2010-06-04 08:10

METAIRIE, Louisiana - BP sliced off a pipe with giant shears Thursday in the latest bid to curtail the worst spill in US history, but the cut was jagged and placing a cap over the gusher will now be more challenging.

BP turned to the shears after a diamond-tipped saw became stuck in the pipe halfway through the job, yet another frustrating delay in the six-week-old Gulf of Mexico spill.

The cap will be lowered and sealed over the leak, said Coast Guard Adm. Thad Allen, the government's point man for the disaster. It won't be known how much oil BP can siphon to a tanker on the surface until the cap is fitted, but the irregular cut means it won't fit as snugly as officials hoped.

"We'll have to see when we get the containment cap on it just how effective it is," Allen said. "It will be a test and adapt phase as we move ahead, but it's a significant step forward."

Even if it works, BP engineers expect oil to continue leaking into the ocean.

The next chance to stop the flow won't come until two relief wells meant to plug the reservoir for good are finished in August.

BP Chief Executive Tony Hayward promised the company would clean up every drop of oil, and "restore the shoreline to its original state."

"We will be here for a very long time. We realize this is just the beginning," Hayward said Thursday.

This latest attempt to control the spill, the so-called cut-and-cap method, is considered risky because slicing away a section of the 20-inch-wide (50-centimeter-wide) riser removed a kink in the pipe, and could temporarily increase the flow of oil by as much as 20 percent.

Hayward conceded the attempt was risky, but said it was reduced when the pipe was cut away.

Live video footage showed oil spewing uninterrupted out of the top of the blowout preventer, but Allen said it was unclear whether the flow had increased.

"I don't think we'll know until the containment cap is seated on there," he said. "We'll have to wait and see."

US President Barack Obama will return to the Louisiana coast Friday to assess the latest efforts, his third trip to the region since the April 20 disaster. It's also his second visit in a week.

The White House said the federal government was sending BP a $69 million bill for costs so far in the spill. Spokesman Robert Gibbs said the bill was the first to be sent to the oil company, which leased the rig that exploded April 20 and sank two days later. Eleven people were killed.

Meanwhile, the Coast Guard's Allen directed BP to pay for five additional sand barrier projects in Louisiana. BP said Thursday the project will cost it about $360 million, on top of about $990 million it had spent on response and clean up, grants to four Gulf coast states and claims from people and companies hurt by the spill.

So far, anywhere between 21 million gallons (80 million liters) and 46 million gallons (174 million liters) of oil has spewed into the Gulf, according to government estimates.

Computer models show oil could wind up on the East Coast by early July, and even get carried on currents across the Atlantic Ocean, by Bermuda and toward Europe. The models showed oil entering the Gulf's loop current, the going around the tip of Florida and as far north as Cape Hatteras, North Carolina. Researchers with the National Center for Atmospheric Research cautioned that the models were not a forecast, and it's unlikely any oil reaching Europe would be harmful.

Oil drifted 6 miles (10 kilometers) from the Florida Panhandle's popular sugar-white beaches, and crews on the mainland were doing everything possible to limit the catastrophe.

Forecasters said the oil would probably wash up by Friday, threatening a delicate network of islands, bays and beaches that are a haven for wildlife and a major tourist destination dubbed the Redneck Riviera.

Officials said the slick sighted offshore consisted in part of "tar mats" about 500 feet (152 meters) by 2,000 feet (610 meters) in size.

County officials set up the booms to block oil from reaching inland waterways but planned to leave beaches unprotected because they are too difficult to defend against the action of the waves and because they are easier to clean up.

Florida's beaches play a crucial role in the state's tourism industry. At least 60 percent of vacation spending in the state during 2008 was in beachfront cities. Worried that reports of oil would scare tourists away, state officials are promoting interactive Web maps and Twitter feeds to show travelers?- particularly those from overseas?- how large the state is and how distant their destinations may be from the spill.

The effect on wildlife has grown, too.

The US Fish and Wildlife Service reported 522 dead birds?- at least 38 of them oiled?- along the Gulf coast states, and more than 80 oiled birds have been rescued. It's not clear exactly how many of the deaths can be attributed to the spill.

Dead birds and animals found during spills are kept as evidence in locked freezers until investigations and damage assessments are complete, according to Teri Frady, a spokeswoman for the National Oceanic and Atmospheric Administration.

"This includes strict chain-of-custody procedures and long-term locked storage until the investigative and damage assessment phases of the spill are complete," she wrote in an e-mail.