BP, operator of the Deepwater Horizon oil rig that sunk April in the Gulf of Mexico, has tried unsuccessfully to stop oil gushing from an underwater well.
The top kill operation involves injecting heavy drilling fluids into the well to control the flow of oil and natural gas. If successful, BP would then seal the well with cement.
"Most of the equipment is on site and preparations continue for this operation, with a view to deployment in a few days," the company said. BP added the unconventional method "involves significant uncertainties."
The company said it continued to siphon oil out of the leaking well at an average rate of 2,010 barrels of oil per day.
BP is at odds with federal and industry analysts over the rate of oil flowing from the well about a mile below the surface. Conservative estimates put the flow at around 5,000 barrels per day.
The British supermajor said Washington has appointed a flow-rate technical team to determine the flow at the leak site. "BP will continue to promptly provide all information necessary to make as accurate an assessment as possible of the rate of flow," the company added in its latest update on the spill.