use gas lift pump on BP Macondo blowout? 4

[Windward]

To capture the leaking oil and gas until it has been stopped, would a gas lift pump work? There is about 40% methane by mass in the leak. This high percentage of gas would create a very powerful gas lift.

Direct the leak -that is, after the oil/gas has left the wellhead and is in the water at the 5000 foot depth (in other words, I am not suggesting using gas lift in the well itself) - into the open bottom end of a pipe running down to the leak from a salvage vessel.

Once this flow starts moving up the pipe, the highly pressurized methane will continuously expand because the pressure above the mixture is constantly falling. This will reduce the average density of the mixture in the pipe. At steady state flow, it will be much lower than the density of the seawater outside of the pipe.

It would be a giant chimney but with a much greater driving force than if the fluids were gases only, because of the much greater densities and the much greater difference in those densities. If the average density in the pipe is 4/5 that of seawater, the driving force at the bottom of the pipe would be more than 400 psi.

The oil/gas/water mixture will exit the pipe at high velocity at the salvage vessel, perfect for separating the liquid from the gas in a cyclone.

No outside power needed, equipment far simpler and cheaper than what they have been trying.

I know that word - CLATHRATES. They will plug up the flow! But will they, with 400 psi driving it? And if they are a problem, do what they are doing with tophat and put some methanol into it, or some warm water. Not hard when we are looking at the complete destruction of marine life in the Gulf of Mexico and the consequences of that.

 

[docellen]

Done. Comments are welcome on the new thread "Better BOP Design ???"

 

[DrillerNic]

waross- the wellbore sketch I have seen with the rupture discs on it is a little unclear where the disks are - they appear to be in the work string of (?) 3-1/2" tubing and 5" drill pipe. These discs could be to allow pressure testing of different parts of the work string, or to allow different fluids to be spotted at different depths without moving the pipe- to put a spacer below a cement plug for example? I don't really know.

They might be in the 16" casing string, but I cannot think of any reason on earth why you would do that in casing....

 

[DennisRevell]

Windward says (15 Jun 10 11:35):

"It seems to me that heating might be the best method to prevent hydrate formation. There is plenty of heat available in the flared gas, but it would take some work to get it down to the location of the leak. I would try a controlled fire in the flow first. It would be easier to send oxygen down to the leak than it would be to send heated water down. We know the stoichiometry, and how much gas and oil would have to burn to raise the temperature of the flow by about 40 Fahrenheit degrees. It wouldn't be much, even if the water was half of the total flow."

Why not go the whole hog, and burn ALL the disgusting stuff at the point(s) of emanation:

http://tinyurl.com/3yeqald

(or for more "confidence": tinyurl preview facility:

http://preview.tinyurl.com/3yeqald)

For further genesis/background/development/further info on idea:

http://tinyurl.com/3ae4jj3

(or via:

http://preview.tinyurl.com/3ae4jj3)

To MY surprise, I've been pretty much right about most likely pitfalls, stuff that BP appeared to me shouldn't really be doing: like when they tried their "Top-Kill". Immediately I saw their first large dome collection effort, I was quizzical as to why sluice gates of some sort didn't seem to be evident on pictures I saw of it - so pretty clearly the thermodynamic conditions would be changed drastically; as it turned out, leading to clathrate formation. This prompted me to generate the following "1st Submission", which also carries a warning against "Top Kill/Junk Shot" in a fairly stark fashion:

http://tinyurl.com/37oeenj

("Sluiced" Dome)

As far as the stoichiometry is concerned, does anyone here have a handle on what the "average fraction" of the gunk is? (I guess I mean roughly the average value of "n" in CH(n+2), ignoring Benzene & stuff!). 'Course the flow rate is a problem, I guess Prof. Wereley's (Purdue Uni.) approx. 25 gals/sec. would be a good first assumption.

I think one of the problems with undersea incineration is not getting it to burn, or keeping it lit (as long as oxidiser is supplied), but owing to the very high pressures, and so the much closer association of molecules, that the burn would be extremely hot - not too good for supply pipe longevity and such.

