Dynamic directional rotary steerable drilling tool

Abstract

A dynamic directional rotary steerable drilling tool comprises a rotary jacket. The rotary jacket is internally equipped with an eccentric mechanism, a guide shaft, a torque transfer mechanism and a sealing device which are connected in sequence from left to right. The eccentric mechanism is composed of internal and external eccentric rings. The internal eccentric ring is installed inside the external eccentric ring, and sleeves a ball seat. The internal and external eccentric rings are each directly connected with a frameless motor through a flange and directly driven by the frameless motor. The left end of the guide shaft is inserted into the ball seat, and the torque transfer mechanism is installed at the right end of the guide shaft. The sealing device is arranged at the right end of the torque transfer mechanism. According to the invention, the frameless motors directly drive the eccentric mechanism to realize offset of the guide shaft, the structural shape size of the tool is reduced, the internal space of the mechanism is saved greatly, and the offset adjusting process is continuous without clearance; the stress state of the drilling tool is improved, and the drilling tool has a longer service life; the drilling tool is not affected by the complex conditions of the formation, and the borehole trajectory can be controlled precisely; and the drilling tool has the advantages of quick response, high reliability and high stability.

Description

technical field [0001] The patent of the present invention relates to a rotary steerable drilling tool in the field of drilling, in particular to a dynamic pointing rotary steerable drilling tool. Background technique [0002] The current downhole rotary steerable drilling tools can be basically divided into four types according to the working mode: static offset pushing type, dynamic offset (modulated) pushing type, static offset pointing type and dynamic offset pointing type. The disadvantage of the static offset push-on type is poor miniaturization ability and complex structure; the disadvantage of the dynamic offset push-on type is that the wear of the drill bit and the drill bit bearing is serious, and the working life is short; the disadvantage of the static offset pointing type is that the core bearing is affected by high strength. The mandrel is prone to fatigue damage due to the alternating stress. As a new design concept, the dynamic pointing rotary steerable dril...

AI Technical Summary

Problems solved by technology

[0003] In China, Tianjin University invented a static pointing rotary steerable tool, which uses a motor to drive the eccentric planetary gear train with a small tooth difference to realize the offset of the mandrel. By connecting the drill string and the mandrel with a hollow universal joint, the improved The force condition of the mandrel, but the space mechanism is complicated, and the mandrel pointing accuracy is average

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