A look at the chemistry of methane hydrates and pipeline process safety issues.
There has been a tremendous amount of speculation about the cause of the rupture of Russia’s Nordstream 2 underwater pipeline, which resulted in a release of gas bubbles half a mile wide that rose to the Baltic Sea’s surface near the Danish island of Bornholm.
Fingers are pointed in many directions.
Speculation has pointed to Russia, whose state-controlled energy company, Gazprom, is the main owner of the pipelines. A spokesman for President Vladimir V. Putin of Russia, Dmitri S. Peskov, dismissed allegations of Russian involvement as “stupid” and pointed a finger at the United States.
The situation bears the hallmarks of a spy thriller. But analysts say that damaging the pipelines could be a significant escalation in the proxy energy war that has been waged since fighting began in Ukraine — a battle that could have serious consequences for millions of homes and businesses throughout Europe. Indeed, whoever damaged the pipelines may have meant to show Europeans that “nowhere is safe,” said Helima Croft, the head of commodity strategy at RBC Capital Markets.
…Construction was completed last year on the second line, Nord Stream 2, which was intended to double those flows, providing a big, modern line into northwest Europe. But it never became fully operational: The German government shelved the project in February, just as Russia began to invade Ukraine.
And while there is plenty of finger-pointing and blame-placing, perhaps it is worthwhile considering that the rupture was an accident. A recent post by “The Law Dog Files” caught my eye, suggesting it may have been an accidental rupture. Because the pipeline was not fully operational, one must consider the idea, especially since the cold ocean waters of the Baltic are one of the many places on Earth that allow for the generation of “methane hydrates.”
However, in this case involving a natural gas pipeline under the pressure of 300 to 360 feet (8 atmospheres to 10 atm.) of water, I’d like you to turn your eyes towards a fun little quirk of nature called “methane hydrates”.
Well, actually, I’d like you to meditate upon “hydrate plug”, but give me a moment.
Under certain circumstances of pressure, temperature, and water presence natural gas/methane will form solid hydrates, with concomitant amounts of fun.
Legal Insurrection readers are already familiar with methane hydrates, which may have contributed to the “Great Dying” of the Permian Extinction discussed in my post about mass extinctions.
There are several possible explanations: Asteroid strike, a massive eruption of lava that formed the enormous Siberian Traps, and the release methane from the methane-hydrate formations deep under the ocean.
I want to expand a bit on the chemistry. Methane hydrates are fire-and-ice, as the explosive methane molecule becomes caged within water molecules at the high pressures at the bottom of the oceans. These compounds form along continental shelves, with organic-rich deposits flowing from the adjacent lands into the region.
These hydrates form plugs in pipelines.
Hydrates cause safety problems for two reasons :
- Upon removal, when hydrate plugs are depressurized improperly, with large pressure gradients across the plug, hydrate projectiles frequently erupt from pipes
- When hydrates are heated, large confined pressure increases cause pipe rupture
The most common way to remove a hydrate plug from a flow channel is by depressurization. Flow is stopped, and the line is slowly depressurized from both ends of the plug. At atmospheric pressure, the hydrate stability temperature is invariably less than that of the surroundings, so heat flows from the environment into the hydrate plug. The plug melts radially inward, detaching first at the pipe wall.
Any pressure gradient across the detached plug causes it to act like a projectile…. with measured plug velocities up to 180 miles/hr for short distances. The hydrate has the density of ice, almost twice that of the surrounding fluid, so at the line velocity, the plug momentum is twice that of the surrounding fluids. When the hydrate projectile encounters an obstruction or change in flow direction, such as a pipe elbow, bend, or valve, the resulting impact or pressure increase frequently causes line rupture, equipment damage, fire, and potential injury or loss of life.
Process safety for pipelines like Nord Steam 2 involves a lot of inspections and maintenance. Given that the Russians who perform this work are drafted to fight in Ukraine, and the pipelines shut down, how likely is it that anyone performed the inspections and maintenance?
It would be great if the situation did not escalate to a robust conflict between nuclear powers….especially if the catastrophic failure of the pipeline was an accident.
BIDEN TO PUTIN: "America is fully prepared with our NATO allies to defend every single inch of NATO territory, every single inch. Mr. Putin, don't misunderstand what I'm saying. Every inch." pic.twitter.com/ta5rzSxHOJ
— Breaking911 (@Breaking911) September 30, 2022
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