Spray head for self-rotating jet drill bit with speed loss-preventing device

Abstract

The invention relates to a spray head for a self-rotating jet drill bit with a speed loss-preventing device. The spray head comprises a rotary spray head and the speed loss-preventing device of the spray head. The rotary spray head comprises a rotary spray head body, a flow guide cavity is formed in the rotary spray head body, a plurality of rock breaking spray holes are formed in the front end, aplurality of chamfering spray holes are formed in the middle, and a plurality of crushing spray holes are formed in the back part. The loss-preventing device of the spray head comprises a porous control shell. The back part of the porous control shell is of a cylindrical structure, the middle part of the porous control shell is an expanded part, the diameter of which is increased gradually, fromthe cylindrical structure forward, and the front part of the porous control shell stretches forward from the expanded part and surrounds the back part of the rotary spray head body. The spray head issimple in structure and simple to operate and maintain, can overcome the problems of rotary speed loss of the spray head and uncontrollable grain sizes of rock waste of an existing self-rotating jet drill bit effectively, exerts multi-spray hole combined screening and rock breaking action of the self-rotating jet drill bit fully, and improves the drilling efficiency and the drilling length.

Description

technical field [0001] The invention relates to the technical field of stratum drilling, in particular to a nozzle for a self-rotating jet drill bit with an anti-stall device, which is suitable for the development fields of coal bed methane, oil, and natural gas. Background technique [0002] In the prior art, there is a self-rotating jet drill bit, which is a drill bit with a special structure derived from the theory of rotating jet flow. One or more groups of nozzle holes are placed obliquely on the nozzle, and the jet reflection is used to The recoil torque generated by the impact due to eccentricity realizes the automatic rotation of the nozzle. During the drilling construction, the nozzle rotates at a high speed, and multiple nozzle holes are combined with scanning rock breaking to form relatively regular large-diameter holes. [0003] Its disadvantages are: (1) When the rotary nozzle hits the front rock wall, it is prone to the problem of nozzle rotation stall, which l...

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide a nozzle for a self-rotating jet drill with an anti-stall device, which has a simple structure and is easy to operate and maintain, and can effectively overcome the problems of the current self-rotating jet drill, such as the stall of the nozzle rotation and uncontrollable particle size of cuttings. , give full play to the rock-breaking effect of multi-jet joint scanning of the self-rotating jet drill bit, and improve the drilling efficiency and drilling length

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