BP tries again to stem oil spill now rated worst in US history

THE Gulf of Mexico oil spill has surpassed the Exxon Valdez as the worst in US history, according to new estimates released yesterday, but the Coast Guard and BP said an untested procedure to stop it seemed to be working.

• Louisiana Governor Bobby Jindal is reflected in oil filled water. Picture: Getty

A team of scientists trying to determine how much oil has been flowing since the offshore rig Deepwater Horizon exploded on 20 April found the rate was more than twice and possibly up to five times as high as previously thought.

Even using the most conservative estimate, that means the leak has grown to nearly 19 million gallons, surpassing the size of the 1989 Exxon Valdez disaster, which at about 11 million gallons had been the nation's worst spill. Under the highest estimate, nearly 39 million gallons may have spilled.

BP did not immediately comment on the new estimate.

The news came as the chief of the agency in charge of offshore drilling stepped down just hours before President Barack Obama extended a moratorium on new deepwater oil drilling.

Minerals Management Service director Elizabeth Birnbaum and her agency came under withering criticism from politicians of both parties over lax oversight of drilling and cosy ties with industry.

An internal Interior Department report released earlier this week found that, between 2000 and 2008, agency staff members accepted tickets to sports events, lunches and other gifts from oil and gas companies and used government computers to view pornography. Ms Birnbaum had run the service since July 2009.

At a White House briefing to announce the six-month moratorium extension, Mr Obama described the oil spill as a "tremendous catastrophe", and his administration was "singularly focused on disaster".

He vowed to use the full force of the federal government to protect US citizens.

"We will hold BP fully accountable and make sure they pay every dime for the damage they have done," he said.

Mr Obama also said that regulators must have more time to review permits for drilling and must pay closer attention to environmental laws.

The president said some proposed drilling lease sales would be cancelled. And he decried what he called a "scandalously close relationship" between regulators and oil companies and said that would be stopped.

Last week, BP inserted a mile-long tube to siphon some of the oil into a tanker. The tube sucked up 924,000 gallons of oil, but engineers had to dismantle it so they could start the risky procedure known as a top kill to try to cut off the flow altogether by shooting heavy drilling fluid into the well.

If that works, BP will inject cement into the well to seal it. The top kill has been used above ground but has never been tried 5,000 feet beneath the sea. BP pegged its chance of success at 60 to 70 per cent.

The top kill operation began yesterday and it could be several days before officials know if it is working.

BP spokesman Tom Mueller discounted news reports that the top kill had worked.

"We appreciate the optimism, but the top kill operation is continuing – that hasn't changed," he said.

If the top kill fails, BP says it has several backup plans, including sealing the well's blowout preventer with a smaller cap, which would contain the oil.

The only permanent solution is drilling a second well, but that will take a couple of months.