Let’s say I’m an oil farmer, and I’ve got a column of flame coming out of my oil well. If I were to drop a significant amount of dynamite or pure nitroglycerin into the shaft of the well, would this put out my fire? Why would this even remotely possibly work?
(This is what I get for watching MacGyver. Specifically, Episode 8, “Hellfire”.)
AIUI dynamite works by blasting the fuel and air away from the flame. I suppose some oxygen might be consumed by the dynamite as well, so it’s not being used by the fire. Fire needs three things: fuel, air, and a source of ignition. By using dynamite you still have the fuel spraying out or lying on the ground, and you still have air (after the explosion); but the open flame is gone.
At least that’s my non-professional understanding of it.
IIRC, the concept of a planned explosion at the flaming wellhead is to deprive the flame front of oxygen long enough to extinguish the flame. Then, conventional capping can take place to shut off the flow.
“Red” Adair was an expert at this technique: http://en.wikipedia.org/wiki/Red_Adair
Go watch John Wayne’s movie Hellfighters.
Yup, that’s how they do it. The best in the game are “Boots and Coots” of Houston. Link here. They have some very cool pictures on the site of well fires, including quite a few from the first Gulf War. These guys will fly anywhere in the world at a moments notice, I believe the phone number is “1-800-BLOWOUT”. I’ve seen a video somewhere of some Russians firing some kind of artillary cannon at a blowout, maybe it’s on youtube.
First of all, that episode is a cheap ripoff of William Friedkin’s Sorcerer, which is itself an adaptation of Henri-Georges Clouzot’s masterful suspense thriller Le salaire de la peur (The Wages of Fear).
Second, as already mentioned, the purpose of the explosive is to deprive the wellhead from oxygen, thereby halting ignition of the escaping raw petroleum. This is both easier and harder than it sounds; the explosive merely needs to be insulated to prevent ignition from the heat of the fire; however, it has to be precisely shaped to create a shock wave that is roughly disk shaped to “cut” across the flame while doing minimal damage to the wellhead itself. (You wouldn’t want to drop the explosive into the well bore even if you could somehow force it down into the high pressure stream of escaping oil.) The ideal substance for doing this isn’t dynamite, (which has insufficient brisance to cut the fire) or pure nitroglycerin (which is shock sensitive and tends to become unstable with age) but some kind of plasticized demolition explosive. Adair was known to have used nitroglycerin-based plastiques and gels (mostly some form of gelignite or blasting jelly) earlier in his career, but he learned (and in many ways developed) the art of using hard plastique shaped charges using combinations of TNT, HMX, and RDX with plasticizer. These have greater shock-insensitivity and/or higher detonation velocity than nitroglycerin-based jellys, and could also be formed into more rigid shapes which provided greater precision in the resultant blast pattern, thus doing less damage to the well-head, often just blowing the stream right over the head without damaging the head-pipe at all, making it easier to cap off the now extinguished but still flowing well.
What was portrayed in the MacGyver episode (from my recollection when it first aired) is nothing short of stupidity. Not only would it be extremely hazardous to use pure nitroglycerin in that context, recovering sweated nitro from dynamite in the manner shown would be extremely foolhardy and useless in practice. The “sweat” would in fact not be pure nitroglycerin but rather contain a bunch of side products that bond with free acids that are far more sensitive to shock and thermal impulse. There are methods to safely dissociate nitro or RDX from binders using a solvent like white gas or methylbenzene, but if the explosive in question is visibly sweating by far the safest and really only intelligent thing to do is detonate it in place.
The movie Hellfighters contains numerous technical and historical errors. (Not to mention that a 6’4" Wayne is almost as out of place playing the 5’7" Adair as he is playing Genghis Khan.) It’s a typical Hollywood biopic, which is to say almost completely inaccurate in every detail, though it does cover the career of Adair to that point in broad strokes.
Stranger
I love this quote from Red’s wiki page:
“I’ve done made a deal with the devil. He said he’s going to give me an air-conditioned place when I go down there, if I go there, so I won’t put all the fires out.”
I heard a story about Red once, which may or may not be true. He was working on a fire in Mexico, and then had to fly to the Middle East right away. When he got there, the fire was out, so he flew back to the states, but by the time he arrived the fire in the Mid East had flared up again, so he caught the very next flight back. He was wearing cowboy boots and work clothes on the plane, probably looking like quite the rube.
A flight attendant asked him “Is this your first flight overseas sir?”
“Actually, maam, it’s my third one today.”
Nope, any oxygen involved in an explosion is provided by the material itself; the event happens way too quickly for oxygen to be drawn from the air. Also, if given the choice, (like Stranger says) I would use some type of PBX (polymer bonded explosive) that uses HMX or RDX as its main ingredient.
Didn’t the Mythbusters put out a fire with an explosion in an episode … uh … last year, I think?
I had a suspicion that my beloved MacGyver was a bit full of BS on this one. I will have to check out how it’s really done, the Red Adair (and maybe Mythbusters) way. Then it might actually make sense!
Now if only Mythbusters would take on another seemingly impossible feat by Mac: escaping inside a coffin that, upon hitting water, turns into… Of course! a jet ski!
A cheap ripoff of Sorceror? The mind boggles. 
Others have mentioned that explosives could be used to put a fire out, however the main problem to solve with a well blow out is not wholly extinguishing the fire, but getting the well back under control and stopping it flowing by getting some pressure control equipment back on the well head. If one puts the fire out you will still have unburned gas and oil spraying all over the place, which can pretty much be guarunteed to go back up in flames again at an inopportune moment. It is not unheard of in cases of a blowout (particularly gas wells) that is not on fire, for the well to actually be ignited (although a large chimney type device is often installed first to keep the actual burning up high so the well head does not get too warm).
Explosives are used, but not to put the fire out, but to get the old well head equipment off and leave a clean stump that new equipment can be stuck back on.
What is often done in this day and age is, after all the junk (destroyed drilling rig etc ) has been hoicked out the way, a large boom with an abrasive cutting head (water jet type stuff) will be moved into position and the damaged well control equipment cut off.
A chimney will then be installed over the stump which will allow personnel to get to the well head and assess the damage.
The chimney then gets removed and new pressure control equipment jammed on the stump of the well. The well can then be shut in by closing valves on the pressure control equipment and further remedial work under taken to stop the well flowing.
This if for when the pressure control has been lost at the well head equipment. There are many different ways for wells to blow out which require different techniques.
ETA these guys are also in the game and have a few pretty pics
Current oil well fire video in Tennessee from CNN.
I remember reading a story about various technologies used during the Kuwaiti project, one was a Russian armored vehicle with a pair of jet turbines that exhausted to the front combined with a set of water pipes that injected into the exhaust streams. I don’t know how well it actually worked.
It was called The Great Wind, Valgard. Here’s a YouTube clip and you can see for yourself.
Not that it really matters, but this story is recounted on one of the History Channel shows ( Modern Marvels I think) by either Boots or Coots as having happened to one or the other of them.
Wow! Thanks for the link.
If you want to see *all *of these techniques in use, buy, rent, or borrow the DVD of Fires of Kuwait, a 1992 IMAX film about putting out the oil well fires that Saddam Hussein set after the first Gulf War. It has some absolutely incredible footage of the fires and the amazing efforts to put them out, a task that was accomplished much more quickly than anyone expected.
Unfortunately, seeing it on your TV is only a pale shadow of seeing it on a six-story IMAX screen with 16,000 watts of sound. But it hasn’t been shown in IMAX theaters in years.
ETA: I think the video of “The Great Wind” in the link was lifted from Fires of Kuwait.