You really need to check with a real estate attorney. I think no matter what anyone ever says, if you buy a house that backs up to vacant land there is a risk that something will be built there that you don't like. Builders reps are notorious for telling people all kinds of things, like nothing will ever be built on that land. I always tell my buyers that you should imagine the worst....perhaps a Wal-Mart. If they did sell or lease to a drilling company hopefully you have the mineral rights to your property and will share in the wealth. If not you may want to attend your city council meetings along with your neighbors and try your best to limit where the rig goes and what time of day they will work.