[MeanWestTexan]

No:

You:(1) case the hole (metal piping as you go);(2) have what is called a pressure control stack on the surface (blow out preventers and a annular) in the event you become underbalanced; and (3) most importantly, you have a colum of drilling fluid of some kind weighing down the formation (lake, in this instance) . . water being the lightest, to brine (all you'd need here), or even some sort of heavier petroleum based mud.

Yes, I am a drilling engineer.

[blam]

"...or even some sort of heavier petroleum based mud."

Loaded with bacteria, germs and etc.

[Toby06]

Use Bentonite with their density-improver Weight-it. at an Sg of 1.6, ought to work pretty well with a column like that!

Pro-mud polymer drilling fluid is fun stuff, too, but you have to run a Ph of 13 to make it really work, and to keep the density up.

However, arent' they just drilling ice? How do you restrain the casing fdrom moving ineither direction? I can't imagine there is much skin friction holding the string.

[cpdiii]

Set you last string of casing a few hundred feet above the lake. Drill out using a foam brine water. Once you get close to the lake the hydrostatic pressure of the foam brine would be much less than the overburden. The water would then flow into the annulus until it reaches equilibrium. You would not contaminate the lake nor would you have a blow out. Since ice is lighter than water the hydrostatic head of the water in the annulus is more than the overburden pressure. Once it reaches equilibrium you would have to pump you samples out. This would not be a very tough engineering problem.

[Walkingfeather]

Very cool. Went to school in West texas....Great BBQ brisket. ( Which I cook here in California) Thanks for the info.