Huntington Beach, Calif. (WNN) – Video of a broken pipeline that spilled thousands of gallons of crude off Southern California shows a thin crack at the top of the pipe that could indicate a slow leak that was initially difficult to detect, experts said Thursday.
Richard Kuprevic, a private pipeline accident investigator and consultant, said the 13-inch-long (33 cm) narrow gash could explain why signs of an oil spill were seen Friday night, but the spill was not detected by the pipeline operator until Saturday morning. walked.
“My experience suggests that this will be a pretty hard leak to determine from afar quickly,” Kuprevic said. “An opening of this type, on a 17-mile-long (27-kilometer) underwater pipe, is very difficult to detect by remote signals. These crack-type releases are low-rate and can last for a long time. “
When pipes experience a catastrophic failure, the breach is usually too large, which is called a “fish mouth” rupture in the industry because it is as wide as a fish’s mouth, he said.
Amplify Energy, a Houston-based company that owns and operates three offshore oil platforms and pipelines south of Los Angeles, said it didn’t know what it was until its employees found an offshore oil on the water at 8:09 a.m. Saturday. Didn’t detect oil shine, so far there was no leak. am
The cause of the leak is being investigated by multiple agencies as cleanup continues for miles along the Orange County coast south of the ports of Los Angeles and Long Beach.
The Coast Guard is investigating whether the ship’s anchor broke the pipeline and tilted it. Amplify has publicly stated that no more than 126,000 gallons (477,000 litres) leaked. But it also told federal investigators that the total amount may have been only 29,400 gallons. (111,300 liters).
Officials said on Wednesday they were investigating whether a ship waiting to unload its cargo may have had anything to do with the leak. Coast Guard investigators boarded the massive German-flagged container ship Rotterdam Express to determine whether it was involved in the spill. The Rotterdam was the closest ship to the pipeline last week.
Hapag-Lloyd, the shipping company that operated the ship, confirmed on Thursday that investigators had boarded the ship while it was docked at the Port of Oakland in San Francisco Bay. According to Nils Haupt, a spokesman for Hapag-Lloyd’s headquarters in Hamburg, Germany, the Coast Guard interviewed the captain and crew and was given access to a logbook showing the ship’s locations.
Later, the Coast Guard called the company to say that Rotterdam was no longer under investigation for the spill, Haupt said. The ship was cleared to depart Oakland which was headed for Mexico.
Investigators said the leak occurred at a depth of about 98 feet (30 meters) over a distance of about 5 miles (8 kilometers). Amplify CEO Martin Wilser has said that a 4,000-foot (1,219 m) section of the pipeline was removed by 105 feet (32 m), which bent like a string at the bow.
Questions remain about when the oil company learned it had a problem and was delaying reporting the spill.
A foreign ship anchored in the waters off Huntington Beach told the Coast Guard that it observed flashes more than 2 miles (3.2 kilometers) long after 6 p.m. It was reported to the Coast Guard after 7 p.m. and 2 a.m. by the National Oceanic and Atmospheric Administration.
Federal pipeline safety regulators have set the time of the incident at 2:30 a.m. Saturday, but say the company didn’t shut down the pipeline until 6:01 a.m. and didn’t report the leak to the Coast Guard until 9:07 a.m. And state rules require immediate notification of the spill.
Type of crack seen in Coast Guard video Kuprewicz said the low pressure is large enough to allow some of the oil to escape, potentially triggering the alarm. But since the pipeline was operating at relatively low pressure, the control room operator would have simply dismissed the alarm because the pressure was not very high to begin with, he said.
Ramanan Krishnamurthy, a professor of petroleum engineering at the University of Houston, said the pipeline could leak for several days before being discovered.
“If you have a big crack or a massive hole, you get a big pressure drop and so you know you have a big leak,” he said. “When you have a hairline crack like this, it’s probably going to last two, three, four days.”
The fact that the San Pedro Bay line in the video was still encased in concrete is another indication that oil was leaking at a low rate. Kuprevic said a major breach on the line with extreme pressure would blow away the concrete.
Because the line is encased in concrete—a means of keeping it weighted on the ocean floor—the Coast Guard video does not reveal the position of the half-inch-thick steel pipe below.
Once federal safety investigators have cut out the damaged part of the pipe and removed it, they will be able to conduct a closer examination looking for signs of corrosion, metal fatigue or other anomalies, making it more vulnerable to failure. Will go Kuprevic said that examination would also reveal whether the crack had grown larger over time.
Associated Press writers Michael Bisker and Michael Balsamo contributed from Washington. Michael R. Blood contributed from Los Angeles.