A test is set today to determine whether an effort to permanently seal the ruptured BP oil well in the Gulf of Mexico can proceed, the company reported.
The "injectivity" test was scheduled for Monday, but was delayed because of a small leak, according to media reports.
Today is also the day that the company could conduct a "static kill," one of two efforts planned to cap the leaking well once and for all.
"During final preparations to commence with the injectivity test, a small hydraulic leak was discovered in the capping stack hydraulic control system," BP said in a statement.
The injectivity test will be delayed until the leak is repaired. In the test, "base oil" will be pumped into the ruptured well bore to determine whether it will go back into the reservoir, BP senior vice president Kent Wells told CNN.
The test will start with the pumping of one barrel a minute, then two, then three. How much is pumped will depend on how the test goes, Wells said. He also said the test is meant to help officials decide whether adjustments need to be made regarding "how and if" the static kill will proceed.
The static kill would involve pouring mud, possibly followed by cement, into the well from above. The goal is to push all of the oil back into the reservoir and seal the well.
Meanwhile, scientists charged with determining the flow from the leaking well said that roughly 4.9 million barrels of oil have seeped from it. Previously, the same group had put the total estimate of oil that leaked from the well prior to its being capped July 15 at 3 million to 5.2 million barrels, CNN reported.
At the moment when the well was capped, scientists said, 53,000 barrels of oil a day were leaking; roughly 62,000 barrels likely were seeping every day from the well at the start of the spill.