How do oil companies stop an oil well blowout that comes from a sea floor oil rig?

On June 3, 1979, a Mexican oil well, Ixtoc 1, blew out when an undersea drill hit a volatile pocket of oil and gas.

The immense pressure of the gas caused the well to throw out an overwhelming 30,000 barrels per day of oil. Some of the oil burned at the surface, some was sucked into cleanup ships, but a great deal spread out over the Gulf of Mexico, eventually stretching to the shores of Texas.

The celebrated oil well fire fighter Red Adair was hired to try to solve the problem. His divers, working at a depth of 160 feet, tried to repair damaged pipes, while 1,500 men and twelve planes and helicopters tried to contain the slick.

Adair’s efforts were not entirely successful, and the slick continued to spread. The underwater gauges and wellhead were partially blocked by debris from the shattered rig, and one diver said the morass of broken drill pipes resembled a “platter of spaghetti.”

It was then decided that the best solution was to drill two intercepting relief wells to tap the oil below the escape point, thereby relieving the pressure.

The Mexican oil company Pemex began to drill Ixtoc 1A and Ixtoc 1B, but the drilling would require months; meanwhile, thousands of barrels of oil continued to spew into the sea. A steel pipe was attached to the kill valve (which was blocked), and Pemex began pumping mud, gelatin, salt water, and then cement into the well, hoping to stanch the flow.

In late June another break occurred farther down the wellhead, and Pemex had to ignite the oil on the surface of the water to prevent its spreading. The drilling inched along. It wasn’t until the end of July that Pemex managed to reduce the flow from 30,000 barrels per day to 21,000 barrels per day, and they went on pumping huge quantities of heavy drilling mud, steel and iron balls, cement, and chemicals into the bore well.

By August 20, Ixtoc 1A was 8,612 feet deep, with 3,000 feet to go before reaching the depth of the runway, and Ixtoc 1B was 6,237 feet deep.

September brought a new plan, called Operation Sombrero, for crushing the blowout. This involved placing a huge, 300 ton inverted steel funnel, which, indeed, looked like a sombrero, over the well. It would collect about 80 percent of the oil at the wellhead, divert this oil into collection vessels, flare the gas, and return the seawater to Campeche Bay. Mechanical flaws halted the operation for several weeks, and although the “sombrero” eventually helped somewhat, it couldn’t stop Ixtoc 1.

The story of the blowout continued far longer than anyone anticipated. The leakage was reduced to a dribble by October, but only in March 1980 did the two directional wells finally shut off Ixtoc 1. Then the hole, which had received so many tons of metal balls and mud, was finally plugged with cement.

Pemex had employed just about every known method for controlling an oil well blowout, and spent $131.6 million along the way.