Combined type polish rod break-off blowout prevention well head device

Abstract

The invention belongs to the technical field of petroleum machinery, and particularly relates to a combined type polish rod breakage blowout prevention wellhead device which comprises a valve body, a horizontally symmetrical penetrating cavity is formed in the valve body, the two ends of the cavity are blocked and fixed through glands, and a vertically-penetrating annular channel is further formed in the valve body and allows an oil pumping polish rod to pass through. Two gate plates are further symmetrically arranged in the valve body corresponding to the horizontally-symmetrical penetrating cavity, a rib plate is arranged on one side of the cover plate, and a right-angle rubber base is fixedly connected between the gate plates and the rib plate through bolts. The device can be automatically triggered after the oil pumping polish rod is broken and disengaged, a blowout channel is rapidly sealed, oil well back pressure spraying is prevented, environment pollution caused by crude oil spraying is avoided, and the device has the function of guaranteeing sealing between a wellhead device and the oil pumping polish rod during normal production of a rod-pumped well. And the wellhead device can be isolated from the shaft when the packing is maintained and replaced by the oil extraction system of the pumping unit.

Description

Technical Field

[0001] The invention belongs to the technical field of oil machinery, and particularly relates to a combined polished rod break-off and blowout prevention wellhead device. Background Art

[0002] During the pumping process of a pumping well, due to long-term use, the polished rod often undergoes mechanical wear or corrosion and suddenly breaks. At this time, it is easy to cause a blowout of the pumping well, which not only causes losses of resources and property, but also the leakage of crude oil will cause great pollution to the environment. Moreover, with the development of digital monitoring in the well site, there is often no one on duty. The existing stuffing box at the wellhead can play a sealing role, but there are deficiencies. After the polished rod at the wellhead breaks off, it cannot be effectively controlled in the first time, resulting in relatively serious environmental pollution at the well site and a large amount of crude oil loss. Currently, the common types of stuffing boxes used for wellhead sealing in oil fields are rack and core eccentric stuffing boxes, double-seal universal deviation-adjusting stuffing boxes, etc. These types of stuffing boxes do not have a polished rod break-off and blowout prevention device. In the case of a sudden break of the polished rod, the wellhead cannot be closed in time and effectively, resulting in the ejection of crude oil and environmental pollution, and there are great potential safety hazards.

[0003] Therefore, we propose a combined polished rod break-off and blowout prevention wellhead device to solve the above problems. Summary of the Invention

[0004] The purpose of the invention is to provide a combined polished rod break-off and blowout prevention wellhead device for the above problems.

[0005] To achieve the above purpose, the invention provides the following technical solution: A combined polished rod break-off and blowout prevention wellhead device includes a valve body. A horizontally symmetric through cavity is arranged in the valve body and is sealed and fixed at both ends by gland covers. A vertically through annular channel is also arranged in the valve body for the pumping polished rod to pass through. Two gate plates are symmetrically arranged in the valve body corresponding to the horizontally symmetric through cavity. A rib plate is arranged on one side of the cover plate. A right-angle rubber seat is fixedly connected between the gate plate and the rib plate by bolts; A gasket is installed in the upper vertical annular channel of the gate body. A plurality of packing rings are sequentially installed above the gasket. A gland is installed at the upper end of the uppermost packing ring. The upper end of the gate body is tightly fixed by a box cover to form a seal by matching the packing rings with the pumping polished rod. A centralizer is also installed above the gland for centralizing the pumping polished rod; An anti-blowout main body is fixedly installed at the upper end of the box cover. The anti-blowout main body is internally provided with a magnet and a steel ball.

[0006] In the above-mentioned combined polished rod break-off blowout prevention wellhead device, an internal thread of the tubing is provided at the lower end of the gate body, which is connected to the tubing in the well. Two guide rail seats are symmetrically welded to the lower end of the gate body. A guide rail bolt is provided on the guide rail seat. The guide rail bolt passes through the guide rail seat and is threadedly connected to the gate body. The part of the guide rail bolt extending into the wall of the gate body serves as a guide rail for the horizontal movement of the gate plate. The gate plate is of an annular structure. A step is provided on one side of the gate plate, and the right-angle rubber seat is installed on the step of the gate plate. A guide groove cooperating with the guide rail bolt is provided on the lower side of the gate plate. A T-shaped groove is provided at the rear side of the gate plate, and a valve rod is clamped in the corresponding T-shaped groove. One end of the valve rod extends outside the gate body and is fixedly connected to a handwheel. A nut is threadedly connected to one end of the valve rod, and a gasket is provided at the connection between the nut and the handwheel.

