Equipment collecting the oil and bringing it to the surface is believed to be nearing its daily processing capacity. A floating platform could be the solution to process most of the flow, BP said.
To burn it, the British oil giant is preparing to use a device called an EverGreen Burner, officials said. It turns a flow of oil and gas into a vapor that is pushed out its 12 nozzles and burned without creating visible smoke.
Methods for gathering and disposing of the oil collected from the seafloor gusher are becoming clearer. What's not is how much oil is eluding capture.
Scientists on a team analyzing the flow said Tuesday that the amount of crude still spewing into the Gulf of Mexico might be considerably greater than what the government and company have claimed.
Their assertions -- combined with BP's rush to build a bigger cap and its apparent difficulty in immediately processing all the oil being collected -- have only added to the impression that BP is still floundering in dealing with the catastrophe.
A cap placed on the ruptured well last week to channel much of the billowing oil to a surface ship collected about 620,000 gallons Monday and another 330,000 from midnight to noon Tuesday, BP said.
That would mean the cap is collecting better than half the escaping oil, based on the government's estimate that around 600,000 to 1.2 million gallons a day are leaking from the bottom of the sea.
A team of researchers and government officials and run by the director of the U.S. Geological Survey is studying the flow rate and hopes to present its findings in the coming days on what is already the biggest oil spill in U.S. history.
In an interview with The Associated Press, team member and Purdue University engineering professor Steve Wereley said it was a "reasonable conclusion" but not the team's final one to say that the daily flow rate is, in fact, somewhere between 798,000 gallons and 1.8 million gallons.
Whatever the amount, all that oil has to end up somewhere. The floating production and storage vessel BP plans to bring in could be part of the answer, officials said.
"It's being brought in because it can handle far more oil than this well is producing," said Wine, who did not know where the vessel would come from or when it would arrive. The burn rig will be moved away from the main leak site so the flames and heat do not endanger other vessels, BP spokesman Max McGahan said.
Depending on which model is used and its settings, it can handle from 10,500 to 630,000 gallons of oil a day, according to promotional materials by Schlumberger Ltd., the company that makes the device and whose website touts it as producing "fallout-free and smokeless combustion."
It's unclear how many times the EverGreen burner has been used, but it has been proposed for at least one offshore rig in the North Sea to get rid of unwanted gases produced during oil processing.
Environmental documents produced as part of that project, an exploration well proposed by Total E&P of Britain, said burning the oil posed "a moderate risk to the environment" that would release sulfur dioxide, nitrous oxides, methane and other chemicals.
But Wilma Subra, a chemist with the Louisiana Environmental Action Network, said BP should avoid burning the captured oil -- which she said raises new health risks -- and instead bring in more processing equipment.
"This is one of those decisions that will have negative impacts," she said. "Even though it's crude dispersed in water, the burning of crude will raise some health issues."
When it sells the oil recovered from the Gulf, BP will use the revenues to create a fund to protect wildlife in the region, the company said.
Attempts to skim the oil from the surface are progressing as well. Boats fanned out across the Gulf on Tuesday, dragging boom in an attempt to corral the oil. But it's an enormous task.
In some spots, the oil is several inches thick and forms a brown taffy-like goo that sticks to everything it touches.
John Young, chairman of Louisiana's Jefferson Parish Council, said additional equipment has been ordered and more dredgers will be moving into the area soon, along with barges that will help block the passes.
"It's nice that BP has put up the money, but they need to ramp up not only the manpower but the equipment out there because we're losing the battle," Young said. "Unfortunately, we're on day 50 and it's too little too late, but I guess it's better late than never."
In the seven weeks since the oil rig explosion that set off the catastrophe, BP has had to improvise at every turn. The most recent government estimates put the total amount of oil lost at 23.7 million to 51.5 million gallons.
When asked why BP did not have containment systems on standby in case of a leak, BP spokesman Robert Wine said there was no reason to think an accident on this scale was likely.
"It's unprecedented," he said. "That's why these caps weren't there before."
President Barack Obama is scheduled to return to the Gulf Coast on Monday and Tuesday for a two-day update on the Gulf oil spill.
Contributing to this report were AP Science Writer Seth Borenstein in Washington and Associated Press writers Matthew Brown in Billings, Mont., Harry R. Weber in Houston, Tamara Lush and Jeff McMillan in New Orleans, and Brian Skoloff in Barataria Bay, La.