The Deepwater Horizon ultra-deepwater oil platform, built by the Korean company Hyundai in 2000, was launched on February 23, 2001. In the same year, it was leased to British Petroleum on a long-term basis and was installed in the Gulf of Mexico in July. In February 2010, the drilling of a well at a depth of 1500 meters began on the Deepwater Horizon platform.
On April 20, an explosion caused the platform to catch fire, which lasted 26 hours. After unsuccessful attempts to extinguish it from firefighting vessels, the platform sank. As a result of the explosion, 11 people went missing and 115 people were evacuated. The oil spill lasted for 152 days and by September 19, 5 million barrels (795 thousand cubic meters) of oil had leaked into the Gulf of Mexico. As of April 29, 2010, an oil slick with a diameter of 190 kilometers reached the mouth of the Mississippi River, on June 4 – the state of Florida; on July 6, oil slicks were found off the coast of Texas and Louisiana. As of August 2010, the size of the underwater oil plume at a depth of 1,100 meters reached 35 kilometers in length.
Attempts to stop the oil leak from the damaged well began almost immediately, but they did not yield the desired result. On May 7, a 100-ton steel dome was installed over the well to cover the pipe damaged in the explosion on the drilling platform and prevent further oil from entering the water, but it proved ineffective. On July 13, a special 75-ton plug was installed and on September 17, the oil leak was stopped by pumping a special cement mortar into the well.
As a result of the oil spill, nearly 2,000 kilometers of coastline were contaminated – all US states with access to the Gulf of Mexico were affected by the oil spill. As of November 2, 2010, 6814 dead animals were collected, including 6104 birds, 609 sea turtles, 100 dolphins and other mammals.
The economy of the coastal states suffered great damage – due to the ban on fishing in a third of the Gulf of Mexico, more than 150,000 fishermen and restaurant workers lost their jobs; a six-month moratorium on deepwater drilling was also imposed, resulting in the loss of 13,000 jobs. Losses to the tourism industry were estimated at $23 billion over a three-year period.
The subsequent investigation showed that the accident was caused by human error, including personnel’s wrong decisions, technical malfunctions and design flaws of the oil platform; the explosion itself was caused by a methane leak that spread through the ventilation system on the drilling platform, and after the explosion, an emergency safety device that was supposed to automatically plug the well and prevent oil leakage in the event of an accident failed.
Under the US law, the holder of an oil production license is liable for environmental damage – as of the beginning of 2012, more than 100,000 lawsuits were filed against BP, Transocean Ltd., Halliburton and Cameron International (co-owners of the licenses) by private individuals; lawsuits for compensation of financial losses related to the oil spill were also filed against BP by the companies’ shareholders, with the main plaintiffs being pension funds of the states of New York and Ohio. In early March 2012, it was announced that BP and 100,000 plaintiffs had entered into a pre-trial agreement under which BP is to pay compensation to the victims in the amount of USD 7,800,000,000.