This is my attempt to help you gain a practical understanding of how BP is going to "plug the d*mn leak". The relief well technique is universally promoted as the solution that works. A simple model will show you how and why.
My model describes a virtual backyard gusher, definitely not something you should actually construct. Fortunately, the idea is simple and easy to visualize.
Many experts have likened the BP gusher to opening a bottle of champagne. We're going to do this on steroids. The gusher is based on the well known effect when a few Mentos mints are dropped into a two liter plastic bottle of Diet Coke.
You don't need to be a geek to understand this model.
First, a safety tip. Don't build this thing. Seriously. It has been reported that the plastic bottle cannot contain the pressure if capped somehow after the Mentos have been dropped into the Diet Coke bottle. It is very likely to explode. Since my model actually will "stop the d*mn leak", the result is exactly the same as if the bottle gets capped.
Second, another safety tip. I didn't build anything. I have no idea how many plastic shards will pierce your eyeballs nor do I know if they'll go all the way through your eyeballs and into your brain. Seriously. There's enough energy here to do more damage than putting a lit firecracker up your nose. Note my convenient timing for a 4th of July fireworks warning. Ok, for the Jackasses out there, at least wear safety glasses, gloves, and heavy clothing. M'Kay?
Ok, let's put this thing together (in our minds). Here's some background. Dropping ten Mentos into a two liter bottle of Diet Coke causes nearly all of the dissolved carbon dioxide (CO2) in the Coke to be un-dissolved, so to speak, into gaseous CO2 within a few seconds. This sudden release of CO2 gas will propel the gas and about 2/3 of the Diet Coke liquid about 10 feet in the air. Impressive, but wimpy for a gusher.
Let's drill a hole in the bottle cap and glue a standard plastic soda straw vertically into the hole in the cap. Now, with the cap/straw assembly screwed onto the 2 liter Coke bottle, magically insert the Mentos. The magic incantation is a secret. Safety first. Those who have only drilled a hole in the cap have reported liquid heights of about 30 feet. Now we're getting somewhere.
The basic gusher model consists of a reservoir of oil and gas (2 liters of Diet Coke in a bottle) and a well (the soda straw) gushing gas and oil (CO2 and Coke) under high pressure (by adding the Mentos). With the real BP oil well, all of this is underground except for the very top of the well (the straw). This high pressure squirting gusher won't be easy to stop. How can this be accomplished?
Let's focus on the "kill" methods; those techniques capable of permanently stopping the gusher. First, the blowout preventer method that failed. Second, the top kill method that was unsuccsessful. Third, the bottom kill or relief well method that has been successful everywhere but isn't yet ready. Fourth, we'll disparage the untried, unknown, insane, when all else fails, bomb the crap out of the well method. Fifth, we'll examine the prayer method.
First, let's model the blowout preventer method. Just squeeze the top of the straw shut. Simple, right? This is what the blowout preventer was supposed to do. Not so simple, though. If you squeeze the top of the straw completely shut, there's more than enough pressure to cause the straw to split, leak, or blow apart. The BOP device is capable of managing the pressures and flows to prevent damage and provide a way to introduce material to quickly stop the leak. But the collapse of the drilling rig damaged the BOP and all the failsafe mechanisms failed. We're not going to model a BOP on the top of the straw, but you can imagine a tiny straw-sized complicated BOP device if you want. Then imagine that your tiny BOP device is broken and does nothing.
Let's model the top kill method. This is where "mud" is pumped into the top of the well under tremendous pressure. The idea is to overcome the upward pressure and gunk up the well enough to stop the gusher or slow it down significantly. For our model, toothpaste is used for "mud". So we jam a new tube of toothpaste on top of the gushing straw and squeeze hard. Odds are pretty good that the toothpaste will just get blown back up and out of the straw. Let's try using caulk instead of toothpaste. Think of this as the BP "junk shot" intended to make the "mud" thicker and heavier. Jam a caulking gun on top of the gushing straw and squeeze. Perhaps the caulk significantly slows things down, but the top of the straw splits open below the caulk plug and the mess starts squirting out the broken and split section of the straw. This probably happened in BP's case. Most experts believe that a few hundred feet of well casing was destroyed. Remember that the pressure coming out of the well has to be overcome in the opposite direction to work. The risk is that the pressure needed is more than the well casing can handle. Apparently, pressure was too high for the casing to hold and not high enough to force enough mud into the well to kill it.
Let's model the relief well (bottom kill) method. This is where "mud" is pumped into the well at a point way below the well head, much closer to the oil reservoir. To model this method, start with a fresh bottle of Diet Coke and a cap with a vertical straw as above. Punch a hole in the vertical straw just above where it's attached to the bottle cap. Glue a short horizontal straw into this hole. Now magically drop Mentos into the Diet Coke. Jam a new tube of toothpaste over the short horizontal straw and squeeze. Note that you won't need to squeeze very hard. The toothpaste is drawn upward into the vertical straw along with the CO2 and Diet Coke. The toothpaste forms a plug that grows in length as it fills the vertical straw and eventually completely stops the gusher. The vertical straw is not subjected to additional pressure so it will not split, leak, or burst. This is how and why the relief well method is expected to be successful. The fundamental difference between the top kill and bottom kill methods really is this simple and straightforward.
What if this fails? Realistically, this method won't fail. True, the relief well might not connect to the well precisely on the first attempt. Odds are pretty good, though. Remember that the technology for precision drilling is very advanced. The drill bit seeks its target electronically and magnetically and is extremely accurate. A second relief well backs up the first.
Even if this method isn't effective, drilling additional wells, both relief wells and primary production wells will reduce the pressure of the gusher. This greatly raises the chances that the top kill method will stop the leak.
Bombing the well head is the worst possible idea. This will only make things worse. It is very likely to make it impossible to permanently kill the well. A bomb of any size is more likely to cause the well to gush until it runs dry, probably for decades. Such a gusher will tip the balance and accelerate global warming beyond the point where we can recover within a decade or two. Really. This is doomsday.
I think that the "bomb" suggestions are from people who recall techniques used to put out oil well fires set by Iraq as they retreated during the Gulf War. Engineers used explosives to blow out the flames. Everything was above ground. Explosives have never been successful under water and never tried in deep water. But go ahead a nuke the sucker. What's worse? 50 years of gushing and irreversable global warming or this plus 100,000 years of radiation and a permanently poisoned Gulf of Mexico? Not a good choice, eh?
Prayer? Praying for guidance or doing a little meditation can do wonders for opening the mind to rational thinking. Nobody thinks clearly when fearful, uncertain, or doubtful. At minimum, prayer will calm you down and give you comfort. So that's good, isn't it?
UPDATE 1:
For those interested in the latest and greatest information or seeking details and diagrams about the actual "kill" methods in process, the BP Disaster Reference is an incredibly useful document. Expect accurate, up to date facts.
If you see anything that predicts that something about the BP oil disaster is going to cause the end of life on Earth or something along those lines, it's probably been debunked several times. The above Reference lists "discredited memes" toward the bottom of the Table of Contents. Resist the urge to share your OMG moment without first checking the facts.
Don't trust BP? I hear you. The BP PR people and the executives have not been truthful. This much is evident. This doesn't mean that everyone affiliated with BP is untruthful. The engineers and experts aren't fabricating garbage. The PR folks are responsible for creating the official garbage.
I have grossly oversimplified the kill methods in the Mentos/Coke model. It does serve to get the idea across, but it also causes engineers to cringe. I've made myself cringe.
My 84 year old mother in law understands this model and she is now less afraid than she used to be.