Published: Aug 03, 2010 11:03 PM EDT
Updated: Aug 04, 2010 4:30 AM EDT

ON THE GULF OF MEXICO (AP) — A leader of the operation to plug up the blown-out oil well at the bottom of the Gulf of Mexico says the process is going well.

Wellsite leader Bobby Bolton says it's possible crews could finish the so-called "static kill" Tuesday after the process began around 3 p.m. Officials, though, have said it could take days.

The effort involves pumping mud and eventually cement down the broken wellhead to plug it up. Officials say they won't know whether it worked until they can finish a relief well nearby in the coming weeks.

Capt. Keith Schultz says he's "very confident we'll be able to kill this well."