[0007] In the above-mentioned combined polished rod break-off blowout prevention wellhead device, the washer is of a hollow annular structure and is placed in the vertical annular channel at the upper part of the gate body. Through holes are provided in the packing. A plurality of packings are placed at the upper end of the washer. The gland is of a hollow annular structure and is placed at the upper end of the packing. The cover is threadedly connected to the upper end of the gate body and provides a pressing force to the packing. The centralizing sleeve is of a hollow annular structure and is placed in the gland. Handles are connected to the opposite sides of the cover through pins.

[0008] In the above-mentioned combined polished rod break-off blowout prevention wellhead device, a vertical annular channel is provided inside the blowout prevention main body. An internal thread of the tubing is provided at the lower part of the blowout prevention main body, which is threadedly connected to the upper part of the cover. A horizontal annular channel is provided on one side of the middle part of the blowout prevention main body. A plug is threadedly connected to the inner part of the end of the horizontal annular channel far away from the blowout prevention main body. The steel ball is loaded at the opening of the horizontal annular channel of the blowout prevention main body and can move freely in the horizontal annular channel. Two nylon sleeves clamped outside the magnet are symmetrically installed on the inner side of the upper end of the blowout prevention main body. Both the magnet and the nylon sleeve are of hollow annular structures, and their inner diameters are the same and smaller than that of the steel ball. The steel ball contacts the lower annular opening of the nylon sleeve to form a seal. A magnet pressing cap is also threadedly connected to the upper end of the blowout prevention main body. The magnet pressing cap is of a hollow annular structure.

[0009] In the above-mentioned combined polished rod break-off blowout prevention wellhead device, a sealing ring groove is provided at the rear end of the gate plate, and a first O-ring is installed in the corresponding sealing ring groove.

[0010] In the above-mentioned combined polished rod break-off blowout prevention wellhead device, an annular sealing ring groove is provided outside the plug, and a second O-ring is installed in the corresponding annular sealing ring groove.

[0011] In the above-mentioned combined polished rod break-off blowout prevention wellhead device, two annular sealing ring grooves are provided outside the magnet pressing cap, and a third O-ring is installed in the corresponding annular sealing ring groove.

[0012] In the above-mentioned combined polished rod break-off blowout prevention wellhead device, the vertical annular channel of the blowout prevention main body is communicated with the middle horizontal annular channel, and the diameter of the vertical annular channel below the communication part is smaller than the diameter of the steel ball, and the diameter of the vertical annular channel above the communication part is larger than the diameter of the steel ball.

[0013] Compared with the prior art, the present invention provides a combined polished rod break-off blowout prevention wellhead device, which has the following beneficial effects: 1. The combined polished rod break-off blowout prevention wellhead device can effectively solve the problem that when the polished rod in the pumping unit oil production system breaks off and falls into the wellbore, the wellhead back pressure sprays out from the wellhead, causing environmental pollution, and improves the safety of the mechanical oil production system.

[0014] 2. The combined polished rod break-off blowout prevention wellhead device can effectively solve the sealing problem between the wellhead device and the pumping polished rod during the normal operation of the pumping unit oil production system.

[0015] 3. The combined polished rod break-off blowout prevention wellhead device can effectively solve the problem of isolating the wellhead device from the wellbore when replacing the packing of the pumping unit oil production system.

[0016] In summary: The present invention can automatically trigger the device after the polished rod breaks off, quickly seal the blowout channel, prevent the wellhead back pressure from spraying out, avoid environmental pollution caused by the spraying of crude oil, and has the function of ensuring the seal between the wellhead device and the pumping polished rod during the normal production of the pumping unit well, as well as the function of isolating the wellhead device from the wellbore when replacing the packing of the pumping unit oil production system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic cross-sectional structure diagram of a combined polished rod break-off blowout prevention wellhead device proposed by the present invention; Figure 2 It is a schematic cross-sectional structure diagram of the blowout prevention main body of a combined polished rod break-off blowout prevention wellhead device proposed by the present invention; Figure 3 It is a schematic cross-sectional structure diagram of the installation of the gate main body and the box cover of a combined polished rod break-off blowout prevention wellhead device proposed by the present invention; Figure 4 It is a schematic cross-sectional structure diagram of the gate main body of a combined polished rod break-off blowout prevention wellhead device proposed by the present invention.

