A centralizer with self-adaptive variable diameter

Abstract

The invention relates to a centralizer with self-adaptive variable diameter used in the field of oil and gas well engineering. It solves the problems of poor centering of the drill string and high frictional resistance of the drill string. The technical solution is: the upper end of the stator shell is connected with the lower end of the upper joint with screws, and the lower end of the stator shell is connected with the upper end of the connecting cylinder with a thread; the rubber stator is fixed in the inner cavity of the stator shell; the screw rotor is placed in the inner cavity of the rubber stator, and the bearing a is installed in the screw. The upper end of the outer circle of the rotor; the transmission screw is placed in the inner cavity of the connecting cylinder, and the transmission screw rotates flexibly in the inner cavity of the connecting cylinder; the upper end of the lower joint is connected with the lower end of the connecting cylinder with screws; the lower end of the roller and the support arm a is hinged, and the roller and the support arm b The lower end is hinged. The present invention can realize the function of effectively changing the diameter in the downhole, the roller and the well wall are fully attached, and the drill string is well centered; the roller and the well wall are purely rolling, the axial friction between the drill string and the well wall is small, and the drill string is fed convenient.

Description

technical field [0001] The invention relates to a centralizer with self-adaptive variable diameter used in the field of oil and gas well engineering. Background technique [0002] In the drilling operations of horizontal wells, directional wells, and extended-reach wells in oil and gas fields, due to the gravity of the drill string, the drill string is easy to deviate in the wellbore or even lie on the well wall, with poor centering and difficult orientation, which seriously affects drilling quality. The traditional rigid centralizer has a large outer diameter, which is not variable, and it is difficult to run in, especially in the corner section with a small curvature radius in horizontal wells and extended-reach wells. However, the traditional elastic centralizer is full of eyes in the initial state. During the process of running into the downhole, the elastic sheet and the well wall continue to rub against each other. The running friction is large, the elastic sheet is e...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is: in order to solve the problem of poor centering of the drill string and large frictional resistance of the drill string, a centralizer with self-adaptive variable diameter is provided.

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