Methane levels 40% instead of normal 5% in Gulf - Scientists are Worried

reply to post by Mike6158


I think the scary part about the frozen methane is its mixed with the sand and salt layers the drill pipe is in and with the heat the pipe is creating it is heating the frozen methane which when it changes from frozen to gas it expands 168 times its frozen size which could cause a land slide. The frozen methane is acting as a bonding agent in the sand mix holding it in place but now is being melted out of it weakening the sea wall. And there is plenty of heat from the oil flowing through the pipe. Oil lines in Alaska are suspended in the air to prevent the melting of the permafrost in the ground due to the heat created from the oil flowing through the pipes. And if there is a land slide the amount of methane released would be huge. Not to mention it could reach the pockets of methane under the sand and salt layers.

reply to post by JBA2848


If you could get a sudden vaporization of the hydrate to happen maybe... but I doubt it. There isn't anywhere near enough energy available in the system to cause anything like a landslide...

reply to post by JBA2848
If a landslide occured would it effect the pressure at that depth. I was wondering if a mass movement underwater could relieve pressure at that depth. This would further destabilize the methane hydrate which forms due to high pressure?

reply to post by Mike6158


Methane does dissolve in water. As do most other gasses. The statistics for it are right in that link that I provided. It was something like 0.05 vol/vol at 35 deg F andd 1.01 atm.

Also, everyone (including BP) is sayiing that the leak is close to 100,000 barrels per day and 40% of that is Methane.

You seem to know your stuff pretty well, but you also seem to be ignoring the well known facts of the leak, and the well known facts of the chemistry of liquids and gasses? Gasses dissolve into liquids, not vice versa. Methane is currently dissolving into the sea water at very low temperatures and high pressures, but soon enough it will drift into high temperatures and low pressures, and it will have to be released.

I don't think I can make it any simpler than that, and if you don't understand, you need to read the links, or buy a chemistry book.

:/

Methane hydrates form because of the pressure, temperature, and the presence of water and methane gas. They aren't magic. They form much, much easier than they sublimate. CO2 can also form a hydrate. So can Ethane.



[edit on 7/1/2010 by Mike6158]

pubs.acs.org...

The amount of methane dissolved in the water phase in the presence of CH4 gas hydrate has been measured at temperatures between 274 and 285 K and pressures ranging from 35 to 65 bar. It was found that the solubility of methane in the presence of hydrate decreases with decreasing temperature in the hydrate formation region. In the absence of gas hydrate the solubility of methane gas in water increases with decreasing temperature as expected. The results show that the hydrate formation process reverses the gas−liquid solubility trend. This confirms theoretical calculations. It was also observed that pressure was not a strong factor on the solubility in the presence of hydrates.

OR

en.wikipedia.org...

Solubility in water 35 mg/L (17 °C)

OR

Methane, a natural gas, dissolves in seawater and some scientists think measuring methane could give a more accurate picture of the extent of the oil spill.

From the OP's article, LOL!
www.abovetopsecret.com...
Whoops, that quote was from the OP of another thread. Got mixed up on where I was typing. Still, it is an established fact.

We can stop debating whether or not the Methane is dissolved in the water. We can stop debating whether or not it is coming out in massive quantities. These two items are mainstream accepted facts.

We can continue to debate how volatile it is, and whether it is more dangerous as an oxygen depleting microbe feeding Gulf Killer, or as an explosive silent creeping monster drifting along the deep water Gulf Killer.

Either way, it is there, and it is a Gulf Killer!

[edit on 1-7-2010 by getreadyalready]

According to a recent paper published by MBARI geologists and their colleagues, methane gas bubbling through seafloor sediments has created hundreds of low hills on the floor of the Arctic Ocean. These enigmatic features, which can grow up to 40 meters (130 feet) tall and several hundred meters across, have puzzled scientists ever since they were first discovered in the 1940s.

This conceptual drawing (not to scale) shows Paull's hypothesis that methane gas from deep hydrate deposits could push sediment up from below the ocean bottom to create a pingo-like feature. The gray lines in the background are from a seismic profile through one of these enigmatic features.
Image: (c) 2007 MBARI

And these pingo-like feature surround the deep horizon leak.

reply to post by getreadyalready

We can stop debating whether or not the Methane is dissolved in the water. We can stop debating whether or not it is coming out in massive quantities. These two items are mainstream accepted facts.

Mainstream? Accepted? Facts? No... no... and no... web based drivel maybe... except for the fact the methane does bubble up in large quantities... that's a fact... but it has nothing to do with the Maconda. Again- you are trying to use pure component logic (or links) to justify your position. The Maconda well is leaking a mixture... not a pure component.

