Last Updated 12:33 p.m. ET
BP says they have learned from the failures of their past efforts to halt the oil leak at the bottom of the Gulf of Mexico. Today they began executing a new operation they say could contain a majority of the oil - but which also risks releasing an even greater amount of crude into the Gulf's waters.
According to government estimates, the spill from the site of the destroyed Deepwater Horizon offshore rig has so far leaked between 20 million and 44 million gallons of oil.
BP's latest plan: Cutting off the broken, leaking riser pipe; capping it; then siphoning off the oil to containment ships. Special Section: Disaster in the GulfBP Shares Plunge Following "Top Kill" FailureAs Gulf Spill Worsens, Charges May Loom for BP
On CBS' "The Early Show"
this morning, Bob Dudley, BP's managing director, said that beginning this morning underwater robots arms with giant shears will begin making a clean, diamond saw cut across the top of the leaking well head, allowing engineers to lower a containment dome over it.
A saw blade mounted onto underwater robots could be seen going into a pipe in video from under the Gulf Tuesday morning. The saw was making cuts to clear extraneous pipes from the area.
A previous attempt to use a containment dome failed when hydrates formed ice-like crystals inside, rendering it unusable at the depth of 5,000 feet.
"We learned a lot from the first time with the formation of these hydrates," Dudley told anchor Harry Smith
. "This time it's a pipe within a pipe. We're going to pump warm sea water down the sides of it with a little methanol injected into it. We think we can overcome those hydrate problems."
Dudley said there was a greater chance of success with this operation than with the "top kill" procedure that was tried last week.
"This is a better chance, definitely better. We're not working with those high pressures and pumping that we weren't sure we were able to even connect up. The guys that are running the robots, this is something that they know how to do. The cutting is probably the critical piece. We may have to try a couple of blades to do it. But from an engineering sense, this is much more straightforward.
"And this is only the first step. Within a couple of weeks, we're going to take the same small city of pipes down there that we used to pump the heavy mud, connect it also to the well, reverse the flow out to create a second channel of oil and gas for the surface."
But a potential problem exists if the dome doesn't work: A clean cut on the riser pipe would mean even more
oil coming out than before.
"Well, there will be a little bit more oil, somewhere between zero and 20 percent more," said Dudley.
"Well, 20 percent is not insignificant, if thousands and thousands of barrels of oil are pouring out of there," said Smith.
"I think you will see that these containment domes will work. We have four of them on the site, depending on how the cut is, to be able to lift it down by the end of the week," Dudley said."
The oil company also announced plans Monday to try attaching another pipe to a separate opening on the blowout preventer with some of the same equipment used to pump in mud during the top kill. The company also wants to build a new freestanding riser to carry oil toward the surface, which would give it more flexibility to disconnect and then reconnect containment pipes if a hurricane passed through.
Neither of those plans would start before mid-June and would supplement the cut-and-cap effort.
For the relief well to succeed, the bore hole must precisely intersect the damaged well, which experts have compared to hitting a target the size of a dinner plate more than two miles into the earth. If it misses, BP will have to back up its drill, plug the hole it just created, and try again.
"The probability of them hitting it on the very first shot is virtually nil," said David Rensink, incoming president of the American Association of Petroleum Geologists, who spent most of his 39 years in the oil industry in offshore exploration. "If they get it on the first three or four shots they'd be very lucky."
The trial-and-error process could take weeks, but it will eventually work, scientists and BP said. Then engineers will then pump mud and cement through pipes to ultimately seal the well.
On the slim chance the relief well doesn't work, scientists weren't sure exactly how much - or how long - the oil would flow. The gusher would continue until the well bore hole collapsed or pressure in the reservoir dropped to a point where oil was no longer pushed to the surface, said Tad Patzek, chair of the Petroleum and Geosystems Engineering Department at the University of Texas-Austin.You're Going to Need a Bigger Containment Dome
All the while it is trying to stop the torrent of oil, BP is working to contain the damage to its reputation as well, reports CBS News correspondent Don Teague
In Washington there is growing anger, and accusations that BP knowingly understated how much oil has leaked to limit its liability.
Appearing Sunday on CBS' "Face the Nation,"
Rep. Edward Markey, D-Mass., said .
"They believed in the first week that it was 1,000 to 14,000 barrels per day. But what they said publicly was that it was 1,000 barrels per day," Markey said.
The cleanup, relief wells and temporary fixes were being watched closely by President Barack Obama's administration. After meeting Tuesday with the co-chairmen of an independent commission investigating the spill, Mr. Obama said that America "will bring those responsible to justice" if crimes were committed that led to the oil leak in the Gulf.
President Obama's energy czar, Carol Browner, said she doesn't want to guess the prospects for success on BP's containment cap.
Interviewed Tuesday on ABC's "Good Morning America," Browner said, "I don't want to put odds on it. ... We want to get this thing contained."
Attorney General Eric Holder plans to meet in New Orleans today with state and federal prosecutors to see if BP should face charges.
Wash. Post: As Gulf Spill Worsens, Charges May Loom for BP
When asked by Smith if BP has anything to worry about in terms of criminal charges being brought against the company, owing to what has happened over the last month and a half, Dudley said, "Well, Harry, I think we've done everything we can to react and respond to this accident that we all want to get to the bottom of and understand why.
"There [were] equipment failures through this accident that are unprecedented in the oil and gas industry. We've mobilized the largest oil and gas spill response along with the Coast Guard. I don't think anybody could say we've stepped back and waited and walked away from this."
"That really wasn't the question," remarked Smith.
The failure of the "Top Kill" procedure sent BP PLC shares plunging Tuesday, losing 15 percent in early afternoon trading on the London Stock Exchange. , wiping some $63 billion off BP's value, since the explosion at the Deepwater Horizon oil rig six weeks ago.
In hard-hit Louisiana, public patience is already running out.
"It doesn't look good. I don't feel confident that they're going to be able to stop this for another two months," said Grand Isle vacationer Patrick Shea.
Closed beaches and fishing areas are keeping tourists away. Moving in: workers in temporary camps, here to clean up oil that washed ashore last week.
In Grand Isle, after a holiday weekend ruined by bans on fishing and swimming, the National Guard is laying down their line in the sand, stretching a huge protective barrier from one end of the island to the other.
"It's like pretty much building a levee basically, kind of like a water-filled levee is how I look at it," said Louisiana National Guard Lt. Clint Gleason.
So far most of the oil making landfall is hitting Louisiana, but CBS News correspondent Terrell Brown reports shifting winds could start moving the crude closer to Mississippi and Alabama.
Oil is now about 20 miles off the Alabama coast.
The process of cutting away that broken riser pipe is underway. There was already a sense of urgency, but today is also , so that urgency is even greater.