(Blogger's note: This post was changed from from an earlier version to correct a factual error in the size and rank of the Exxon Valdez oil spill. Also, the IXTOC 1 accident occurred June 3, 1979, not 1980.)
If it winds up taking months, the better part of a year or longer for experts to finally stop the flow of oil into the Gulf of Mexico from the uncontrolled well head left by the destroyed Deepwater Horizon, there's precedent for that.
It was an oil platform called IXTOC 1 which was in the Gulf of Mexico about 600 miles south of Texas in the Bay of Campeche. The accident occurred June 3, 1979 when a two-mile exploratory well blew out. What happened next sounds similar to what happened on the Deepwater Horizon.
The IXTOC 1 accident is considered the world's second worst oil spill with 140 million gallons of oil released into the waters. The worst was the oil spill into the Persian Gulf as a result of the 1991 Gulf War against Saddam Hussein's Iraq when Iraqi troops opened the Kuwaiti oil field valves which allowed as much as an estimated 520 million gallons of crude to flow into the Gulf.
The sinking of the Exxon Valdez in Alaska's Prince William Sound spilled an estimated 10.8 million gallons, making it the worst spill in U.S. history.
From a description on a National Oceanic and Atmospheric Administration website:
The oil and gas blowing out of the well ignited, causing the platform to catch fire. The burning platform collapsed into the wellhead area hindering any immediate attempts to control the blowout. PEMEX hired blowout control experts and other spill control experts including Red Adair, Martech International of Houston, and the Mexican diving company, Daivaz. The Martech response included 50 personnel on site, the remotely operated vehicle TREC, and the submersible Pioneer I. The TREC attempted to find a safe approach to the Blowout Preventer (BOP). The approach was complicated by poor visibility and debris on the seafloor including derrick wreckage and 3000 meters of drilling pipe. Divers were eventually able to reach and activate the BOP, but the pressure of the oil and gas caused the valves to begin rupturing. The BOP was reopened to prevent destroying it. Two relief wells were drilled to relieve pressure from the well to allow response personnel to cap it. Norwegian experts were contracted to bring in skimming equipment and containment booms, and to begin cleanup of the spilled oil. The IXTOC I well continued to spill oil at a rate of 10,000 - 30,000 barrels per day until it was finally capped on March 23, 1980. Keyword: Boom, Corexit 9527, skimmer, manual removal, volunteers, blowout, fire, evaporation, blowout preventer, relief well, submersible..
Some key points to take away from this: It took nearly 10 months for the responders to stop the oil from flowing in the IXTOC 1 accident. And this was a well that was in only about 164 feet of water. That allowed divers to be sent down to cap the well.
The Deepwater Horizon wellhead is under 5000 feet of water. That is nearly double the depth at which atmospheric diving suits and manned submersibles can operate.
Technology has obviously advanced immensely during the past 30 years. Still, the story of the IXTOC 1 is sobering considering how far under the gulf this well is and the difficulty that are being encountered by the crews operating in what can be a very hostile environment. And hurricane season is only weeks away.
The Associated Press had a report on the comparisons being made between the IXTOC 1 spill and the current accident and why the Deepwater Horizon spill has so many experts worried.
Most Americans think of Exxon Valdez when it comes to spills. But the potential and likelihood here "is well beyond that," said University of Rhode Island ocean engineering professor Malcolm Spaulding. Because the Deepwater Horizon well has not been capped and may flow for months more, it should be compared to a bigger more dangerous one from a well explosion in 1979, said Tunnell. That was Ixtoc 1, off the coast of Mexico. It was the worst peacetime oil spill on record.
The current spill "is kind of a worst case scenario," Tunnell said.
What makes this spill relentless and most similar to Ixtoc 1 is that it's an active well that keeps flowing. The Exxon Valdez was a tanker with a limited supply of oil. The rig 40 miles from the Gulf Coast may leak for months before a relief well can be drilled to stop the flow, Kinner said.
And LSU's Overton said: "I'm not very optimistic that they'll be drilling a relief well in three months."
The type of oil involved is also a major problem. While most of the oil drilled off Louisiana is a lighter crude, this isn't. It's a heavier blend because it comes from deep under the ocean surface, Overton said.
"If I had to pick a bad oil, I'd put this right up there. The only thing that's not bad about this is that it doesn't have a lot of sulfur in it and the high sulfur really smells bad."