I'll see your link that backs you up with one that doesn't
LINK

Methane, (CH4) has a tetrahedral shape. (Like the four points of a pyramid). Since each Hydrogen on the carbon atom have the same charge (because they are the same thing), there is no dipole moment / delta +/-. This means methane is non-polar.Water does have a dipole moment because the two electron pairs on the oxygen have a bigger negative charge than the Hydrogen's. This creates a net dipole moment. This means water is polar. Polar molecules easily dissolve other polar molecules because the delta+ side of the molecule is attracted to a delta- of another molecule. Nonpolar molecules dissolve other nonpolar molecules becuase there is no charge one way or another, so the are neither attracted nor repelled to one another. Polar molecules and nonpolar molecules do not dissolve well because there is typically more than one of each molecule in the solution. The polar molecules of water will stick together and the nonpolar molecules of methane will congregate as well.

I don't need to read a chemistry book (btw- it's called organic chemistry)... I did that years ago... I still look through my organic chemistry text but I don't need it for this discussion. I'm not the one that has no experience in the business. Have you ever tried to clear a hydrate from a farm field or the piping of a running gas plant? We once had a pipeline leak in a rice field. The hydrate that formed was the size of a small car. It took over a week for it to sublimate. We couldn't move it with equipment because of the danger of fire or explosion. We considered burning it but were afraid of crop damage. At some plant in our system there will be an incident with a dehydrator and there will be a blockage from hydrate formation. Everyone involved knows that step one is to lower the pressure in the plant to as low as possible, to inject methanol, and to increase the gas temperature (120°F is usually the max due to equipment design constraints) as much as possible. If you don't lower the pressure injecting methanol and increasing gas temperature won't cut it. The pressure has to be lowered.

[edit on 7/2/2010 by Mike6158]

[edit on 7/2/2010 by Mike6158]

Originally posted by JBA2848

According to a recent paper published by MBARI geologists and their colleagues, methane gas bubbling through seafloor sediments has created hundreds of low hills on the floor of the Arctic Ocean. These enigmatic features, which can grow up to 40 meters (130 feet) tall and several hundred meters across, have puzzled scientists ever since they were first discovered in the 1940s.

This conceptual drawing (not to scale) shows Paull's hypothesis that methane gas from deep hydrate deposits could push sediment up from below the ocean bottom to create a pingo-like feature. The gray lines in the background are from a seismic profile through one of these enigmatic features.
Image: (c) 2007 MBARI

And these pingo-like feature surround the deep horizon leak.

I don't disagree with the premise that methane hydrate is formed at the ocean floor and in the sands. That has nothing to do with the Maconda. It's not a new discovery. It's new to people that are just now getting interested in where their gas and products derived from petrochemicals comes from because someone screwed up and caused a disaster of epic proportions.

[edit on 7/2/2010 by Mike6158]

reply to post by Mike6158


You are correct that I don't have oil field experience. However I do have a degree in Chemistry, and all of my labs and research were done in Organic Chemistry. It has been years since I was in school, and I don't work as a chemist, so I am a little rusty.

Still, it seems you are arguing about the Methane Hydrate mounds on the sea floor from the preexisting fissures and leaks, while I am arguing the mixture pumping out of the wellhead at high velocity and immediately disbursing into the sea water? No? From all the ROV's I don't see mountains of Methane Hydrate forming? Maybe a little around the BOP structure and Top Hat. They stop and blow it off every now and then, but that is not my concern.

My concern is the mixture. The gas does not have to be polar to suspend in the sea water, and you can look at my links, or the MSDS, or any of the accepted reference books for properties of Methane to see just how much Methane would "dissolve" "suspend" "dissociate" into the sea water.

It is there, and it is growing, and I honestly do not understand how you can continue to debate that fact? I am not disputing any of your facts about the hydrates, I am simply ignoring them as a secondary concern. Now please address my primary concern of the suspended/dissolved gasses in the sea water itself, and don't say they aren't there. If all the Methane was forming Hydrates, at even the most conservative estimates say 40,000 barrels per day and 5% Methane, that would equal 2000 barrels of Methane gas forming Hydrates around the well head each day? Do you see approximately 120,000 barrels of Hydrate building around the well head?

reply to post by getreadyalready


I think that you are messing up the volume calc. When they say 5% they mean mol % not liquid volume percent. Methane cannot spontaneously separate itself completely from a mixture...

Its a mixture and the methane is bonded to the other "C's and H's" . The bond is very strong and the methane leaving the wellhead isn't going to spontaneously separate from the mixture at the pressure and temperature in the deep ocean...

However- Weeding through your last post I think we actually may be in agreement on the meat of this discussion. Within a few weeks of the accident I got into a disagreement with a Petroleum Engineer (they deal with high pressure and hot temperatures where phase behavior gets wonky) because he thought I was nuts when I said that the bulk of the well stream was pooling below the surface of the ocean. I starting thinking about the amount of oil NOT coming to the surface because all of the news reports described it as a sheen or patches. When I checked the normal pressure and temperatures at the floor of the ocean I saw that they were HIGHER than what we deal with in the processing industry and pretty cold. Cold enough to ensure that the bulk of the stream was going to be liquid. I knew it was a gas well as opposed to a heavy oil well. That info came from a contact within TransOcean. So, I made some guesses about composition and delta P across the leak, called an engineer friend of mine and asked him to run it on Hysis. Some of the C1 and C2 leave as vapor (and probably form a hydrate "snow"), the rest of the stream is liquid. As it rises in the ocean the lighter ends will begin to separate and "bubble off". Eventually all that will be left is the stuff that can be liquid at the surface which is what causes the mess. I've said it was pooling below the surface for almost two months.

