Do you own the surface as well? Be wary of where your water well is in location to where they would want to drill, frakking is bad, and yes alot of landmen are crooked, plain and simple, most double if not triple bill, and/or buy minerals themselves and package them in neat tidy bundles for a hefty profit, Source? I work as a contract landman, only doing due dilligence and final report vetting from my house currently, the business is rife with the plague of speculation, de-regulatory practices, and unsound fiscal responsibility. The best thing to do is find a LOCAL oil and gas attorney, or speak with the judge if it's a small town, I have found that the local Judge 9 out of 10 times owns a GREAT deal of minerals in those country county's, families that produce Judge's tend to invest in things properly.