As far as getting hold of the humungus compressor or compressors required, I realise that the Corporatocracy doesn't permit much Govt power these days, but I think there's a good case in this emergency to darn-well REQUISITION whatever is available NOW, even to the extent of ripping apart existing non-critical installation(s).

See also a thread I started on this at a well-known Brit. newspaper's talk board (which is how I found eng-tips ( ... ;-) ... ):

http://talk.guardian.co.uk/WebX?14@359.V5m5kVy5tKc@.77615155/0

It's a Brit. talkboard, so the ... er ... language can get a bit ... er ... loose there ... including mine - I'm Brit. too. ;-)

All the Best,
Dennis Revell

 

[DennisRevell]

CORRECTION:

Sorry screwed up one of the PDF file-links (have so many versions on my PC, I'm losing track ;-). Eng-tips seems a bit strict on going back to re-edit ;-) (Guardian newspapar talkboards give 30 mins to make corrections). Anyway, here's the relevant para, same words used to indicate correct replacment point in my last post:

[BEGIN CORRECTION:]
"For further genesis/background/development/further info on idea:

http://tinyurl.com/2coku5f

(or via:

http://preview.tinyurl.com/2coku5f)"

[:END CORRECTION]

Thanks,

Dennis Revell.

 

[Windward]

Dennis, your comments are interesting and I will read the information at your links.

Regarding the possibility of starting a fire in the flow at the 5000 foot depth, I haven't had time yet to review Le Chatelier's principle and the chemistry of it. Maybe it wouldn't work because of the high pressure, but if it would, I believe the fire could be managed to prevent any damage to the piping.

If we can't collect all of the oil, either at first or after many attempts to do so, I agree that it would be better to burn it rather than allowing it to enter the water. However, burning it at the 5000 foot depth would require an enormous flow of oxygen, far greater than what would be required for the fire I am suggesting.

On the Oil Drum, I proposed that they burn all of it at the surface, if that could be done safely. This would require a tight seal on the BOP. I believe that is what they are approaching now, very cautiously, because of uncertainty about the condition of the casing below the mudline. There is much more to say about these things, too much to go into in one post.

In the beginning there was about 40% by mass of natural gas in the blowout. That has declined a little since then, but even now the fraction is far above the average for an oil find.

On the clathrate problem, I now have a copy of the book by E.D. Sloan that whammet listed above. I will comment later on what I find there.

I also agree, if they need any equipment, requisition it now and settle later.

If you have been right about this thing all along, and I have no reason to doubt that since I haven't studied your proposals yet, then that is probably why you are not in a position to do much about it. Corporate culture and government agencies - should I say the human race? - do not like those who don't conform to groupthink.

Sometimes this makes sense, for example when sea monsters and 100,000 psi gas bubbles and sinking a million ton nuclear battleship (must build one first) on the blowout are being discussed by some in this case. But so far, I haven't seen any good ideas from those in charge either. In particular, why weren't we prepared for a blowout like this? That was assured on paper but never in practice. This is what we get from the free market ideologues who have been running things for a long time now, who believe self-regulation always works and corporations always act responsibly.

 

[docellen]

Sorry if this is a dumb question, but why do we need to heat anything if we just keep the water out? It is clear from the video that there is a positive pressure in the cap, driving oil out the open vents. If they close those vents, the pressure can only increase, driving more oil and gas up the pipe. Maybe heating it will give some more gas lift, but it sure seems like there is plenty of pressure to do all the pushing we need. Maybe they just need a bigger riser. Or maybe they need more than one riser.

 

[Windward]

docellen, I tried to explain the requirement for heating the water in earlier posts, but in case I was not clear, here is a further explanation.

In a blowout under water, we must have some way of capturing the oil and gas AFTER it is in the water. If there were always a BOP or some piping left after the accident, and if we could always put a tight seal on it, and if we could always accomplish the job quickly, then relatively little oil and gas would get into the water at the blowout depth. (What to do with it after it has been brought to the surface is another matter.) Also, because of the tight seal, there would be no chance of hydrates forming and stopping the flow. If we can always meet all of these requirements, then there would be no need for a device such as a gas lift pump. And there would be no need to consider how to make it work, which in some cases would require heating the water.

