Well plugging device
By designing a well sealing device and utilizing the automatic sealing function of the flow suppression box cover and flow suppression ball, the problems of polished rod damage and oil spraying at the wellhead were solved, achieving the effects of automatic sealing and environmental protection.
Patent Information
- Application Number
- CN202410248228.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-05
- Publication Date
- 2025-09-05
AI Technical Summary
The polished rod of the pumping unit is prone to scraping against the inner wall of the wellhead during its reciprocating motion at the wellhead, causing damage to the polished rod and possible breakage, resulting in oil spraying and environmental pollution.
A well plugging device was designed, including a well plugging device, an upper connecting pipe, and a lower connecting pipe. A flow suppression box cover and a flow suppression ball were used to automatically plug the well when the polished rod broke off. Lubricating oil and polytetrafluoroethylene were used to reduce friction and protect the polished rod from damage.
It can automatically seal the wellhead when the polished rod breaks off, reduce polished rod damage, prevent oil from blowing out, protect the environment, and reduce the frequency of polished rod replacement and production costs.
Smart Images
Figure CN120592579A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of oilfield safety and environmental protection production, and in particular to a well plugging device. Background Art
[0002] The polished rod of a pumping unit connects the pumping unit's donkey-head wire rope, downhole sucker rod, and other equipment. During operation, it reciprocates up and down at the wellhead, driving the sucker rod and pump, allowing oil to enter the tubing from the wellbore, thereby achieving oil collection. Due to the limitations of the wellhead structure and its use, the polished rod has a high surface finish and a diameter of only 28mm, making it susceptible to breaking. During normal production in a pumping well, a sudden increase in downhole load due to uncertain factors can cause the polished rod to break, leading to a blowout. Oil can then be ejected through the polished rod channel at the wellhead, causing losses to oil production and environmental pollution. The cleanup of oil spills is time-consuming and labor-intensive.
[0003] During oil well production, the reciprocating up and down motion of the pumping unit's donkey head drives the downhole pump through the polished rod and sucker rod, pumping oil from the well to the surface. During the pumping process, the seal between the packing box and the polished rod is primarily used to ensure a tight seal at the wellhead. Currently, the most common packing boxes use a pressure cap to squeeze the rubber packing to achieve this seal. This presents two major issues: First, the pressure cap and the polished rod are both made of relatively hard materials, which easily cause friction during movement, causing damage to the polished rod. Second, during the packing tightening process, the rubber packing deforms and continuously conforms to the polished rod to achieve sealing. However, due to uneven force, the polished rod shifts, and the axis of the polished rod does not completely coincide with the axis of the packing box. As the polished rod reciprocates, it scrapes against the inner wall of the wellhead sealer, damaging the polished rod. Summary of the Invention
[0004] (1) Technical issues to be resolved The present invention provides a well plug device to overcome the problems in the prior art in that the polished rod is damaged by scraping against the inner wall of the well plug during reciprocating motion, and the polished rod breaks off after long-term wear, causing overflow.
[0005] (2) Technical solution To achieve the above-mentioned object, the present invention provides a well plugging device, comprising: a well plugging device, an upper connecting pipe and a lower connecting pipe; The well sealer passes through the outer walls of both sides of the lower connecting pipe, and the well sealer includes: a well sealer body and two well sealer baffles, and the two well sealer baffles include: a first well sealer baffle and a second well sealer baffle; The well sealer body is a hollow cylindrical structure, with internal threads at both ends, a first well sealer baffle and a second well sealer baffle respectively provided in the well sealer body, and a through hole provided on the outer wall of the well sealer body; The lower end of the upper connecting pipe is provided with a lower connecting pipe, the upper end of the upper connecting pipe is provided with a flow suppression box body, the flow suppression box body is limited by the flow suppression box cover, a flow suppression ball is provided between the flow suppression box body and the flow suppression box cover, and a polished rod is provided in the upper connecting pipe and the lower connecting pipe; A packing box is provided at the lower end of the flow suppression box body. The flow suppression box body and the packing box are made as one body. A packing gland is provided at the lower end of the packing box. Packing is provided between the packing gland and the upper connecting pipe.
[0006] Preferably, the polished rod is a cylindrical structure, and passes through the lower connecting pipe, the well plug, the upper connecting pipe, the packing, the packing gland, the packing box, the flow suppression box body and the flow suppression box cover from bottom to top.
[0007] Preferably, the flow suppression box cover is a hollow cylindrical structure, the flow suppression box cover is provided with a step on the outer edge, the lower end of the flow suppression box cover is provided with an upward conical surface, the conical surface is used to change the flow direction of the liquid, and the flow suppression box body is provided with a downward conical surface.
[0008] Preferably, the flow suppression ball can move in the annular space formed by the flow suppression box cover, the flow suppression box body and the polished rod.
