Well dispute

Hello! I am helping a farmer and his landlord deal with a well dispute. There is a well on the border (perhaps right in the middle of the property line) that has been abandoned for a long time (1950’s). Both property owners do not have a well agreement nor proof of ownership. I could not find any description on the deeds of both properties, no other public records filed with the county nor could I have find any well agreements at the water district of this county. It seems there is no documentation of this well and who the owner is. Would the ownership of the well be awarded to the farmer where it lies after surveying the property line? What if it runs right through the middle of the well? Is there any where else I can find a well agreement recorded?