A Hole Is To Dig

September 29, 2005 12:46 PM

Behold the Chikyu! Japan has built and launched a drilling ship with which they will drill what they hope will be the world's deepest hole into the Earth's crust and mantle.
posted by fandango_matt (33 comments total)

I thought mantle-drilling was earthquake-encouraging. No?
posted by cali at 12:57 PM on September 29, 2005

Oh, crap.
posted by Faint of Butt at 12:58 PM on September 29, 2005

They're gonna crack the world in two, I know they will.
posted by marxchivist at 12:59 PM on September 29, 2005

"Aiiieee!! The Earth is actually a gigantic egg! And we've cracked it!!"
posted by Artw at 1:05 PM on September 29, 2005

By my figuring, this + that = Hello!
posted by Pliskie at 1:08 PM on September 29, 2005

I thought mantle-drilling was earthquake-encouraging. No?

Why did you think that?

Seriously, why do this with a ship, and not from a stationary ground site? Seems like any advantage you get from drilling into thinner areas is negated by the hassle associated with maintaining the ship's position.

We're talking about ten extra miles...
posted by delmoi at 1:09 PM on September 29, 2005

Ballon-like pop and subsequent venting of molten rock to space in 3... 2... 1...
posted by CynicalKnight at 1:09 PM on September 29, 2005

If a plume blows out and rises, it can sink the ship. Escaping gas can also spark catastrophic explosions and fires. But geophysicists believe that the risk is worth taking.

Particularly if said geophysicists are sitting in an office back in Tokyo...
posted by pitchblende at 1:35 PM on September 29, 2005

to quote Hobbes, "well, now i don't feel so bad about setting up that ira last year."

been fun knowing you guys...
posted by TheStorm at 1:40 PM on September 29, 2005

"NO KILL I"

I read the article and I'm still not clear on why?
posted by tkchrist at 1:43 PM on September 29, 2005

"One risk in drilling to the mantle--or any seafloor drilling--is tapping into a pocket of gas hydrates. If a plume blows out and rises, it can sink the ship"
That'd be some bloop.
I wonder what the environmental implications are for a project like this? A 7000m deep well could produce a lot of contaminated drill cuttings
posted by flagellum at 1:46 PM on September 29, 2005

I'm hoping they awake a giant primeval reptile that's been sleeping under the sea floor for millions of years. It will then go on a rampage and smash Tokyo.

These Japanese scientists... first messing with the giant squid, now this...
posted by Artifice_Eternity at 1:49 PM on September 29, 2005

What if the hollow earth guys are right and the sea drains down the hole?
posted by radiobishop at 1:50 PM on September 29, 2005

Maybe they'll awaken a giant reptile, AND it will fight the squid.

That would be cool.
posted by Artifice_Eternity at 1:53 PM on September 29, 2005

They're gonna crack the world in two, I know they will.
posted by Marxchivist at 3:59 PM EST on September 29 [!]

Yep.
posted by unreason at 1:56 PM on September 29, 2005

In the borehole pressure mines 100km beneath Planetsurface, at the Mohorovicic Discontinuity where crust gives way to mantle, temperatures often reach levels well in excess of 1000 degrees Celsius. Exploitation of Planet's resources under such brutal conditions has required quantum advances in robotic and teleoperational technology.

Morgan Industries, Ltd.
"Annual Report"

[/gamer]
posted by Foosnark at 2:25 PM on September 29, 2005

In the borehole pressure mines 100km beneath Planetsurface, at the Mohorovicic Discontinuity where crust gives way to mantle, temperatures often reach levels well in excess of 1000 degrees Celsius. Exploitation of Planet's resources under such brutal conditions has required quantum advances in robotic and teleoperational technology.

But . . . YOU CAN'T CONSTRUCT BOREHOLE IMPROVEMENTS AT SEA!!!

[/SMAC addict]
posted by ToasT at 2:32 PM on September 29, 2005

There's already a pretty deep hole started. Maybe they should start there.
posted by klarck at 3:02 PM on September 29, 2005

cali: I thought mantle-drilling was earthquake-encouraging. No?

No.

tkchrist: I read the article and I'm still not clear on why?

When your entire nation sits on the Pacific Ring of fire, isn't the "why" obvious?
posted by KirkJobSluder at 3:29 PM on September 29, 2005

Wasn't there some big-budget disaster movie about something like this recently? What was it called? "The Crust?"
posted by scarabic at 3:29 PM on September 29, 2005

What new information will this produce that wasn't discovered or found in the movie The Core?
posted by Atreides at 3:34 PM on September 29, 2005

But . . . YOU CAN'T CONSTRUCT BOREHOLE IMPROVEMENTS AT SEA!!!