[0009] Preferably, one end of the well sealer baffle is a cylindrical structure and the other end is provided with a rectangular baffle extending outward from the center; one end of the cylindrical structure of the well sealer baffle is provided with an external thread matching the well sealer body; one end of the rectangular baffle of the well sealer baffle is provided with a half rectangular hole opening outward; the first well sealer baffle and the second well sealer baffle are relatively installed to form a complete rectangular hole.
[0010] Preferably, the flow suppressing ball is a hollow ball filled with hydrogen. The flow suppressing ball can seal the lower end of the flow suppressing box cover under the action of buoyancy and thrust of the well fluid when well fluid injection occurs.
[0011] Preferably, the packing gland is a hollow cylindrical structure, and the packing gland is used to fasten the packing.
[0012] Preferably, lubricating oil is injected into the annular space formed by the flow suppression box cover, the flow suppression box body and the polished rod to protect the polished rod from damage and reduce the number of times the polished rod needs to be replaced.
[0013] Preferably, the packing gland is made of polytetrafluoroethylene, which reduces the friction between the packing gland and the polished rod.
[0014] (3) Beneficial effects The present invention provides a well sealing device, which can automatically seal the wellhead of the pumping unit at the first time when a rod breakage accident occurs at the wellhead of the pumping unit, thereby blocking the oil from gushing out. The well sealing device changes the previous double-layer sealing structure, reduces the friction generated when the light rod deviates during operation, and reduces the damage to the light rod. A flow suppression ball is used between the flow suppression box cover and the flow suppression box body to seal the flow suppression box cover from the inside under the action of downhole pressure at the first time when the light rod breaks and causes oil to gushed out, thereby solving the problem of oil gushing out after the light rod breaks, thereby achieving the purpose of reducing costs and increasing efficiency while protecting the environment from pollution. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 A schematic structural diagram of a well plugging device according to the present invention is shown; Figure 2 A schematic cross-sectional view of a well plugging device according to the present invention is shown.
[0016] Among them: 1: flow suppression box cover; 2: flow suppression ball; 3: flow suppression box body; 4: packing box; 5: packing gland; 6: well sealer body; 7: bare rod; 8: well sealer baffle; 9: well sealer; 10: packing; 11: upper connecting pipe; 12: lower connecting pipe. DETAILED DESCRIPTION
[0017] The present invention is described in detail below with reference to the accompanying drawings and embodiments, providing a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0018] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by “up”, “down”, “left”, “right”, “inside”, “outside”, “top”, “bottom”, etc. are all based on the directions or positional relationships shown in the accompanying drawings. The purpose is only to facilitate the description of the present invention and simplify the description. It does not indicate or imply that the referred parts must have a specific direction, be constructed and operated in a specific direction. Therefore, it cannot be understood as a limitation on the present invention.
[0019] like Figure 1-2 As shown, the present invention provides a well plugging device, comprising: a well plugging device 9, an upper connecting pipe 11 and a lower connecting pipe 12; The well sealing device 9 includes: a well sealing device body 6 and two well sealing device baffles 8, the well sealing device body 6 and the two well sealing device baffles 8, the two well sealing device baffles 8 include: a first well sealing device baffle and a second well sealing device baffle; The well sealing device body 6 is a hollow cylindrical structure. A through hole is provided in the center of the outer wall of the well sealing device body 6. Internal threads are provided at both ends of the well sealing device body 6. A first well sealing device baffle and a second well sealing device baffle are provided in the well sealing device body 6. The well sealing device baffle 8 is threadedly connected to the well sealing device body 6. One end of the well sealing device baffle 8 is a cylindrical structure, and the other end is provided with a rectangular baffle extending outward from the center. The outer wall of one end of the cylindrical structure of the well sealing device baffle 8 is provided with an external thread matching the well sealing device body 6. The well sealing device baffle 8 is provided with a rectangular baffle with a half rectangular hole opening outward at one end. The two well sealing device baffles 8 are installed relative to each other to form a complete rectangular hole, which can allow the polished rod 7 to pass through. The upper and lower arc-shaped surfaces of the well plugging device body 6 can reduce stress concentration, thereby reducing friction when the polished rod 7 deviates during operation; The upper connecting pipe 11 is a hollow cylindrical structure. A lower connecting pipe 12 is provided at the lower end of the upper connecting pipe 11. The upper connecting pipe 11 is threadedly connected to the lower connecting pipe 12. The lower end of the lower connecting pipe 12 is provided with an external thread. The lower connecting pipe 12 is used to install the well sealing device to the wellhead. A flow suppression box body 3 is provided at the upper end of the upper connecting pipe 11. The flow