Preparations were under way today to replace the containment cap over the damaged oil well in the Gulf of Mexico, BP said.
Remotely operated vehicles will be used to start the process of removing the current cap and installing the new sealing cap this weekend.
It is estimated the work will take between four and seven days to complete.
The company warned oil is expected to temporarily flow uninterrupted into the sea while the operation is carried out.
BP said its new sealing cap would ease the leak and increase the amount of oil collected.
Improvement plans were delayed by last week’s disrupted sea conditions as Hurricane Alex passed through the Gulf of Mexico, but the company said it was now taking advantage of the favourable weather.
A BP spokesman said: “The new cap creates the potential to increase oil and gas containment capacity to greater than 50,000 barrels per day and should improve containment efficiency during hurricane season by allowing shorter disconnect and reconnect times.”
The company said the sealing cap installation procedure was intended to run in parallel with the start-up of the Helix Producer system – a containment ship intended to mop up leaking oil – which could begin as early as tomorrow.
It added: “This new sealing cap has not been deployed at these depths or under these conditions, and there can be no assurance that the sealing cap will be successfully installed or installed within the anticipated timeframe.
“Contingency LMRP (lower marine riser package) caps are positioned on the seabed and it should be possible to return to the current containment configuration if needed.”
The company is unlikely to be able to fully control the leak until two relief wells are completed.
Work to drill the wells began in May and they are expected to be ready early next month.
It said the new containment cap could “increase the probability of success” for the relief wells.
BP said this week clean-up costs for the oil disaster had passed the $3.1bn mark.
The blue chip firm has lost close to 50% of its stock market value since an explosion sunk the Deepwater Horizon rig on April 20, killing 11 workers and causing the worst US oil spill in history.
The company’s shares increased by 2% on Monday as speculation mounted over the group’s efforts to raise capital.
Reports stated it had launched a hunt to find a strategic investor in a Barclays-style move to ward off hostile takeover attempts from rivals such as Exxon Mobil or Royal Dutch Shell.
As well as the ongoing cost of the operation and claims, BP has also set aside a $20bn compensation fund for those affected by the spill.