"BP will start replacing the cap over the blown-out oil well in the Gulf of Mexico over the weekend, reports say. It is hoped the new cap will significantly increase the amount of oil being captured from the sea-bed. However while it is being replaced oil will flow unimpeded into the sea. BP's submersible robots could start removing the current containment cap from the ocean floor as early as Saturday, the Coast Guard commander overseeing the response said. Admiral Thad Allen said the flow of leaking oil could be shut off by Monday. But in that time hundreds of thousands of barrels of oil could flow unabated into the ocean. ""We have a significant chance to dramatically reduce the oil that's being released into the environment and maybe shut the well in altogether in the next week,"" he said."