suppression box body 3 is threadedly connected to the upper connecting pipe 11. The flow suppression box body 3 is positioned by the flow suppression box cover 1. A flow suppression ball 2 is provided between the flow suppression box body 3 and the flow suppression box cover 1. The lower end of the flow suppression box body 3 is provided with a packing box 4, and the flow suppression box body 3 and the packing box 4 are made into one body. The lower end of the packing box 4 is provided with a packing gland 5. A packing 10 is provided between the packing gland 5 and the upper connecting pipe 11. The packing gland 5 is used to position and tighten the packing 10. The packing 10 can effectively prevent the fluid from leaking from the gap between the upper connecting pipe 11 and the polished rod 7, ensuring the sealing performance of the device. The packing gland 5 can adjust and replace the packing 10 to adapt to different working conditions and sealing requirements. The polished rod 7 is a cylindrical structure, and the polished rod 7 passes through the lower connecting pipe 12, the well plug 9, the upper connecting pipe 11, the packing 10, the packing gland 5, the packing box 4, the flow suppression box body 3 and the flow suppression box cover 1 in sequence from bottom to top; The flow suppression box cover 1 is a hollow cylindrical structure. The flow suppression box cover 1 is provided with a step on the outer edge, so that the flow suppression box cover 1 and the flow suppression box body 3 can be better fixed and sealed. The lower end of the flow suppression box cover 1 is provided with an upward conical surface, which is used to change the flow direction of the liquid and reduce the resistance of the liquid during the flow process. The flow suppression box body 3 is provided with a downward conical surface. The flow suppression ball 2 can move in the annular space formed by the flow suppression box cover 1, the flow suppression box body 3 and the polished rod 7; The flow suppressor ball 2 is a hollow sphere filled with hydrogen. The flow suppressor ball 2 can cooperate with the flow suppressor box body 3 and the conical surface inside the flow suppressor box cover 1. When the polished rod 7 breaks, the flow suppressor ball 2 can roll to the bottom center position of the flow suppressor box body 3 under the cooperation of the conical surface of the flow suppressor box body 3. When well fluid jetting occurs, the flow suppressor ball 2 follows the conical surface inside the flow suppressor box cover 1 to seal the lower end of the flow suppressor box cover 1 from the inside under the action of buoyancy and the thrust of the well fluid, thereby effectively suppressing well fluid jetting and preventing crude oil loss. The packing gland 5 is a hollow cylindrical structure and is used to fasten the packing 10. The packing gland 5 is made of polytetrafluoroethylene (PTFE), which has better chemical stability, corrosion resistance, and high temperature resistance. PTFE also has the smallest surface tension among solid materials and will not adhere to any substance. The static friction coefficient of PTFE is only 0.04, which is the smallest among plastics. This reduces the friction between the packing gland 5 and the polished rod 7, effectively reducing the friction between the packing gland 5 and the polished rod 7, reducing the wear of the polished rod 7, and thus extending its service life. Lubricating oil is injected into the annular space formed by the flow suppression box cover 1, the flow suppression box body 3 and the polished rod 7 to protect the polished rod 7 from damage and reduce the number of replacement times of the polished rod 7.
[0020] The actual working scenario of the well plugging device is introduced in detail below.
[0021] In actual work, the well sealer device is installed to the wellhead through the external thread provided at the lower end of the lower connecting pipe 12, the first well sealer baffle and the second well sealer baffle are screwed into the two ends of the well sealer body, and the polished rod 7 is passed through the rectangle formed by the first well sealer baffle and the second well sealer baffle, so that the polished rod 7 is placed in the center of the upper connecting pipe 11 and the lower connecting pipe 12, and the upper connecting pipe 11 is used to connect the upper end of the lower connecting pipe 12. The upper end of the upper connecting pipe 11 is inserted into the packing 10 and tightened by the packing gland 5, the packing box 4 and the flow suppression box body 3 are put on the outside of the upper connecting pipe 11, lubricating oil is added to the flow suppression box body 3, the flow suppression ball 2 is placed, and the flow suppression box cover 1 is used to seal it.
[0022] When the polished rod 7 breaks during operation, the lower half of the polished rod 7 will slide down the well under the action of gravity, and the upper half will fall out of the wellhead under the pulling action of the pumping unit. At this time, the running channel of the polished rod 7 is open, and the flow suppression ball 2 will roll onto the running channel of the polished rod 7 under the action of the conical surface inside the flow suppression box body 3 to close the channel. When the well fluid is sprayed upward under the action of pressure, the flow suppression ball 2 will move upward under the action of the well fluid pressure and the hydrogen in the flow suppression ball 2 and cooperate with the conical surface at the lower end of the flow suppression box cover 1 to seal the flow suppression box cover 1 from the inside, completely blocking the well fluid spraying route, effectively suppressing well fluid injection, improving environmental pollution prevention and control efforts, and avoiding crude oil loss.
