HOUSTON With a final shot of cement, BP Plc permanently "killed" its deep-sea well in the Gulf of Mexico that ruptured in April and unleashed the worst oil spill in U.S. history, the top U.S. spill official said on Sunday.
Some 153 days after the Macondo well ruptured, the U.S. government confirmed that BP had succeeded in drilling a relief well nearly 18,000 feet below the ocean surface and permanently sealing the well with cement.
"The Macondo 252 well is effectively dead," retired Coast Guard Admiral Thad Allen, who has overseen the U.S. government's response, said in a statement. "We can now state, definitively, that the Macondo well poses no continuing threat to the Gulf of Mexico."
President Barack Obama, whose public approval ratings were hurt by public discontent over the U.S. government's initial response to the spill, welcomed the long-awaited development as an "important milestone."
Obama said his administration was now focused on making sure the Gulf Coast "recovers fully from this disaster."
"This road will not be easy, but we will continue to work closely with the people of the Gulf to rebuild their livelihoods and restore the environment that supports them," Obama said in a statement.
On Thursday, a relief well bored into the bottom of the Macondo well to pump in cement and seal the reservoir for good. BP pumped cement for seven hours on Friday, and finished a pressure test early on Sunday that showed the well was permanently clogged, Allen said.
The development provided an anticlimactic end to the disaster nearly five months after the well ruptured on April 20, causing an explosion aboard the Deepwater Horizon drilling rig that killed 11 workers and spewed more than 4 million barrels of oil into the sea.
Tony Hayward, BP's gaffe-prone chief executive who absorbed the brunt of public anger over the spill, called the final plugging "a significant milestone," and reiterated the company's commitment to cleaning up the mess.
The spill marred the coasts of four U.S. Gulf states, prompted a ban on new deepwater drilling and left BP's image in tatters in the United States, home to 40 percent of the London-based oil giant's business.
The disaster also wiped about $70 billion from BP's market value and spurred BP to replace Hayward with an American, Bob Dudley, effective October 1.
Oil spewed unchecked into the sea from the mile-deep (1.6 km deep) well for 87 straight days until July 15, when BP engineers sealed it with a cap. By then, the well had gushed more than 16 times as much as the 257,000 barrels of oil spilled by the Exxon Valdez disaster in Alaska in 1989.
For the U.S. offshore drilling industry, which is reeling from a deepwater drilling ban imposed by the White House soon after the spill, uncertainty still abounds.
Operators in the Gulf -- long considered a haven from the political uncertainties of Venezuela and Russia -- will now have to contend with stricter federal regulations that will make it harder and more expensive to drill.
"There's clearly a sense that the page has been turned now," said Daniel Yergin, oil industry historian and chairman of IHS CERA. "It's now the day after for the oil and gas industry in the Gulf."
In New Orleans, which has seen its tourism and seafood industries hurt by the spill, word of the well's permanent demise brought little rejoicing.
"I feel like any world citizen would in this crisis -- that it was a threat to the entire world ecology," said Carey Beckham, a partner at Beckham Bookshop in the French Quarter. "I'm relieved, but the jury's still out."
(Additional reporting by Chris Baltimore in Houston, Ross Colvin in Washington and Mary Rickard in New Orleans; Editing by Philip Barbara)