Moderator Post (s) for this thread: >WellsbyBillhart on 12/30/2006
Sounds like it is a jet pump. The jet is in the well and one pipe is the supply to the jet and the other is the reutrn line.
I don't know of any reason for copper lines to a well except for a bubbler system to monitor the water level. But that would only take one tube and I have never seen it done in a home. That is more of an industrial system.
You might try digging on the outside to see where they go.
The only thing that I can think of would be to cut couple of inches off the end on each tube and send it to a lab for presents of any oil residue.
But don't do that on your own until the buyer agree to acept the results and agree on a lab.