Companies Investigate Oil Sheen Off Gulf of Mexico

The Associated Press is reporting the investigation into an oil sheen that was spotted off the Gulf of Mexico last week. Various oil companies, including BP, are trying to figure out where the sheen came from.

An oil sheen (not the same as a spill) happens when a thin layer of oil settles on top of the water shimmering in different colors and can come from leaks or spills.

BP sent remotely controlled mini-submarines to look for the source of the sheen, though it is claiming the oil is not from one of their wells, the AP reports.

Some oil naturally seeps from the floor of the Gulf and the AP has reported that at least 27,000 abandoned oil and gas wells in the Gulf are not routinely inspected when plugged or subsequently monitored for leaks.

BP says the site of the sheen is near two abandoned exploration wells in the Green Canyon Block of the Gulf of Mexico, south west of Macondo, the site of the April 2010 BP Oil Spill.  A U.S. official said the Macondo area is clear, AP reports.