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BP is cutting the riser right now!
BP.com ^ | 05/31/2010 | BP

Posted on 05/31/2010 2:38:39 PM PDT by omega4179

Very interesting.

(Excerpt) Read more at bp.com ...


TOPICS: Business/Economy; Extended News; US: Louisiana
KEYWORDS: bop; bp; canada; chomper; fumbles; livefeed; oilspill; topcap; topkill
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To: maxsand

I agree.. I think they’re just checking the overall well integrity with the addes backpressure of the cap.

Most likely, have not started trying to make the seal... yet.


4,301 posted on 06/03/2010 7:48:54 PM PDT by SomeCallMeTim
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To: Rumierules

7th


4,302 posted on 06/03/2010 7:49:06 PM PDT by luckybogey
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To: Rumierules
It looks bad now but they’ll get it all locked down in place and the leaks should stop. A pipe and hose will carry the crude oil and gas to a tanker above.
4,303 posted on 06/03/2010 7:49:38 PM PDT by Errant
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To: Errant

That is what we all are looking for, but I would really not count chickens before they hatch here.


4,304 posted on 06/03/2010 7:50:43 PM PDT by emax
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To: maxsand

agree


4,305 posted on 06/03/2010 7:51:04 PM PDT by Errant
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To: nascarnation

You don’t see the entire BOP rocking back and forth?


4,306 posted on 06/03/2010 7:51:53 PM PDT by Royal Wulff
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To: maxsand

It turns out, apparently, there is no seal.


4,307 posted on 06/03/2010 7:52:29 PM PDT by Royal Wulff
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To: Royal Wulff

so.. what is this they are spraying? More Methanol? Does this mean, they have methane rock problems again? Or, are they conditioning the O-ring before making the seal?


4,308 posted on 06/03/2010 7:53:59 PM PDT by SomeCallMeTim
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To: editor-surveyor; Red_Devil 232

See a more technical discussion here on an engineers news group:

http://www.eng-tips.com/viewthread.cfm?qid=272697&page=1

Relevant quotes - from engineers I trust far more than anyone on ABCNNBCBS on that thread:

“Based on an analysis of the fluid velocity out the vent, one of my friends at BP estimated a flowing “wellhead” pressure over 15,000 psig. That makes reservoir pressure in the neighborhood of 25,000 psig.

People keep saying “why can’t they just stick a plug in the pipe?”. It would be much like hanging a plumb bob on the end of a string and trying to force it into the end of an operating power washer.”

“I think the 25k bottom hole pressure estimate is pretty reasonable. I got 22.5 myself, but probably a little low because I didn’t add the 2166 psi water pressure (or the 14.7 psi atmospheric pressure).”

“The riser is 21” OD, 1” wt (19” ID). The drill pipe is 6-5/8 OD, 1/2” wt (5-5/8” ID).

No one knows where the drill pipe ends as far as I can tell (there seems to be a lot of confusion about this, they can’t tell where the bit was when the elevators stopped due to the explosion). I would assume that the flow out the end is both annular and drill pipe, and the the flow from the holes in the riser are just annular.”

...-—...-—...-—

My own calc’s follow:

Assume “only” 6000 psi flow from a 21 inch diameter pipe with 1 inch walls:

Inside diameter of the outside pipe = 19 inches, area = 283 sq inches.

Outward force = 283 x 6000 = 1,700,000 pounds force = 850 tons.

(Now, some experts think the pressure inside the inner pipe is 15,0000 psi. Once the outside pipe is plugged, this pressure from the inside pipe fills the outside pipe and must be resisted:

15,0000 x 283 sq inches = 4,245,000 pounds force or 2122 tons.

So any theoretical “plug” anyone on TV is talking about must not go only be able to go back INTO the hole against 850 tons of force coming OUT of the hole, but it must (somehow) grip the walls of the pipe and continue to resist those 2122 tons of force after it is down inside in the hole.

