Multifunctional cementer

Abstract

The invention discloses a multifunctional cementer, aiming to overcome the defect of well cementation quality accidents caused by high probability of loose closing of a cementing circulation passage and backward flow of cement slurry due to need of closing the cement injection circulation passage by inserting a plug and building pressure after completion of cementing operation of the conventional cementer. An upper joint (1), a central pipe (7) and a lower joint (16) of the cementer are sequentially and fixedly connected from top to bottom to form a fixed pipe string (21); a piston assembly (24) is arranged in an inner hole on the upper end part of the fixed pipe string (21); an outer switch valve (22) is arranged between the upper joint (1) and the lower joint (16) on the outer circle of the fixed pipe string (21); the upper end face of the outer switch valve (22) is in circular-arc surface contact with the lower end face of the upper joint (1); and the lower end of the outer switch valve (22) is fixedly connected with the lower joint (16). The cementer has the beneficial effects of simple and rational structure, easiness in operation, reduced operation processes, increased working efficiency and safety and reliability in opening and closing of the cementing passage.

Description

Technical field [0001] The invention relates to a cement injection device for well completion operation in petroleum drilling engineering, in particular to a multifunctional cement injection device. Background technique [0002] The use of cement injectors in vertical wells, directional wells, and horizontal wells for upper cementing and lower screen completion can improve cementing quality, reduce construction risks, and provide reliable technical guarantee for well completion projects. [0003] At present, most of the graded cementing devices used in well completion construction need to inject plugs into the pipe string to suppress the pressure and close the circulation channel to complete the cementing and cementing operation. When plugging and suppressing pressure to close the circulation channel, because the liquid is incompressible, the liquid between the blind plate and the rubber plug seat cannot be removed, which may easily lead to the lax closure of the radial ceme...

AI Technical Summary

Problems solved by technology

[0004] In order to overcome the shortcomings of the existing cement injectors that need to plug the plug to hold down the pressure to close the cement injection circulation channel after the cement injection operation is completed, the cement injection circulation channel is prone to lax closure, and the cement slurry is poured backwards, thereby affecting the quality of cementing. The invention provides A multifunctional cement injector

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