Ixtoc I oil spill facts for kids
Quick facts for kids Ixtoc 1 |
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| Location | Bay of Campeche, Gulf of Mexico Campeche, Mexico |
| Coordinates | 19°24′30″N 92°19′30″W / 19.408333°N 92.325°W |
| Date | 3 June 1979 – 23 March 1980 |
| Cause | |
| Cause | Wellhead blowout |
| Operator | Pemex |
| Spill characteristics | |
| Volume | 3 million barrels (130,000,000 U.S. gallons; 480,000 cubic meters) |
| Area | 2,800 km2 (1,100 sq mi) |
| Shoreline impacted | 261 km (162 mi) |
The Ixtoc 1 was an oil well being drilled in the Bay of Campeche in the Gulf of Mexico. It was about 100 kilometers (62 miles) northwest of Ciudad del Carmen, Campeche, Mexico. The water depth there was about 50 meters (164 feet).
On June 3, 1979, the well had a serious accident called a blowout. This caused a huge oil spill. At the time, it was the largest oil spill in US history. Today, it is still the second largest, after the Deepwater Horizon oil spill.
Contents
What Caused the Ixtoc 1 Spill?
Mexico's state-owned oil company, Pemex, was drilling for oil. They were drilling about 3 kilometers (1.8 miles) deep. During the drilling, the rig, named Sedco 135, lost its "drilling mud" circulation.
Drilling mud is a special liquid used to keep pressure balanced in the well. It also helps bring rock pieces to the surface. Without this mud, the pressure from the oil and gas underground became too strong. This pushed the oil and gas up the well, causing the blowout.
The oil and gas caught fire. The Sedco 135 rig was badly burned and later sank.
How the Blowout Happened
The day before the accident, the drill bit hit a soft layer of rock. This caused the drilling mud to escape into cracks in the rock. So, the mud was not returning to the surface. This meant the pressure inside the well was no longer controlled.
Pemex decided to pull out the drill bit. They planned to pump materials down the well to seal the cracks. But as they pulled out the drill pipe, oil and gas suddenly rushed up. This is called a "kick."
Normally, a safety device called a blowout preventer (BOP) would seal the well. The BOP has strong "rams" that can cut and seal the pipe. However, the drill collars (thick steel parts of the drill pipe) were in the way. The BOP rams could not cut through them. This led to the massive blowout.
Oil and gas flowed out of the well at a very fast rate. The fumes exploded when they touched the rig's pump motors. This started a fire that damaged the rig's pipe leading to the seafloor. This damage to the BOP allowed a huge amount of oil to escape into the Gulf.
How Much Oil Spilled?
When the spill first started, about 30,000 barrels of oil leaked each day. One barrel of oil is about 159 liters (42 gallons). In July 1979, pumping mud into the well helped reduce the flow to 20,000 barrels a day. By early August, they pumped nearly 100,000 steel, iron, and lead balls into the well. This reduced the flow to 10,000 barrels per day.
Pemex said that about half of the oil burned on the surface. They also claimed a third of it evaporated. The rest was either collected or spread out. Mexican authorities also drilled two "relief wells" to lower the pressure. However, oil kept flowing for three months after the first relief well was finished.
In total, about 138.6 million US gallons (3.3 million barrels) of oil spilled. This happened over nearly 10 months until the leak finally stopped.
Cleanup Efforts
Pemex hired a company called Conair Aviation to spray a chemical called Corexit 9527 on the oil. This chemical helps break up the oil. They flew 493 missions, treating about 1,100 square miles (2,800 square kilometers) of oil slick.
In Texas, the focus was on protecting the coast, especially the bays and lagoons. Workers used special equipment like skimmers and booms to collect oil. They also cleaned beaches by hand, using rakes and shovels. This helped avoid removing too much sand.
About 71,500 barrels of oil reached 162 miles (261 kilometers) of US beaches. Over 10,000 cubic yards (7,600 cubic meters) of oily material were removed from the beaches.
Stopping the Leak
Over the next nine months, many experts and divers worked to stop the oil leak. Famous oil well firefighter Red Adair was among them. The well leaked about 10,000 to 30,000 barrels of oil per day.
Finally, on March 23, 1980, the well was capped. This was almost 10 months after the blowout began. Like the Deepwater Horizon oil spill 31 years later, they tried many ways to stop the leak. These included lowering a cap over the well, plugging it with mud and other materials, using dispersants, and drilling relief wells.
What Happened After the Spill?
Ocean currents carried the oil towards the Texas coastline. The US government had two months to prepare booms to protect important inlets. Pemex spent $100 million to clean up the spill. They avoided most claims for money by saying they had "sovereign immunity." This means a state-run company cannot be sued without its permission.
The oil slick reached Rancho Nuevo in Tamaulipas, Mexico. This is a very important nesting site for Kemp's ridley sea turtles. These turtles are an endangered species. To save them, thousands of baby sea turtles were flown to a clean part of the Gulf of Mexico.
Long-Term Effects of the Oil Spill
The oil from the blowout polluted a large part of the Gulf of Mexico. It also affected many coastal areas, including sandy beaches and lagoons.
About 6,000 metric tons of oil were found on Mexican beaches in early September. Experts believe about five times that amount actually landed there. Investigations along the Texas coast showed about 4,000 metric tons of oil, which is less than 1 percent of the total spill. The rest of the oil, about 120,000 metric tons (25 percent), sank to the bottom of the Gulf.
Impact on Ocean Life
The oil had a very bad effect on crabs and mollusks living on the beaches. For example, the ghost crab (Ocypode quadrata) population was almost wiped out in many areas. Crab populations on coral islands also dropped to only a few percent of their normal numbers about nine months after the spill.
Studies showed that the coastal lagoons and estuaries had the most lasting problems. These areas are important for the breeding and growth of many types of fish.
The oil washed ashore, in some places up to 30 centimeters (1 foot) deep. It was pushed north by winds and currents. Two months later, it crossed the Texas border. Eventually, it covered almost 170 miles (270 kilometers) of US beaches.
The beach that caused the most worry in Mexico was Rancho Nuevo. This is a key nesting ground for the critically endangered Kemp's ridley sea turtles. The turtles had already laid their eggs before the oil reached the shore. By the time the eggs hatched, the oil was there.
Mexican authorities banned or limited fishing in the polluted areas. Fish and octopus catches dropped by 50 to 70% compared to 1978. Some species with longer lifespans took longer to recover. The population of Kemp's ridley turtles only started to recover in the late 1980s. These turtles lay only a few hundred eggs each year, much less than shrimp, which lay millions.
See also
In Spanish: Ixtoc I para niños
- List of oil spills
- Notable offshore well blowouts
- Deepwater Horizon oil spill
- Ocean Ranger
- Piper Alpha
Images for kids
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The Ixtoc 1 oil spill in September 1979.
