What are you wanting to do? Is the well a shallow, hand dug and lined well, a shallow driven well, a drilled, cased water supply well? Is it a deeper petroleum well? There are a number of ways to "find out what's down there", some more expensive than others. Mineral exploration holes by mining industry are simply called "holes", not wells. Generally speaking, liquids and gases come out of wells (produced). Can you describe the well, its setting and suggest a likely purpose? Are there other similar wells in the area? I have a fair amount of experience around wells (and holes) but need more info. Are you certain that is a water well? Is it open to the atmosphere at the surface?