Oil Spill Risk Analysis for Assessing Environmental Contact Probabilities in the Gulf of Mexico

Abstract

ABSTRACT 2017-051: The U.S. Department of the Interior (DOI) Bureau of Ocean Energy Management (BOEM) maintains a leasing program for commercial oil and gas development on the Outer Continental Shelf in U.S. territorial waters. To evaluate the potential impacts of these activities, BOEM performs oil spill risk analysis (OSRA) using, in part, a statistical model for estimating the movement of hypothetical oil spills on the ocean surface based on model-generated surface wind and surface current. OSRA examines oil spill risks over long periods of time ranging from 5 years to decades. The latest OSRA analysis estimated the contact probabilities of oil spills in the Gulf of Mexico (GOM) region by modeling over 40 million hypothetical oil spill trajectories over extended areas of the U. S. continental shelf and tabulating the frequencies with which the simulated oil spills contacted designated natural resources within a specified number of days. The modeled ocean currents and wind fields used in the GOM analysis are from 1993 to 2007 (15 years). The OSRA model was also applied to analyze the contact probabilities of the Ixtoc Oil Spill, which happened on June 3, 1979 in the Bay of Campeche of the GOM and lasted for 10 months. The Ixtoc I Oil Well suffered a blowout, resulting in one of the largest oil spills in history and 3 million barrels of oil spilled. The OSRA model was applied to simulate particle trajectories released at the Ixtoc location using the same GOM current and wind field data from 1993 through 2007. The model results for the Ixtoc simulation were consistent with the descriptions of the oil spill by Hooper (1982), which shows that the OSRA model can provide a reasonable projection of the contact probabilities of hypothetical oil spills.