Oil Spill Prediction

[Shaggy Hiker]

Yeah, I think I was once, since there were a couple dozen representatives present, which is about all that shows up for most things.

[dbasnett]

If you walk around the halls of the Capital building or the House / Senate Office buildings, the lobbyist are thick, and they are not hard to spot.

One of the first times I went into the House Chambers there was a representative giving a quite animated speech to a handful of his aids. I asked what was going on and was told that it was for the folks back home. If you watch C-SPAN and see someone giving a speech, and the camera angle never changes, that is what is going on.

[Shaggy Hiker]

While I understand the need for openness in a representative system, cameras just lead to posturing.

[Code Doc]

It all depends on how much oil is actually coming out of that pipe. The original BP estimate was 1,000 barrels/day, which became 5,000 based on a NOAA estimate. More recent analysis puts the rate between 40,000-100,000 barrels/day.

The Exxon Valdez spill was 257,000 barrels. Assuming the lower end of the range that is agreed upon by unaffiliated experts reviewing the video, the spill exceeded Exxon Valdez roughly five days after it began.

The 2-mile-deep exploratory well, Ixtoc I, blew out on June 3, 1979 in the Bay of Campeche off Ciudad del Carmen, Mexico. By the time the well was brought under control in March, 1980, an estimated 140 million gallons of oil had spilled into the bay.

That means that BP 2010 has likely already exceeded the Ixtoc I spill. The wellhead sits on 50 million barrels of proven reserves, or over 2 billion gallons. If only 10% of that emerges into the Gulf of Mexico, BP 2010 will be by far the worst oil spill catastrophy in history. Based on Shaggy Hiker's data, I think that it's already the worst.

[Spoo]

Moving, for the moment, from a math-based discussion to a
physics-based question ... how can the top-kill process work?

I understand it conceptually, well, sort of.

The mud is supposedly heavier than the oil .. ok, so far, so good.
However, the oil is under pressure.
So, the mud has to overcome the pressure as well.

If the "mud column" was 1 mile tall, the pressure at the bottom would be quite large
But, it can't be more than about 20 feet (the height of the blow-out preventer).
So.. how on earth can the "mud column" overcome the pressure of the rising oil?

Spoo

[Shaggy Hiker]

It's probably considerably more complicated than that. There may be friction with the pipe walls to take into consideration, and interactions between the particles in the mud such that a force upwards on one particle is spread to all the particles above it, and outwards to the walls of the pipe. After all, if you were to plug a garden hose with a wad of chewing gum, it would take greater force than the weight of the chewing gum alone to dislodge it. Of course, in this case, there is considerably more force, so there are probably several possible scenarios.

[Spoo]

I like that garden hose analogy..

My understanding is that they are injecting the
mud from the sides of the pipe.

Hence, with the garden hose analogy, the wad
of gum would be "inserted" at the side of the hose,
say, 5 inches from the end of the hose.

For this scenario, the gum will not be allowed
to come back out from the side of the hose.

However, given the water flow, wouldn't the gum
just get pushed along by the water and squirt
out the end of the hose too?

[Shaggy Hiker]

I think everybody is hoping that will NOT happen.

I haven't been clear on how the top kill process works. I know they are working on drilling down beside the pipe with the intention of slant drilling into the pipe and trying to kill it from there, too, but I thought that was the process that is not slated to be completed until August.

[dbasnett]

This is my understanding of what it looks like

|  |
|  |
|  |
|  |
|  |
| --------
|  < MUD
| --------
|M |
|U |
|D |
|  |
|O |
|I |
|L |
|  |
|  |
|  |

They are injecting mud at pressures that cause some of it to flow down the hole. What you see on TV is the mud that isn't making it down.

Mr Obama made it clear in his Press Conference an hour ago that the government was taking BP's word for just about everything.

[Spoo]

Shaggy

I think the "August" effort is effectively a bottom-kill approach.

My understanding is that they hope to drill down to the oil itself,
(ie, 1 mile of water and 4+ miles of bed-rock), and plug the
pipe from the bottom.

