New Orleans, Louisiana (CNN) -- BP removed the failed blowout preventer from atop its plugged well deep below the Gulf of Mexico, the company said Friday.
The device was detached at 1:20 p.m., BP spokesman Daren Beaudo said, and a vessel was slowly raising it from its position thousands of feet below the surface.
The removal "appears to have gone very smoothly and as planned," Beaudo said. He added that steps also are being taken to reposition a drilling rig over the well site, in preparation for attaching a replacement blowout preventer on the well.
Joint investigation teams, engineers and the Department of Justice are closely monitoring the status of the blowout preventer, as it may hold important forensic evidence as to why it failed on April 20, triggering the world's largest accidental oil spill after a deadly explosion killed 11 workers aboard the Deepwater Horizon rig.
The government's national incident commander, Adm. Thad Allen, issued a statement on the successful removal of the blowout preventer.
"This procedure was undertaken in accordance with specific conditions I set forth last week in a directive authorizing the capping stack removal, which was completed yesterday, and BOP replacement," Allen said. "BP will continue to follow these required conditions during the lifting of the damaged BOP and as the device is replaced."
Allen estimated that it would take 24 to 36 hours for the approximately 1 million pound contraption to be lifted to the surface.
The detaching of the equipment was somewhat in question earlier this week because of the unknown status of thousands of feet of drill pipe believed to be suspended below the blowout preventer. Last week, BP conducted "fishing experiments" in order to draw out pieces of pipe within the well due to concerns they could affect the integrity of the blowout preventer. Those operations were terminated after officials determined there was a low probability the pipe would cause serious damage.
"No pipe was visible when the blowout preventer was lifted off the wellhead," Beaudo said.
Thursday afternoon, crews removed the cap on the formerly leaking well. The 160,000 pound, 30-foot-tall cap was a key piece of equipment that stopped the flow of oil into the Gulf on July 15.
Next, the oil giant plans to install a new blowout preventer. Once it is successfully tested, BP will drill the last remaining feet of a relief well to intercept the damaged well. Finally, the company will execute a "bottom kill" -- a measure that fills the well from the bottom with mud and cement. That is believed to be the only assured way to seal the well for good.
"Depending upon weather conditions, mid-September is the current estimate of the most likely date by which the relief well will intercept the MC252 well," BP said in a statement Friday, using the shorthand reference to the well's official designation, Mississippi Canyon Block 252.
Also Friday, BP said the total cost of the response to the oil gusher amounted to nearly $8 billion. That figure includes containment, relief well drilling, killing the well, grants to Gulf states, claims paid and federal costs, the company said. While oil no longer is spilling into the Gulf, nearly 29,000 people, more than 3,200 vessels and 63 aircraft are involved in current response efforts.
On Friday, the National Oceanic and Atmospheric Administration reopened 3,114 square miles of federal waters in the Gulf off of the western Florida panhandle to commercial and recreational fishing. That followed the reopening Thursday of 5,130 square miles off the western Florida panhandle, Alabama, Mississippi, and eastern Louisiana.
"We are pleased to continue moving forward with reopening portions of Gulf federal waters to recreational and commercial fishing," NOAA Administrator Jane Lubchenco said. "I'd like to thank everyone for their patience throughout this process, as we work to ensure seafood safety remains our primary objective."
NOAA said the reopening was done in consultation with the Food and Drug Administration and the Gulf states. At its closest point, the area reopened is about 55 miles northeast of the oil spill site.
A little less than 40,000 square miles, or about 17 percent of the federal waters in the Gulf, remain closed, NOAA said. At the height, on June 2, 37 percent was closed.
From CNN's Vivian Kuo