Lori,
I would contact the oil company first to verify everything before you pay the taxes. Just call the oil company or operator and tell them the situation and send them a copy of the deed (by fax is quicker) to make certain the previous owner did own mineral interest (now your interest, if any). The previous owner may have not owned 100% of the mineral interest. If the operator has not been sent a change of ownership they will keep paying who they have on record as it is your responsibility to inform them. If they cannot pay the owner they show of record then it will be paid to the state in the name of the owner the operator has on their records.