Air and nitrogen alternating displacement exploitation method for mid-deep zone low-permeability thin oil reservoir

The invention relates to an air and nitrogen alternating displacement exploitation method for a mid-deep zone low-permeability thin oil reservoir. An air and nitrogen alternating displacement flooding well network is arranged in a direction parallel to a major fracture, a slug of air is continuously injected into a gas injection well in the flooding well network, next, a slug of nitrogen is continuously injected in a converted manner, alternating displacement is realized by means of repeatedly switching gas injection, and a production well in the flooding well network is used for continuously producing oil. By the aid of the air and nitrogen alternating displacement exploitation method for the mid-deep zone low-permeability thin oil reservoir, a fracture water displacement low-permeability reservoir with the burial depth of more than 1000 meters and permeability lower than 20 mD can be alternately exploited, recovery ratio is increased by more than 10% on the basis of water displacement, a mid-deep zone water-sensitive low-permeability reservoir unsuitable for water displacement can be effectively exploited, and the recovery ratio can be higher than 40%.