I was wondering if it would be possible to help a heat pump work better at lower temps by using well water circulating through pipes with fins placed on the outside of the coil? My thinking is the fins with water constantly flowing through the pipes would be warmer than the outside temps during the winter in north east Ohio. The air passing over the fins would help warm the coil and possibly make the heat pump work better at lower temps, and the fins would cool the air to work better during the summer.

Anything that will raise the temperature of the outside coil in the winter will make a HP run more efficient/increase output.

This has already been done with water source heat pumps. There is a freezing problem associated with the way you are taking about doing it for winter usage. For more info look on Google for water source heat pumps.