[0018] In the figure: 1. Gate body; 2. Guide rail seat; 3. Guide rail bolt; 4. Gate plate; 5. Right-angle rubber seat; 6. Rib plate; 7. Bolt; 8. First O-ring seal; 9. Gland; 10. Valve stem; 11. Handwheel; 12. Gasket; 13. Nut; 14. Washer; 15. Packing; 16. Gland; 17. Centering sleeve; 18. Cover; 19. Pin; 20. Handle; 21. Blowout preventer body; 22. Steel ball; 23. Magnet; 24. Nylon sleeve; 25. Magnet cap; 26. Plug; 27. Second O-ring seal; 28. Third O-ring seal. Detailed implementation mode

[0019] The following embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Embodiment 1

[0020] Please refer to Figures 1-4 , a combined polished rod break-off blowout preventer wellhead device, including a gate body 1. The valve body 1 is provided with a horizontally symmetric through cavity, and both ends are sealed by a gland 9. The valve body 1 is also provided with a vertically through annular channel for the polished rod of the pumping unit to pass through. The right-angle rubber seat 5 is fixed between the rib plate 6 and the gate plate 4 by bolts 7, and is integrally installed in the horizontal cavity of the gate body, and slides horizontally under the push of the valve stem 10. A pair of right-angle rubber seats 5 cooperate with the polished rod of the pumping unit to form a seal; A washer 14 is installed in the upper vertical annular channel of the gate body 1, and several packings 15 and glands 16 are installed in sequence above it. The packings 15 are pressed tightly by the cover 18, so that the packings 15 cooperate with the polished rod of the pumping unit to form a seal. A centering sleeve 17 is installed in the upper groove of the gland 16 for centering the polished rod of the pumping unit; The blowout preventer body 21 is arranged at the upper end of the device, and a magnet 23 and a steel ball 22 are arranged inside. When the polished rod of the pumping unit breaks off and falls into the wellbore, the steel ball 22 in the device quickly closes the oil outlet channel under the action of the magnetic force of the magnet 23 to prevent the back pressure of the oil well from spraying out. Embodiment 2

[0021] Please refer to Figures 1-4, a vertical annular channel is provided inside the blowout preventer body 21, and an internal thread for tubing is provided at the lower part, which is connected to the external thread for tubing on the upper part of the box cover 18 to play a role in connection and sealing. An annular groove is provided on the blowout preventer body 21 to facilitate the retraction of the tool during the machining of the internal thread for tubing. A horizontal annular channel is provided on one side of the middle part of the blowout preventer body 21, and an internal thread is provided on the side away from the blowout preventer body 21 in the channel. The plug 26 is provided with an external thread and is connected to the internal thread in the horizontal annular channel of the blowout preventer body 21. The plug 26 is provided with an annular sealing ring groove, and the second O-ring 27 is installed. The steel ball 22 is installed at the opening of the horizontal annular channel of the blowout preventer body 21 and can move freely in the horizontal annular channel. The vertical annular channel of the blowout preventer body 21 communicates with the middle horizontal annular channel. The diameter of the vertical annular channel below the communication point is smaller than the diameter of the steel ball 22, and the diameter of the vertical annular channel above the communication point is slightly larger than the diameter of the steel ball 22. The steel ball is a solid ball. The magnet 23 is clamped between the two nylon sleeves 24. The nylon sleeves 24 are installed in the upper vertical annular channel of the blowout preventer body 21. Both the magnet 23 and the nylon sleeves 24 are hollow annular structures with the same inner diameter, and the inner diameter is smaller than that of the steel ball 22. The steel ball 22 contacts the lower annular opening of the nylon sleeve 24 to form a seal. The magnet compression cap 25 is a hollow annular structure. The magnet compression cap 25 is provided with an external thread and is connected to the internal thread provided in the upper vertical annular channel of the blowout preventer body. The magnet compression cap 25 is provided with two annular sealing ring grooves, and two of the third O-rings 28 are installed. The magnet compression cap 25 has a fixing effect on the magnet 23 and the nylon sleeves 24. Embodiment 3

