1979 Ixtoc I Oil Well

Ixtoc (ISH-tok) 1 was an exploratory oil well being drilled in the southwestern Gulf of Mexico by Mexico’s government-owned oil company Pemex in 1979. On June 3, circulation of drilling mud to the well failed, causing a blowout, explosion, and fire that resulted in the destruction and sinking of the rig.

For nearly ten months, the well poured oil into the Gulf at a rate initially estimated to be 30,000 barrels per day. That was later reduced by about one-third by pumping nearly 100,000 metal balls into the well. The well was eventually capped on March 23, 1980, after having released an estimated 126 million gallons of oil.

A combined research cruise by the NOAA ship Researcher and contract vessel Pierce in September 1979 collected more than 1,000 samples for biogeochemical and microbiological studies and made detailed hydrographic surveys of the waters around the Itxoc 1 well. The cruise helped greatly advance knowledge of how oil behaves in the Gulf of Mexico.