CN103982160A - Novel pressure balancing type plug valve - Google Patents

Abstract

The invention relates to a novel pressure-balanced plug valve for oil and gas wells, in particular to a kelly plug valve, which belongs to downhole devices for oil and gas drilling. It is mainly composed of a valve body, an upper valve seat, a lower valve seat, a valve ball, a shift block, a knob, a stopper, a retaining ring, a snap ring and a spring. There is a cock valve upper cavity between the upper end surface of the valve ball and the valve body, a cock lower cavity between the lower end surface of the valve ball and the valve body, and a stopper is installed between the lower valve seat and the valve ball for positioning. , to limit the upward movement of the lower valve seat; the valve ball is provided with a balance hole, which connects the upper cavity of the plug valve and the lower cavity of the plug valve, and balances the pressure difference between the upper cavity of the plug valve and the lower cavity of the plug valve when the valve ball is closed. The invention has a reasonable structure, overcomes the complex process of setting a balance channel on the valve body, can automatically balance the pressure of the upper and lower cavities of the plug valve, reduces the opening moment, avoids the failure of the rotation of the plug valve, and improves the safety of drilling operations.

Description

A New Pressure Balance Plug Valve

technical field

The invention relates to a novel pressure-balanced cock valve for oil and gas wells, in particular to a kelly cock valve, which belongs to downhole devices for oil and gas drilling.

Background technique

At present, the blowout prevention tools in plug valves used in oil and gas wells are mainly composed of valve body, upper valve seat, lower valve seat, valve ball, knob switch and special knob wrench. The plug valve is normally open. When kick or overflow occurs, use a special wrench to turn the knob clockwise, and drive the valve ball to rotate 90° through the dial to close the channel and prevent blowout accidents in high-pressure drilling.

During the long-term field use, the valve ball is difficult to open when encountering blowout high-pressure fluid after the valve ball is closed, which leads to the rotation failure of the cock valve. Therefore, it is necessary to design a cock valve with a balanced channel. At present, the main method of balancing the pressure of the upper and lower cavities of the plug valve is to open a balance hole on the valve body to communicate with the upper and lower cavities. However, the method of opening holes inside the valve body is difficult to process, the manufacturing process is complicated, and it will affect the strength of the valve body, resulting in a fracture accident of the valve body. Therefore, there is a need for a new blowout prevention tool in a plug valve with a simple structure and automatic pressure balance.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a new type of pressure balanced plug valve, which can balance the pressure difference between the upper and lower chambers when the plug valve is closed, and overcome the rotation failure of the current valve ball caused by the excessive pressure difference. As well as the problem of valve body fracture due to the balance channel, the reliability and rationality of the kelly plug valve are improved, and the safety of drilling operations is ensured.

The technical scheme that the present invention takes is:

The invention is a novel pressure balanced plug valve, mainly composed of a valve body, an upper valve seat, a lower valve seat, a valve ball, a dial block, a knob, a stop block, a retaining ring, a snap ring and a spring. There is a plug valve upper cavity between the upper end surface of the valve ball and the valve body, and a lower plug valve cavity between the lower end surface of the valve ball and the valve body; the bottom end of the lower valve seat is positioned by the steps of the valve body , a spring is set at the lower valve seat and the positioning step of the valve body; a stopper is set between the valve ball and the lower valve seat to limit the upward movement of the lower valve seat, and the stopper is positioned by the knob and the steps of the valve body; the valve ball is balanced The hole connects the upper cavity of the plug valve and the lower cavity of the plug valve, and balances the pressure difference between the upper cavity of the plug valve and the lower cavity of the plug valve when the valve ball is closed.

Advantages and beneficial effects of the present invention: 1. The structure of the present invention is reasonable, which overcomes the complex process of setting a balance channel on the valve body; 2. A balance hole is set on the valve ball to connect the upper and lower chambers, avoiding the sealing between the lower valve seat and the valve ball. When it is not tight, the fluid enters the cavity between the valve ball and the upper and lower valve seats through the gap, causing the knob to be in a high-pressure state; 3. The present invention can automatically balance the pressure. After the valve ball is closed, the lower valve seat is in the blocking position. The valve ball cannot move upward under the restriction of the block, and the valve ball moves upward for a certain distance under the high pressure at the bottom of the well, breaking away from the lower valve seat, and the fluid enters the cavity between the valve ball and the upper and lower valve seats through the gap between the lower valve seat and the valve ball The body enters the upper chamber of the plug valve through the small hole on the valve ball, automatically balances the pressure difference between the upper and lower chambers of the valve ball, and reduces the opening torque; avoids the failure of the plug valve to rotate, and improves the safety of drilling operations.

