A self-grouting back pressure valve

Abstract

The invention discloses a backpressure valve capable of achieving automatic slurry injecting, and belongs to the technical field of drilling equipment. The backpressure valve comprises a valve body, a valve element and a support base and a valve base which are arranged in the valve body, wherein the support base is located under the valve base. The backpressure valve is characterized in that a piston is arranged in the valve body and arranged on the valve element in a sleeving mode, the valve base comprises an upper valve base body and a lower valve base body, the upper valve base body is located between the piston and the valve body, a slurry reflux tank hole is formed in the upper valve base body and communicated with an inner cavity of the valve body, and a slurry reflux hole is formed in the valve body and communicated with the slurry reflux tank hole. According to the backpressure valve, due to the fact that slurry in a well can be automatically injected into a drill pipe and does not need to be injected into the drill pipe by connecting a slurry injection device to the drill pipe whenever a part of the drill pipe is put down, the work amount is greatly decreased, the slurry injecting cost is effectively reduced, the condition that the slurry in the well is reversely sprayed into the drill pipe through an inner cavity of the valve body is effectively prevented, and then well drilling safety is guaranteed.

Description

technical field [0001] The invention relates to the technical field of drilling equipment, in particular to a self-grouting back pressure valve. Background technique [0002] The back pressure valve is a device for preventing internal blowout during the drilling process. It is a check valve. The back pressure valve can effectively prevent the formation fluid from entering the drilling tool through the water hole of the drill bit. The existing back pressure valve mainly includes a valve body, a support seat, a valve core and a valve seat. Its structural principle is that there is a conical movable valve core in the water eye of the tool. When installing, its large end faces down and the small end faces upward. When the mud flows from the water eye to the top and bottom, the flow resistance is small and it can pass through smoothly; When the mud flows from the bottom to the top of the drill string, the large end receives a greater thrust, which prompts the conical movable dev...

AI Technical Summary

Problems solved by technology

[0005] 1. When running in the drill, every time a part of the drill pipe is put down, it is necessary to connect the grouting device to pour the mud into the drill pipe. After the grouting is completed, remove the grouting device and put it into the next section of the drill pipe. Repeat this to complete the drilling action , the project volume is very large, time-consuming and labor-intensive, a large amount of mud needs to be poured, and the cost of grouting is high

[0006] 2. A spring is installed between the valve core and the base of the back pressure valve. The spring is sleeved on the valve stem of the valve core. One end of the spring is connected to the base, and the other end is connected to the tapered block of the valve core. The diameter of the back pressure valve is small. During the long-term use of the back pressure, the valve core will move up and down, and the spring will continue to return and compress. Quick, effective and accurate reset cannot fit well with the taper surface of the valve seat, thus failing to achieve the purpose of blocking the water eye; and when the spring is compressed and reset, the spring swings and continuously hits the valve stem of the valve core, causing the valve The rod breaks and the spool loses its function, causing the mud to spray back, resulting in extremely serious consequences

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