Can't airdrop into the sea either, sadly.
posted by Foosnark at 3:55 PM on September 29, 2005

Chikyu, meet Glomar.

ROUND 1, FIGHT!
posted by PROD_TPSL at 4:04 PM on September 29, 2005

In the movie department there was also Crack in the World from 1965. The title kinda tells you where it's going.
posted by Joeforking at 4:19 PM on September 29, 2005

Are they going to bury anything in it when they are done? Like a time capsule or maybe pirate treasure!
posted by TwelveTwo at 4:25 PM on September 29, 2005

I'll have you wags know that The Core was probably the best bad sci-fi that I've seen in years. It fucking rocked the Day After Tomorrow bullshit so hard that its rocking must be expressed in scientific notation.
posted by klangklangston at 4:48 PM on September 29, 2005

"the earth, this globe we live upon... we are not to conceive it to be a full bulky mass to the center, but rather that 'tis somwhat like a suckt Egg, in great part an hollow sphear, so that what we tread upon is but as it were, an Arch or Bridge, to divide between the upper and the lower regions..."
posted by misteraitch at 6:07 AM on September 30, 2005

You ivory tower intellectuals must not lose touch with the world of industrial growth and hard currency. It is all very well and good to pursue these high-minded scientific theories, but research grants are expensive and you must justify your existence by providing not only knowledge, but concrete and profitable applications as well.

CEO Nwabudike Morgan
"The Ethics of Greed"
posted by dreamsign at 6:19 AM on September 30, 2005

WAIT a minute. I've seen this movie, and I don't think we're going to like how it turns out.
posted by lexalexander at 8:48 AM on September 30, 2005

"As a communist I don’t believe in heaven or the Bible but as a scientist I now believe in hell." [Although Age Rendalen has a different take.]
posted by moonbiter at 10:20 AM on September 30, 2005

When your entire nation sits on the Pacific Ring of fire, isn't the "why" obvious?

LOL. SNEAK ATTACK!
posted by tkchrist at 5:25 PM on September 30, 2005

You SMAC quoting bastards have just ruined the weekend.

From my wife's perspective, anyway.
posted by PinkStainlessTail at 6:26 PM on September 30, 2005

One of the fun things about this project is that it is only in the last couple of years that a hole of this depth has become genuinely feasible.

The big problem with very deep wells is that the changes in the down-hole environment tend to require different techniques of drilling. Increasing pressures mean that the density of the drilling mud be increased to match, so the hole doesn't collapse (best case) or the fluids in the hole come to pay a visit at surface (worst case); different rocks require different types of drill bit; the weighting of the various elements of the drill string need to be changed to prevent dangerous resonances; and so on ...

What is appropriate to drill one hole section may not be appropriate for another.

The classical way to deal with this is to "case off" sections of hole when a change in technique is required. For example, if you were drilling hole of 12 1/4" and knew that you would have to change the way you were drilling soon, you would put down the hole a casing of, say, 9 7/8" outside diameter and pump cement down it and around the outside. You would then drill on with an 8 1/2" drill bit using whatever parameters the new section required without worrying about the stuff you had drilled above.

The problem here is that you can easily get down to a very small hole size if you have to do this frequently - 3 1/2" hole is about as far as you can go. This is fiddly to deal with, reduces the yield of the well and puts a limit on how many changes in downhole conditions you can deal with. It used to represent an absolute limit on drillable depth for each location.

However, there is way around this now. Drill 12 1/4" hole; run special casing inside it; expand that casing so it fits snugly inside the hole; cement as usual (there is always enough "roughness" to allow the cement to get in there).

Of course, it seems that even if the outside diameter of the casing equals the diameter of the hole, the next drill bit must be smaller and the problem I mentioned above has not gone away.

So, you use a bi-centre bit - one that (to simplify) has its spin axis off centre. As a result you can drill new hole (below the expandable casing you set) at 12 1 /4".

You could, in theory, repeat this process indefinitely, although the heat and pressure downhole would cause huge problems well before reaching the MoHo.

My point is that any really deep well is going to be in better shape than it would otherwise be if getting to the horrible stuff doesn't in itself require you going down to 3 1/2" hole and thereby leaving you with no room to maneuver afterwards.
posted by thatwhichfalls at 9:07 PM on September 30, 2005