Gulf oil spill: Results of 'top kill' operation won't be known for 24 hours
It will be at least 24 hours before BP officials will know whether their high-risk effort to plug the wellhead spewing crude into the gulf has succeeded, the Chief Executive Tony Hayward said Wednesday afternoon.
He said the effort is proceeding as planned and cautioned that the televised images of the oil plume do not give an indication of how the operation is going or whether the oil flow is increasing or decreasing.
Engineers worked through Tuesday night to prepare for the "top kill" procedure, running diagnostic and other tests to ensure that conditions were right. The effort involves injecting dense drilling mud into the blown-out wellhead and then sealing it with cement.
After receiving the go-ahead from the Obama administration, BP started pumping the heavy mixture at 1 pm central time. Several hundred engineers in Houston have prepared for the effort for weeks. It has been done before, but never at the 5,000-foot depth of the BP leak, and officials have cautioned that there is no guarantee of success.
If executed incorrectly, it could even increase the flow of oil, which has poured into the gulf for more than a month. The spill has tainted tens of thousands of square miles of water and washed up on 100 miles of Louisiana shoreline.
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