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Abandoning the Capped Oil Well: What Could Possibly Go Wrong?
What could possibly go wrong?
One
expert warns
that increasing pressure might have an unintended danger:
Bill
Gale, a California engineer and industrial explosion expert who is
a member of the Deepwater Horizon Study Group, said… that gas
hydrate crystals could be plugging any holes in the underground
portion of the well, and they could get dislodged as pressure
builds.
(Gale was formerly Chief Loss Prevention
Engineer for Bechtel in San Francisco, obtained his undergraduate degree
in Chemical Engineering, Masters in Civil Engineering and PhD in Fire
Safety Engineering Science from the University of California,
Berkeley. Gale is a registered professional engineer in both
mechanical engineering and fire protection engineering, and has more
than forty years of industrial loss prevention, process safety
management, and fire protection/fire safety engineering experience.)
In
other words, there may have been a destruction of a portion of the
steel well casing which was temporarily
plugged by methane hydrate crystals. Leaving the well cap may
slowly raise the pressure in the well to the point where the hydrate
crystals are dislodged, in which case the well might really start leaking.
Sound farfetched?
Maybe.
But
remember that the top hat containment dome failed because it got plugged
up with methane hydrate crystals.
And remember that there's a lot of methane down there. Indeed,
while most crude oil contains 5% methane, the crude oil gushing out of
the blown out well is 40%
methane.
Although even less likely, scientists say that the
methane could disturb the seafloor itself. As the St. Peterburg Times points
out:
Disturbing
those [methane hydrate] deposits — say, by drilling an oil well through
them — can turn that solid methane into a liquid, leaving the ocean
floor unstable, explained [Carol Lutken of the University of
Mississippi, which is part of a consortium with SRI which has been
conducting methane research in the Gulf of Mexico for years].
***
Generally
the oil industry tries to avoid methane areas during drilling for
safety reasons. But the U.S. Energy Department wants to find a way to
harvest fuel from those methane deposits, Lutken said. [I've previously discussed
that issue in detail.]
So what's the bottom line?
I
am not predicting that anything bad will happen. Hopefully, when the
storm is over and the underwater ROV submersibles return to the spill
site, everything will be peaceful and stable.
But there are many variables such as methane hydrates which - in a
worst-case scenario - could complicate matters.
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Are you saying the Bea quote is wrong/has been disproven? Here's the quote again:
Your second point suggests that the temperature in the ground under the sea floor is warmer than the temperature (of the water) at the bottom of the ocean. Which would imply that the "large chunk of frozen hydrate" idea is wrong.
I'm just trying to interpret the quotes from the engineer. I'm sure he knows his business. I could certainly be misinterpreting what he was saying.
I'm saying when Bea made the quote, the operating hypothesis was that there were 2 pipes in the BOP. Even BP agreed and planned on strapping the 2 pipes together before installing the new flange. However, when they removed the old flange, there was only one pipe inside the BOP.
Your understanding of my second point is correct. There might be large chunks of hydrates .... gas bubbles that have made it to the sea floor and transitioned into hydrates and accumulated as such.
I agree ... I did a poor job.
I removed the temperature part. Now it's fixed.
Well temperature, pressure, phase relationships of Methane Hydrates are well known, as you said ... so who needs a stinkin chart?
speaking of kicking, this may be an irrational or just
uninformed fear, but what if this sitting full straw is a ticking
time bomb due to phase changing methane brought about
by thermal distributions and unknown circulatory characteristics
of these contained or semi contained materials. for some
reason i can't think this through right now? maybe it's the drugs
and alcohol, or the lack of proper punctuation and adherence to
standard capitalization protocols? i hope someone gave it the
consideration it deserves, some sober someone with superior
spelling skills.
.
key sentence of concern: " At sea level, the volume of the gas is 600 times greater than the original liquid."
Maybe you could consider going out for a drive until the buzz wears off -- then you post.
Just a thought.
never again.
hydrate crystals, frozen methane with some water, is along the USA Atlantic shore line as well as other places. Not uncommon and of some concern if the oceans start to warm up. It is also a fuel that we dont know how to capture. Assuming that the earth gets warmer the deeper you go, the oil that is escaping from the warm depths may melt the forzen hydrate that it layed out under the ocean floor. If this goes sideways, it will seek soft areas to escape. Even the smart guys dont really know a bunch about what is down there for sure. I am 3rd generation oil field trash and have some respect for the industry. However, there is too much unknown with too much major risk to continue off shore production drilling without some NASA type oversight. It will also require intellegent leadership in DC. We can not find out what we dont know -- like this----- again.
well said.
