Q. How far has the oil advanced along the Gulf Coast? How far could it travel, and what variables are at play? Have any communities been bypassed and spared?
A. So far, oil has made landfall along hundreds of miles of the Gulf Coast, from Freshwater Bayou in the middle of Louisiana’s coastline, all the way to the Florida panhandle to just outside Panama City. The impact has not been uniform; some areas have been greatly affected, while others have been spared. For example, Mississippi’s mainland coast, excepting its barrier islands, has been largely untouched by heavy oil, though that appears likely to change in the next few days.
The oil, either in the form of tar balls, sheen or heavier “mousse,” is brought near the coast by currents, but the wind is usually responsible for the final push, bringing streams of oil onshore. Coast Guard officials frequently describe the oil as a series of spills rather than one big slick, and that is reflected in the impact: oil is heading in all directions at the same time.
Shoreline trajectories, based on currents and wind patterns, are only dependable for roughly 72 hours. But scientists using computer models at the National Center for Atmospheric Researchsuggested that the oil reaching the loop current in the Gulf of Mexico could come around Florida’s southern tip within weeks. have
After that, the modeling indicates, it would travel up the Atlantic Seaboard to North Carolina’s Outer Banks, before joining the Gulf Stream and heading east across the Atlantic toward Europe. They caution, however, that this is not a forecast but merely a possibility, and that it is unclear how much the oil would dissipate as it traveled in these currents
Q. How much oil has spilled so far?
A. The exact rate at which oil is leaking from the well is not known. Although estimates of the flow rate have changed drastically — to 35,000 to 60,000 barrels a day now, from 1,000 barrels a day originally — it is also not known if the actual rate has changed in the two months since the gusher began.
Calculating the spill to date using the current estimate, and factoring in the approximately 365,000 barrels collected so far from the wellhead, results in a total of about 1.9 million to 3.5 million barrels, or about 80 million to 150 million gallons since the rig exploded on April 20.
By contrast, the Exxon Valdez spill off Alaska in 1989 released an estimated 10.8 million gallons of oil.
Q. How might BP plug the leak?
A. BP has tried a lot of methods to seal the well or contain the leak and until recently did not have much success. On June 3, however, technicians succeeded in cutting the riser — the large pipe that connected the well at the seafloor to the drilling rig and that collapsed when the rig sank — and two days later lowered a containment cap on it.
Although the cap did not make a perfect seal, it collected about 15,000 barrels of oil a day.
In normal operation, the oil collected by the cap travels up a pipe to a drill ship, the Discoverer Enterprise, where it is stored and later loaded onto a tanker before heading to a refinery. Natural gas is separated from the oil and burned on a long boom extending from ships.
On June 16, a second system began operating, in which oil is collected through a pipe at the base of the blowout preventer, the stack of safety valves at the top of the well on the seafloor. The oil flows up to a drill rig, the Q4000, where both the oil and the gas it contains are burned using special equipment that produces far less soot than open-air burning of oil.
Q. Is there a sure long-term fix for the spill? When could that happen, best case and worst case?
A. Drilling experts say that two relief wells being drilled near the site of the blowout are the ultimate solution to stopping the gusher. Relief wells have been used to “kill” runaway wells in the past, and the basic procedure is straightforward.
The relief well is drilled at an angle to intersect the damaged well just above the oil reservoir — in this case, about 18,000 feet below sea level. Then heavy drilling mud is pumped down the relief well into the runaway well. As more and more mud is pumped in, it builds up a column of mud that produces enough downward force to counteract the upward pressure of the gas and oil, stopping the leak. Cement is then pumped into the well to entomb it permanently.
Only one relief well should be needed, but BP is drilling a second in case anything goes wrong with the first. Both wells should be completed by late July or August, although they could be delayed. The wells have to find a seven-inch steel pipe that forms part of the runaway well, and although they have plenty of high-tech tools and data-gathering equipment to do that, there is no guarantee they will succeed on the first try.
