BP Plc said it expects to attach a new cap to contain the leaking Gulf of Mexico wellhead later on Monday.
"We have the cap very close, and later today we'll be attaching it," Doug Suttles, the company's chief operating officer, said during a media briefing. "It could take well through the day to complete."
Once it is installed, Suttles said BP will shut down two vessels siphoning oil from the leak -- one of which is expected to start up on Monday -- to monitor pressure and check the integrity of the blown-out well.
Those tests could last 48 hours or longer, Suttles said. If the cap works as intended, all crude oil should be contained, BP said.