Houston - BP on Saturday resumed its strenuous efforts to permanently stop the oil spill in the Gulf of Mexico, as Tropical Storm Bonnie began to fade after delaying the work for a few days.
A United States coast guard official said the company expects to launch the "static kill" operation, which will permanently plug the well by pumping in heavy drilling mud and possibly cement, in three to five days.
BP had managed to seal the leak last week with a tight-fitting containment cap, choking off the flow of oil for the first time since a 20 April rig explosion spilled millions of gallons of oil into the sea, causing the worst US environmental disaster ever.
US Coast Guard Admiral Thad Allen said two ships remained on site overnight to monitor the temporary cap as other ships pulled out ahead of the storm, and the well retained its integrity.
On Saturday, Development Driller 3 (DD3), one of 10 ships that evacuated the area ahead of Bonnie, arrived back at the Gulf of Mexico well site to resume its operations of drilling a relief well to finally stop the oil spill.
BP and US officials currently plan two operations to kill the well. The first one, the so-called "static kill," involves pumping heavy drilling fluids known as mud through the blowout preventer valve system that sits on top of the well, and then injecting cement to seal it.
However, only the second one involving the relief wells will be the ultimate solution. Using the same process as the "static kill," drilling fluid will be pumped via the relief well until the flow of crude is overcome, allowing the damaged well to be sealed with cement.
Either work will only begin in three to five days to allow for preparation work.
Officials had set mid-August as a target date for completing the work, but Allen said the work could now be delayed seven to nine days due to the storm.
Bonnie was downgraded from a tropical storm to a depression on Friday as it weakened on its trek across Florida into the Gulf. It could dissipate into a broad area of low pressure if its sustained winds fall another 8 km per hour.
The US National Hurricane Centre said the storm was unlikely to strengthen and could degenerate into an area of low pressure later on Saturday.
The BP oil spill explosion also killed 11 workers and soiled coastlines in five US states and devastating tourism and fishery industries. Facing millions of dollars of compensation claims, the British oil giant company has set up a fund of $20 billion to compensate people for financial losses.
