image: Oil at the sea surface above the Deepwater Horizon spill released volatile compounds into the atmosphere. view more
Credit: Image courtesy of National Oceanic and Atmospheric Administration.
Researchers report the effect of subsea dispersant injection during the Deepwater Horizon disaster. The Deepwater Horizon blowout in April-July 2010 released 600,000-900,000 metric tons of petroleum liquid and natural gas into the Gulf of Mexico, approximately one quarter of which did not reach the sea surface. However, the effect of injecting chemical dispersant at the wellhead, a process that was carried out to mitigate the environmental impact of the disaster, has remained unclear. Samuel Arey and colleagues developed a physical model of the jet of petroleum liquid droplets and gas bubbles gushing from the wellhead during the period from June 4-July 15, after the riser pipe was cut, taking into account liquid-gas transitions and dissolution rates of petroleum compounds. Model simulations, which were validated with field observations, indicated that injecting chemical dispersant at the wellhead increased the entrapment of many volatile organic compounds in the deep sea, thereby reducing the release of these compounds into the atmosphere at the sea surface. For example, subsea dispersant injection reduced atmospheric emissions of benzene, a carcinogenic compound, by 2,000-fold for a representative day, according to the model. Subsea dispersant injection therefore decreased human health risks to response workers, likely accelerating the response effort, according to the authors.
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Article #16-12518: "Petroleum dynamics in the sea and influence of subsea dispersant injection during Deepwater Horizon," by Jonas Gros et al.
MEDIA CONTACT: J. Samuel Arey, Swiss Federal Institute of Aquatic Science and Technology, Dübendorf, SWITZERLAND; tel: +33-78-459-2768; e-mail: samuel.arey@eawag.ch
Journal
Proceedings of the National Academy of Sciences