[0022] Please refer to Figures 1-4 , the washer 14 is a hollow annular structure and is placed in the upper vertical annular space of the gate body. The packing 15 is provided with through holes, and several of the packings 15 are placed on the washer 14. The gland 16 is a hollow annular structure and is placed on the packing 15. The packing 15 is compressed by the pressure applied by the box cover 18. The centering sleeve is a hollow annular structure and is placed in the gland 16. The box cover 18 is threadedly connected to the upper part of the gate body 1. The handle is connected to the box cover 18 through the pin 19. Embodiment 4

[0023] Please refer to Figures 1-4, an internal thread for an oil pipe is provided at the lower end of the gate body 1 and is connected to the downhole oil pipe. The guide rail seat 2 is welded to the gate body 1. The guide rail bolt 3 passes through the guide rail seat 2 and is threadedly connected to the gate body 1. The part of the guide rail bolt 3 extending into the cavity of the gate body serves as a guide rail for the horizontal movement of the gate plate 4. The gate plate 4 is of an annular structure and is provided with a step. The right-angle rubber seat 5 is installed on the step of the gate plate 4 and is fixedly pressed on the gate plate 4 through a rib plate 6 and a bolt 7. The gate plate 4 is provided with a guide groove that cooperates with the guide rail bolt 3. The gate plate 4 is provided with a sealing ring groove, and the first O-ring 8 is installed therein to cooperate with the horizontal annular cavity wall of the gate plate 4 to form a seal. The gate plate 4 is provided with a T-shaped groove, and the valve stem 10 is installed in the T-shaped groove of the gate plate 4. The gland 9 is threadedly connected to the gate body 1. The gland 9 is provided with a trapezoidal internal thread that cooperates with the trapezoidal external thread of the valve stem 10. The handwheel 11, gasket 12, and nut 13 are installed on the valve stem 10. When the handwheel 11 is rotated clockwise, the gate plate 4 is pushed to move horizontally. When the right-angle rubber seat 5 contacts the polished rod of the pumping unit, a seal is formed.

[0024] The operating principle of the present invention is described as follows: The gate body 1 is provided with a horizontally symmetrical through cavity, and both ends are sealed by the gland 9. The gate body 1 is also provided with a vertically penetrating annular channel for the polished rod of the pumping unit to pass through. The right-angle rubber seat 5 is fixed between the rib plate 6 and the gate plate 4 through the bolt 7 and is integrally installed in the horizontal cavity of the gate body 1 and slides horizontally under the push of the valve stem 10. A pair of right-angle rubber seats 5 cooperate with the polished rod of the pumping unit to form a seal, aiming to isolate the wellhead from the wellbore when replacing the packing. A washer 14 is installed in the upper vertical annular channel of the gate body 1. Above the washer 14, several packings 15 are installed in sequence and are pressed tightly by the box cover 18 to cooperate with the polished rod of the pumping unit to form a seal, aiming to isolate the wellhead from the wellbore when the pumping unit oil production system is working normally. The blowout prevention body 21 is arranged at the upper end of the device and internally contains a magnet 23 and a steel ball 22. When the polished rod of the pumping unit breaks and falls into the wellbore, the steel ball 22 in the device quickly closes the oil outlet channel under the action of the magnetic force of the magnet 23, preventing the backpressure of the oil well from spraying out and avoiding environmental pollution caused by the spraying of crude oil.

[0025] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A combined polished rod break-off blowout prevention wellhead device, comprising a valve body, characterized in that: A horizontally symmetric through cavity is arranged inside the valve body, and both ends are sealed and fixed by gland (9). An annular channel vertically passing through is also arranged inside the valve body for the polished rod for pumping oil to pass through. Two gate plates (4) are symmetrically arranged inside the valve body corresponding to the horizontally symmetric through cavity. A rib plate (6) is arranged on one side of the cover plate. A right-angle rubber seat (5) is fixedly connected between the gate plate (4) and the rib plate (6) by bolts (7). A washer (14) is installed inside the upper vertical annular channel of the gate body (1). A plurality of packing rings (15) are sequentially installed above the washer (14). A gland (16) is installed at the upper end of the uppermost packing ring (15). The upper end of the gate body (1) is tightly fixed by a box cover (18) to form a seal between the packing rings (15) and the polished rod for pumping oil. A centralizing sleeve (17) is also installed above the gland (16) for centralizing the polished rod for pumping oil. A blowout preventer body (21) is fixedly installed at the upper end of the box cover (18). A magnet (23) and a steel ball (22) are arranged inside the blowout preventer body (21).