[0023] It can be understood that the above-mentioned embodiments mentioned in the present invention can be combined with each other to form combined embodiments without violating the principle logic. Due to space limitations, the present invention will not elaborate on them.
[0024] Those skilled in the art will understand that in the above-mentioned method of the specific implementation method, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.
[0025] The well sealing device provided by the present invention can automatically seal the wellhead of the pumping unit at the first time when the rod breaks at the wellhead of the pumping unit, thereby blocking the oil from spraying out. The well sealing device changes the previous double-layer sealing structure, reduces the friction generated when the light rod 7 deviates during operation, and reduces the damage to the light rod 7. The flow suppression ball 2 between the flow suppression box cover 1 and the flow suppression box body 3 is used. At the first time when the light rod 7 breaks and causes oil to spray out, the flow suppression ball 2 closes the flow suppression box cover 1 from the inside under the action of downhole pressure, thereby solving the problem of oil spraying out after the light rod 7 breaks, thereby achieving the purpose of reducing costs and increasing efficiency while protecting the environment from pollution.
[0026] While various embodiments of the present invention have been described above, the above descriptions are intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.
Claims
1. A well plugging device, characterized in that: include: A well sealing device (9), an upper connecting pipe (11), and a lower connecting pipe (12); The well sealing device (9) passes through the outer walls of both sides of the lower connecting pipe (12), and the well sealing device (9) comprises: a well sealing device body (6) and two well sealing device baffles (8), and the two well sealing device baffles (8) comprise: a first well sealing device baffle and a second well sealing device baffle; The well sealing device body (6) is a hollow cylindrical structure, and internal threads are respectively provided at both ends of the well sealing device body (6). A first well sealing device baffle and a second well sealing device baffle are respectively provided in the well sealing device body (6), and a through hole is provided on the outer wall of the well sealing device body (6); A lower connecting tube (12) is provided at the lower end of the upper connecting tube (11), a flow suppression box body (3) is provided at the upper end of the upper connecting tube (11), the flow suppression box body (3) is limited by the flow suppression box cover (1), a flow suppression ball (2) is provided between the flow suppression box body (3) and the flow suppression box cover (1), and a polished rod (7) is provided in the upper connecting tube (11) and the lower connecting tube (12); A packing box (4) is provided at the lower end of the flow suppression box body (3), the flow suppression box body (3) and the packing box (4) are made into one body, a packing gland (5) is provided at the lower end of the packing box (4), and packing (10) is provided between the packing gland (5) and the upper connecting pipe (11).
2. The well plugging device according to claim 1, characterized in that: The polished rod (7) is a cylindrical structure, and the polished rod (7) passes through the lower connecting pipe (12), the well sealing device (9), the upper connecting pipe (11), the packing (10), the packing gland (5), the packing box (4), the flow suppression box body (3) and the flow suppression box cover (1) in sequence from bottom to top.
3. The well plugging device according to claim 1, characterized in that: The flow suppression box cover (1) is a hollow cylindrical structure. The flow suppression box cover (1) is provided with a step on the outer edge. The lower end of the flow suppression box cover (1) is provided with an upward conical surface, which is used to change the flow direction of the liquid. The flow suppression box body (3) is provided with a downward conical surface.
4. The well plugging device according to claim 1, characterized in that: The flow suppression ball (2) can move in an annular space formed by the flow suppression box cover (1), the flow suppression box body (3) and the polished rod (7).
5. The well plugging device according to claim 1, characterized in that: One end of the well sealing device baffle (8) is a cylindrical structure, and the other end is provided with a rectangular baffle extending outward from the center. One end of the cylindrical structure of the well sealing device baffle (8) is provided with an external thread matching the well sealing device body (6). One end of the rectangular baffle of the well sealing device baffle (8) is provided with a half rectangular hole opening outward. The first well sealing device baffle and the second well sealing device baffle are relatively installed to form a complete rectangular hole.
6. The well plugging device according to claim 1, characterized in that: The flow suppression ball (2) is a hollow ball filled with hydrogen. The flow suppression ball (2) can seal the lower end of the flow suppression box cover (1) under the action of buoyancy and thrust of the well fluid when well fluid injection occurs.
7. The well plugging device according to claim 1, characterized in that: The packing gland (5) is a hollow cylindrical structure, and the packing gland (5) is used to fasten the packing (10).
8. The well plugging device according to claim 1, characterized in that: Lubricating oil is injected into the annular space formed by the flow suppression box cover (1), the flow suppression box body (3) and the polished rod (7), thereby protecting the polished rod (7) from damage and reducing the number of times the polished rod (7) needs to be replaced.
9. The well plugging device according to claim 1, characterized in that: The packing gland (5) is made of polytetrafluoroethylene, which reduces the friction between the packing gland (5) and the polished rod (7).