Oil Spill Response Planning For Amazon Region–A Crude Carrier Study Case

Abstract

It is well-known that an adequate planning process is paramount for a response success in oil spill events. This is especially true for tankers leakages due to its dynamic nature and potential to cause severe environmental harms. Moreover, one of the most challenging planning dimensions for an adequate response is, certainly, the human and material mobilization logistics, which can be strongly limited in remote regions. In South America, one of the most worldwide preserved rainforest areas, the Amazon, which consists of more than 5 million square kilometers and contains a thousand rivers, is also one of the most remote area, with important logistics challenges for almost any human activity. Despite all these difficulties, however, since 1986 Brazil has been producing an average of 35.000 bpd of oil at Urucu Field, located close to the city of Coari, around 400 miles from the province capital, Manaus. Once produced, this oil is pumped through a pipeline until a terminal at Solimões river, where is loaded in tankers destined to Manaus. Although contingency facilities exist in these two cities, there is no support installation in any point over the 342 nautical miles of the journey. Therefore, this study aimed at identifying the major operational risks of this naval transport and at analyzing some specific contingency planning aspects. Initially, a total of 12 safety critical areas were identified during a field inspection trip along Solimões and Amazon rivers. For each point, a qualitative risk analysis was developed, using tropical environmental sensitivities indexes and an empirical oil slick forecast modelling, as well as an oil weathering modelling using the ADIOS2 computational package. Finally, a verification checklist with a scorecard system was developed and applied, in order to assess the oil spill response feasibility and rank the critical spots over the rivers courses. For all the points evaluated, around 30% of all accidental hypothesis were associated with a catastrophic risk, with most being identified as potentially causing a severe environmental impact. Besides, all the estimated response times calculated were insufficient to avoid oiling of the riverbanks. Finally, due also to strong currents and other limiting environmental conditions, all critical point displayed low scores for the response feasibility evaluation, with poor logistics being a key parameter. From these results, navigational safety recommendations and oil spill response planning guidelines were developed in order to minimize an accident occurrence probability and, hence, the risk associated with it.