Oil pumping unit underground load unloading device

Abstract

The utility model relates to the technical field of mechanical oil extraction production, in particular to an underground load unloading device of a pumping unit. Comprising a lower supporting assembly and an upper supporting assembly, the lower end of the upper supporting assembly is inserted into the lower supporting assembly in a sliding mode, the upper supporting assembly and the lower supporting assembly are concentric and elastically connected, a lower groove is formed in one side of the upper supporting assembly, and the length direction of the lower groove is parallel to the radial direction of the lower supporting assembly; an upper groove is formed in the upper supporting assembly, the length direction of the upper groove is parallel to the radial direction of the upper supporting assembly, and the upper groove and the lower groove are arranged in a staggered mode. By means of the elastic connection design of the lower supporting assembly and the upper supporting assembly, namely the inner spring and outer spring double buffering structure, buffering can be provided when the clamp is unloaded and impacted, the inertia impact of the underground load is effectively absorbed, and the problems that a beam hanger inclines, a polish rod sealer bends laterally and the clamp is scull-buckled are solved.

Description

Technical Field

[0001] This utility model relates to the field of mechanical oil production technology, specifically to a downhole load unloading device for a pumping unit. Background Technology

[0002] When adjusting the anti-impact distance, pump contact, verifying dynamometer cards, or replacing crank pins, the downhole load on the pumping unit needs to be unloaded. The commonly used unloading method involves installing unloading clips on the polished rod. When the pumping unit is started, its inertia allows the unloading clips to settle on the polished rod seal during the downward movement of the polished rod. Simultaneously, when the load clips above the suspension cable are a certain distance away from the suspension cable, the brakes are engaged. This transfers the downhole load on the pumping unit to the polished rod seal, achieving the unloading purpose.

[0003] Patent document CN221256692U discloses a suspension point load unloading device for oil pumping wells, comprising an upper support part, a support body, an arc-shaped locking part, and a limiting component. The upper support part is shaped like a dome and has an annular upper groove inside. The support body includes a middle support part and a lower support part fixedly connected, with the central axes of the middle support part and the lower support part coinciding. The lower support part has an annular lower groove. The upper support part and the middle support part are threadedly connected. The annular upper groove and the annular lower groove are located at opposite ends of the middle support part, with their openings facing each other. The sidewalls of the upper support part and the support body each have irregularly shaped openings. The irregularly shaped openings on the support body sequentially penetrate the middle support part and the lower support part. The irregularly shaped openings on the sidewalls of the upper support part and the arc-shaped locking part on the sidewalls of the support body... The irregularly shaped openings are connected to each other; the arc-shaped locking part is rotatably disposed between the upper support part and the lower support part, with the top end of the arc-shaped locking part located inside the annular upper groove and the bottom end of the arc-shaped locking part located inside the annular lower groove; the arc-shaped locking part coincides with the central axis of the upper support part and the support body; the limiting component includes an upper limit and a lower limit, the upper limit being an arc-shaped inclined surface, the upper limit being fixedly disposed at the bottom of the annular upper groove, and the lower limit being the bottom of the annular lower groove, the bottom of which is an arc-shaped plane; when the arc-shaped locking part is in the locked state, the arc-shaped locking part rotates to the position corresponding to the irregularly shaped opening and covers the irregularly shaped opening on the side wall of the middle support part, at which time the arc-shaped locking part is limited and locked to the upper support part and the lower support part by the limiting component.

[0004] However, during on-site operation, due to the heavy load and large inertia, the suspension cable is prone to tilting and the bare rod seal may bend after impact. Moreover, it is difficult to control the degree of braking during operation, which poses a great safety hazard.

[0005] Patent document CN217380508U discloses a downhole load unloading device for a pumping unit, comprising an inverted U-shaped hollow shell, which sits on the upper end of the wellhead device and partially surrounds the outside of the sucker rod. An inverted U-shaped piston plate is slidably and sealed inside the shell. Multiple vertical push rods are fixed to the upper end of the piston plate, with the upper end of the push rods penetrating through the top plate of the shell and slidingly engaging with the top plate. A connector is fixed to the lower end of the shell, which communicates with the shell portion below the piston plate. A transverse pin is fixed to the rear left end of the shell, with a baffle fixed to the left end of the pin. An L-shaped support plate is fixed to the front left end of the shell. A longitudinal limiting plate is provided on the left side of the shell, with an opening at the rear end of the limiting plate through which the pin passes. A transverse bolt is threaded to the middle of the limiting plate, and a universal ball is installed at the right end of the bolt, making rolling contact with the outer edge of the sucker rod. To prevent issues such as unloading clamp lock-up, suspension cable tilting, and wellhead device bending caused by heavy loads and high inertia, this device uses a piston plate and push rod to move the sucker rod upwards via the unloading clamp during load unloading. This technical solution can solve the problems of unloading clamp lock-up, suspension cable tilting, and wellhead device bending. However, it requires power to be supplied to the device during load unloading, making it inconvenient to use. Utility Model Content

[0006] The main purpose of this utility model is to provide a downhole load unloading device for oil pumping units that is easy to use and can avoid phenomena such as unloading clamps, suspension rope tilting, and polished rod seal bending caused by heavy loads and large inertia during unloading.

