Dual-flap-valve type downhole safety valve

Abstract

The invention discloses a dual-flap-valve type downhole safety valve which comprises an outer shell formed by sequentially connecting an upper short piece, a middle short piece and a lower short piece, wherein the inner cavity of the middle short piece is provided with a spring; the inner cavity of the upper short piece is provided with a piston pipe; the piston pipe is of a cylinder structure; the pipe wall of the upper short piece is internally provided with at least two plunger holes for mounting plungers along an axial direction; the upper ends of the plunger holes are connected with the outside by virtue of a hydraulic pipeline joint; each plunger hole is internally provided with a group of plunger assemblies; the lower opening of the middle short piece is connected with an upper valve base by virtue of threads; an upper flap valve is arranged below the upper valve base; the convex shoulder of the inner cavity of the lower short piece is connected with a lower valve base by virtue of threads, and a lower flap valve is arranged below the lower valve base is provided with. According to the dual-flap-valve type downhole safety valve, a dual-flap-valve structure is adopted and the two plungers are adopted for driving, so that double shut of downhole pressure is realized, the dual-flap-valve type downhole safety valve is simple in structure and reliable in operation.

Description

Technical field [0001] The invention belongs to the technical field of oil and gas equipment, and relates to a double flap valve type downhole safety valve. Background technique [0002] The downhole safety valve is one of the downhole tools installed on the oil and gas field completion production string. The main function of the downhole safety valve is to automatically close the production string in time to prevent accidents in the event of fire, blowout, pipeline rupture and other emergency situations. Development or further expansion. [0003] Downhole safety valves have broad application prospects, high technical difficulties, and high added value of products. Domestically, all offshore oil and gas wells and some high-risk and high-yield oil and gas wells on land must be equipped with downhole safety valves. [0004] The existing downhole safety valves have a single structure, which are basically single plunger, single flap valve or central pipe piston safety valves. They have ...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to provide a double disc valve type downhole safety valve, which solves the problem that the downhole safety valve in the prior art cannot meet the requirements of the pressure bearing capacity, service life and reliability in the complex marine environment

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