BP awaits test results on bid to plug oil leak

BP MAY not need a relief well to drill into the bottom of its ruptured Gulf of Mexico well if a test shows that cement poured in from the top last week killed the leak.

The test could indicate BP already cleared the last hurdle to terminate the source of the world's worst offshore oil spill, according to retired Coast Guard Admiral Thad Allen, who is co-ordinating the mission.

"A bottom kill finishes this well. The question is: has it already been accomplished through the static kill?" he said.

The relief well is only about 45ft from reaching BP's Macondo well after having already drilled through 12,900ft of the seabed.

Last week BP resumed preparations to finish drilling the relief well. Drilling had been suspended because of a tropical depression in the Gulf.

The biggest US environmental response operation passed a critical milestone last week with what is known as a static kill - smothering oil and gas in the deepwater well with heavy drilling mud, followed by a cement seal.

The Macondo well, a mile down in the Gulf of Mexico, was provisionally capped on 15 July after spewing an estimated 4.9 million barrels of oil into the Gulf.

The disaster oiled marshlands, fisheries and tourist beaches along several hundreds of miles of the Gulf Coast, and vaporized more than a third of BP's market value.

Allen has consistently called the relief well the final solution to plug the well.

This week he said cement injected into the Macondo well may have done the job. A pressure test BP started last Thursday should help scientists figure that out, he said. A pressure rise could indicate oil is still flowing in the inches between the pipe and the surrounding rock layers.