Crimping the pipe cannot stop the flow completely, but it could reduce it - the crimped pipe however will lose its ability to resist the inside pressure, and so is likely to crack completely open up and down the pipe at the crimped point. Cracking is particularly possible at the cold temperatures down 5000 feet below.

Crimping force: There are many complications in calculating the actual crimping (collapsing and folding and buckling and bending and shearing (cutting) the steel are all going on at the same time. As a rough estimate, think of the force needed to simply shear an equal flat plate of simple steel.

Assume 70,000 psi shear strength. Area of metal of the two pipes that need to be sheared = pi(r_outside^2 - r_inside^2)

= 3.14 *(3.3125^2 - 2.8125^2) + 3.14 * (21^2-19^2)
= 9.616 + 251.2
= 260.8 sq inches

Force to shear an equal strength plate (which is related to force to crimp the pipes but isn’t exactly equal to it) =

70,000 psi * 260.8 sq inches = 18,200,000 pounds force.

And this force must be applied in that single limited area of the crimp - you can’t spread it out over a wide area.

(Note: I don’t know the actual strength of the BP drill pipe - Cheap steel is only 36,000 pounds strength, but that type isn’t used (shouldn’t be used) for drill steel.


4,309 posted on 06/03/2010 7:54:15 PM PDT by Robert A Cook PE (I can only donate monthly, but socialists' ABBCNNBCBS continue to lie every day!)
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To: SomeCallMeTim

Dispersant


4,310 posted on 06/03/2010 7:54:25 PM PDT by Royal Wulff
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To: Royal Wulff

Sure there is. It is evenly distributing the oil plume around the entire cap.


4,311 posted on 06/03/2010 7:55:02 PM PDT by Pan_Yan
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To: Robert A. Cook, PE

Note to self - Correct 15,0000 to 15,000 psi internal pipe pressure.


4,312 posted on 06/03/2010 7:55:23 PM PDT by Robert A Cook PE (I can only donate monthly, but socialists' ABBCNNBCBS continue to lie every day!)
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To: Errant

The leak that looks real bad must be a relief that they have opened so that the hat can be piped and sealed?


4,313 posted on 06/03/2010 7:55:25 PM PDT by refermech
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To: SomeCallMeTim

Spraying dispersant.


4,314 posted on 06/03/2010 7:55:57 PM PDT by Red_Devil 232 (VietVet - USMC All Ready On The Right? All Ready On The Left? All Ready On The Firing Line!)
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To: emax

Even if this seal doesn’t work or the pipe is too small, they can replace them. As long as the integrity of the well is good, they can fix the rest in short order.


4,315 posted on 06/03/2010 7:58:51 PM PDT by Errant
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To: Errant

That is ture, I just meant that there are an endless number of ways it can still go wrong. I personally would feel bad about jinxing it at this point, maybe that is just me. We can both try to keep up hope of course. At least it seens the seal has not broken yet and the oil has not completely broken it yet. Unless it just happned now.


4,316 posted on 06/03/2010 8:00:37 PM PDT by emax
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To: emax

This is true, sorry about that. And also, it is also cuase for great concern since any and all delays they have at this point are going to lead to big political and economic consequences.


4,317 posted on 06/03/2010 8:01:46 PM PDT by emax
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To: emax

*Cause for concern, damn it, now I’m getting so tense I can’t type worth crap


4,318 posted on 06/03/2010 8:02:25 PM PDT by emax
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To: refermech

It’s leaking out around were the top hat sits on the BOP. A seal if there is one would prevent this if inflated or top cap locked down. According to info above I’m now not sure that this design of the top cap included a seal. I’m not sure why they wouldn’t. If pressure was a concern then just leave the top valve open but then you might have blockage from methane crystal formation.


4,319 posted on 06/03/2010 8:05:27 PM PDT by Errant
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To: Errant

This is getting stranger now. I had thought just an hour ago they were getting ready to put a seal on and that is what the O Rings and stuff were for. Did they actually not have a seal to begin with, or just now get rid of the seal ? Just when it can’t get crazier.


4,320 posted on 06/03/2010 8:09:16 PM PDT by emax
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