[Spoo]

DB

Nice sketch .. let me add my 2 cents

_______
   |         |   |
   |         |   |
 20 ft       |   |
   |         |   |
back-flow    |   |
preventer    |  --------
   |         |  < MUD   <<  top-kill
   |         |  --------
   v         | M |
-------------| U |--------------------------- sea bed
   |         | D |
   |         |   |
   |         | O |
4 +/-        | I |
miles        | L |
   |         |   |
   |         |   |
   |         |   |
   v         |   |
------------ |   |----------------------top of oil resevoir

                     << bottom kill

[dbasnett]

If you are asking is that what they are going to do, the answer is yes. By the end of the summer the other holes should be done.

[Spoo]

DB

Actually, it was for Shaggy's benefit... but, thanks anyway

Spoo

[dbasnett]

DB

Actually, it was for Shaggy's benefit... but, thanks anyway

Spoo

Shaggy, I think, understood the slant drill / seal method. It was the top kill he didn't understand.

[Spoo]

DB

OK, maybe I'm the one that doesn't understand the
slant drill / seal method , aka the "August" method
(ie, the one BP won't be able to complete until August)

Shaggy seems to suggest BP will drill to mid-depth
in the bedrock, and thus inject mud from the side.

My understanding was that BP will drill all the way thru
the bedrock, and inject mud from bottom.

Who'd you say has it right?

Spoo

[dbasnett]

I'd say, somewhere deep, but it doesn't have to be the bottom. It is about pressure, so anywhere that they have the advantage and can get a good seal will suffice. Surely you have noticed that they do what is in the economic interest of BP, and drilling is expensive, so shallower is better. One day when this is all over, and they allow drilling again, they will go right back down the hole and get the resources that they know are there.

It is not unusual for a well to pass through different hydrocarbon products. The way it was explained to me was that they drill down and extract a resource. They then cement that level and move up to the next resource, and so on.

[Shaggy Hiker]

I have recently heard that the slant drill method is intended to be pretty deep, possibly down at the oil level.

So top kill has failed, and we are about to see Son of Containment Cap. I hope this one works. It's some fascinating attempts, I just wish the cost of failure wasn't quite so high.

I should also say that the amount of effort you people put into text based graphics is both impressive and absurd at the same time. Nice job, though.

[dbasnett]

I have recently heard that the slant drill method is intended to be pretty deep, possibly down at the oil level.

So top kill has failed, and we are about to see Son of Containment Cap. I hope this one works. It's some fascinating attempts, I just wish the cost of failure wasn't quite so high.

I should also say that the amount of effort you people put into text based graphics is both impressive and absurd at the same time. Nice job, though.

Absurd? Me? Hardly ever.

[Spoo]

Absurd? Me? Never

[dbasnett]

Some classic character art (select image from upper right dropdown)
http://www.rtty.com/gallery/gallery.htm

[NeedSomeAnswers]

Is it a requirement that oil spill clean-up operations like military operation have to have daft names ?

i am just waiting for "Operation Backshaft" and "Operation Giant Squid" in which the first one they use a pipe to fire oil at the oil in a effort to push it back into the hole, and the second were they catch a giant squid and ... well you get the picture.

[dbasnett]

Is it a requirement the oil spill clean-up operations like military operation have to have daft names ?

i am just waiting for "Operation Backshaft" and "Operation Giant Squid" in which the first one they use a pipe to fire oil at the oil in a effort to push it back into the hole, and the second were they catch a giant squid and ... well you get the picture.

I think so. Big picture what they are trying to do they call "Shut In". The first orientation I went to they told us never, never, push the "Shut In" controls that were everywhere.

[NeedSomeAnswers]

I think so. Big picture what they are trying to do they call "Shut In". The first orientation I went to they told us never, never, push the "Shut In" controls that were everywhere.

What is "Shut In" ?, last i heard they were carrying out "Operation Top Hat 2" which could almost be a film sequel !

[dbasnett]

What is "Shut In" ?, last i heard they were carrying out "Operation Top Hat 2" which could almost be a film sequel !

Shutting in is lowering the amount of product produced to lower than available, an emergency shut-in is an attempt to set the amount produced to 0.

Every attempt since the very beginning has been an emergency shut-in attempt.

[NeedSomeAnswers]

Every attempt since the very beginning has been an emergency shut-in attempt.

Aha i see, its just TopKill, TopHat, Junk Shot e.t.c sound far cooler for the Media.

