Gary Coffman wrote:

On Wed, 16 Jul 2003 15:21:51 GMT, (John Flanagan) wrote:
On Tue, 15 Jul 2003 23:11:41 GMT, (Gary Coffman)
wrote:
Well, I may have mentioned dropping a wrench down a well. I did
it deliberately after the squib failed to work. We had a 2.5 gallon
shot down the well. One of our crews had been killed hoisting a
shot out of a well to replace a faulty squib, and I didn't want to
duplicate that event. So I walked over and dropped a crescent
wrench down the bore. It set off the shot very nicely.

The explosive is used to break up the rock to increase flow?

Yes, the idea is to create a series of micro-fractures in the vicinity
of the hole to improve the infiltration of fluids.

What
kind of explosive was it that a wrench falling on it would set it
off???

Nitroglycerin. We used 2.5 gallon shots, prepackaged in tubes
kept in liquid nitrogen dewars on the truck. We'd take one out
of the truck and lower it down the hole while still frozen (the stuff
is pretty safe when frozen). Then we'd wait for it to thaw out and
fire the squib to detonate it.

But if the squib failed, you had a choice, raise the now warm
nitro back up to the top of the hole to fit a new squib, or drop
something down the hole and let the impact set it off. The one
time it happened to us, I dropped a wrench.

Gary

Did you recover the wrench when it came back up?

Bill K7NOM