1 psi equals 6,894.757 Pa
6500 psi == 44815.92 kPa
Based on the known presence of hydrate crystals, we're talking the low-digit sub-zero centigrade range at present.
So we've got about 17-23 degrees C of play before the killer bubbles eat Nawlins.
BP says the oil is 140 degrees F (60 degrees Celsius); see comment #484915 above for source.
if it is at 140F than solid hydrates cannot exist within the well bore. True? And if they do exist, they would have to exist at -0C. True?
I agree. I comment below that this implies the hydrate ice, if it exists, would have to be in the ground outside the well casing (but still blocking any holes).
I can't figure out what she means by "can turn that solid methane into a liquid". The liquid phase of methane is not shown on the chart you provided and niether can I find it referenced on the web. Still looking though....
Plus, I don't get how gas hydrate crystals can exist inside the well casing since the temperature must be at 32F or below, regardless of pressure. I think the oil/gas in the well bore is at a higher temperature than that. I don't get this whole article.
REALLY!?!?!? Come on...Regardless of pressure?
Read the chart. Sorry there is no youtube video.
My sarcasm meter is malfunctioning due to lack of sleep. Apologies if you were being sarcastic.
The source article for the quote is http://www.tampabay.com/news/environment/water/scientists-from-st-peters... and it's worth checking out.
The key here is that the methane deposits are deep under the sea floor. They're natural and they've been there for a long long time (millions of years). They are frozen (which surprises me because the deeper you go into the earth, the hotter it gets). "Disturbing the deposits" can turn them into liquid (all substances have a solid, liquid, and gas phase; they go from solid to liquid to gas, depending on pressure and temperature). Not sure what "disturbing" does to the deposits -- heat them up? Shake them?
If the deposits turned to liquid, it's easy to see how that might "leave the ocean floor unstable." The article says the deposits are vast; the scientists had been studying them as a potential energy source. The article also says that the methane may have caused the original accident.
"frozen" has "nothing" to do with temperature in this context.
it just means in the "solid" phase which is determined by the
combined influences of pressure and temperature and the
"nature" of the material compounds under consideration. this
is what phase diagrams attempt to communicate. the corresponding
conditions that one can predict phase change. in this instance,
problems and potentially solutions.?
The "solid" phase corresponds very closely to 0C on the chart. Therefore I used the word "frozen". I.E. at above 0C the seawater is saturated with methane. At less that 0C the sea ice is saturated with methane. That's what is really going on I think.
no, the line on this phase diagram depicts the corresponding conditions
of temperature and pressure that, when met, will produce a phase
transition. above the line, by either reducing the temperature or
increasing the pressure will result in the compound changing phase from
gas to liquid. and visa versa, so to speak. key point, the visa versa,
the change from liquid to gas is accompanied by expansion 600 fold. that
is the "kick" of it. problem and very dangerous.
also the reduction in volume associated with the transition from gas to
liquid is also a kick or clap. violent shit my friend.
.
so you can have the material "freeze" at any number of temperatures
providing the appropriate pressure, not really given by this phase diagram
because it does seem to be missing something, or should i say "did"
cause i think it was removed from the post.?
No, again you are wrong. It is not a "compound". It is a molecule of methane trapped within a lattice of several water molecules. Again, pressure is independant of phase transition from liquid to solid in regards to methane hydrate. Why do you make stuff up?
Again, you have it wrong. What you are talking about is LIQUID METHANE, not LIQUID METHANE HYDRATE (or, methane saturated seawater).
Yeah, I think Carol Lutken meant to say "disturbing the solid methane hydrate could turn it into liquid methan hydrate", which is not how she was quoted. Whether it is solid or liquid seems to be contingent on the temperature, i.e. whether or not the water that it is associated with is frozen or not. By "disturbing" it, she must be implying that the temperature is raised, since pressure is irrelevant according to the chart.
In my comment #484912, I misread the article as saying the methane deposits were deep under the ocean floor when it only says "deep under the ocean."
This could mean the deposits are in the ground OR that they are merely resting on the ocean floor. I assumed the former.
In the latter case, it's not clear how disturbing them could "leave the ocean floor unstable." Perhaps these deposits are under the ocean floor but not very deep. Also in the latter case, the deposits might be young (not millions of years old as they would have to be if they were deep under the floor).
Yes, I missed that the first time, but I agree. My understand is that they lie on the surface of the seafloor and not under it.
no, pressure is entirely relevant according to the phase diagram.
one reduces pressure by relieving pressure. as pressure is reduced
the phase changes from solid to liguid to gas, in this direction, temperature
held constant. as temperature is increased you get the same phase
transition direction. s,l,g,. the spooky part is the expansion from liquid
to gas. very destructive "kicking". bleve.
http://en.wikipedia.org/wiki/BLEVE
.
if i understood your comment?
