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"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO, BP

**********************
"Being GREEN isn't easy" ..Kermit

 
Flow estimates seem to be "sound bites of the day" for the ABCNNBCBS talking heads - and their "chosen" academic experts.

Rah.

I read everything on TV and the net from 12,000 bpd to 100,000 bpd.

But my calc's for flow velocity seem badly off compared to the very high pressures (22-26 kpsi) above - from readers whose information I trust much more than the TV by the way.

Ignore the 100,000 bpd high number and assume 20,000 bpd.

35,000 gph
1.30 ft3 per second

Assume the 21 inch pipe (wall thickness = ??) has 314 sq inch flow area => get 2.18 ft2
Velocity = 1.30 ft3 per sec/2.18 ft2 = 0.60 ft/sec

But that seems much too low for the pressures given.

Something I'm missing?

 
Isn't the actual flowing pipe inside the case a 9" diameter? I thought I heard that somewhere.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO, BP

**********************
"Being GREEN isn't easy" ..Kermit

 
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.

David
 
I understand that in all fairness estimated initial oozing out flow rate might have been around 20000~25000 bpd ever since the tragic catastrophe.

As liquid entrained un-controlled mixed methane flow images make the estimations wavered.

However with multiple openings/leakage points this may at time go around 30-35000 bpd,but remotely beyond.

The media reported figures of around 85-95000 bpd though seem somewhat exaggerated.Since accurate judgement very difficult to ascertain from the images,I believe.

Best Regards
Qalander(Chem)
 
One research ship is taking underwater samples at various depths to try to determine quantity and extents of "plumes". That may wind up telling more about escaped quantities than actually trying to estimate present flowrates and guessing about what the average might have been since day 1. Those guesses have been all over the place with many probably having been just thrown out there with considerable self-interests to protect on behalf of all sides.

Until we get a good calculation from the well I can touch, see and eat, I'll go with my estimate from pump capacity at site. If they can pump up to 80,000 BBLS per day down, well than we should be thinking that 80,000 BBLS could be easily be flowing out. More or less. The only variation from that would be via the gas to liquid ratios that perhaps go back and forth from time to time. I'd just work with the maximums for damage projections, equipment requirements and resulting cleanup response and let the lawyers sort out the actual GTR at some later date.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO, BP

**********************
"Being GREEN isn't easy" ..Kermit

 
Dear BigInch
I honor your conception always as highly valuable and among most accurate one's.

Undoubtedly for considering the environmental pollution and damages this approx. 80000 bpd quantity ma be considered as worthwhile.

I strongly second you indeed

Best Regards
Qalander(Chem)
 
what you all forget about is that its not a 21" line, its about a 9 to 11" ID line down hole. I ran the verticle simulation model and depending on the GOR, the actual oil (oil is defined as those HC chains that are not vapor at 80F and 14.696psi) is no more than 20,000 bbls/day. More likely to be in the 15,000 bbl/day.
 
BP apparently was able to cut the pipe with a hydraulic cutter today, but if they could cut it that way, why couldn't they crimp it closed that way?

TTFN

FAQ731-376
 
Thank you.

Can we tell why the original attempt at using a "capture envelope" and (later) piping the oil failed?

Bad bottom conditions (interferences) that prevented it from landing correctly over top of the well head and then sealing to the bottom?
 
Both the riser and the drill pipe are VERY hard steel. The chance of the pipe crimping shut at the ocean temperature instead of failing spectacularly is very low. If they were to somehow do that (maybe by heating the pipe first? or some other magical method), the transition of 30[°]F pipe from 8k psi to over 20k psi in a few seconds would certainly cause brittle failure.

I was curious as to why they didn't cut the riser flange instead of cutting the pipe above the flange. Seems like that would have been less likely to distort. I just saw the cut off end and it is pretty ugly (the shear cut is a foot or so above the saw cut and sealing it is going to be fun, it doesn't look nearly as bent up as I expected).

David
 
They supposedly cut as far away from the BOP as possible to give themselves some "error" room, i.e., if that failed, they would still have some usable pipe to work on. There was still supposedly the option of dropping another BOP on top of the existing one.

TTFN

FAQ731-376
 
zdas04 (Mechanical)
26 May 10 12:46
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.

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

---...---...

Based on that, outward force would be =
3.14/4*(5.625^2) * (15,000 psi) or about 375,000 pounds.
(625,000 lbsf counting reservoir pressure)
"squeeze off" flow, you'd have to counter that net force - though admittedly, you'd be squeezing the flow into an ever-decreasing nozzle-like shape, plus the force to crush 21 inch pipe collapsed, then the force to crush the inner 6 inch pipe to completely collapsed.

But if you squeeze the pipe "almost shut" you still won't have stopped the flow, and now you have nothing available to attach the permanent solution to. Unless you dig out more unbent pipe from under your collapsed region. And that "good" pipe has un-isolated oil pressure behind it.
 
I'm not sure the final cost is linearly proportional to the number of gallons released. There is an upper limit on how much it costs to influence elections, politicians, judges, journalists, and to support a strong legal defense.

Ultimately the decision on the reibursed costs will be a legal/political decision, and such decisions are not neccesarily rational or predictable.

It seems more likely the company will be spun-off and sold in pieces to competitors long before the legal sut has settled. That spin-off process is great for losing evidence .
 
Dear BigInch
How do you consider relevance of my 3rd June post estimations are they now somewhat showing reasonable rationale or what?

Best Regards
Qalander(Chem)
 
Of course its really hard to say precisely. My gut feeling is that it was probably close to 60K BOPD at one time, primarily because I counted the number of times Hayward glanced up and to the right during one interview back then. Then another time, one guy always looked down when he said 5000. I gave it 10k for each glance, and I really don't think they'd be out there in 5000 ft of water for only $1MM a day anyway. I'd have thought it would take something more like $ 5MM to get really interested. 20,000 BOPD would be an absolute minimum. OMG. Isn't it so creepy that 5,000,000 / $75/bbl = 66666.66666666666666666... Man that can't be no coincidence!
a16.gif


"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit[frog]
 
iTV just says that Cameron is going to try to slap a muzzle on Obama. Too many pension funds at stake now to sustain that butt-kicking retoric. This could be the start of some good action.

"We have a leadership style that is too directive and doesn't listen sufficiently well. The top of the organisation doesn't listen sufficiently to what the bottom is saying." Tony Hayward CEO BP
"Being GREEN isn't easy." Kermit[frog]
 
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