Gulf oil spill: 'Top kill' procedure begins
Engineers have begun the "top kill" maneuver aimed at stanching the gush of oil from a blown-out well at the bottom of the Gulf of Mexico, BP and U.S. Coast Guard confirmed.
The much-awaited procedure began at 1 p.m. Central Daylight Time, according to BP.The maneuver, which BP officials warned could take hours or days to complete, would attempt to overpower the upward flow of oil by pumping drilling fluid -- and eventually a cement mixture -- at high pressure down the well. Several hundred engineers in Houston have prepped for the effort for weeks.
If executed incorrectly, however, the top kill could blow the fail-safe systems, dramatically increasing the flow of oil.
Engineers had worked through the night to gauge pressure and run other diagnostic tests associated with the billowing oil. In a sign of the critical importance of the effort, Energy Secretary Steven Chu -- a Nobel-winning physicist -- personally joined the diagnostic team in Houston.
-- Jim Tankersley in Washington