Scientists from Woods Hole Oceanographic Institution and University of California, Santa Barbara used a novel fingerprinting technique to identify the source of oil sheens that appeared in late 2012 near the site of the Deepwater Horizon disaster.
←After researchers retrieved oil-coated screens used to collect samples from surface sheens, each screen was sectioned into several pieces for analyses. Some were reserved for DNA extraction; others analyzed for drilling fluids and shared with the National Oceanic Atmospheric Administration for standard petrochemical analyses. (Photo by Christoph Aeppli, Woods Hole Oceanographic Institution)
The sheens contained a mixture of Macondo well oil and alkenes (commonly called olefins) that are used in drilling operations. Researchers found that the sheens most likely came from pockets of Macondo well oil that were on the rig before it exploded and are now in the debris field on the ocean floor. They also showed conclusively that the oil was not leaking from the Macondo well which was “shut-in” in the summer of 2010. They published their findings in the June 2013 issue of Environmental Science & Technology: Recurrent oil sheens at the Deepwater Horizon disaster site fingerprinted with synthetic hydrocarbon drilling fluids.
In mid-September 2012, the US Coast Guard received reports from BP of oil sheens near the site of the Deepwater Horizon incident. There was concern that the Macondo Well, capped in July 2010, might be leaking. Identifying the source of the oil was important because of environmental and legal issues and also to estimate the magnitude of the problem and inform the response process.