Mechanical problems or bad weather could also delay the work. A hurricane or other severe storm could also push back completion dates by a week or more, as the drilling rigs would have to shut down and move to a safe location. Bad weather would also affect the containment operation, as all the other vessels at the site of the blowout would have to depart and the well would be left uncapped until the storm had passed.
Q. Doomsday scenarios described online suggest that the pipe that lines the well is deteriorating, or that there may be other problems with the well that may cause it to fail completely, leaving an utterly uncontrolled gusher that could prove difficult or impossible to control. Is this true?
A. There is a lot of speculation about the condition of the well, but it is not really possible to know what kind of shape it is in. BP suggested that one reason that a procedure called the “top kill” failed was because there may have been damage to the well lining about 1,000 feet down. But no one knows for sure.
What does seem clear is that there is enough concern about not making the situation worse that BP is now pursuing only the containment option at the top of the well. They have abandoned efforts to permanently plug the well from the top because that would build up pressure that might cause damage. The well will be permanently sealed starting from the bottom, using one or both relief wells.
Q. Who is in charge of stopping the oil that is already spilled from spreading and reaching the gulf shoreline?
A. The Coast Guard, led by Adm. Thad W. Allen, has been designated the lead agency. In practice, day-to-day decisions are made jointly by Coast Guard personnel and their BP counterparts. At the spill response center in Venice, La., BP officials or contractors in charge of a certain task — setting cleanup priorities, for instance, or allocating resources like containment boom — are matched with Coast Guard officials with the same responsibility. One Coast Guard petty officer described the division of authority in percentage terms: “It’s 51-49, and we’re the 51.”
A unified command center has opened in New Orleans and incident command posts operate in Houma, La., Mobile, Ala., and Miami. Satellite posts exist elsewhere along the coast in places like Port Fourchon, La. and Venice, La.
Q. How many people are working on the response, and what are they doing?
A. Some 36,000 people are involved, according to the Deepwater Horizon Response Web site overseen by BP. A BP official said that included 1,185 Coast Guard personnel, 1,282 National Guardsmen and 667 BP officials. But the bulk of the personnel — a total of nearly 31,000 — work for contractors hired by BP, ranging from United States Environmental Services, based in New Orleans, to O’Brien’s Response Management in Houston.
Out on the waters around the broken well, some 27 vessels with 230 crew members and support personnel are burning oil. Some 14,500 people are serving as mariners, crew members or captains on 2,680 “vessels of opportunity” recruited for the cleanup. Some are skimming oil — either at sea, from specialized skimming vessels, or closer to shore with so-called “drum” skimmers, cylinders with surfaces that attract oil, which is then squeegeed off as the drum spins.
Others are laying “hard” vinyl boom and soft absorbent boom — more than 475 miles of it — to protect the marshes and beaches.
The State of Louisiana has enlisted National Guardsmen to install 1.6 miles of welded-mesh steel barriers on one coastline; the goal is to cover eight miles. The guardsmen are also deploying cylindrical “tiger dams” on Grand Isle.
The state-sponsored construction of sand berms was started in two places off Louisiana’s fragile barrier islands and wetlands to keep the oil at bay, state officials say. But a dispute between state and federal authorities over where it is safe to dredge halted one project this week after 690,000 cubic yards of dredged material had been made available for berms.
In addition to the engineers and cleanup workers, more than 500 federal and state wildlife specialists are working on rescuing oiled animals and oiled habitat, said a BP spokesman, John Curry. That does not include an undetermined number of staff members and wildlife experts from nonprofit organizations and advocacy groups.
Q. How are vessels assigned to work in various areas of the spill?
A. The captains of these so-called vessels of opportunity register with the joint command and are assigned to work in a lottery, with the number picked on any given day based on regional need, said Michael R. Abendhoff, BP’s director of government and public affairs. “We’re focusing on getting fishermen to work in an area they know,” he said.
EJERCICIO.-
1.-What areas of the Gulf Coast have been spared by this problem?
R.- Mississippi’s mainland coasts
R.-It brings streams of oil onshore.
R.- by the cap travels up a pipe to a drill ship
R.- Mechanical problems or bad weather like a hurricane
R.- The State of Louisiana has enlisted National Guardsmen
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