Double layered air jetting sleeve head

The utility model relates to a double layered air jetting sleeve head for underbalance drilling a horizontal well adopting temporary sleeve jetting technique in petroleum drilling engineering, which is mainly composed of a conversion four-way for a blow-out preventer, a temporary sleeve hanger, a technical sleeve hanger, an external casing of a sleeve head, an inflation through hole, etc. The utility model is characterized in that the conversion four-way for the blow-out preventer is provided with a screw hole, and the temporary sleeve hanger is fixed by a fixed set screw on the screw hole; the inner wall of the technical sleeve hanger has inner steps matched with the temporary sleeve hanger, and the inner steps is used for hanging the temporary sleeve hanger; the external casing of the sleeve head and the technical sleeve are provided with inflation through holes, through which air is jetted into a well in an annular space between a technical sleeve and a temporary sleeve. The utility model can realize the suspension and fixation of the temporary sleeve and the communication of an air jetting channel as well as can realize the reclamation of the temporary sleeve, and the height of the sleeve head is not increased.