Based on our own production experience, as well as experience in conducting industrial safety expertise of documentation for the conservation and abandonment of hazardous production facilities of the oil and gas production complex «Well stock» (as the certified expert), the methodological approaches are proposed to ranking on various signs (criteria) of oil and gas wells that are being brought (brought) to conservation and being abandoned (abandoned) for the reasons specified by the current regulatory framework. The method is proposed related to ranking of the brought to conservation and (or) abandoned oil and gas wells composing hazardous production facility «Well stock» for one or another field. The set of criteria is defined that characterize and determine the conditions for physical existence and functioning of oil and gas wells before and after conducting activities on conservation and (or) abandonment of their bore holes. The proposed method provides for conducting procedure of well ranking taking into account factors that consider the specifics of well production history before bringing them to the state of conservation and (or) abandonment. This method gives the opportunity to make objective and informative assessment of the current situation, which characterizes the state of industrial safety of the hazardous production facility «Well stock».