Concerning these relief wells being drilled by BP... how is this possible?

[OneTenthofOnePercent]

Think about it...

These drilling strings (and thus the well bores) are about 24" in diameter?
The ocean is roughly 1 mile deep, another mile below the ocean floor the relief wells will begin curving to intersect the original well, and once a depth of three miles is reached all the wells should converge and intersect.

To recap, we are aiming for a 24" wide window roughly 3 miles below the sea surface with a 24" wide drill that has to curve on it's way there. That's roughly 1moa (minute of angle) accuracy held over a distance of ~3 miles. FYI, the best precision rifles on earth do not have this kind of accuracy at those distances.

And all this assumes they know what they're aiming for. Do they even know the exact position of the wellbore that deep into the earth? As I understand it, wells are not perfectly straight lines and even then accurately curving a well bore seems imprecise at best. Can wells be so precise as to be curved with extreme precision?

IMO, blindly intersecting two wellbores at a depth of 15000+ feet seems to be quite impressive.

[LeftyFingerPop]

1. Stating this quite seriously...

It is very possible they could miss.

[OneTenthofOnePercent]

6. Is missing a big deal?

Once they get "close" (close, being a relative term here) can they just poke around a 'lil bit?
Do they have to start over if they miss?

I really don't know what they can doo in a situation where they miss.
Honestly, I'm not even sure how they reliably "curve" the whole well to begin with. That's just fucked up, IMO.

[LeftyFingerPop]

9. Good question. I don't know...

I'm not sure if they have to hit it exactly. I'm also not sure if they miss if they can back the bit off and take a different direction. Sure seems harder than hell to do, doesn't it?

[OneTenthofOnePercent]

11. I'm sure Bruce Willis could tell us.

In Armageddon he played deep sea driller and even NASA asked him for help.
I'm thinking BP has Bruce Willis on speed-dial, no?

[LeftyFingerPop]

14. Ha!

Sure, they should call him! :D

[Robb]

2. I sat next to a guy on a plane a few years ago who wouldn't shut up.

:D

Anyhow, he was a driller for some gas company or other, or I think leased them some kind of clever electronic crap. He talked about how they would have these two drilling projects inside mountains that would take six months to reach one another and would match up within 1/100th of an inch.

So, who knows, maybe they can do it. :shrug:

[Sal Minella]

3. If arrogance could suddenly be converted into expertise,

we'd be doing a lot less worrying, wouldn't we.

[Winterblues]

4. I don't think they actually have to intercept the other drill hole.

I think all they have to do is go near the well into the same basin and relieve the pressure so the oil will flow up the new well site instead. :shrug: but I know about as much about it as Sarah Palin does..

[Redbear]

15. I think that is correct. As long as they are in the same oil field.

The new well will "drink" the other well's "milkshake."

[OneTenthofOnePercent]

17. Too many straws in one drink...

There was a joke or gag I heard some time ago about a couple of buddies (four, I think) trying to see how fast they could collectively finish a drink if they all used their own straws. 4 guys, 1 cup...???

Anyways, after they finish (very quickly) one guy says, I'll bet we could've done it alot faster.
Another guy says, what makes you say that?.
The first guy responds, because while all of you were sucking I was spitting.

[sfwriter]

5. It is impressive...

I think they move a great deal slower than a speeding bullet allowing for greater accuracy. Also, as long as they know exactly where the bore is going in, then the geometry of the actual drilling is fixed from the sea floor to the original well shaft.

Still, the math and precision is just staggering.

[tridim]

7. I've been wondering the same thing since the day the relief well was announced.

I can't really think of any measuring device that would tell them they're definitively on target.

Any experts here who can answer this?

[OneTenthofOnePercent]

10. I know, right?

How do you know exacty what is happening 1mile below solid rock?
Ultrasound? Ultramegasound?

[tridim]

12. Ultrasound would be difficult on land, let alone at that depth.

As far as I know there is only one data point in this experiment, the initial bore hole.

We have to be missing something. Right?

[muriel_volestrangler]

18. If they have an accurate record of the course of the original drill hole

then I think the new equipment would be able to aim for it. Just at a guess, you could use a laser as you're boring to measure very precisely the direction you've gone in so far.

As a comparison, when they bored the Channel Tunnel in the 1990s, they came at it from each end, and were 14 inches out, when each had drilled about 15 miles.

[SidDithers]

8. Precision rifes are "fire and forget"...

the wells are being drilled with constant feedback and correction as to their depth and direction.

Sid

[Webster Green]

13. It is amazing what they can do.

I worked on the mud platform on a drilling rig for a month or so. They were boring a cable run under a canal. They drilled down and then made a curved path under the water and back up the other side. I was amazed at that shit, but what these guys are doing at those depths is absolutely incredible to me.

[dipsydoodle]

16. Its not an underground lake of oil

Its rock with oil in the fissures across a wide area under high pressure. Drilling a hole allows the oil to released.

[yella_dawg]

19. If I understand what they are attempting...

If I correctly understand what they are attempting, they aren't trying to hit the well bore, rather the producing formation is the target. Basically, it's like Slime for a tire. They pump goo into the zone which then gets pushed into the blown out well bore where it hopefully gunks up the hole until it stops leaking. They may use more precise techniques in underwater drilling, but on land, direction and angle are a bit vague at best. Logging tools can describe the hole once it's bored, but during the actual drilling, it gets pretty close to guesswork. They hope to get close enough to the blown well with the relief well that one affects the other through underground flow patterns. The industry is pretty good at such things, in general, but every situation is unique, which is why they are drilling two relief wells, I suspect.

[fatbuckel]

20. BP is only concerned with getting the oil. Period.

[ashling]

21. It really doesn't make any difference

because the real reason they are drilling them is to get more oil