Self-grouting backpressure valve

Abstract

The invention discloses a self-grouting backpressure valve, and belongs to the technical field of well drilling equipment. The self-grouting backpressure valve comprises a valve, a valve element, a valve seat and a supporting seat, and is characterized in that a slide sleeve is arranged in the supporting seat, a lateral hang groove and a vertical slide groove are formed in the slide sleeve and are communicated with each other, the valve element comprises an upper valve rod, a conical block and a lower valve rod which are connected with one another, a guide hole is formed in the valve seat, the upper valve rod can axially move in the guide hole and penetrates the guide hole, and a hang pin is arranged on the lower valve rod and is hung on the slide sleeve. The self-grouting backpressure valve has the advantages that slurry in wells can be automatically poured into drill rods by the self-grouting backpressure valve, accordingly, the engineering quantities can be reduced to a great extent, and the grouting cost can be effectively lowered; self-grouting channels can be forcibly closed in case of well blowout and well overflow in drill-down procedures, and accordingly well blowout and well overflow can be prevented; integral self-grouting actions can be completely carried out without slurry backflow channels on the valve, accordingly, the strength of the valve can be guaranteed, and the service safety and reliability can be improved.

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. [0003] 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 mo...

AI Technical Summary

Problems solved by technology

[0007] 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

[0008] 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

[0009] 3. The back pressure valve capable of self-grouting in the existing technology, if a blowout occurs during the run-in process, the self-grouting channel cannot be closed forcibly, and the blowout and kick cannot be effectively prevented. The mud return channel is usually set on the valve body to reduce the Increase the strength of the valve body, resulting in poor safety and reliability

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