Pressure bearing device for screen pipe for petroleum well cementation

Abstract

The invention provides a pressure bearing device for a screen pipe for petroleum well cementation, and belongs to the field of petroleum drilling. The device comprises a tubular shell, a tubular sliding sleeve, a pressure building ball seat, limiting balls and a blind plate, the shell is provided with a first groove in the inner wall and a first radial through hole, the tubular sliding sleeve is arranged on the inner side of the shell and is adjacent to the shell, the sliding sleeve is provided with a second radial through hole, the pressure building ball seat is fixed to the inner wall of the sliding sleeve through shear pins, the limiting balls penetrate through the sliding sleeve and are connected with the first groove in the shell through ejection of the ball seat so that the sliding sleeve can be fixed relative to the shell, the blind plate is arranged in the tubular sliding sleeve, the first radial through hole and the second radial through hole are aligned with each other in the primary state, the shear pins can be shorn off after the pressure building ball seat receives a pressure building ball and carries out pressure building so that the first radial through hole and the second radial through hole can be staggered, and fluid communication inside and outside the shell is cut off. The device can be beneficial for releasing water power agitation, the phenomenon that hole opening of a classification hoop is performed ahead of time is prevented, and expansion sealing of a packer and safe operation are guaranteed.

Description

technical field [0001] The invention relates to a pressure-bearing device for a screen pipe used for petroleum cementing, in particular to a pressure-bearing device for a cementing process on the top of the screen pipe, belonging to the field of petroleum drilling. Background technique [0002] refer to figure 1 , the cementing process at the top of the screen generally adopts a string combination 10 including a screen 1 , a blind plate 2 , a packer 3 , a step collar 4 and a casing 5 . The string combination 10 is run down to the designed well depth. The pressure is suppressed by injecting mud into the pipe. The packer 3 is inflated and sealed successively by two pressure levels, so that the hole of the grading hoop 4 is opened. First, the pressure is suppressed through the blind plate 2, and the pressure is continued to about 9MPa. The packer 3 is inflated and sealed by the pressure difference, and then the pressure is suppressed to 18Mpa. The shear nails of the grading ...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the above-mentioned problems in the prior art, that is, in order to effectively release the hydraulic shock caused by the separation of the blind plate and prevent the corresponding hydraulic shock from opening the grading hoop in advance, the present invention proposes A pressure-bearing device for oil well cementing screen

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