With some 1,200 offshore oil rigs operating today, oil spills are
still relatively rare. But experts warn that safety procedures and
cleanup methods have not kept pace with drilling at ever-deeper
The Deepwater Horizon oil spill has put a spotlight on the
dangerous world of offshore oil drilling. With a well spewing
thousands of barrels of crude (estimates range from 5,000 to 100,000
barrels) a day into the Gulf of Mexico, many are wondering if the
industry has been too lightly regulated.
The Deepwater Hori-zon spill is shaping up to be among the
biggest in American history - now estimated to be at least 6 million
gallons according to US Coast Guard and British Petroleum figures.
But such massive blowouts remain rare for offshore rigs. Thousands
of drilling rigs operate all over the world every day without
disaster. As they pursue oil in deeper waters, however, leaks become
more difficult to contain. Safety procedures and clean-up techniques
have not kept pace with the race to drill in deeper and deeper
How many offshore rigs are there, and where are they located?
According to Rigzone, an industry website, there are currently
about 1,234 exploration rigs. (Spills are more common during
exploration, as with the Deepwater Hori-zon.) One hundred and forty-
six are in Europe's North Sea. The Gulf of Mexico is home to 114.
The remainder are off the coasts of Brazil, Venezuela, and West
Africa; in the Persian Gulf; and in the seas of south and southeast
IN PICTURES: Louisiana oil spill
What have been the worst spills from offshore oil rigs?
Ixtoc I oil spill, Gulf of Mexico, 1979: Generally considered the
second-worst oil spill in history (first is a 1991 disaster at a
Persian Gulf oil port during the first Gulf War), the Ixtoc spill
occurred when the Mexican state-owned Pemex was drilling an
exploratory well in shallow water in the Bay of Campeche. The Ixtoc
suffered a blowout, and more than 3 million barrels of oil gushed
from the well for more than nine months before engineers were able
to cap it. The spill contaminated more than 162 miles of beach in
Nowruz oil field, Persian Gulf, 1983: After a tanker hit a rig
off the coast of Iran, the rig began leaking 1,500 barrels a day.
Because Iran and Iraq were at war, the oil flow was not stopped, and
the platform was later attacked by Iraqi warplanes. Later, a second
platform was attacked, and initially spilled 5,000 barrels a day
before slowing to 1,500. Two years passed before Iran capped the
wells, but by then some 733,000 barrels of oil had spilled into the
Santa Barbara, Calif., 1969: A blowout at a well five miles off
the coast of Santa Barbara caused a leak that flowed for 11 days.
According to a report by the Uni-ver-sity of California, Santa
Barbara, the spill affected 800 square miles of ocean and coated 35
miles of coastline with oil. …