I think you are wrong. The plot line (curve) is only showing the transition phase to GAS. The transition from solid to liquid appears on the chart as only relevant to temperature. Here is the chart: http://upload.wikimedia.org/wikipedia/commons/b/b4/Methane_Hydrate_phase_diagram.jpg
the flaw in this diagram for the purposes of this discussion
is that is does not attempt to distinguish between methane
hydrate liquid and methane hydrate solid, just methane gas
and methane hydrate. the blue area vs. the beige relates to
the water component and is designated methane hydrate and ice.
it doesn't indicate anything concerning the phase change from
liquid to solid methane hydrate with regards to pressure and temp.
if it is accurate how are crystals formed in the collection sombrero,
or in subsurface sediments with temperatures greater than 0 degrees?
So according to the graph, in order for the methane hydrate to turn to methane gas, at or near the top of the well bore where the pressure is at its least (45000 kilopascals or so), the temperature would have to be at or around 80F. Is this what we are going to worry about for the next 24 hours? Seriously?
True ... I guess that's what we have to worry about.
Come to think of it... back on 4/21 or so the drilling platform blew-up (that's how we ended up in this mess). The available evidence indicates that can reach 80F (or what ever minimal conditions are required for the sudden uncontrolled release of large amounts of Methane).
From http://www.chron.com/disp/story.mpl/business/7032202.html :
the oil is pretty hot, no? so the methane may be in gas phase at some
locations at some times in the "capped" well, no? up the straw... as he says.
.
http://planetforlife.com/dwphysics/drillmacondo.html
.
The Science Underlying the Deepwater Horizon Blowout.
"Methane is a gas at ordinary temperatures and pressures. The gas that cooks your food and heats your house is mostly methane. But methane is a liquid at the pressures found within the Macondo reservoir. Methane as a liquid is miscible with crude oil. If you mix olive oil and canola oil you will see what miscible means. They don't separate the way a water and oil mixture would.
The methane in the Macondo reservoir becomes a gas if the pressure is reduced. At sea level, the volume of the gas is 600 times greater than the original liquid. Methane's conversion from liquid to gas happens fast when the pressure goes below 100 bars. This has implications when methane goes up the straw.
Methane and water do something unusual at high pressure and low temperature. They form methane hydrate which is essentially little balls of ice enclosing methane molecules as the picture illustrates. Methane hydrate is a stable solid at the temperature and pressure encounterred one mile deep. But it decomposes into water and methane at atmospheric pressure. The decomposition can be rapid if ethane and/or propane is in the hydrate. This rapid decomposition is part of the mechanism of a "kick."
Methane hydrate is the stuff that stopped BP's early attempt to cap the blowout preventer."
.
http://www.mh21japan.gr.jp/english/mh/05kussaku.html
Very good RESEARCH blindman. Perhaps we could have GW forward this point to Mr. Bill Gale of the full paragraph of expertise none of which is in the energy field and ask him one teensy little question. "If methane hydrates are plugging up the "possible leaks in the underground portions of the well" where did the water to form those hydrates come from?" He IS a chemical engineer and will understand you need lots of water molecules to surround the methane molecule while forming the hydrates...........I hope we can all agree that it's quite unlikely water was flowing down into the pipe in significant quantities against the pressure of all that flow, especially since it was not possible to PUMP against it successfully?
GW can be quite dense at times but even he can probably see that's a LITTLE different than the situation of the "top hat" capturing a stream of fluid flowing through the ocean....................................
"If methane hydrates are plugging up the "possible leaks in the underground portions of the well" where did the water to form those hydrates come from?"
The drillers were pumping sea water down the pipe because it is cheaper than drilling mud. If the casing is ruptured the water could be anywhere.
Furthermore it is not necessary for the hydrate to melt in order for a hydrate plug to fail. It is only necessary for the pressure to build to the point where it breaks through the hydrate.
How strong is methane hydrate anyway? It sounds like it is a form of ice. If you had a broken pipe plugged by ice, how much pressure would blow it out?
We may be about to find out.
Leaking sub surface unattended...what could go wrong indeed!
At this point all we can do is wait and see...I'm hoping for the best but preparing for the worst.
Ask sarah palin she knows it all !!!!!!!!!!!!!!!! Spill baby spill !!!!!!!!!!
Sarah won't be in charge for a few years.
Until then its Barry and the dems, handling this expertly for us.
Right. And on task they are. Well, on message at least.
Oh, is it my tee time already?