Saturday, June 26, 2010
Deep Water Horizon Methane Tsunami Next?
The Petronobyl worst case scenarios took a new ominous turn recently with new concerns about a potentially catastrophic methane release. Helium discusses why this might add to the list of things that should keep one up at night:
"Disturbing evidence is mounting that something frightening is happening deep under the waters of the Gulf of Mexico—something far worse than the BP oil gusher.
Warnings were raised as long as a year before the Deepwater Horizon disaster that the area of seabed chosen by the BP geologists might be unstable, or worse, inherently dangerous.
What makes the location that Transocean chose potentially far riskier than other potential oil deposits located at other regions of the Gulf? It can be summed up with two words: methane gas.
More than 12 months ago some geologists rang the warning bell that the Deepwater Horizon exploratory rig might have been erected directly over a huge underground reservoir of methane.
Documents from several years ago indicate that the subterranean geologic formation may contain the presence of a huge methane deposit.
None other than the engineer who helped lead the team to snuff the Gulf oil fires set by Saddam Hussein to slow the advance of American troops has stated that a huge underground lake of methane gas—compressed by a pressure of 100,000 pounds per square inch (psi)—could be released by BP's drilling effort to obtain the oil deposit.
Current engineering technology cannot contain gas that is pressurized to 100,000 psi.
By some geologists' estimates the methane could be a massive 15 to 20 mile toxic and explosive bubble trapped for eons under the Gulf sea floor. In their opinion, the explosive destruction of the Deepwater Horizon wellhead was an accident just waiting to happen.
Yet the disaster that followed the loss of the rig pales by comparison to the apocalyptic disaster that may come.
A cascading catastrophe
According to worried geologists, the first signs that the methane may burst its way through the bottom of the ocean would be fissures or cracks appearing on the ocean floor near the damaged well head.
Evidence of fissures opening up on the seabed have been captured by the robotic submersibles working to repair and contain the ruptured well. Smaller, independent plumes have also appeared outside the nearby radius of the bore hole itself."
mi2g goes on to document further concerns:
"Older documents indicate that the subterranean geological formation below the "Macondo" well in the Gulf of Mexico may contain the presence of a huge methane deposit. It has been a well known fact that the methane in that oil deposit was problematic. As a result, there was a much higher risk of a blow out. Macondo shares its name with the cursed town in the novel "One Hundred Years of Solitude" by the Nobel-prize winning writer Gabriel Garcia Marquez.
By some geologists' estimates, the methane could be a massive bubble trapped for thousands of years under the Gulf of Mexico sea floor. More than a year ago, geologists expressed alarm in regard to BP and Transocean putting their exploratory rig directly over this massive underground reservoir of methane. Warnings were raised before the Deepwater Horizon catastrophe that the area of seabed chosen might be unstable and inherently dangerous.
Methane and Poison Gas Bubble
The US Environmental Protection Agency (EPA) has found high concentrations of gases in the Gulf of Mexico area. The escape of other poisonous gases associated with an underground methane bubble -- such as hydrogen sulfide, benzene and methylene chloride -- have also been found. Recently, the EPA measured hydrogen sulfide at more than 1,000 parts per billion (ppb) -- well above the normal 5 to 10 ppb. Some benzene levels were measured near the Gulf of Mexico in the range of 3,000 to 4,000 ppb -- up from the normal 0 to 4 ppb. Benzene gas is water soluble and is a carcinogen at levels of 1,000 ppb according to the EPA. Upon using a GPS and depth finder system, experts have discovered a large gas bubble, 15 to 20 miles wide and tens of feet high, under the ocean floor. These bubbles are common. Some even believe that the rapid release of similar bubbles may have caused the sinking of ships and planes in the Bermuda Triangle.
50,000 to 100,000 PSI
The intractable problem is that this methane, located deep in the bowels of the earth, is under tremendous pressure. Experts agree that the pressure that blows the oil into the Gulf waters is estimated to be between 30,000 and 70,000 pounds per square inch (psi). Some speculate that the pressure of the methane at the base of the well head, deep under the ocean floor, may be as high as 100,000 psi -- far too much for current technology to contain. The shutoff valves and safety measures were only built for thousands of psi at best. There is no known device to cap a well with such an ultra high pressure.
A methane bubble this large -- if able to escape from under the ocean floor through fissures, cracks and fault areas -- is likely to cause a gas explosion. With the emerging evidence of fissures, the tacit fear now is this: the methane bubble may rupture the seabed and may then erupt with an explosion within the Gulf of Mexico waters. The bubble is likely to explode upwards propelled by more than 50,000 psi of pressure, bursting through the cracks and fissures of the sea floor, fracturing and rupturing miles of ocean bottom with a single extreme explosion.
Cascading Catastrophe Scenarios
1. Loss of Buoyancy
Huge methane gas bubbles under a ship can cause a sudden buoyancy loss. This causes a ship to tilt adversely or worse. Every ship, drilling rig and structure within a ten mile radius of the escaping methane bubble would have to deal with a rapid change in buoyancy, causing many oil structures in its vicinity to become unstable and ships to sink. The lives of all the workers, engineers, coast guard personnel and marine biologists -- measuring and mitigating the oil plumes' advance and assisting with the clean up -- could be in some danger. Therefore, advanced safety measures should be put in place.
2. First Tsunami with Toxic Cloud
If the toxic gas bubble explodes, it might simultaneously set off a tsunami travelling at a high speed of hundreds of miles per hour. Florida might be most exposed to the fury of a tsunami wave. The entire Gulf coastline would be vulnerable, if the tsunami is manifest. Texas, Louisiana, Mississippi, Alabama and southern region of Georgia might experience the effects of the tsunami according to some sources.
3. Second Tsunami via Vaporisation
After several billion barrels of oil and billions of cubic feet of gas have been released, the massive cavity beneath the ocean floor will begin to normalise, allowing freezing water to be forced naturally into the huge cavity where the oil and gas once were. The temperature in that cavity can be extremely hot at around 150 degrees celsius or more. The incoming water will be vaporised and turned into steam, creating an enormous force, which could actually lift the Gulf floor. According to computer models, a second massive tsunami wave might occur.
The danger of loss of buoyancy and cascading tsunamis in the Gulf of Mexico -- caused by the release of the massive methane and poisonous gas bubble -- has been a much lower probability in the early period of the crisis, which began on April 20th. However, as time goes by and the risk increases, this low probability high impact scenario ought not to be ignored, given that the safety and security of the personnel involved remains paramount. Could this be how nature eventually seals the hole created by the Gulf of Mexico oil gusher?"
Given BP's apparent inability to deal with the truth and the government's wishy-washy approach to the whole thing leads me to believe this is a credible concern which will dwarf our present problems should it come to pass.