Gulf of Mexico oil spill: How bad is it?
The oil spill that resulted from the explosion and sinking of an oil rig in the Gulf of Mexico last week is becoming more worrying as it continues to spread and efforts at stemming the flow of the leaking oil are being met with difficulties.
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The purpose of the relief well is two-fold, explained Terrell. The first part is to lessen the amount of oil that is leaking, while simultaneously blocking the current flow of oil by hardening and capping the well to prevent further leakage.Skip to next paragraph
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"The drilling rig would begin drilling down at an angle, and they would meet up with the well, and that would release some of the oil that is currently in it. The oil would go up in the relief well," Terrell said. "The other part is [that] they would put a heavy liquid in there – heavier than the oil. It would harden and make a cap in that well that would prevent the flow of oil from those two leaks, which is what the blowout valve would have done."
The relief well, which would stop the flowing oil, will take several months to complete, but is meant to be a more permanent solution to the oil leak situation.
How are they trying to clean up the oil?
Efforts are already in place to collect some of the oil that was spilled into the Gulf of Mexico.
Skimmers, which are large vessels that attempt to remove as much oil from the water as possible, have been on the scene to clean parts of the spill.
"So far, they've been able to collect more than 260,000 gallons (984,207 liters) of the oily water mix," Terrell stated.
According to the U.S. Coast Guard, more than 29,280 feet (8,925 meters) of boom has been assigned to surround and contain the spill, and 49 response vessels are being used, including skimmers, tugs, barges and other recovery vessels.
Engineers are also working on building domes that could be placed over the leaks to cordon off the area and collect the oily water. The domes, which would reach all the way to the ocean floor, would be placed over each leak, essentially closing off the area, and inside, large tubes would funnel the oil to the water's surface for collection by clean-up crews.
The specifications of the collection domes are still being worked out, and engineers are figuring out how to employ them effectively and safely.
"Collection domes have been used in the past, but in shallower waters," Terrell said. "So, they've never been used at depths of 5,000 feet (1,524 meters)."
Why would they try to burn the oil slick?
Burning oil spills is a known an accepted practice to clean up oil spills. "It's one of the tools in the toolbox of things you can do to help mitigate any oil spill," said Edward Overton, a professor emeritus of environmental sciences at Louisiana State University, though this method is typically used more in marshes close to shore.
If crews do attempt to burn the current slick in the Gulf of Mexico, as was announced today, it would be one the largest spills that burning has been tried on, according to Overton. "I'm not aware of something of this magnitude," he said. "Everything about this [spill] is uncommon."
To do a controlled burn, boats will first have to round up the oil with large V-shaped floating booms — the oil collects at the crux of the V. After it's collected, the oil is ignited in a remote area. The workers will try to burn the oil at the surface, where it still has plenty of its most flammable compounds and before it spreads too thin to effectively ignite. Although the oil burns quickly (a burn lasts for about an hour), workers would need to keep collecting and burning oil, probably a couple of times a day. It would likely be an ongoing process until the well on the ocean floor is capped, Overton said.
This maneuver would be "incredibly difficult to do," Overton said. Partly this is because of the gunky components — called asphaltenes, similar to the materials used to make asphalt roads — that are still in crude oil. These gunky components don't burn as easily.