Squeeze / pinch the oil-pipe closed (why didn't they listen to me?)

Why BP didn't pinch the pipe with hydraulic device to close or slow th
spill? (sufficient clamping force would close any steel tube tight).
had this idea for some time now. After I googled it I saw there ar
also other people with this idea.

• Issues with this idea
- - - - -
Static oil/gas pressure difference could be the reason why. If it i
higher than pipe wall can handle (one inch thick, right?) then there i
no way to 100% stop the flaw AFTER blowout preventer. Pipe ruptur
shouldnt be the issue before BOP. I don't know exact pressure figures
My calculation shows that static oil/gas pressure difference is no
problem if it is smaller or equal 4*S*W/D, whe S=steel strength, W=tub
wall thickness, D=inner diameter of tube. But it could be irrelevant i
flaw is supposed to be stopped during normal use at some valve afte
blowout preventer since it this case tube is sufficiently dimensione
to withstand static pressure difference.

Although static oil/gas pressure difference could really be enormous
dynamic pressure must be many times smaller. Why? Because viscou
resistance rises with square of speed. And flow needs speed. After fe
miles of viscous traveling inside pipe, dynamic pressure will dro
significantly. Here lies beauty of this solution: clamped section o
pipe will act as resistance valve. In other words, if speed gets to
slow, pressure will rise and open the pinch as much as needed. It wil
reduce flaw significantly and remaining spill they can pick with "to
hat" or whatever.

Another problem could be behavior of steel at corners of pinched pip
(cracks because of exceeding of steel elongation capacity). This one i
easy tested on actual tube if one has sufficient clamping force. If not
it can be tested at smaller scale model (diameter/tube wall ratio shoul
be the same). This is what I will try to do. Even if pipe cracks at th
ends, there are measures that can prevent or reduce this cracking. I
should be interesting...

• Seeing is believing
- - - - -
I did pinching test on smaller scale tube. Absolute dimensions don'
matter for principle testing as long as relative proportions are kept
Tube outer diameter was 60.3 mm (2.374 in) with wall thickness 4.8m
(0.189 in) making ratio of outer diameter (o.d.) to tube wall equal
12.56. As far as I know raiser pipe has o.d. 21 inch and wall 1 inc
with ratio 21.00. Therefore my test tube was "thicker" and more pron
to cracking when pinched flat than the actual raiser pipe (this is tru
as long as material of both pipes have same elongation capacity)
Material of test pipe was low carbon steel (S235 or equivalent) wit
theoretical elongation at break somewhat higher than 20%).

I used my company 100t press. I flat pressed two pipe specimens: on
small slice and one longer segment. And it was clear success! Pipe wa
closed shut with no material cracks.

Pipe was closed tight with relatively small force (around 50t). As lon
as force is applied it remained completely shut. I made photos an
video. Below is just few photos. More photos and video on link here
Also I will upload video of pinched tube on youtube. Here is forum t
discuss. Stay tuned...

• How much clamping force is needed for the real thing?
- - - - -
Initial fazes of pipe pinching go without much resistance. The las
part when pipe is crushed shut requires serious force. Based on scal
ratio from my experiment I think sufficient force for 21 inch pipe wil
be 435 t. This should be no problem.

pictures and video:
http://www.kontakt-ing.com/oil_spill_pipe_pinch.html

 

Heard today BP finally stop the flow of oil




They placed a large wedding ring over the pipe and the well stop producing.

 

Can anyone say "O Rings"...Like space shuttle disaster O
RINGS.Management is always management.BAD