July 10, 2010 3:13 p.m. EDT
Workers in Waveland, Mississippi, clean up oily globs that washed ashore Friday from the Deepwater Horizon oil spill
New Orleans, Louisiana (CNN) -- Crews removed a containment cap on the ruptured underwater well in the Gulf of Mexico, BP said Saturday afternoon. The next move will be placing a better-fitting one on the well.
Live video Saturday afternoon showed robots removing bolts from the apparatus so that the new cap can be positioned. Oil was again flowing freely during the transition.
Speaking earlier in a conference call with reporters, BP senior Vice President Kent Wells said the sealing cap operation is expected to take four to seven days, with favorable weather helping the process along. In upcoming weeks, there will be an increase in oil containment work.
"As we start to ramp up the additional containment capacity, we should see less and less flow," Wells said.
If successful, the effects of the containment cap operation could halt the oil gusher that started April 20 after a deadly explosion on the Deepwater Horizon rig in the Gulf of Mexico.
Officials have said such a fix would be temporary, and the permanent solution would still be completion of a relief well. There are two relief wells under construction, with one expected to be completed in August.
The company also says the sealing cap work "is intended to run in parallel with the installation and start-up of the Helix Producer," an oil recovery vessel.
Wells said crews are in the final stages of hooking up the Helix to the well. The vessel is expected to begin collecting oil by Sunday and officials hope to reach full collection capacity of 20,000 to 25,000 barrels (840,000 to 1.5 million gallons) per day within three days.
BP says there will be a period of decreased oil and gas capture from the wellhead during the cap replacement. It said another recovery vessel, the Q4000, "should continue to capture and flare oil and gas."
There will be other recovery vessels and skimmers deployed.
"This can be done very effectively," Wells said.
Wells also said there will be "significant measurement capability" added to new cap so officials can get a good idea of the flow rate.
Over the next two to three weeks, 60,000 to 80,000 barrels (2.52 million to 3.36 million gallons) a day should be contained, Wells said. Scientists estimate that 35,000 to 60,000 barrels of oil are spewing daily from BP's breached Macondo well.
BP said in a statement that the new cap "should improve containment efficiency during hurricane season by allowing shorter disconnect and reconnect times."
Wells echoed much of what retired Coast Guard Adm. Thad Allen said Friday.
Allen said he approved the cap-switch plan in order to take advantage of favorable weather predicted for coming days and because, once the switch is complete, the resulting capacity to contain oil "will be far greater than the capabilities we have achieved using current systems."
Allen stressed that once the capping device is on, "we would get the most accurate flow rate to date," he said.
In a separate advance, federal responders expressed optimism Friday about a new aerial weapon in their arsenal. A 178-foot U.S. Navy blimp, the MZ-3A, was flown from New Orleans to Mobile, Alabama, to be used to survey the disaster area as soon as Saturday, depending on the weather.
Officials said they hope surveys from the blimp will help them cut the time needed to get skimmers to the scene of oil slicks.
CNN's Sanjay Gupta, Vivian Kuo and Aaron Cooper contributed to this report