CN201412115Y - Front-mounted screw drilling tool bypass valve - Google Patents

Abstract

A front-mounted bypass valve of a screw drill overcomes the defect of the prior bypass valve that is likely to fail resulting from the escaping of a snap spring out of a snap spring groove due to thechange of flow rate. A valve port assembly (4) is fixedly mounted in a radial hole of a valve body (1); a valve jacket (7), a spring (5) and a valve core (3) are sequentially mounted in the inner holeof the valve body (1); the inner hole of the valve body (1) is a shoulder hole with an larger upper part and a smaller lower part; the valve jacket (7) is located on the lower step of the shoulder hole; a snap spring (2) is mounted in the inner hole of the valve body (1) on the upper end of the valve core; and a gap is formed between the upper end face of the valve core (3) and the snap spring (2). The pre-mounted structure with the valve jacket supported on the inner hole step of the valve body can achieve stable operation in high-pressure mud action, and has the advantages of high reliability and prolonged service life.

Description

Front-mounted screw drilling tool bypass valve

Technical field

The utility model relates to a screw drilling tool for well drilling, in particular to a front-mounted screw drilling tool bypass valve.

Background technique

Screw drilling tools are widely used downhole power tools in petroleum exploration and development, and are suitable for drilling/workover operations in special craft wells such as directional wells, horizontal wells, sidetracking and window opening. The screw drilling tool is composed of a bypass valve assembly, a motor assembly, a cardan shaft assembly and a transmission shaft assembly in sequence. The function of the bypass valve is: when drilling, the mud in the annular space is allowed to flow from the valve port hole on the side of the bypass valve body to the inner hole of the drill pipe; It flows into the annular space, prevents the mud from overflowing on the well platform when drilling, and protects the motor effectively. The traditional bypass valve structure adopts a rear-mounted structure, that is, the valve core is installed in the inner hole of the valve body. Due to the assembly relationship of the valve core, spring and valve sleeve, after the valve sleeve is installed, a circlip is installed in the inner hole of the valve sleeve below it. Block the valve body from moving down. Therefore, when working, the force on the circlip is relatively large, and the flow change is likely to cause the circlip to pop out due to unstable force, and the bypass valve will fail, so that the drilling tool cannot work normally, which will greatly affect the utility of the drilling tool.

Utility model content

In order to overcome the disadvantages that the circlip in the bypass valve of the existing screw drilling tool is easy to pop out of the circlip groove due to the unstable force of the flow change, which will cause the bypass valve to fail, make the drilling tool not work normally, and affect the utility of the screw drilling tool. The utility model provides a front-end screw drilling tool bypass valve.

The technical solution adopted by the utility model to solve the technical problem is: the front-mounted screw drilling tool bypass valve, including the valve body, circlip, valve core, valve sleeve, spring, valve port assembly, and the valve port assembly is fixedly installed In the radial hole of the valve body, the valve seat, spring, and valve core are installed in the inner hole of the valve body in sequence. A circlip is installed in the valve inner hole at the upper end of the spool; there is a gap between the upper end surface of the spool and the circlip.

The beneficial effect of the utility model is that, adopting the front structure of the valve sleeve supported by steps in the inner hole of the valve body, the bypass valve can work stably under the action of high-pressure mud, has high reliability, and prolongs the service life of the bypass valve.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the bypass valve of the front screw drilling tool of the present invention.

In the figure: 1. valve body, 2. circlip, 3. valve core, 4. valve port assembly, 5. spring, 6. Y-shaped sealing ring, 7. valve sleeve, 8. O-shaped sealing ring.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is described further.

Fig. 1 is a structural schematic diagram of the bypass valve of the front-mounted screw drilling tool of the present invention, the left half of the figure is in the closed state of the bypass port, and the right half is in the conductive state of the bypass port. The utility model is composed of a valve body 1, a circlip 2, a valve sleeve 7, a valve core 3, a spring 5, a valve port assembly 4, etc., the valve port assembly 4 is fixedly installed in the radial hole of the valve body 1, and the valve sleeve 7. The spring 5 and the valve core 3 are installed in the inner hole of the valve body 1 in turn. The inner hole of the valve body 1 supports the valve sleeve 7. The inner hole of the valve body 1 at the upper end of the valve core 3 is installed with a circlip 2 to realize the high-pressure mud Under the action, it works stably, with high reliability, and prolongs the service life of the bypass valve.

When the screw drilling tool is working, when the mud flow rate is greater than the minimum flow rate, the mud passes through the inner hole of the valve core 3, and a pressure difference is generated at both ends of the hole. The pressure at the upper end is greater than the pressure at the lower end. With the bypass hole closed, the mud flows through the motor, converting pressure energy into mechanical energy. When the pump is stopped on the ground or the flow value is too small and the pressure difference is less than the spring force, the spring 5 will lift the valve core 3 and the bypass hole will be connected. Since the step in the inner hole of the valve body 1 is used as the support seat of the valve sleeve 7, the pressure bearing capacity is strong, which can ensure the reliable operation of the bypass valve under the action of high-pressure mud.

In order to ensure the sealing performance of the bypass valve, the contact surface of the valve sleeve 7, the valve core 3 and the inner hole of the valve body 1 is sealed with an O-shaped rubber sealing ring 8, and the contact surface of the valve sleeve 7 and the valve core 3 is sealed with a Y-shaped rubber sealing ring 6 , Effectively prevent the leakage of mud.

There is a gap between the circlip 2 and the upper end surface of the valve core 3 of the front-mounted screw drilling tool bypass valve of the utility model, and the circlip 2 only plays the role of preventing the valve core 3 from falling out of the valve body 1, and the force it bears during work is very large. Small, the bypass valve will not fail due to the damage of the circlip 2.

Claims (2)

1. A front-mounted screw drilling tool bypass valve, including a valve body, a circlip, a valve core, a valve seat, a spring, and a valve port assembly, the valve port assembly is fixedly installed in the radial hole of the valve body, and the valve The sleeve, spring, and valve core are installed in the inner hole of the valve body in sequence, and the characteristics are: the inner hole of the valve body (1) is a stepped hole with a large upper part and a smaller lower part, and the valve sleeve (7) sits on the lower step of the stepped hole; A jump ring (2) is installed in the inner hole of the valve body (1) at the upper end of the spool (3). 2. The front-end screw drilling tool bypass valve according to claim 1, characterized in that there is a gap between the upper end surface of the valve core (3) and the retaining spring (2).

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