Retired U.S. Coast Guard Adm. Thad Allen said scientists and BP officials still need to determine how best to complete the relief well. There are fears if the relief well is used to pump more mud into the well, pressure could increase to the point where seals at the top are affected. Tests are under way to determine the effectiveness of the so-called static kill, although there is no way of determining how thick the cement sealing the well bore, or annulus, is, The New York Times reported.
"The relief well will be finished," Allen said during a press briefing in Schriever, La.
Though he stopped short of declaring victory over the leak that began April 20 when the Transocean Deepwater Horizon oil rig leased by BP exploded, killing 11, and then sinking two days later, triggering a spill that saw millions of barrels of oil pour into the Gulf of Mexico for more than two months, Allen said there appears to be no "communication" between the oil beneath the gulf floor and the surface.
Allen said BP estimates as much as 1,000 barrels of oil is trapped in the well.
Bad weather in the gulf forced suspension of drilling the relief well Wednesday.
The disaster has spread oil to 670 miles of Gulf Coast shoreline and 52,395 square miles of the Gulf of Mexico remain closed to fishing.