Unless they are expressly listed in the sale as not transferring, they would automatically go to the new owner too. The problem with subsurface mineral rights is that companies, can and do steal them all the time. The days of vertical shaft oil and gas well are long gone. Now a drilling rig can run a horizontal well from over a mile away and pump out a reservoir under your feet and you will never know unless they come to you and pay you royalties (which they are supposed to)