So far, they have been afraid to use a tight seal on the Macondo BOP. It would increase the pressure on the casing below the mud line, and they discovered during Top Kill that the casing might be damaged. Increasing the pressure on it might make the blowout worse - oil and gas blowing up outside of the casing through the sea floor, therefore less of it collected with the hat.

They have been slowly closing down on the seal, reducing the amount of oil and gas that leaks and sending more of it up the riser. They also plan to install another riser. Going slowly, they can determine whether they have reached a point where they must stop tightening the seal, to avoid further damage to the casing.

Maybe they will eventually get a tight seal and capture the entire flow. In the meantime, millions of barrels of oil have leaked into the water. The only good part about this is that the leak keeps water from entering the flow, so they don't have to worry about hydrates plugging the riser.

I believe that a gas lift pump could have been capturing all of the oil and gas at Macondo almost from the beginning, if they had been ready with it. The oil and gas is ALREADY entering the water, and it is taking a very long time to stop even a fraction of it. This requires some means of capturing the oil and gas AFTER it is in the water, and a gas lift pump is the best solution, in my humble opinion.

For a gas lift pump to work, one of the problems we must solve for a blowout like Macondo is that the water is nearly freezing and the pressure is very high. These conditions ensure that hydrates will form rapidly. Since we can't reduce the pressure, we must heat the water - actually the water/oil/gas mixture - enough to prevent hydrates, because a gas lift pump also has a riser, and hydrates would plug it up.

However, not all blowouts would require heating of the flow to make a gas lift work. It depends on the pressure and temperature at the blowout.

As long as we drill underwater, we will need some device of this kind. There will be blowouts that cannot be controlled with the BOP, for example Ixtoc. That is, there will always be blowouts that cause oil and gas to enter the water at the depth of the blowout, and it will be too late for any tight seals, and impossible to install them anyway. When Ixtoc blew, twelve thousand feet of drill pipe and other equipment fell onto the BOP from the rig above. It was difficult for divers to reach the BOP, and when they did manage to close it, it soon failed and they were back to a blowout.

After nine months and two relief wells, the well was finally killed. In the meantime, because the blowout was so large and all of it was entering the water, they tried Operation Sombrero - a gas lift pump. But this idea had never been tried before, and they did not have a proven design or a way to install it. They had to work all of that out first, which took several weeks.

After they installed it, the Sombrero worked to some extent, not perfect, and it captured about 10% of the oil and gas in the entire blowout. But after two months of operation it was damaged by heavy seas and removed.

They didn't need to heat the water at Ixtoc, which was in the southern GOM. The water was already warm - not near freezing as it is at Macondo - and heating was not required because the blowout was only 150' deep, so the pressure was far below what would have caused hydrate formation at that temperature.

You can read about the Ixtoc blowout and Operation Sombrero in the book "Offshore Pioneers: Brown and Root and the History of Offshore Oil and Gas (authors Pratt, Priest and Castaneda, 1997). There are other references on the Oil Drum, just search for Ixtoc.

If research had continued on the Sombrero, we could have used it at Macondo. But the oil companies didn't want to spend the money (!), and the government did not force them to develop it because the regulatory agency MMS was a wholly owned subsidiary of the oil companies. We will see if renaming the agency does any good. Whoever dreamed up the new name ought to retire. The acronym alone is a mouthful, BOEMRE, pronounced “bummer”. Maybe the bureaucrat has a dark sense of humor.

The Associated Press published a good article yesterday, "Little Spent on Oil Spill Cleanup Technology":

http://www.google.com/hostednews/ap/article/ALeqM5i0-vrkse69xsLJHx1KBZUj7rDJyAD9GJ5A6O2

From the article:

“’Why they didn’t start working on it after the (Ixtoc 1) Mexican spill [sic] in 1979 is beyond me,’ said Gerald Graham, president of World Ocean Consulting, an oil spill prevention and response planning firm in British Columbia. “Now they’re trying to catch up.’”

I wonder what Dr. Graham himself was doing about it before Macondo. Did he just get into the business?

