There has been a persistent oil sheen near the site of BP's Macondo well blowout in the Gulf of Mexico ever since the well was shut in and eventually plugged in late 2010. Alarmists use that oil sheen as some kind of evidence that the well is flowing, alleging a massive conspiracy to cover up the fact that it can't be controlled. It's not flowing. As I wrote about over a year ago, the well, and the relief wells near it, have been permanently plugged, and have been monitored to confirm that they are not flowing oil. In fact, the likely formation pressure remaining in the blowout well is probably not high enough to buck the hydrostatic pressure of the drilling mud, cement, and the ocean water that holds that pressure back, so it simply can't produce more oil.
However, there is a real problem at the site. Oil is definitely there, and it is a true problem. Think about it. From April 20, 2010 to July 15, 2010, the well flowed something around 5 million barrels of oil into the ocean environment. Only a small portion of that oil was recovered or burned. Much has been dispersed or bio-degraded; however, that was a lot of oil, and much of it is still in the environment. Also, the wreckage of the rig, the riser, and the failed containment dome are still on the bottom near the wellhead. You'll recall that, during the height of the crisis in May 2010, an idiotically designed and applied containment dome was placed over the leaking riser. It immediately became plugged with hydrates, which are similar to ice crystals with oil entrained within. The effort was quickly abandoned, and the dome was scuttled on bottom about 1,500 feet from the wellhead. I say the operation was idiotic because it would have never worked, and I believe BP conducted it to appear to the public that they were actually doing something while they figured out what to really do to kill the well. The spectacular failure, though, demonstrated just how unprepared the industry was to deal with a deepwater subsea blowout.
When the containment dome was abandoned on bottom, it was still full of hydrates and oil. The openings in the dome were never plugged, and oil has since continued to leak from those openings. BP acknowledged the oil leaking a few weeks ago, and plugged the openings this week with remote operated vehicles (ROVs), in an effort to stop the seeping oil. The rest of the wreckage remains on bottom, some still containing residual oil.
I believe, unless much of the wreckage is removed, we'll continue to see oil sheen at the Macondo site for possibly years to come. It doesn't take much oil to cause a large sheen on the surface, and unless the oil soaked wreckage is removed (a risky operation in itself), the problem will persist.