Researchers Eye Effects of Drilling in Deep Sea Ecosystems

New Wave Media

December 31, 2012

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  • science direct
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Recent studies regarding how deep-sea organisms are impacted by natural and human impacts have focused on oil production and drilling. According to the National Oceanographic and Atmospheric Administration (NOAA), there are 3800 offshore wells in the Gulf of Mexico alone. In the UK there are over 9000 wells at depths greater than 30 meters including 328 deeper than 200 meters. There are major wells around the world that reach a maximum depth of over 3000 meters. Scientists are now trying to decipher the impact this makes on deep-water communities as well as the recovery time needed to rebuild the ecosystem. As they drill the first few hundred meters of the well called the top hole. There is initial release at the seafloor of cuttings, ground rock mixed with lubricating drilling mud, which make a volcano-shaped pile. Following this, a BOP (blow-out preventer) is put onto the well. The cuttings are then brought to the surface where they are processed and discharged. In most open ocean environments these are then spread over a large area and are difficult to detect when they reach the seafloor. At shallower sites the surface-discharged cuttings add directly to the top hole cuttings pile. Researchers have found that the cutting piles are likely to have the greatest impact. Researchers have conducted research in two recovery areas in the Norwegian Sea and off the coast of Northern Scotland. The study has shown recovery happening in 3 years, but not complete recovery until 10 years or more if complete recovery is possible. Research also shows that although an individual well may have a small foot print on the ocean bottom little is known about the cumulative effect of thousands of wells presently in existence.

 

Image;Deepseanews/Sciencedirect