Abstract: A flow splitting device for gas reverse circulation drilling, including: an upper joint for connecting with a double-wall drill pipe; an inner tube which is arranged in the upper joint and defines a first passageway in communication with an inner chamber of the double-wall drill pipe, a second passageway in communication with an annular space in the double-wall drill pipe formed between the inner tube and the upper joint; a lower joint, having an upper end fixedly connected with the upper joint and a lower end for connecting with a drill tool; and a flow guiding member provided between the upper joint and the lower joint. A flexible sealing mechanism is provided outside the upper joint. The flexible sealing mechanism extends radially outward relative to the upper joint and the lower joint to form a sealing contact with a wellbore wall.

Abstract: An annular shaped-charge and blasting housing and a use method thereof are provided. The annular shaped-charge and blasting housing includes a PVC segment and multiple notch grooves. Grooves are notched on a W-shaped PVC segment formed by machining. The notching angle of the groove and the spacing distance between the grooves can be adjusted according to use requirements. And, the W-shaped PVC segment after being cut may not be limited to have eight notch grooves, and the number of the notch grooves of a single one PVC segment can be adjusted according to actual working conditions. The PVC segment can be folded and closed to form the annular shaped-charge and blasting housing. Therefore, the housing of the embodiments is simple in production, the linear segment can be bended and folded by utilizing the plasticity of the PVC material. The manufacturing process of the housing is simple and feasible.

Abstract: An annular shaped-charge and blasting housing and a use method thereof are provided. The annular shaped-charge and blasting housing includes a PVC segment and multiple notch grooves. Grooves are notched on a W-shaped PVC segment formed by machining. The notching angle of the groove and the spacing distance between the grooves can be adjusted according to use requirements. And, the W-shaped PVC segment after being cut may not be limited to have eight notch grooves, and the number of the notch grooves of a single one PVC segment can be adjusted according to actual working conditions. The PVC segment can be folded and closed to form the annular shaped-charge and blasting housing. Therefore, the housing of the embodiments is simple in production, the linear segment can be bended and folded by utilizing the plasticity of the PVC material. The manufacturing process of the housing is simple and feasible.

Abstract: A flow splitting device for gas reverse circulation drilling, including: an upper joint for connecting with a double-wall drill pipe; an inner tube which is arranged in the upper joint and defines a first passageway in communication with an inner chamber of the double-wall drill pipe, a second passageway in communication with an annular space in the double-wall drill pipe formed between the inner tube and the upper joint; a lower joint, having an upper end fixedly connected with the upper joint and a lower end for connecting with a drill tool; and a flow guiding member provided between the upper joint and the lower joint. A flexible sealing mechanism is provided outside the upper joint. The flexible sealing mechanism extends radially outward relative to the upper joint and the lower joint to form a sealing contact with a wellbore wall.