BP was forced to remove the cap collecting oil from its disastrous leaking well in the Gulf of Mexico yesterday, after an undersea robot collided with the collection equipment.

Although the ‘lower marine riser package cap containment system’ has now been reinstalled, the accident likely allowed thousands more barrels of oil to pollute the Gulf.

BP removed the cap at 0845 CDT and reinstalled it at 1830 CDT. The day before, BP reported collecting 8,195 barrels of oil over a 12 hour period, although this included oil collected through a ‘choke line’ as well as through the cap.

Coast Guard Admiral Thad Allen, National Incident Commander for the spill, told reporters that a remotely operated vehicle had bumped into and closed a vent that is supposed to carry warm water into the containment cap to prevent the formation of methane hydrates, which could block oil flow.

“Out of abundance of caution the Discover Enterprise [the collection ship] removed the containment cap with the riser pipe and moved away until they could assess the condition,” Allen said yesterday (transcript).