 

[waross]

One thing that makes second guessing bp a bad idea is that bp seems to be guessing in the first place and some important guesses have turned out to be disasterously wrong. Their partial successes may indicate that the Peter principle supervisors have, in desperation, stepped aside and let the guys who ar too smart to be promoted start solving the problem.
A very important step in problem solving is to define the problem. Another important step is to identify and quantify the factors that may be affecting the problem.
Trying to solve this problem based on the information that bp is releasing is an excercise in futility.
Why can't bp collect more oil? In case you missed it, they based their plans on a quantity of 5000 BPD, even though they were told that they were probably leaking much more. Hubris prevailed. They are now playing catch-up and trying to get more facilities on site.
To answer the question;
"Why don't they just close the vents?"
Not safe. They are collecting and flaring all the oil and gas that safety will allow. When they get more ships on site and are able to collect and/or flare more, they may indeed close the vents. As for hydrates, there may be water in the oil/gas stream.
They may be heating to separate the gas at a lower level for some reason.
Who knows?
Let's hope the relief well goes well!!


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[docellen]

Windward, thanks for your explanation, which answered my question in the first paragraph. Sorry you had to write all that again. I was thinking only of the current situation, which I believe can be solved without letting any water into the flow.

As for the danger to the well casing in closing the cap vents, that doesn't make sense to me. The pressure in the cap is only a few hundred psi at the most. The pressure in the well casing is thousands, if I understand it right. They already added a few thousand more in the top-kill attempt, and the casing survived. So I think adding a few more tens of psi by closing the vents won't make much difference down in the well.

Waross, I like your Peter Principle theory. I can easily imagine the top brass at a company like BP not listening to their engineers. I can also imagine that the Coast Guard doesn't listen to engineers either. What I'm having a hard time imagining is how Steven Chu might have gotten roped into some misleading story. If anyone can punch through the organizational politics, and ask the right questions, it would be him.

I also understand your caution that we can't solve the problem with only the information BP is releasing. Still, I am finding this a fascinating mystery. There are plenty of clues, including what Dr. Chu has published on the DOE website

http://energy.gov/open/oilspilldata.htm.

 

[waross]

The problem with collecting more oil at this time is topside, not at the seabed, as I understand it. Onboard one vessel there is a limit to the amount of gas that they are able to safely separate. This limit may have been reached. Onboard the other vessel, there is a limit to how much gas and oil mix may be safely flared. This limit may have been reached.
Why? It looks as if bp believed their own Bullshot that there was only 5000 BPD leaking and planned accordingly.
Usually an engineering disaster is blamed on one of the victims. In this case, the downward pressure on the share prices and the dividends may result in the share holders meting out to the directors and senior executives a just reward for the "Profit at any expense" culture that they have allowed to develop.
My sympathies are with the victims, both immediate and long term and with the thousands of good people in the bp organization who may suffer from the effects of this disaster. No sympathy for the supervisors, managers and executives who developed this culture, and not much for the shareholders who have benefitted from the extra profits generated by the risk taking over the years. I hope that pension fund managers are taking note and considering how companies achieve the bottom line instead of looking at the bottom line to the exclusion of other factors.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[docellen]

Waross, I agree with you completely, except for the part about shareholder profits. As a small BP shareholder myself, I can tell you we had no idea what was going on. We shareholders are victims also, and the few pennies of profit we gained from managers cutting corners on safety are irrelevant.

Shareholders should pay the cost of this disaster, not because we deserve to be punished, but because it is the right thing to do. As for punishment of those responsible, I think BP shareholders will see to that. The other oil companies should consider themselves lucky. I believe the problems we are seeing are industry-wide.