[Shaggy Hiker]

What is "Shut In" ?, last i heard they were carrying out "Operation Top Hat 2" which could almost be a film sequel !

Yeah, for Monopoly, The Movie.

And Junk Shot sounds like something out of adult films.

[dbasnett]

Hey, it is the Stock Predictor!

[Shaggy Hiker]

When I wrote that, I was thinking that perhaps I should add the punchline to the post, but decided against it, since it was more fun letting people think about it. After all, it was kind of a lame punchline, so the guesswork was all the entertainment people would get from it.

[Spoo]

Guys

OK, now that Top Kill died, let's examine why --
...the mud column wasn't "heavy" enough.

Maybe this would work...

---------------------------------------------- sea level
   |
 4000 ft
   |      
-------------
   |         |   |
   |         | M |
   |         | U |
   |         | D |
 1000 ft     |   |
   |         |   |
new pipe     |   |
   |         |   |
   v         |   |
-------------|   | 
   |         |   |
   |         |   |
 20 ft       |   |
   |         |   |
back-flow    |   |
preventer    |  --------
   |         |  < MUD   <<  top-kill
   |         |  --------
   v         |   |
-------------|   |--------------------------- sea bed
   |         |   |
   |         |   |
   |         | O |
4 +/-        | I |
miles        | L |
   |         |   |
   |         |   |
   |         |   |
   v         |   |
------------ |   |----------------------top of oil resevoir

If they were to add open pipe at the top of the back-flow preventer, then

• no real difficulty
  
  • not dealing with pressure in pipe since top is open
  • pipe segments could be made neutrally-bouyant by adding air-bag ring at top of each segment
  • a "simple" collar joint would probably suffice
• then, inject mud at back-flow preventer (as before)
• this time, the mud column can develop enough weight to overcome oil pressure

Piece of cake.

Anyone care to venture how tall the pipe-stack would need to be?
My guess is 1000 ft. Could be much less.

Spoo

[Shaggy Hiker]

Suppose you were to taper the pipe that was added on, thereby creating a narrower vent? If the mud were sufficiently viscous, you wouldn't need as much, as it would not compress well getting out the vent. If you were to then taper it further, you would decrease the mud needed. Of course, you could taper it all the way, or just add a valve that could be closed, and you wouldn't need any mud at all. All you would need would be a fairly tight seal between the new pipe and the old. Apparently, that can't be done.

However, if the idea is that a mud seal would also be able to wedge into any gap between the old and new pipe, the concept would have merit...IF you could get enough mud into the pipe fast enough that it would plug the pipe before it was forced out by the oil. The injection volume would have to be pretty high, or else you are effectively repeating Top Kill.

Of course, if you CAN add a length of pipe onto the top of the existing pipe, then why not make the pipe long enough to reach the surface. Then, even if the oil does come out, you would still be able to collect it....which is what is now being called Top Hat II.

[Code Doc]

Spoo, I think the problem is directly related to the enormous pressure that the oil is overcoming to escape. The seawater alone is exerting 2300 psi on the wellhead and the oil is laughing at that as it escapes. It also laughed at the topkill approach.

Try to imagine holding back the pressure of an ordinary garden hose with something heavy over the top of it. Even in that rather trivial case, you need a cap with screws and a good washer seal to stop the water from escaping. Trying to do even that with the hose operating is a chore to say the least.

The heavy mud also tends to be less heavy due to the water's buoyancy force. I never even gave the topkill a 30% chance of working.

[dbasnett]

Should one of the things that come out of this be that the government provides, tests, monitors, etc. blow-out preventers?

I would want it to work like brakes on trains, some kind of pressure from above keeps the hole open, remove the pressure a valve closes.

[Spoo]

Doc

I agree with your garden hose analogy ... sort of.
Let's look at 3 scenarios:

Givens:

1. hose is point straight up
2. water pressure is 100 psi
3. hose's cross-section area is 1 square inch
4. water weighs 64 lb/cubic foot, or 0.037 lb/cubic inch

Calculation: To obtain a water column that has a 100 psi
pressure at its base, you'd need 100 lbs of water (since the
area of the hose is 1 sq-inch)

• 100 / 0.037
• = 2,700 inches
• = 225 feet

Scenarios:

1. Plug: Try to screw a nozzle that is closed to end of hose -- darn near impossible.
   Water just squirts out the sides, resisting your attempts to "plug the hole"
2. 225-ft hose: Try to screw a 225 foot hose (that is dangling straight down from a tree)
   to the end of the hose -- again, darn near impossible, for similar reasons.
3. 1-ft hose: Try to screw a 1 foot hose -- seems like this would be the easiest to do,
   as water would only need to overcome the 1-ft height to squirt freely out the
   open end. Repeat this 225 times.. would get progessively easier.

