HOUSTON — Reporting its first success in containing the massive Gulf oil leak nearly a month after it started, BP on Sunday said oil and natural gas were flowing via a mile-long pipe to a ship at the surface.
Yet even as the company reported the success, scientists warned oil that has already spewed into the Gulf could have dire consequences for the environment. Computer models show the black ooze might have already entered a major current flowing toward the Florida Keys, a researcher said Sunday.
The contraption used by BP was hooked up successfully and sucking oil from a pipe at the blown well Sunday afternoon after being hindered by several setbacks. Engineers remotely guiding robot submersibles had worked since Friday to place the four-inch tube into a 21-inch pipe nearly a mile below the sea.
"So far it's working extremely well," BP Senior Executive Vice President Kent Wells said of the strategy.
Still, Wells offered a tempered response to the news. "It's a positive move, but let's keep it in context," he added. "We're about shutting down the flow of oil from this well."
"We're very slowly increasing the rate" to get more oil and natural gas up, he told reporters. "We will just learn as we go with this approach." Siphoning oil from a mile down had never before been successful.
It's not clear how much of the overall leak is being captured, Wells said, but that should be known in the next day or two.
Crews will slowly ramp up how much oil the tube collects over the next couple of days. They need to move slowly because they don't want too much frigid seawater entering the pipe, which could combine with gases to form icelike crystals that would clog it.
Mud could follow
The first chance to choke off the flow for good should come in about a week. Engineers plan to shoot heavy mud into the crippled blowout preventer on top of the well, then permanently entomb the leak in concrete. If that doesn't work, crews also can shoot golf balls and knotted rope into the nooks and crannies of the device to plug it, Wells said.
The final choice to end the leak is a relief well, but it is more than two months from completion.
Meanwhile, scientists warned of the effects of oil that has already leaked into the Gulf.
Computer models show the black ooze may have already entered the loop current — which is the largest in the Gulf — said William Hogarth, dean of the University of South Florida's College of Marine Science. A research vessel is being sent to the Gulf on Tuesday to collect samples and learn more.
One computer model shows that the oil has already entered the current, while a second model shows the oil is 3 miles from it — still dangerously close, Hogarth said. The models are based on weather, ocean current and spill data from the U.S. Navy and the National Oceanic and Atmospheric Administration, among other sources.
The current flows in a looping pattern in the Gulf, through the area where the blown-out well is, east to the Florida Keys National Marine Sanctuary and beyond.
Other scientists warned that miles-long underwater plumes of oil discovered in recent days could poison and suffocate sea life across the food chain, with damage that could endure for a decade or more.
At least 210,000 gallons of oil — perhaps much more — has been gushing into the Gulf of Mexico since an oil rig exploded April 20 and sank two days later. Eleven people were killed in the blast.
BP's latest idea seems to have the best chance for success so far, said Ed Overton, a Louisiana State University professor of environmental studies. At the surface this would be easy, Overton said, but using robots at that depth with oil gushing out of the pipe makes things much more difficult.
"It's something like threading the eye of a needle. But that can be tough to do up here. And you can imagine how hard it would be to do it down there with a robot," Overton said.
The tube could capture more than three-quarters of the leak; BP also must contend with a smaller leak that's farther away.
Video: White House plays hardball A week ago, the company tried to put a massive box over the leak, but icelike crystals formed and BP scrapped that plan.
Meanwhile, BP began spraying undersea dispersants at that leak site and said the chemicals appear to have reduced the amount of surface oil.
Federal regulators on Friday approved the underwater use of the chemicals, which act like a detergent to break the oil into small globules and allow it to disperse more quickly into the water or air before it comes ashore.
The decision by the Environmental Protection Agency angered state officials and fishermen, who complained that regulators ignored their concerns about the effects on the environment and fish.
"The EPA is conducting a giant experiment with our most productive fisheries by approving the use of these powerful chemicals on a massive, unprecedented scale," John Williams, executive director of the Southern Shrimp Alliance, said in a news release.
Louisiana Health and Hospitals Secretary Alan Levine sent a letter to BP outlining similar concerns, but the company and the Coast Guard said several tests were done before approval was given.
"We didn't cross this threshold lightly," Coast Guard Rear Adm. Mary Landry said. "This is a tool that will be analyzed and monitored."
Reuters and The Associated Press contributed to this report.