 

[waross]

I was on a short term high paying job (almost $5000 per week plus benifits, current and in the bank at about a 2:1 ratio) and tried to diplomatically point out to a contractor that there may be a problem with safety at a large plant. As fast as the contractor could complete the paper work, I was gone. I considered legal action, but decided not to jeapordise future employment.
A few years later I was on another short term contract with the same contractor. The same procedures were still in effect. Kept my mouth shut and kept my job. A few days after a legitimate layoff, there was an incident due to the "short cut" procedures. Fortunately no injuries, but sending men to work on an energized transformer with a flawed lock-out plan is not a nice thing to do. The owners safety department removed the contractor from site immediately, but allowed the workers to transfer to the replacement contractor. It was nice to see.
You understand my predudice.
And I didn't say no sympathy, just not much.
Remember, bp bet the lives of 11 men against your return and lost. A little pressure from pensioners on pension plan managers to do a little more due diligence may be in order.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[docellen]

MMS (or whatever it is called now) needs a hotline, where anyone can leave an anonymous tip for the inspector. The inspectors need to be experienced drillers, and know all the tricks and evasions. They should be like tenured professors, can't be fired for doing their job. The inspectors need to on the rigs, at least during critical times when a blowout might occur, and they should make all decisions involving schedule vs safety. There should never be direct pressure from the company man on the driller. All such discussions should have the inspector as an intermediary. Might even be good to keep the company man off the rig.

 

[DennisRevell]

Hi Windward, thanks for your reply. Much better than the one I got over the 'phone from Thom Hartmann a couple of weeks or so ago, who cut me short ('phone call literally disconnected) with the same 1st reply I got at the physicsforum.com website:

http://www.physicsforums.com/showpost.php?p=2778465&postcount=204.

I wonder if they're one and the same person? One must be careful, however, to remember that Thom Hartmann is the font of all wisdom and knowledge - no matter what the subject. Watching/listening to his TV/Radio program for just a short time should establish that this must be the case ...

And so to my reply to some of yours:

"Dennis, your comments are interesting and I will read the information at your links."

Thank you.

"Regarding the possibility of starting a fire in the flow at the 5000 foot depth, I haven't had time yet to review Le Chatelier's principle and the chemistry of it. Maybe it wouldn't work because of the high pressure, but if it would, I believe the fire could be managed to prevent any damage to the piping."

I think you'd need more than Le Chatelier's Principle, which is, pardon me, kind of "airy-fairy" and hand waving. You'd need to get deeper into Gibbsian Thermodynamics: Chemical Potentials, Law of Mass Action-Equilibrium Constants, Degrees of Reaction, Chemical Affinities, van't Hoff Isobar (for combustion temperature calculations), and the like. The calculations can, in principle, be done, but would be horrendous - a different one for each fraction in the gunk, then the whole lot "summed" together, or as one huge most likely intractable heterogeneous system (which is what we have here). I had occasion to (re-?)read, and understand - though a lot of the stuff is ... er .. tricky - an old copy of Zemansky's "Heat & Thermodynamics" from soup-to-nuts, beginning a couple or so years ago. I have the 5th edition, and in that the relevant chapters are Chapters 16 ("Chemical Equilibrium") to the end of the book (Chapter 18: "Heterogeneous Systems") - few in number but all "heavy" chapters. In addition a reader pretty much has to understand most of the stuff in the preceding chapters to follow the relevant materials in those last chapters!

My copy is probably unreadable by anyone else now - as virtually every page is covered in my pencilled scribblings - but they're legible to me, and so though I'm now rusty on it (as you get on pretty much anything not used every day), a quick glance prompted by your post makes enough it come back comprehensibly. And indeed the calculations would be horrible. Hence in light of a) not having information on the gunk fraction makeup b) only guestimates as to the gunk flow rate c) It being extremely likely that combustion reactions of the various gunk fractions have not been characterised under the P-T conditions at the sea floor - so you'd be guessing, for example, at a value for the Ks - the Equilibrium Constants, or at best making very rough calculations/extrapolations, I decided not to bother! Hell, even assuming if I could do it, I haven't the time to do everything myself ;-)

