Deepwater Drilling

According to the U.S. government, deepwater drilling refers to any offshore drilling operation taking place more than 500 feet below the surface of the ocean. Many rigs drill much deeper, however. Before it exploded and sank, the Deepwater Horizon rig drilled a well more than six miles deep while operating in 4,130 feet of water. [1] Deepwater drilling, which produces over 5 million barrels of oil per day, is underway in many parts of the world, but the vast majority is concentrated in the Gulf of Mexico and off the coasts of Brazil and West Africa, in particular Angola and Nigeria. [2]

  • Deepwater drilling in the Gulf of Mexico produces 1.6 million barrels of oil per day, more than any other place on earth. More than a fifth of the world's mobile offshore drilling units are located in the Gulf. [3] According to a 2009 Minerals Management Service report, there were 36 deepwater rigs in the Gulf in 2008. Deepwater drilling represents about 70 percent of all Gulf oil production. [4]
  • The Deepwater Horizon spill began when the rig exploded on April 20, 2010, killing 11 people and injuring 16 others. The spill lasted for 86 days and was the largest oil spill in human history. [5]
  • BP and the government initially claimed that only 5,000 barrels of oil per day were leaking into the Gulf, and asserted that precise measurement of the spill was impossible. [6][7] Despite the objections of independent experts, the media quickly accepted the number. Independent estimates, which have since been widely accepted, range from 54,000 barrels to 84,000 barrels a day. [8]
  • Although it will be years before we know just how much damage the spill has done, it's already clear that the Gulf has suffered irrevocable damage. Thousands of dead animals, including hundreds of dead baby turtles and dolphins, have been collected, and many thousands more are presumed dead. [9] At least half of the oil spilled into the Gulf remains on the ocean floor or as massive underwater plumes, and the presence of oil-consuming bacteria has depleted the oxygen supply in the Gulf, expanding the already massive dead zone that has plagued the Gulf for years.[10] [11] Over 1,000 miles of fragile coastal ecosystems were contaminated by oil, much of which remains severely damaged as a result of the spill. [12] 
  • The ecological and public health effects of the 1.84 million gallons of toxic chemical dispersants sprayed and injected underwater during the spill have not been sufficiently studied and are poorly understood. [13] Cleanup workers and Gulf Coast residents have reported mysterious illnesses following the spill, although the government and BP claim that dispersants do not pose a threat to public health. [14] 
  • This is not the first time a deepwater rig has been destroyed by an accident. The Piper Alpha rig exploded in 1988, killing 167 people. The Petrobas 36 platform exploded off the coast of Brazil in 2001, killing 11. The Thunder Horse rig, owned by BP, capsized in the Gulf in 2005. [15] That same year, Hurricane Katrina destroyed 47 platforms and seriously damaged 20 more. [16] Later, Hurricane Rita destroyed 66 offshore drilling platforms, and caused serious damage to 32. [17] 
  • Offshore oil production entails well-known risks, from spills to well blow-outs, but it also produces massive amounts of waste water every day. A Gulf of Mexico rig dumps about 90,000 tons of drilling fluid and cuttings over its lifetime.[18]


[1] Transocean: "Deepwater Horizon Drills World's Deepest Oil and Gas Well."
[2] Hargreaves, Steve. "Oil's Future is in Deepwater Drilling." CNN Money, January 11, 2011
[3] ibid.
[4] Johnson, Toni. "U.S. Deepwater Drilling's Future." Council On Foreign Relations, Updated January 11, 2011
[5] "Gulf of Mexico Oil Spill (2010)." New York Times Topics, Updated February 21, 2012
[6] Video: "The BP Oil Spill: One Year Later." Greenpeace (2011)
[7] Gillis, Justin. " Size of Spill Underestimated, Scientists Say." The New York Times, May 13, 2010
[8] Harris, Richard. "Gulf Oil Spill May Far Exceed Official Estimates." NPR, May 14, 2011
[9] Video: "The BP Oil Spill: One Year Later." Greenpeace (2011)
[10] "Gulf of Mexico Oil Spill (2010)." New York Times Topics, Updated February 21, 2012
[11] ibid.
[12] Shogren, Elizabeth. "In Cleaning Oiled Marshlands, A Sea of Unknowns." NPR, April 20, 2011
[13] Foster, Joanna M. "Impact of Gulf Spill's Underwater Dispersants Is Examined." Green: A Blog About Energy and the Environment, The New York Times, August 26, 2011
[14] Zelman, Joanna. "Gulf Oil Spill Cleanup Workers Report Mysterious Illnesses Year After Disaster." The Huffington Post, April 18, 2011
[15] Jonsson, Patrick. "Transocean Deepwater Horizon Oil Rig Explosion Shows New Risks." The Christian Science Monitor, April 21, 2010
[16] "Hurricane Katrina 2005"
[17] "Hurricane Rita 2005"
[18] "No Offshore Drilling: Committee Against Oil Exploration (CAOE)." Culture Change, 2010