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Oil pipeline damage can have occurred months before a major oil spill: NPR

This week, workers clean oil-contaminated sand in Newport Beach, California.

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This week, workers clean oil-contaminated sand in Newport Beach, California.

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Huntington Beach, CA — Southern California Underwater Oil pipeline The US Coast Guard announced on Friday that it was likely that it was anchored months to a year ago before the spill spilled tens of thousands of gallons of crude oil.

Lieutenant Jason Neubauer, Coast Guard’s Director of Investigation and Analysis, said that a large vessel smashed a concrete casing into a huge pipeline, but not necessarily caused a small crack in the oil squirt last weekend. Said not.

The longer timeline was partly based on ocean growth found on pipes in underwater surveys.

He added that the pipe, which turned out to be intact last October, may have been struck several other times by anchors from other vessels during the period.

However, the ship has not been identified.

“We will look at the movement of all vessels on that pipeline and all close intrusions from anchors throughout the year,” said the captain.

The pipeline was dragged 105 feet along the seabed, Neubauer said.

He said it indicates that a large ship was involved. Cargo ships with multi-ton anchors travel regularly from the ports of Los Angeles and Long Beach to the area.

An oil spill seen this week in Newport Beach, California.

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An oil spill seen this week in Newport Beach, California.

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The leak polluted the beach and killed seabirds.

Since 1986, at least 17 accidents in pipelines carrying crude oil or other dangerous liquids have been suspected of anchor strikes or anchor strikes, according to an Associated Press review of more than 10,000 reports submitted to federal regulators. Is related to.

Federal records show that anchor strikes may not be conclusively proven, such as a 2012 leak from the ExxonMobil pipeline in the shallow Barataria Bay of Louisiana. Direct strikes by barges and other boats were also considered possible.

Elsewhere, evidence of anchor strikes was clear. During Hurricane Andrew in 1992, a 30,000-pound anchor was dragged by a drilling rig drifting over the Texaco pipeline in the Gulf of Mexico, causing a broken dent when the line was later reopened.

In 2003, a 7,000-pound anchor was found about 10 feet from a small spill in the shell oil pipeline in the bay.

A Coast Guard video released Thursday seems to show a trench on the bottom of a sandy beach with a curved submerged line, but experts say that the importance of short, grainy shots varies. I gave my opinion. Earlier videos featured a 13-inch thin burst of lines.

Robert Bea, a professor of engineering at the University of California, Berkeley and a former shell oil engineer, said the second video appears to show an undersea groove created by a drag anchor leading to a damaged pipeline.

However, investigators are expected to consider other forces that may have moved and damaged the pipe, such as water streams moving on the ocean floor.

It takes time.

“We need to validate the results of our analysis — it’s backed up. This process can raise even more questions,” says Bea. “The shape of the crack indicates that it was due to the internal pressure of the pipeline, but if that is true, why didn’t the pipeline leak?”

Frank G, President of Houston-based Interface Consulting International. Adams said in an email that the slight bends in the lines shown in one video “do not necessarily look like anchor damage.”

“It usually causes physical damage that can lead to fractures,” he said, when the pipeline hits an anchor or other heavy object.

A possible spill from Huntington Beach was first reported on Friday night, but no leaks were found until Saturday morning. The magnitude of the spill is unknown, but on Thursday the Coast Guard slightly revised the estimated parameters to at least about 25,000 gallons, less than 132,000 gallons.

The Coast Guard said about 5,500 gallons of crude oil had been recovered from the sea. Oil has spread southeast along the coast, with small amounts reportedly landing in San Diego County, about 50 miles from its original location.

Local health officials said on Friday that air samples from areas where oil could diffuse are within background levels, in other words, similar to air quality on a normal day, and the pollutants measured in California. He said he was below the health standards of.

So far, the impact on wildfires has been minimal, with 10 dead birds and an additional 25 alive, healed and treated, but environmentalists say the long-term impact is far greater. Warns that it can be large. Some beaches in Laguna Beach reopened on Friday as the beaches continued to be cleaned, but the general public is still unable to enter the water.

Investigators are trying to identify what happened at an important early time after the first report of a possible oil spill arrived.

A narrow rift seen in one video could explain why the signs of an oil slick were seen on Friday night, but the spill escaped more than 12 hours of detection by the pipeline operator.

“In my experience, I suggest this would be a terrible hard leak for remote and quick decisions,” said Richard Cuprewitz, a private investigator and consultant for pipeline accidents. “This type of opening in a 17-mile long underwater pipe is very difficult to find on a remote display. These crack type emissions are low and can last for a considerable period of time.”

When a pipe suffers a catastrophic failure, the damage is usually much greater. In the industry, it is called a “fish mouth” rupture because it has a wide gap like a fish mouth.

Houston-based Amplify Energy, which owns and operates three offshore oil platforms and a pipeline in southern Los Angeles, spills until workers detect oil luster on the surface of the water at 8:09 on Saturday. He said he didn’t know it was.morning

According to investigators, the spill occurred about 5 miles offshore and about 98 feet deep. Martyn Willsher, CEO of Amplify, says the 4,000-foot section of the pipeline has moved 105 feet and bent back like a bow strap.

Jonathan Stewart, a professor of civil and environmental engineering at the University of California, Los Angeles, said that moving most of the pipe so far causes “bending deformation.” The other was bent inward, so Stewart said.

Stewart said there was too little information to conclude on the cause, but such pressure alone could lead to breaks. The sharp part of the anchor can penetrate the pipeline, but “just bending it can damage it.”

“Because we are pulling the pipe, these bending stresses can occur in the pipe and eventually become large enough to cause the pipe to burst,” he said.

Questions remain as to when oil companies learned that there was a problem and could delay reporting spills.

A foreign vessel moored off Huntington Beach reported to the Coast Guard that it had more than two miles of luster after 6 pm on October 1, and satellite images from the European Space Agency that night. It showed the possibility of an oil slick. , Reported to the Coast Guard on Saturday at 2:06 am, after a review by US National Oceanic and Atmospheric Administration analysts.

Federal pipeline safety regulators have set the time of the incident on Saturday at 2:30 am, but the company says it did not shut down the pipeline until 6: 1. Problem — And did not report the leak to the Coast Guard until 9:07 am. Federal and state regulations require immediate notification of spills.

According to Amplify, the line was already shut down by 6am, restarted for 5 minutes to “read the meter”, and then shut down again. The meter reading shows the amount of oil that goes in and out of the line. Kuprewicz and Ramanan Krishnamoorti, professors of petroleum engineering at the University of Houston, said they could have used this information to see if the pressure change alarm sounded because of a line leak.

According to the company, the boat found oil on the surface of the water at 8:09 am.

Oil pipeline damage can have occurred months before a major oil spill: NPR

Source link Oil pipeline damage can have occurred months before a major oil spill: NPR

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