dnwiebe@cis.ohio-state.edu (Dan N Wiebe) (03/13/91)
From: dnwiebe@cis.ohio-state.edu (Dan N Wiebe) The following has got to be a dumb idea, because nobody does it, but I'm curious as to why it's dumb. Back a Herky-bird or some other aircraft with a rough-field capability and lots of prop- or jet-wash up close to a burning well, in order to blow the rising smoke and fumes over to one side. Then have one of those big twin-rotor Chinook choppers haul a large hollow steel hemisphere to right over the well, and lower (or drop) it to the ground. 'Twould seem that this course of action might keep oxygen from the fire long enough for the hot things to cool off, at which point the big bowl could be removed and the well capped. I assume that more oil would well up under the bowl, but if it was heavy enough, it seems that the oil would stay under there until the bowl was full (cut a small hole in the top to let out the air), and act as a coolant. Of course, maybe the downblast from the Chinook would interfere with the backblast from the Hercules and the smoke would smother the Chinook operators; in that case, replace the Chinook with a big crane. What's wrong with this picture? Dan Wiebe [mod.note: I'd think that any steel bowl a Chinook could lift would be floated away by the rising oil... just my guess. - Bill ]
gary@gatech.edu (Gary Coffman) (03/18/91)
From: ke4zv!gary@gatech.edu (Gary Coffman) In article <1991Mar13.004310.8409@cbnews.att.com> dnwiebe@cis.ohio-state.edu (Dan N Wiebe) writes: >in order to blow the rising smoke and fumes over to one side. Then >have one of those big twin-rotor Chinook choppers haul a large hollow >steel hemisphere to right over the well, and lower (or drop) it to the >ground. 'Twould seem that this course of action might keep oxygen from >the fire long enough for the hot things to cool off, at which point the >big bowl could be removed and the well capped. > What's wrong with this picture? >Dan Wiebe >[mod.note: I'd think that any steel bowl a Chinook could lift would >be floated away by the rising oil... just my guess. - Bill ] Oil wells vary from zero natural pressure to over 2,000 PSI. The ones in Kuwait tend toward the high end of this scale. Now the wellhead is a mass of junk so you would need a hemisphere of between 10 and 50 feet diameter to have the rim touch ground all around and make a seal. This would result in a total pressure against the hemisphere of between 226080000 and 2826000000 pounds. The hemisphere would have to be heavier than this to avoid being pushed off. No helicopter or crane can pick up this much weight. Considering that the soil of Kuwait is very sandy, just making a seal with the ground that could withstand 2000 PSI with- out blowing out would be very tricky. If you don't get a good seal, the flames just start up *around* the edges of the dome. A new technique will be tried in Kuwait to put out the fires. A very large dry ice making machine will be brought to the site and dry ice in large quanities will be pumped over the wellhead. The combination of the intense cold and the boiling gaseous CO2 is expected to put out the fire and cool the junk so it won't relight. This has been tried on small fires here in the states, but this will be the first time it's tried on a high pressure well fire. Regardless of how the fire is snuffed, the major problem is clearing away the junk and getting to undamaged casing so that a cap valve can be put in place. One spark during this process and *VOOM* the fire starts again. By keeping the wellhead smothered in a blanket of CO2 during the capping process, it's hoped to make this operation much safer. Gary
chidsey@smoke.brl.mil (Irving Chidsey) (03/20/91)
From: Irving Chidsey <chidsey@smoke.brl.mil>
In article <1991Mar18.134342.18503@cbnews.att.com> ke4zv!gary@gatech.edu (Gary Coffman) writes:
<From: ke4zv!gary@gatech.edu (Gary Coffman)
<
<A new technique will be tried in Kuwait to put out the fires. A very
<large dry ice making machine will be brought to the site and dry ice
<in large quanities will be pumped over the wellhead. The combination
<of the intense cold and the boiling gaseous CO2 is expected to put out
<the fire and cool the junk so it won't relight. This has been tried
<on small fires here in the states, but this will be the first time
<it's tried on a high pressure well fire.
<
<Gary
Dry ice is a solid, and solids don't pump well. Grinding to a powder
and fluidizing might work, but the wells might not last till we got the kinks
out. It is my understanding that CO2 only liquifies under considerable
pressure.
My Dad was in the ice cream business, and they always had big blocks
of dry ice to keep ice cream frozen. There was never any liquid.
According to my Handbook of Physical Calculations, the melting point
at 1 atmosphere should be -57 C, and the boiling point should be -80 C.
Irv
--
I do not have signature authority. I am not authorized to sign anything.
I am not authorized to commit the BRL, the DA, the DOD, or the US Government
to anything, not even by implication. They do not tell me what their policy
is. They may not have one. Irving L. Chidsey <chidsey@brl.mil>