BP Plc said Sunday efforts to install a new cap on the gushing oil well in the Gulf of Mexico in a bid to halt the leak were going well, dpa reported.
"We're pleased how it's going," BP vice-president Kent Wells told reporters, but stressed there is still much work to be done.
"This is a four-to-seven-day operation," he said. "We're just starting day two now. It will take another three to five, six days. If everything goes extremely well we'll be on the shorter side of three to six days."
The British oil giant on Saturday removed a defective cap over the well in the first step in replacing it with a tighter one that is intended to allow ships on the surface to suck up more oil than is currently being collected from the oil well rupture.
If everything goes as planned, the new cap and an additional processing ship would allow workers to effectively halt the leak by siphoning off more oil than is currently spilling into the Gulf.
Simultaneous efforts to hook up another processing ship, the Helix Producer, were also on track and it could begin work as early as Sunday evening, Wells said. It would, however, take several days for the ship to be ramped up to full capacity.
In the meantime, oil was again flowing largely unabated into the Gulf of Mexico and onto the coastal areas that are already the scene of ecological disaster. Once the Helix Producer comes online it will be able to siphon off some of that oil even before the new cap is in place.
Oil has been gushing from the well since end-April, when the rig exploded and sank, causing the worst spill in US history that is leading to massive ecological degradation in the ocean and along the coastline of five Gulf states.