Description of drawings

Fig. 1 is the structural representation of a kind of novel pressure balance type plug valve of the present invention;

Fig. 2 is a partial view of the valve ball of the present invention under high pressure at the bottom of the well after it is closed.

In the figure: 1. Valve body, 2. Upper cavity of plug valve, 3. Snap ring, 4. Retaining ring, 5. Upper valve seat, 6. Block, 7. Knob, 8. Shift block, 9. Valve ball , 10. Block, 11. Lower valve seat, 12. Spring, 13. Lower cavity of plug valve, 14. Balance hole, 15. Balance hole.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figures 1 and 2, a novel pressure-balanced plug valve of the present invention is mainly composed of a valve body 1, an upper chamber body 2 of the plug valve, a snap ring 3, a retaining ring 4, an upper valve seat 5, a stopper (6 , 10), knob 7, dial block 8, valve ball 9, lower valve seat 11, spring 12, cavity body 13 under the cock valve. There is a cock valve upper cavity 2 between the upper end surface of the valve ball 9 and the valve body 1, and a cock lower cavity 13 between the lower end surface of the valve ball 9 and the valve body 1; the bottom of the lower valve seat 11 The end is positioned by the step of the valve body 1, and a spring 12 is set at the positioning step of the lower valve seat 11 and the valve body 1 to slow down the impact wear of the valve ball 9, the upper valve seat 5 and the lower valve seat 11 caused by vibration during drilling.

As shown in Figures 1 and 2, a stopper 10 is set between the valve ball 9 and the lower valve seat 11 to limit the upward movement of the lower valve seat 11, and the stopper 10 is positioned by the knob 7 and the steps of the valve body 1. Under the action of high-pressure fluid at the bottom of the well, ensure the gap between the valve ball 9 and the lower valve seat 11, and ensure the gap between the valve ball 9 and the lower end surface of the upper valve seat 5, the upper end surface of the lower valve seat 11, and the valve body 1. The cavity 13 under the valve is connected, and the bottom hole fluid can enter the central channel of the valve ball 9 . The valve ball 9 is provided with a balance hole 14 to connect the upper cavity 2 of the cock valve and the lower cavity 13 of the cock valve to balance the pressure difference between the upper cavity 2 of the cock valve and the lower cavity 13 of the cock valve when the valve ball 9 is closed.

As shown in Figure 2, a balance hole (14, 15) is set on the valve ball 9. When the cock valve is opened, the balance hole 15 is used to balance the water eye and the gap between the valve ball 9 and the upper valve seat 5 and the lower valve seat 11. The pressure difference between the cavities reduces the torque when the plug valve is closed; after the plug valve is closed, the valve ball 9 will move upward for a certain distance under the action of the high-pressure fluid at the bottom of the well, and the lower valve seat 11 is restricted by the stopper 10 and cannot move upward. Move, there is a certain gap between the lower valve seat 11 and the valve ball 9. A balance hole 14 is set on the valve ball 9 to connect the upper cavity 2 of the plug valve, and the high pressure of the lower cavity 13 of the plug valve is released through the balance hole 14, which reduces the pressure difference between the upper cavity 2 of the plug valve and the lower cavity 13 of the plug valve , reduce the opening torque of the valve ball 9, and avoid the phenomenon that the plug valve cannot be opened. The balance hole 14 is arranged on the cock 9 , the manufacturing process is simple, and the problem of reducing the strength of the valve body 1 caused by opening holes on the valve body 1 is overcome.

Claims (1)

1. A new type of pressure balanced plug valve, mainly composed of valve body (1), plug valve upper cavity (2), snap ring (3), retaining ring (4), upper valve seat (5), stopper ( 6, 10), knob (7), shift block (8), valve ball (9), lower valve seat (11), spring (12), cock valve lower cavity (13), it is characterized in that: A stopper (10) is set between the valve ball (9) and the lower valve seat (11) to limit the upward movement of the lower valve seat (11), and the stopper (10) is positioned by the steps of the knob (7) and the valve body (1); The valve ball (9) is provided with a balance hole (14), which connects the upper cavity (2) of the plug valve and the lower cavity (13) of the plug valve. When the balance valve ball (9) is closed, the upper cavity (2) and the lower cavity of the plug valve are connected. The differential pressure of the lower cavity (13) of the plug valve.