[0007] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0008] A downhole load unloading device for a pumping unit includes a lower support assembly and an upper support assembly. The lower end of the upper support assembly is slidably inserted into the lower support assembly. The upper and lower support assemblies are concentric and elastically connected. A lower groove is formed on one side of the upper support assembly, with its length direction parallel to the radial direction of the lower support assembly. The closed end of the lower groove is arc-shaped and concentric with the lower support assembly. An upper groove is formed on the upper support assembly, with its length direction parallel to the radial direction of the upper support assembly. The closed end is arc-shaped. The closed end of the upper groove is concentric with the upper support component. The upper and lower grooves are staggered. A slider is slidably installed on the outside of the upper support component along its axial direction. The slider is slidably engaged in the opening end of the lower groove. After the slider exits from the opening end of the lower groove, the upper support component can rotate inside the lower support component. A stabilizing component is installed at the lower end of the lower support component. The lower support component is installed on the upper end of the smooth rod seal. The stabilizing component cooperates with the upper end cover of the smooth rod seal to position the lower and upper support components. The smooth rod passes through the closed ends of the lower and upper grooves.

[0009] Specifically, the lower support assembly includes a lower plate, with a lower cylinder concentrically fixed to the upper end of the lower plate, and a protruding edge protruding outward from the upper end of the lower cylinder.

[0010] Specifically, the upper support assembly includes an upper cylinder, with an upper plate concentrically fixed at the upper end of the upper cylinder, and the lower end of the upper cylinder slidably inserted into the lower cylinder. Multiple inner springs are evenly distributed and fixed on the upper end of the lower plate inside the lower cylinder, with the upper ends of the inner springs contacting the lower end of the upper cylinder.

[0011] Specifically, multiple outer springs are evenly distributed and fixed around the lower end of the upper plate on the outer side of the upper cylinder. The upper end of the outer spring is fixedly connected to the lower end of the upper plate, and the lower end of the outer spring is in contact with the upper end of the convex edge.

[0012] Specifically, the outer edge of the upper cylinder is provided with a sliding groove corresponding to the lower groove. The length direction of the sliding groove is parallel to the axial direction of the upper cylinder. A locking block is slidably arranged in the sliding groove, and the slider is fixedly connected to the locking block.

[0013] Specifically, the stabilizing component includes an inverted U-shaped protective cover with an opening corresponding to the opening of the lower groove. Pins are provided through the two free ends of the protective cover. When the lower support component is installed on the smooth rod sealer, the upper end cover of the smooth rod sealer is located inside the protective cover. After the pins are installed on the protective cover, the upper end cover of the smooth rod sealer is restricted between the protective cover pins.

[0014] Specifically, a handle is fixed to the outer edge of the upper plate.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0016] 1. Through the elastic connection design of the lower support component and the upper support component, namely the double buffer structure of inner and outer springs, it can provide buffer when the unloading clamp impacts, effectively absorb the inertial impact of downhole load, and avoid problems such as suspension cable tilting, polished rod seal bending and clamp buckling.

[0017] 2. The upper support component achieves rapid unlocking and rotation through the sliding engagement mechanism between the slider and the lower slot. Combined with the staggered upper and lower slot structure, the light rod forms a closed-loop lock within the slot, which not only ensures the stability of the light rod under load but also simplifies the operation process.

[0018] 3. The stabilizing component consisting of the inverted U-shaped cover and the pin rod, by wrapping the upper end cover of the polished rod seal and pinning it to limit the position, forces the device to align with the wellhead axis, avoids device shaking or displacement caused by load offset, and improves the overall resistance to lateral pressure.

[0019] 4. The load transfer is achieved using a purely mechanical structure, without the need for hydraulic or electrical drive. The load release is completed solely through the downward inertia of the smooth rod and the spring rebound, reducing operational complexity and external dependence, and improving on-site safety.

[0020] 5. The handle design of the upper plate allows manual force to rotate and adjust the alignment of the slots. Combined with the axial sliding linkage of the slide and the locking block, it enables quick alignment and installation of the device and the smooth rod, greatly shortening the operation time and reducing the risk of operational errors. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the device.

[0022] Figure 2 This is a schematic diagram of a smooth rod passing through the upper groove.

[0023] Figure 3 This is a schematic diagram of the lower support component.

[0024] Figure 4 This is a bottom view of the lower support component.

[0025] Figure 5 This is a schematic diagram of the upper support component.

[0026] Figure 6 This is a schematic diagram of the upper cylinder sliding upwards.

