Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution , Woods Hole, Massachusetts 02543, United States.
Environ Sci Technol. 2013 Aug 6;47(15):8211-9. doi: 10.1021/es4024139. Epub 2013 Jul 17.
We used alkenes commonly found in synthetic drilling-fluids to identify sources of oil sheens that were first observed in September 2012 close to the Deepwater Horizon (DWH) disaster site, more than two years after the Macondo well (MW) was sealed. While explorations of the sea floor by BP confirmed that the well was sound, they identified the likely source as leakage from an 80-ton cofferdam, abandoned during the operation to control the MW in May 2010. We acquired sheen samples and cofferdam oil and analyzed them using comprehensive two-dimensional gas chromatography. This allowed for the identification of drilling-fluid C16- to C18-alkenes in sheen samples that were absent in cofferdam oil. Furthermore, the spatial pattern of evaporative losses of sheen oil alkanes indicated that oil surfaced closer to the DWH wreckage than the cofferdam site. Last, ratios of alkenes and oil hydrocarbons pointed to a common source of oil found in sheen samples and recovered from oil-covered DWH debris collected shortly after the explosion. These lines of evidence suggest that the observed sheens do not originate from the MW, cofferdam, or from natural seeps. Rather, the likely source is oil in tanks and pits on the DWH wreckage, representing a finite oil volume for leakage.
我们使用在合成钻井液中常见的烯烃来识别油迹的来源，这些油迹于 2012 年 9 月首次在深水地平线（DWH）灾难现场附近观察到，距离 Macondo 井（MW）被密封已经过去了两年多。虽然 BP 对海底的勘探证实了油井完好无损，但他们确定的可能来源是 2010 年 5 月用于控制 MW 的 80 吨围堰的泄漏。我们采集了油迹样本和围堰油，并使用全面二维气相色谱法对它们进行了分析。这使得我们能够识别出油迹样本中不存在于围堰油中的钻井液 C16 到 C18-烯烃。此外，油迹油烷烃蒸发损失的空间模式表明，石油浮出水面的位置比围堰地点更接近 DWH 残骸。最后，烯烃和油碳氢化合物的比例表明，油迹样本和爆炸后不久从覆盖着石油的 DWH 残骸中回收的石油具有共同的来源。这些证据表明，观察到的油迹不是来自 MW、围堰或自然渗漏。相反，可能的来源是 DWH 残骸上的油罐和坑中的石油，代表着有限的漏油体积。
