Booms have been placed around the spill and along the coastline in an effort to try to prevent oil from washing ashore. The slick is predicted to cover about 200 miles of the Gulf of Mexico.