Oil gushes without check again as BP gets ready to fit new cap on well

OIL was yesterday spewing unchecked into the Gulf of Mexico after BP uncapped its gushing well in order to install a new containment system.

Engineers are preparing to apply a new, more effective cap, which they hope will catch virtually all the oil leaking from the bottom of the ocean.

However, before installing it they had to remove an existing cap, leaving hundreds of thousands of gallons of oil leaking without check into the water.

Yesterday, BP officials said the work was going to plan. However, it could take up to six days, by which time as much as five million gallons could pour into the water.

And there is no guarantee of success for the delicate operation nearly a mile below the surface.

Kent Wells, a senior BP vice-president, said yesterday he was pleased with the progress, but cautioned that unforeseen difficulties could lie ahead.

He said: "We've tried to work out as many of the bugs as we can. The challenge will come with something unexpected."

Coast Guard spokesman Captain James McPherson warned: "It's not just going to be, you put the cap on, it's done. It's not like putting a cap on a tube of toothpaste."

The previous cap was able to capture only about a third of the oil leaking from the well.

A senior adviser to President Barack Obama said the administration is confident that BP's latest effort to contain the oil spill will work.

But at the same time, David Axelrod acknowledged that BP's engineers were in "uncharted waters" when it came to dealing with the leak.

Robotic submarines removed the existing cap on Saturday that had been placed on top of the leak in early June.

The new cap, called "Top Hat 10", weighs 150,000lb and is designed to seal the leak fully.

It contains valves that can restrict the flow of oil and stop it escaping. However, it remains to be seen whether the device can withstand the pressure of the oil.

Paul Bommer, a professor of petroleum engineering at the University of Texas at Austin, said the pressure might prove to be too great.

"If the new cap does work and they shut the well in, it is possible that part of the well could rupture if the pressure inside builds to an unacceptable value," he said.

It is now more than two and a half months since the explosion on the Deepwater Horizon rig, which killed 11 workers.

Mayor Tony Kennon, of Orange Beach, Alabama, said any halt to the leak came too late to save the tourist season.

However, he added: "I want to believe it (will work], and I'm going to take them at their word because it's good news."

Hope for permanently plugging the leak lies with two relief wells, the first of which is due to be finished by mid-August.

• BP IS in talks over an 8 billion asset sell-off to help it to meet the costs of tackling the oil spill, it was reported yesterday.

The assets up for grabs in the talks with United States rival Apache Corporation include a big stake in Alaska's giant Prudhoe Bay oilfield, it was reported.

BP has been wrestling with the growing disaster in the Gulf since the Deepwater Horizon rig exploded and collapsed on 20 April, killing 11 workers.

The deal with Apache would more than fulfil its target of raising $10 billion (6.6bn) from disposals and give some assurance to markets over its ability to tackle the costs.

The sale of a stake in Prudhoe Bay - one of BP's prize assets which produces 390,000 barrels of oil a day - would also give a huge boost to Apache.