[ronnoles]

I did read the article, but it's simply wishful thinking to believe that all toxic substances could be flushed from a 3,800m deep hole. They say 1.5 cubic meters of lubricants and antifreeze came to the surface. Where did the rest go?

[ceejayoz]

> They say 1.5 cubic meters of lubricants and antifreeze came to the surface. Where did the rest go?

The lake water, which is under pressure from the ice, forced 1.5 cubic meters out of the top of the hole. The rest of the four kilometer high column of lubricants and antifreeze is still in the hole.

[ebbv]

There's no evidence that there is any more. They only need the lubricant at the point of contact with the drill bit.

[ronnoles]

If this was anything like a typical process, drilling fluid would be pumped under pressure down the drill pipe. Not a few drops - rather hundreds (or thousands) of liters. Obviously, this is not hard-rock drilling so I'd assume the volume of drilling fluid would be reduced. It would still have to be a substantial amount, definitely more that 1.5 cubic meters.

[D_Alex]

It is not much like a typical drilling process. The article includes a pretty decent infographic abt 2/3 way down, which shows the drilling principle on the last slide. Worth a look.

[dromidas]

So now that the drilling hole is flushed of antifreeze and its filled with prehistoric lake water... what's to stop it from freezing and closing off the hole again?