So I looked for a contemporary comparison: No doubt there are others, but I figured the Space Shuttle main engine combustor chamber has no problem whatever maintaining a very intense burn at a pressure of 3,000 psi. Of course, there are important differences: we're talking H2 & O2, with undoubtedly very well known thermodynamic characteristics, and a Degree of Reaction almost infinitesimally close to unity under virtually all imaginable conditions. In addition, the external pressure is 14.5 psi and not ~2,000 psi. So, this is my handwaving part: it's difficult to imagine that the Shuttle main engine would not burn its fuel well even fighting against a much higher external pressure of ~2,000 psi. Oil fractions are also normally extremely flammable - even the more exotic ones, as a quick read of the "high flammability" warnings on the more exotic HC derivatives in my garage reveals. I therefore think it more than reasonable to conjecture that the Degrees of Reaction for most of these fractions will also be close enough to unity under the conditions pertaining at the sea floor - assuming an appropriately sized incinerator chamber of appropriate geometry, of course.

In fact, I feel so strongly that this is the case, though, as said proviso'd as still being hand-waving, that currently I see more reason to be more concerned with the burn temperature being just too high. That's why the PDFs I've prepared pretty much all now insist on a refractory lining for the incineration chamber; so I'm more concerned with the "knock on" heating effect on oxidiser feed pipe(s), and now that they've cut off the broken riser (darn) the effect on what's left of the LMRP/BOP. A complication, but it may be best to provide some heat insulation mechanism between those and the incineration chamber. That's why I "lifted" Fig. 2 into the latest PDF update - that, or a variation on it does seem to give more opportunity for heat/combustion chamber insulation from the LMRP/BOP.

"If we can't collect all of the oil, either at first or after many attempts to do so, I agree that it would be better to burn it rather than allowing it to enter the water. However, burning it at the 5000 foot depth would require an enormous flow of oxygen, far greater than what would be required for the fire I am suggesting."

Yes, it would be an enormous flow. My concerns here are 1) I'm not happy about using pure O2 for likely combustion temperature reasons given above - perhaps some "happy compromise" mix between pure O2 and air - to prevent associated steel items from burning up themselves? Also I've wondered if it may be possible to feed some non-gaseous chemical high oxidiser down with the air/O2, to reduce the prodigious volume requirements for the latter? 2) The shock of the oxidiser gas flow would have to be considered - this is why I show two "balancing" oxidiser inputs in the first figure in the PDF. In addition the law of the conservation of angular momentum may be put to good use here: If the inputs are angled (looking down against the plane of the sea bed) more than shown in that figure, a vortex flow would be established. In addition to these being known to be extremely stable, lateral shock/forces on the incinerator system would be minimised (in theory would be zero).

"On the Oil Drum, I proposed that they burn all of it at the surface, if that could be done safely. This would require a tight seal on the BOP. I believe that is what they are approaching now, very cautiously, because of uncertainty about the condition of the casing below the mudline. There is much more to say about these things, too much to go into in one post."

That would be ideal. I'm forced to believe, however, given the "progress" on this catastrophe, that either i) A tight seal is impossible to achieve or ii) BP/others are now pretty well convinced it would wreck the stuff below the sea bed - which they most likely caused some damage to themselves in their, IMO, inadvisable "Top Kill" attempt.

...

"On the clathrate problem, I now have a copy of the book by E.D. Sloan that whammet listed above. I will comment later on what I find there."

Well, I can only imagine that the only thing of use would be accurate Clathrate Phase/Eutectic diagrams. Those would pretty much be the "deciders". I did some more arm-waving here, more intuitive than not, I hope: Obviously (and sadly!) blocking Clathrate build up does not occur with unrestricted flow - so the "trick" is that whatever collection method is had better not make the Thermodynamic State drift too close to an undesirable place on those phase diagrams: so (without external heating) the flow rate (and so the back pressure) can not be too much interfered with. Catch 22 somewhat.

"I also agree, if they need any equipment, requisition it now and settle later."

But according to some, even not counting the Supreme Court, that would be interfering with the "God" given rights of Corporations as living breathing individual souls ... ;-) ... .


