15 December 2017
Minimising oil spill impacts - how can science protect business?
Luis Perez Calderon, University of Aberdeen
Deep-sea exploration for oil and gas is a direct response to the increase in world energy demand. Tapping into previously inaccessible resources poses technical and environmental challenges. Proof of this is the Deepwater Horizon accident (DwH), which resulted in the death of 11 crew members and the release of 4.9 million barrels of crude oil to the Gulf of Mexico (GoM). Effective oil spill response requires a thorough understanding of how spilt oil behaves in the environment. Our present knowledge of oil spill science underpins the decision-making process after a spill to minimise environmental, social and economic fallout.
The impacts of released oil are many and varied. Spilt oil sticks to seals, birds, dolphins and other marine animals. In most cases, they do not survive. Furthermore, carcinogenic hydrocarbons found in crude oil (polyaromatic hydrocarbons) are readily assimilated by marine life and can be transferred up the food chain to humans. Economic impacts include the closing of fisheries, loss of market value for involved operators and reduction of tourism. DwH resulted in a market value drop of over 50 % for BP and the expenditure on handling the spill is estimated in the tens of billions of dollars. The Exxon Valdez oil spill (Alaska, 1989) resulted in the loss of over 26,000 jobs in the tourism industry alone and 27 years on the industry has not fully recovered.
DwH gave the scientific community perspective on the effects of a deep-sea oil spill. Future spills in the GoM will likely result in far less environmental damage thanks to the extensive research conducted during and after the spill. However, the GoM has a unique set of oceanographic conditions which are different in other areas of oil and gas exploration. Here in the UK, if a DwH-like oil spill took place the lessons learned may not be directly transferable due to lower temperatures (frequently below 0°C) and rough seas which make responding to spills far more challenging. Therefore, studying oil spill fates in all possible environmental conditions is important to understand their knock-on effects on the environment and build effective response strategies. This is further emphasised by the increased pressure of oil and gas operators to explore in arctic waters where further difficulties arise.
Key knowledge gaps in oil spill science include estimating how much oil settles on the seabed and what its subsequent fate is. Understanding biogeochemical interactions between spilt oil and the seabed helps us predict the environmental consequences of oil spills and how to facilitate ecosystem recovery. Increasing our understanding of oil spills in the North Sea is more important than ever before now that deep-sea oil and gas exploration is on the rise as more accessible reservoirs become depleted. My research aims to understand how spilt oil moves into and out of North Sea sediments. To achieve this, I simulate various oil-seabed interaction scenarios under different environmental conditions and determine which components of spilt oil remain the water column, entrain the seabed or stick to sediment particles. Another key point of my research is to evaluate the implications of chemical dispersant application on oil-water-sediment transport processes. The use of dispersant is a debated issue in the scientific community at the moment as it remains unclear if it minimises oil spill impacts or actually exacerbates them.
I believe that my research is at the intersection of science and business because oil spills can have a profoundly negative effect on both the environment and the economy. The conclusions of my research will hopefully improve current oil spill prediction models and aid responders in the decision-making process to minimise oil spill impacts.