Hydraulic-control double-stage well test blowout preventer

Abstract

The invention discloses a hydraulic-control double-stage well test blowout preventer, comprising a lower joint, a connecting body, a seal sleeve, a seal box, a primary piston, a secondary piston and a hydraulic cylinder, wherein the upper end of the lower joint is tightly connected with the lower end of the connecting body; the upper end of the connecting body is tightly connected with the lower end of the seal sleeve; the seal box is arranged inside the seal sleeve; the secondary piston is arranged inside the primary piston and arranged inside the hydraulic cylinder together with the primary piston; a primary seal mechanism is arranged inside the seal sleeve; a secondary seal mechanism is arranged inside the seal box; the primary piston acts on the primary seal mechanism; the second piston acts on the secondary seal mechanism, and the secondary seal mechanism can play a part only when the primary seal mechanism becomes invalid. By adopting the hydraulic-control double-stage well test blowout preventer, the problems of bad use effect, difficult tripping of a well test tool, low operating efficiency, short service life, and poor reliability of the existing hydraulic-control blowout preventer are solved.

Description

technical field [0001] The invention belongs to the technical field of well test blowout preventers in oil and gas fields, and in particular relates to a hydraulically controlled two-stage well test blowout preventer. technical background [0002] At present, the blowout preventers used in steel wire well testing in oil and gas fields are all single-stage hydraulically controlled steel wire blowout preventers, and the steel wire is sealed by pressing a group of sealing packings through hydraulic pistons. When the wellhead pressure is high, in order to better seal, it is usually adopted to increase the compression force of the piston to compress the sealing packing. However, after the compression force increases, the resistance of the steel wire lowering will increase, making it difficult for the tool to enter the well; at the same time, in the well testing operation of high-pressure oil and gas wells, the sealing packing of the existing blowout box is subject to the wear and...

AI Technical Summary

Problems solved by technology

[0003] The technical problem solved by the present invention is to provide a hydraulically controlled double-stage well test blowout preventer, which solves the problem of poor use effect of the existing hydraulic control blowout preventer, difficulty in running well test tools, low operating efficiency, short service life, and poor reliability The problem

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