2. The combined polished rod break-off blowout prevention wellhead device according to claim 1, wherein: The lower end of the gate body (1) is provided with an internal thread for oil pipe, which is connected to the downhole oil pipe. Two guide rail seats (2) are symmetrically welded at the lower end of the gate body (1). A guide rail bolt (3) is arranged on the guide rail seat (2). The guide rail bolt (3) passes through the guide rail seat (2) and is threadedly connected to the gate body (1). The guide rail bolt (3) extends into the wall part of the gate body (1) to serve as a guide rail for the horizontal movement of the gate plate (4). The gate plate (4) is of an annular structure. A step is arranged on one side of the gate plate (4), and the right-angle rubber seat (5) is installed on the step of the gate plate (4). A guide groove matching with the guide rail bolt (3) is arranged on the lower side of the gate plate (4). A T-shaped groove is arranged at the rear side of the gate plate (4), and a valve rod (10) is clamped in the corresponding T-shaped groove. One end of the valve rod (10) extends out of the gate body (1) and is fixedly connected with a handwheel (11). A nut (13) is threadedly connected to one end of the valve rod (10). A gasket (12) is arranged at the connection between the nut (13) and the handwheel (11).

3. The combined polished rod break-off and blowout prevention wellhead device according to claim 1, characterized in that: The washer (14) is of a hollow annular structure and is placed inside the upper vertical annular channel of the gate body (1). The packing rings (15) are provided with through holes. A plurality of the packing rings (15) are placed at the upper end of the washer (14). The gland (16) is of a hollow annular structure and is placed at the upper end of the packing rings (15). The box cover (18) is threadedly connected to the upper end of the gate body (1) and provides a pressing force to the packing rings (15). The centralizing sleeve (17) is of a hollow annular structure and is placed inside the gland (16). The two opposite sides of the box cover (18) are connected with a handle (20) by pins (19).

4. A combined polished rod break-off blowout prevention wellhead device according to claim 1, characterized in that: Inside the blowout preventer body (21), a vertical annular channel is provided. At the lower part of the blowout preventer body (21), an internal thread for the oil pipe is provided, which is threadedly connected to the upper part of the box cover (18). On one side of the middle part of the blowout preventer body (21), a horizontal annular channel is provided, and at the end of the horizontal annular channel far from the blowout preventer body (21), a plug (26) is threadedly connected inside. The steel ball (22) is loaded at the opening of the horizontal annular channel of the blowout preventer body (21) and can move freely in the horizontal annular channel. On the inner side of the upper end of the blowout preventer body (21), two nylon sleeves (24) sandwiching the magnet (23) are symmetrically installed. Both the magnet (23) and the nylon sleeve (24) are of a hollow annular structure, and their inner diameters are the same and smaller than the diameter of the steel ball (22). The steel ball (22) contacts the lower annular opening of the nylon sleeve (24) to form a seal. The upper end of the blowout preventer body (21) is also threadedly connected with a magnet pressing cap (25), and the magnet pressing cap (25) is of a hollow annular structure.

5. The combined polished rod break-off blowout prevention wellhead device according to claim 2, wherein: At the rear end of the gate plate (4), a seal ring groove is provided, and a first O-ring seal (8) is installed corresponding to the seal ring groove.

6. The combined polished rod break-off and blowout prevention wellhead device according to claim 4, wherein: An annular seal ring groove is provided outside the plug (26), and a second O-ring seal (27) is installed in the corresponding annular seal ring groove.

7. A combined polished rod break-off and blowout prevention wellhead device according to claim 4, characterized in that: Two annular seal ring grooves are provided outside the magnet pressing cap (25), and a third O-ring seal (28) is installed in the corresponding annular seal ring groove.

8. The combined polished rod break-off and blowout prevention wellhead device according to claim 4, wherein: The vertical annular channel of the blowout preventer body (21) is communicated with the middle horizontal annular channel. The diameter of the vertical annular channel below the communication point is smaller than the diameter of the steel ball (22), and the diameter of the vertical annular channel above the communication point is larger than the diameter of the steel ball (22).

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