Gulf leak tops Valdez as nation's worst spill

The company is trying to revive hopes that it might cap the well with a “top kill’’ technique that involves pumping heavy drilling liquids to counteract the pressure of the gushing oil.

BP officials, who along with government officials created the impression early in the day that the strategy was working, disclosed later that they had stopped pumping the night before when engineers saw that too much of the drilling fluid was escaping along with the oil.

It was the latest setback in the effort to shut off the leaking oil, which federal officials said was pouring into the Gulf at a far higher rate than original estimates suggested. BP resumed pumping heavy drilling mud into the blown-out well after an 18-hour delay.

Doug Suttles, BP’s chief operating officer for exploration and production, struggled to offer guidance on whether the latest effort was likely to succeed.

“It’s quite a roller coaster,’’ Suttles said. “It’s difficult to be optimistic or pessimistic. We have not stopped the flow.’’

President Obama, who planned to visit the Gulf today, ordered a suspension of virtually all current and new offshore oil drilling activity pending a comprehensive safety review, acknowledging that oversight until now had been seriously deficient.

His action halted planned exploratory wells in the Arctic due to be drilled this summer and planned lease sales off the coast of Virginia and in the Gulf of Mexico. It also halts work on 33 exploratory wells being drilled in the Gulf.

Obama said at a news conference in Washington that he was angry and frustrated about the catastrophe, and he shouldered much of the responsibility for the continuing crisis.

“Those who think we were either slow on the response or lacked urgency, don’t know the facts,’’ Obama said. “This has been our highest priority.’’

But he also blamed BP, which owns the stricken well, and the Bush administration, which he said had fostered a “cozy and sometimes corrupt’’ relationship between oil companies and regulators at the Minerals Management Service.

The chief of that agency for the past 11 months, S. Elizabeth Birnbaum, resigned yesterday, less than a week after her boss, Interior Secretary Ken Salazar, announced a broad restructuring of the office.

“I’m hopeful that the reforms that the secretary and the administration are undertaking will resolve the flaws in the current system that I inherited,’’ she said in a statement.

Government scientists said the oil has been flowing at a rate 2.5 to five times higher than what BP and the Coast Guard previously estimated. Two teams of scientists calculated the well has been spewing between 504,000 and more than a million gallons a day, the Associated Press reported.

Even using the most conservative estimate, that means about 18 million gallons have spilled so far. Using the worst-case projection, 39 million gallons have leaked. That larger figure would be nearly four times the size of the Exxon Valdez disaster, in which a tanker ran aground in Alaska in 1989, spilling nearly 11 million gallons.

Obama plans today to inspect the efforts in Louisiana to stop the leak and clean up after it, his second trip to the region since the explosion of the Deepwater Horizon rig on April 20. He will also visit with people affected by the spreading slick that has washed ashore over scores of miles of beaches and wetlands.

Even as Obama acknowledged that his efforts to improve regulation of offshore drilling had fallen short, he said that oil and gas from beneath the Gulf, now about 30 percent of total domestic production, would be a part of the nation’s energy supply for years to come.

“It has to be part of an overall energy strategy,’’ Obama said. “I mean, we’re still years off and some technological breakthroughs away from being able to operate on purely a clean-energy grid. During that time, we’re going to be using oil. And to the extent that we’re using oil, it makes sense for us to develop our oil and natural gas resources here in the United States and not simply rely on imports.’’

In the top-kill maneuver, a 30,000-horsepower engine aboard a ship injected heavy drill liquids through two narrow flow lines into the stack of pipes and other equipment above the well to push the escaping oil and gas back down below the sea floor.

As hour after hour passed after the top kill began Wednesday afternoon, technicians along with millions of television and Internet viewers watched live video images showing that the dark oil escaping into the gulf waters was giving way to a mud-colored plume.

That seemed to be an indication that the heavy liquids known as “drilling mud’’ were filling the chambers of the blowout preventer, replacing the escaping oil.

In the morning, federal officials expressed optimism that all was going well.

“The top kill procedure is going as planned, and it is moving along as everyone had hoped,’’ Admiral Thad W. Allen of the Coast Guard, the leader of the government effort, told CNN.

And Robert Dudley, BP’s managing director, said on the “Today’’ program on NBC that the top kill “was moving the way we want it to.’’

It was not until late afternoon that BP acknowledged that the operation was not succeeding and that pumping had halted at 11 p.m. Wednesday.

“We have not yet stopped the flow, so the operation has not achieved its objective,’’ Suttles said, adding that “nothing has gone wrong or has been unanticipated.’’

Engineers had feared the top kill was risky because the high-pressure mud could have punctured another gaping hole in the pipes, or dislodged debris clogging the blowout preventer and pipes and intensified the flow.