Diploma Thesis Defense by Ms Alexandra Tzamara

"The effect of pressure on the effectiveness of Corexit dispersants for combating deep sea oil spills "

Thesis Title:The effect of pressure on the effectiveness of Corexit dispersants for combating deep sea oil spills

Friday 5 October 2018, at:13:00, Venue: Hall Κ2. Α7

Examination Committee

  • Professor Nicolas Kalogerakis (advisor)
  • Professor Nikolaos Pasadakis
  • Dr. Eleftheria Antoniou

Abstract:

Dispersants provide a reliable response to catastrophic oil spills that can be used when the preferable option of recapturing the oil cannot be achieved. Especially, concerning deep sea oil spills due to the unique subsea conditions and the nature of the spill, the response challenges are multiple. The following thesis consists a research concerning the effectiveness of Corexit chemical dispersants in subsea applications for combating deep sea oil spills. The main purpose of this thesis is the evaluation of the effect of pressure on the dispersion of oil, through the quantification of the effectiveness of Corexit 9500A, Corexit 9500Bκαι Corexit 9527A under high pressure conditions. The trigger for this thesis , was the tragic blowout of the Deepwater Horizon rig , where for the first time  Corexit dispersants were applied, right on the wellhead where the oil leak took place at depth of approximately 1000 m below the sea surface. These deep sea pressure conditions (100 bar), were possible to be emulated by the use a high pressure reactor. The effectiveness of the dispersants was initially tested under atmospheric pressure according to the American Environmental Protection Agency (EPA) for marine oil spill response. The protocol was properly modified to the high pressure reactor, so as to test the dispersant effectiveness at the pressures of 25, 50, 75 and 100 bar. The results of the effectiveness given by the protocol in atmospheric pressure were used as a reference point, so as to assess the performance of the dispersants under high pressure conditions and evaluate the effect of pressure on their effectiveness of dispersing oil.