Where we disagree is the "sudden vaporization" theory. Short of a asteroid hitting or a volcano erupting there isn't enough energy available to break the bonds and cause a sudden and catastrophic release of single components. It's simple chemistry and physics...


[edit on 7/2/2010 by Mike6158]

reply to post by Mike6158


To a certain extent you are correct about the volume calculation. When sources say the Methane is 40% of the leak vs. the typical 5%, they don't say if this means vol/vol or mol/mol or mass/mass, etc.

Also, the pressure of the reservoir at 18,000 feet or possibly even 30,000 feet depending on if you go by BP's permits, or BP's actual drilling, and the increasing diameter pipe as it gets closer to the surface, and the much lower relative pressure at the wellhead means that the stuff coming out at the seafloor is already rapidly expanding, so what do we extrapolate from that? Is the Gas coming out in liquid form due to the pressure and temperature, or is it in gas form due to the rapid expansion, or is it in hydrate and solid form as you mention, because it is still bonded with the crude? It is hard for someone like me or anyone in the press to make assumptions, but with your experience in the industry, hopefully you can shed some light on that part.

I agree 100% that the oil/gas mixture is not coming to the surface. Only a small percentage of the lightest stuff is making it to the surface. I would guess less than 5% is making it to the surface for many reasons.
1. The depth of the leak. Things don't just float up from 5000 feet like a bathtub. The pressure there keeps things submerged, even if they are lighter than water.
2. The use of dispersant, sprayed at the well head and specifically intended to keep the oil down.
3. The breakdown of the components. Only the lighter components will surface, much of the crude is higher density than water, and it would sink anyway.

As for our disagreement about the rapid gassification of the dissolved Methane. We can agree to disagree. I admit that it is a remote possibility, but I contend that it becomes more and more likely as the days drag on, because the seawater is becoming saturated, and the dissolved gasses are traveling to warmer waters and lower pressures at shallower depths. This is a bad combination in my opinion, but you are still welcome to yours, and I hope you are the correct one!

"Normally" natural gas composition is 80% - 90% Methane, 8%-10% Ethane, and the rest is Propane plus. 40% is probably the C1 mol% if the flare gas stream from the barge. An extremely rich gas stream might be as low as 60% C1 but that's weird...

It's not 30,000'... guaranteed... It's closer to 18,000' counting the 5,000' of water above the ocean floor.

Google Joule-Thomson effect and you'll find that when gas expands it gets colder (adiabatic expansion) which further subcools the mixture. Think about a propane bottle that supplies a propane grill or even better a big burner for boiling water. The bottle gets very cold because as the volume depletes so does the pressure inside and in order for the propane to be at equilibrium it has to get colder.

1/2/3- The only thing I would disagree with is in item 3. Crude does not have greater density than water. It gets close due to cold temperatures but it's always lighter. However... I still think that the density gradient is so small that the oil is in suspension (but it will come to see us some day)

Agreed...

Originally posted by getreadyalready
reply to post by Mike6158

 

To a certain extent you are correct about the volume calculation. When sources say the Methane is 40% of the leak vs. the typical 5%, they don't say if this means vol/vol or mol/mol or mass/mass, etc.

Also, the pressure of the reservoir at 18,000 feet or possibly even 30,000 feet depending on if you go by BP's permits, or BP's actual drilling, and the increasing diameter pipe as it gets closer to the surface, and the much lower relative pressure at the wellhead means that the stuff coming out at the seafloor is already rapidly expanding, so what do we extrapolate from that? Is the Gas coming out in liquid form due to the pressure and temperature, or is it in gas form due to the rapid expansion, or is it in hydrate and solid form as you mention, because it is still bonded with the crude? It is hard for someone like me or anyone in the press to make assumptions, but with your experience in the industry, hopefully you can shed some light on that part.

I agree 100% that the oil/gas mixture is not coming to the surface. Only a small percentage of the lightest stuff is making it to the surface. I would guess less than 5% is making it to the surface for many reasons.
1. The depth of the leak. Things don't just float up from 5000 feet like a bathtub. The pressure there keeps things submerged, even if they are lighter than water.
2. The use of dispersant, sprayed at the well head and specifically intended to keep the oil down.
3. The breakdown of the components. Only the lighter components will surface, much of the crude is higher density than water, and it would sink anyway.

As for our disagreement about the rapid gassification of the dissolved Methane. We can agree to disagree. I admit that it is a remote possibility, but I contend that it becomes more and more likely as the days drag on, because the seawater is becoming saturated, and the dissolved gasses are traveling to warmer waters and lower pressures at shallower depths. This is a bad combination in my opinion, but you are still welcome to yours, and I hope you are the correct one!