We agree that Scenario 1 is virtually impossible.
Likewise, Scenario 2 very tough -- and this equivalent to Top-Kill 2

Nonetheless, if we had more than a 225-ft tall hose, do we at least
agree that no water would escape from the top open end?

Spoo

[Spoo]

DB

Good ideas.

Along the lines of your train brakes concept, I'd take it
one step further -- assure that it is truly "fail safe."

Did you happen to catch the 60 Minutes show a few
weeks back? Apparently, the drilling crew tried to pull
up the drill string while the anular ring in the back-flow
preventer was "locked", effectively destroying the
anular ring (bits of rubber were seen to come out of
the drill string) -- or at least something along those lines
happened. My understanding is that this event is what
damaged the back-flow preventer.

Lesson: make it impossible to do that.

Spoo

[abhijit]

The Government has reeled in James Cameron for advice on the Oil Spill.


This was on news this morning.

[Spoo]

Abhi

LOL ... btw, The Abyss was a great flick.

Spoo

[Code Doc]

Spoo, this is an interesting engineering discussion to say the least. Doing all this above ground would probably be a piece of cake, but trying to do it 5,000 feet underwater has proven imposible.

The sea water exerting 2300 psi on the wellhead is actually preventing this leak from becoming a virtual geyser, but it also made the topkill mud too light to do its job because of the buoyancy force. Even if they got 100 lb/cu ft mud, the water suddenly made it 37 lb/cu ft equivalent. So the oil pushed it right back out.

I'm not sure what the oil pressure against the sea water actually is. If I knew that, and the diameter of the well head opening, we might be able to calculate the height of the column required and then add another 100 ft for good measure. I think you have to assume that the absolute oil pressure is about 2500 psi and work from there, but I assure you that I am firing from the hip.

Has BP measured and announced the absolute pressure that the well head is exerting? Anyone know?

[Shaggy Hiker]

And does anyone believe them? They've low balled every estimate so far....except one. Apparently, in the pre-drilling documentation, they estimated that the flow from a blowout would be in the vicinity of 160,000 barrels per day, which is considerably higher than the highest estimate of the current flow.

[Code Doc]

And does anyone believe them? They've low balled every estimate so far....except one. Apparently, in the pre-drilling documentation, they estimated that the flow from a blowout would be in the vicinity of 160,000 barrels per day, which is considerably higher than the highest estimate of the current flow.

SH, I understand your frustration and so do thousands of others, including petroleum engineers, mechanical engineers, scientists, etc. This whole catastrophic event has been hush-hushed since the explosion. We are only allowed to read what BP and the feds allow us to read.

All of the potential solutions contain risk. Some are far worse than others. Nuclear detonation 5,000 or more feet below the surface has never been attempted. We are treading on untested ground and thin ice at the same time. I guess they never thought about that when they started to drill.

[dbasnett]

SH, I understand your frustration and so do thousands of others, including petroleum engineers, mechanical engineers, scientists, etc. This whole catastrophic event has been hush-hushed since the explosion. We are only allowed to read what BP and the feds allow us to read.

All of the potential solutions contain risk. Some are far worse than others. Nuclear detonation 5,000 or more feet below the surface has never been attempted. We are treading on untested ground and thin ice at the same time. I guess they never thought about that when they started to drill.

Old naive me thought that was the governments job, make sure the catastrophic couldn't happen. How many failures led to this? If the government wasn't so cozy with the industry would this have happened? And the one thing that isn't rocket science, protecting the coast from the oil, the government can't even handle that.

It is going to be a long time before an incumbent politician gets my vote. Businesses are, and have always been, willing to push the edges, just as far as the government lets them. These past couple of years have shone a bright light on who controls the country. If Mr. Lincoln were writing today it would be "...and that government of business, by business, for business, shall not perish from the earth."