Oil in water is not leaking from Macondo oil well

The sheen of oil in water in the Gulf of Mexico is likely from the wreckage of the Deepwater Horizon oil rig. A chemical analysis of the oil sheen has found that it is most likely from pockets of oil that have been trapped in the rig wreckage and not due to a further oil leak.

The Woods Hole Oceanographic Institution and the University of California were both involved in the study, which found that the sheen of oil present on the water near to the wreckage is not due to another leak in the Macondo well. The sheen was initially reported by oil company BP and the US Coast Guard in September of 2012, which sparked concern that another leak had sprung in the well.

Following chemical analysis it was determined that the Macondo well - site of the 2010 oil spill disaster - was still successfully capped and not leaking. Analysis also found that the sheen was not due to the natural oil leaks that can occur in many areas of the Gulf of Mexico.

The research, published in Environmental Science and Technology, used a new method to assess the chemical makeup of the substance causing the oil sheen. By measuring the level of evaporation of gasoline-like compounds found within the sheens, researchers were able to estimate the area that the sheens were leaking from.

The 14 samples that were collected by researchers all contained evidence and trace amounts of certain chemicals that are used during the process of oil drilling. These chemicals were not found in the samples that were collected from the well itself, meaning that the source of the oil sheen had to contain both oil and the industrial chemicals. This made the conclusion that the oil is coming from the wrecked Deepwater Horizon rig highly likely.

The levels of oil sheen in the water in the area around the rig have lessened since their discovery in 2012. BP has released a statement stating that there was 'minimal to no sheening' found in the most recent analysis of the area.