"If you have been right about this thing all along, ... "

That may have been a slightly overenthusiastic claim on my part ;-). More specifically, I started looking at this thing because I was immediately quizzical that the 1st large dome (the 125 ton thing) appeared not to have "sluice gates" or pressure relieving mechanism of some sort, and its top seemed rather restricted. Apart from the more obvious problem of the dome becoming buoyant when the lighter that sea water gunk started to fill it, it seemed to me that the Thermodynamic State would also be changed somewhat drastically - leading, I'm convinced, to the very Clathrate build up that was alleged to be the cause of abandonment of that attempt. Indeed, whether they know it or not, and even if they do, I certainly don't expect BP to acknowledge it, their current attempts, with their "flapped" domes are a pretty convincing mimic of my "sluiced" dome "Submission#1". Cack handed attempts IMO: the smaller "dome" makes undesirable back pressure more likely. I'd guess they've figured pics. on the TV of the intitial badly failed large dome, but "sluiced", would be oh, such bad PR, even though it would probably work better. Of course, it too, would not be capable of collecting all the gunk.


"and I have no reason to doubt that since I haven't studied your proposals yet, then that is probably why you are not in a position to do much about it. Corporate culture and government agencies - should I say the human race? - do not like those who don't conform to groupthink."

That's how it feels to me! Even Bill Nye the "Science" Guy, or at least those in his orifice, must figure he's some kind of rock star, prima-donna or something ... not to be bothered by we "hoy-polloy". I E-Mailed him, and called his office - from the number given on his resume at his website - to confirm receipt and the hope that the E-Mail would be brought to his attention ('cos I realised he must get a lot - esp. after his TV appearances on the GOD). All the lady I spoke to could talk about was insisting that I tell her how I got "this number". She was all but calling me a liar even when I insisted it was on his website! I managed to avoid using expletives on that occasion, but I probably will not in any future similar situation.

"Sometimes this makes sense, for example when sea monsters and 100,000 psi gas bubbles and sinking a million ton nuclear battleship (must build one first) on the blowout are being discussed by some in this case."

Yeah, I realise and appreciate all that. But be assured I have almost literally been banging my head against a brick wall to get some attention paid to this - just one reply, for example from Prof. Chu, or Prof. Michio Kaku, say, to the effect that the combustion temp would reach 4,500 degs C, and no known materials/mechanism that would withstand that can be quickly assembled would have stopped me from pestering all these apparent rock stars (bad example: I'd have just said make a bigger chamber! ... ;-) ... ).


"But so far, I haven't seen any good ideas from those in charge either. In particular, why weren't we prepared for a blowout like this? That was assured on paper but never in practice. This is what we get from the free market ideologues who have been running things for a long time now, who believe self-regulation always works and corporations always act responsibly."

Yes, the Milton Friedmanites and the Grover Nyquisters will be lauding the "Free" Market right up to the very day it puts an end to us all.

All the Best,

Dennis Revell.

P.S: I've uploaded a file (at least I tried to) that "zengineer" posted at the innocentive website (you have to register there even just to view the threads - so I'm pretty much stopped going there). The upload should be with this post. It's extremely simple, and as I said to him in a reply there, I can't figure why it wouldn't work (well at least before BP compromised the piping/equiptment with their ill-advised "Top Kill" attempt).

 

[docellen]

We can stop all speculation about damage to the casing from pressure at the top hat. The pressure at the well head is 4400psi, and it drops at each partially-closed BOP valve, down to 2250psi in the cap (just barely above the water pressure outside the cap. See "Pressure Data within BOP" at

http://energy.gov/open/oilspilldata.htm.

Closing the vents can't add any significant pressure at the wellhead. There must be some other explanation as to why they continue to let the oil flow into the water.

I talked with a retired petroleum engineer who has written articles on methane hydrates, and he suggested there might be a problem with the water already in the oil coming from the reservoir. Unfortunately, he was not an expert in oil drilling, so he couldn't do anything more than speculate. I'm still finding it hard to believe that a small increase in pressure in the cap would cause a huge increase in hydrate formation.

 

[Windward]

Dennis, good post. I concur with your Thom Hartmann comments.

I was glad to have the combustion information. I thought I would start with Le Chatelier’s Principle, to see if that simple method would nix my idea. But if it did not, until I read your post I did not realize how much more work would lie ahead. I defer on this to anyone who has heavily annotated every page of a thermo text. Zemansky’s book sounds like a real treatise in the old style.

