Sometimes old wells can be re-entered, usually not that old because of reasons of integrity. Wells that are re-entered can be recompleted in the original producing formation, drilled deeper to a new formation, plugged back and completed in a shallower formation. Having a dry well from many years ago does not necessarily mean there is not oil or gas, but some areas have no oil or gas. I have successful wells in a section where up to 7 dry or modestly producing wells were drilled that eventually went dry 30 to 50 years ago. If there is other production not too far from your old well, a new well might find something to produce in paying quantities.