Monday 14 February 2011

Size of Spill in Gulf of Mexico Is Larger Than Thought


Chris Graythen/Getty Images
A boat sailed through crude oil that had leaked from the Deepwater Horizon wellhead in the Gulf of Mexico.
NEW ORLEANS — Government officials said late Wednesday night that oil might be leaking from a well in the Gulf of Mexico at a rate five times that suggested by initial estimates.

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In a hastily called news conference, Rear Adm. Mary E. Landry of the Coast Guard said a scientist from the National Oceanic and Atmospheric Administration had concluded that oil is leaking at the rate of 5,000 barrels a day, not 1,000 as had been estimated. While emphasizing that the estimates are rough given that the leak is at 5,000 feet below the surface, Admiral Landry said the new estimate came from observations made in flights over the slick, studying the trajectory of the spill and other variables.
An explosion and fire on a drilling rig on April 20 left 11 workers missing and presumed dead. The rig sank two days later about 50 miles off the Louisiana coast.
Doug Suttles, chief operating officer for exploration and production for BP, said a new leak had been discovered as well. Officials had previously found two leaks in the riser, the 5,000-foot-long pipe that connected the rig to the wellhead and is now detached and snaking along the sea floor. One leak was at the end of the riser and the other at a kink closer to its source, the wellhead.
But Mr. Suttles said a third leak had been discovered Wednesday afternoon even closer to the source. “I’m very, very confident this leak is new,” he said. He also said the discovery of the new leak had not led them to believe that the total flow from the well was different than it was before the leak was found.
The new, far larger estimate of the leakage rate, he said, was within a range of estimates given the inexact science of determining the rate of a leak so far below the ocean’s surface.
“The leaks on the sea floor are being visually gauged from the video feed” from the remote vehicles that have been surveying the riser, said Doug Helton, a fisheries biologist who coordinates oil spill responses for the National Oceanic and Atmospheric Administration, in an e-mail message Wednesday night. “That takes a practiced eye. Like being able to look at a garden hose and judge how many gallons a minute are being discharged. The surface approach is to measure the area of the slick, the percent cover, and then estimate the thickness based on some rough color codes.”
Admiral Landry said President Obama had been notified. She also opened up the possibility that if the government determines that BP, which is responsible for the cleanup, cannot handle the spill with the resources available in the private sector, that Defense Department could become involved to contribute technology.
Wind patterns may push the spill into the coast of Louisiana as soon as Friday night, officials said, prompting consideration of more urgent measures to protect coastal wildlife. Among them were using cannons to scare off birds and employing local shrimpers’ boats as makeshift oil skimmers in the shallows.
Part of the oil slick was only 16 miles offshore and closing in on the Mississippi River Delta, the marshlands at the southeastern tip of Louisiana where the river empties into the ocean. Already 100,000 feet of protective booms have been laid down to protect the shoreline, with 500,000 feet more standing by, said Charlie Henry, an oil spill expert for the National Oceanic and Atmospheric Administration, at an earlier news conference on Wednesday.
On Wednesday evening, cleanup crews began conducting what is called an in-situ burn, a process that consists of corralling concentrated parts of the spill in a 500-foot-long fireproof boom, moving it to another location and burning it. It has been tested effectively on other spills, but weather and ecological concerns can complicate the procedure.
Such burning also works only when oil is corralled to a certain thickness. Burns may not be effective for most of this spill, of which 97 percent is estimated to be an oil-water mixture.
A burn scheduled for 11 a.m. Wednesday was delayed. At 4:45 p.m., the first small portion of the spill was ignited. Officials determined it to be successful.