I have read your pdf “Undersea Flare Dome (UFD) Effective Mitigation for Gulf Oil Leak”. I see now why you are concerned about the heat, since your fire would be a lot larger than the one I am proposing. I offer this approximation: the temperature of the inside of the steel wall of your furnace would be very close to the outside temperature, since steel conducts heat pretty well. This is a rule of thumb in heat transfer, rough but useful.

For example, from the 39th Edition of “Steam” (Babcock and Wilcox, 1978): “In evaluating the overall resistance [to heat transfer], the metal resistance may be neglected without serious error.” If there is cold seawater on the outside of the furnace, and the seawater is well-circulated over the walls, then the inside metal temperature will not be very much higher than that of the seawater. I am now prepared to be corrected on this by the experts, and possibly others.

I was thinking about the space shuttle main engine also. I believe that the combustion chamber is cooled by the LOX and liquid hydrogen, by directing them through channels or piping surrounding the combustion chamber. This also heats and expands them somewhat, aiding combustion.

Concerning the pumping of liquid oxygen (see earlier posts on this speculation), a pump of sufficient pressure and flow for my proposed small fire must have been developed for the space shuttle. Your large fire would require several pumps.

You have done a lot of work on your idea and it deserves an analysis and reply from BP. The only change I would make to your pdf is to add an abstract, to explain immediately that you are proposing to burn the entire flow right at the blowout. I knew this before I read it, but for those who don’t, an abstract would make it clear.

Docellen’s point about pressures seems right. Concerning water in the flow, water that comes up with the oil and gas from a reservoir is called produced water. On the Oil Drum awhile back, someone posted a chart and comments to indicate that there is no produced water at Macondo. Hence, there would be no hydrate problem if the flow going up the riser is not contaminated with seawater, however this may be accomplished.

 

[waross]

As an alternative, how about mounting the combustion chamber close to the surface? This will make combustion much easier and oxegen supply very much cheaper.
Alternately, a small combustion at depth to generate some gas lift in the riser and enough heat to nulify hydrate formation. Then the main combustion close to the surface. And if the near surface combustion device is comprised of a primary and secondary burner the velocity of the waste gas and unberned oil exiting the primary burner may be sufficient to use a venturi to supply air to the secondary burner.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[DrillerNic]

I agree Windward, that there is unlikely to be any produced water in the flow from the Macondo well. I doubt they targetted the oil/ water contact (that's usually the target for the next well- the first appraisal well) and there hasn't been enough production to bring the oil / water contact upwards. Any water in the flow stream will almost certainly be entrained seawater.

 

[Windward]

waross, suppose a small fire at depth would make a gas lift pump work at a blowout like Macondo. All of the oil and gas and seawater will be blasting up the riser. The less seawater the better, and that would be a point of design.

Since a high velocity has already been generated at the surface, it should be possible to separate the flow with a centrifugal separator. Then the oil and water could be captured for further separation, and the gas flared. Would this not be better than burning all of the oil either at depth or higher up?

For an alternative to a small fire at depth, electric heating elements could be assembled as a screen on the bottom end of the riser over the BOP. Seawater flowing over them into the flow up the riser would pick up enough heat to prevent hydrates. The screen could be designed to keep the seawater flow to a minimum. It might be easier to send electric current down to the screen than sending oxygen down for a fire.

DrillerNic, suppose they start to get produced water, although that sounds unlikely from what you have said. I read that the temperature of the blowout is at least 150F at the BOP. If all of the flow was going up a riser that is tightly connected to the BOP - no seawater entering - do you think the temperature would drop fast enough to cause hydrates? The pressure would also be dropping, acting against hydrates. I wish I had time to do some calculations, after a long review of how to do them.

 

[DrillerNic]

Windward- if they got all flow up the riser, and even got produced water in the flow as well, I doubt if the temperature would drop enough flowing up the riser to form hydrates- separator temperature would be well above 4° or so.

The issue is when cold seawater mets free gas at high pressure- that's how you get the temeprature, pressure and composition combination to form hydrates.