Ixtoc I was an exploratory oil well in the Gulf of Mexico, about 600 miles (970 km) south of the U.S. state of Texas. On June 3, 1979, the well suffered a blowout and is recognized as the second largest oil spill in history.
Mexico's government-owned oil company Pemex (Petróleos Mexicanos) was drilling a 2-mile (3.2 km) deep oil well, when the drilling rig lost drilling mud circulation. In modern rotary drilling, mud is circulated down the drill pipe and back up the casing to the surface. The goal is to equalize the pressure through the shaft and to monitor the returning mud for gas. Without the circulating mud, the drill ran into high pressure gas which blew out the oil (known as a blowout). The oil caught fire and the platform collapsed.
In the next few months, experts were brought in to contain and cap the oil well. Approximately 10 thousand to 30 thousand barrels per day were discharged into the Gulf until it was finally capped on March 23, 1980. Prevailing currents carried the oil towards the Texas coastline. The US government had two months to prepare booms to protect major inlets. Mexico rejected US requests to be compensated for cleanup costs.
The oil slick surrounded Rancho Nuevo, in the Mexican state of Tamaulipas, which is one of the few nesting sites for Kemp's Ridley sea turtles. Thousands of baby sea turtles were airlifted to a clean portion of the Gulf of Mexico to help save this rare species.