Eccentric rotation following sealing device for rotary blowout preventer

Abstract

The invention discloses an eccentric rotation following sealing device for a rotary blowout preventer. The eccentric rotation following sealing device for the rotary blowout preventer comprises an outer shell mounted outside a rotating shaft in a sleeving manner; an upper cover and a lower cover are respectively mounted at the upper end and the lower end of the outer shell; a sealing cavity is formed between the upper cover and the lower cover; a following sealing piece and a compensating sealing piece are mounted in the sealing cavity in sequence from inside to outside in the sleeving manner;the center of the compensating sealing piece is protruded towards the following sealing piece, and a hydraulic cavity is formed between the center of the compensating sealing piece and the inner sideof the outer shell; and a liquid inlet hole which communicates with the hydraulic cavity is formed in the side wall of the outer shell. By adopting the structure disclosed by the invention, the compensating sealing piece is extruded to deform through hydraulic force and continuous compensation is performed on the following sealing piece, so that tight fitting between a sealing lip of the following sealing piece and a rotating shaft can be ensured all the time when the rotating shaft generates unpredictable eccentric swinging in a radial direction under the action of external force; a sealingsurface does not leak; and a sealing effect is ensured, and the service life of the sealing pieces is prolonged.

Description

technical field [0001] The invention relates to the technical field of blowout preventers, in particular to an eccentric rotation following sealing device of a rotary blowout preventer. Background technique [0002] In the current field of oil drilling and exploitation, in order to implement underbalanced (gas phase, liquid phase) and air pressure drilling operations, a rotary blowout preventer must be installed and used at the wellhead of the drilling well. The core component of the rotary seal of the rotary blowout preventer mainly includes three parts: the rotary mandrel, the rotary seal assembly, and the fixed shell. The rotary seal assembly between the rotary mandrel and the fixed shell is the key to ensure the service life and reliability of the rotary blowout preventer. The key components. During the drilling process, once the rotating sealing assembly of the rotating blowout preventer fails, drilling must be stopped immediately to replace the rotating blowout preven...

AI Technical Summary

Problems solved by technology

The device uses a combined sealing structure to reduce the wear on the surface of the seal and reduce the heat generation of the seal itself to increase the service life of the seal. However, the gap between the sealing surfaces is still to use the elastic deformation of the elastic material itself to squeeze the lip of the seal. To carry out, in the course of use is still inevitable the emergence of the above problems

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