"J. D. Slocomb" wrote in message
...
On Sat, 10 Jul 2010 18:43:52 -0400, Wes
wrote:

"Bill Noble" wrote:

for those interested, the Skandi Neptune video feed is showing what's
happening as BP replaces the cap on the blowout preventer and takes other
action - it's pretty interesting some times, boring at others. If you
don't
have the sites bookmarked, look for 'spillcam" or go here
http://globalwarming.house.gov/spillcam


The page on Rep Markey's site was smaller than normal. I went here to
pick a non-embeded
web stream.

http://www.bp.com/genericarticle.do?...ntId=706 2605

I hope this attempt works.


From what I've read, the BOP had one blind shear that a joint of pipe
could foul. It
would seem that a second shear would have been plain common sense. My
automation systems
use dual path circuits to control control power to things that can hurt
one. Single point
failure in a BOP is idiotic. JMHO.

Wes

The usual configuration is one set of shear rams, a second section
with pipe rams and finally the annular "bag" BOP that is usually the
top set. So the congenial setup is three separate BOPs. One set on the
top that can close around various diameter tubulars, a second set to
close around the drill pipe and finally the shear rams that are
capable of shearing off the drill pipe, although usually only between
tool joints (at each end of a joint). So there are usually three
separate and distinct BOP's installed. Each one with its own closing
system.

This is how a land rig is configured. For sub-sea the BOPs may be
configured as one large device but I believe that the three separate
systems are still incorporated into the device.

Cheers,

John D. Slocomb
(jdslocombatgmail)

Sitting a BOP on top of a piece of pipe topside is fun enough. Under a mile
of water with cameras, it must be really fun. Those things are huge and
heavy.

Steve

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