[0027] The parts in the attached diagram are named as follows: 1. Lower cylinder; 2. Lower plate; 3. Protruding edge; 4. Protective cover; 5. Pin rod; 6. Upper end cover of the smooth rod sealer; 7. Smooth rod; 8. Lower groove; 9. Inner spring; 10. Upper cylinder; 11. Slider; 12. Slide groove; 13. Outer spring; 14. Upper plate; 15. Handle rod; 16. Upper groove. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0029] Example 1: Refer to Figures 1-6 As shown, a downhole load unloading device for a pumping unit includes a lower support assembly and an upper support assembly. The lower end of the upper support assembly is slidably inserted into the lower support assembly. The upper support assembly and the lower support assembly are concentric and elastically connected.

[0030] A lower groove 8 is provided on one side of the upper support component. The length direction of the lower groove 8 is parallel to the radial direction of the lower support component. The closed end of the lower groove 8 is arc-shaped and concentric with the lower support component.

[0031] The lower support assembly includes a lower plate 2, with a lower cylinder 1 concentrically fixed at the upper end of the lower plate 2, and a protruding edge 3 protruding outward from the upper end of the lower cylinder 1.

[0032] The upper support assembly has an upper groove 16. The length direction of the upper groove 16 is parallel to the radial direction of the upper support assembly. The closed end of the upper groove 16 is arc-shaped and concentric with the upper support assembly.

[0033] The upper support assembly includes an upper cylinder 10, with an upper plate 14 concentrically fixed to its upper end. A handle 15 is fixed to the outer edge of the upper plate 14. The lower end of the upper cylinder 10 is slidably inserted into the lower cylinder 1. Multiple inner springs 9 are evenly distributed and fixed to the upper circumference of the lower plate 2 inside the lower cylinder 1, with the upper ends of the inner springs 9 contacting the lower end of the upper cylinder 10. Multiple outer springs 13 are evenly distributed and fixed to the lower circumference of the upper plate 14 on the outer side of the upper cylinder 10. The upper ends of the outer springs 13 are fixedly connected to the lower end of the upper plate 14, and the lower ends of the outer springs 13 contact the upper end of the protruding edge 3.

[0034] The upper slot 16 and the lower slot 8 are staggered. The smooth rod 7 passes through the closed ends of the lower slot 8 and the upper slot 16.

[0035] A slider 11 is slidably disposed on the outer side of the upper support assembly along its axial direction. The slider 11 is slidably engaged in the opening end of the lower groove 8. After the slider 11 is disengaged from the opening end of the lower groove 8, the upper support assembly can rotate within the lower support assembly. Specifically, a groove 12 corresponding to the lower groove 8 is opened on the outer edge of the upper cylinder 10. The length direction of the groove 12 is parallel to the axial direction of the upper cylinder 10. A locking block is slidably disposed in the groove 12, and the slider 11 is fixedly connected to the locking block.

[0036] When it is necessary to unload the downhole load, the slider 11 moves upward and exits from the lower groove 8. The upper cylinder 10, upper plate 14, outer spring 13, and slider 11 are rotated by the lever 15. When the opening ends of the upper groove 16 and lower groove 8 are aligned, the lower plate 2 sits on the upper end cover 6 of the polished rod sealer, and the polished rod 7 is located within the lower groove 8 and upper groove 16. Then, by rotating the upper cylinder 10, upper plate 14, outer spring 13, and slider 11 by the lever 15, the upper groove 16 and lower groove 8 are misaligned, preventing the upper and lower support components from separating from the polished rod 7. When the slider 11 aligns with the opening end of the lower groove 8, the slider 11 slides and engages within the opening end of the lower groove 8, thereby limiting the upper and lower support components in the circumferential direction. At this time, the upper end of the inner spring 9 is tightly pressed against the lower end of the upper cylinder 10, and the lower end of the outer spring 13 is tightly pressed against the upper end of the flange 3.

[0037] An unloading clamp is installed on the polished rod 7 section above the upper plate 14. The polished rod 7 is moved downward by the pumping unit. When the unloading clamp hits the upper plate 14, the upper support assembly can move downward within the lower support assembly, and the inner spring 9 and outer spring 13 are compressed. After the unloading clamp hits the upper plate 14, it can buffer the unloading clamp and avoid phenomena such as unloading clamp buckling, suspension cable tilting, and polished rod seal bending caused by heavy downhole load and large inertia. When the load clamp above the suspension cable is separated from the suspension cable by a certain distance, the pumping unit brake can be tightened.

[0038] Example 2: Based on Example 1, referring to... Figures 1-4 As shown, a stabilizing component is provided at the lower end of the lower support component. The lower support component is installed on the upper end of the smooth rod seal. The stabilizing component cooperates with the upper end cover 6 of the smooth rod seal to position the lower support component and the upper support component.

[0039] The stabilizing component includes an inverted U-shaped protective cover 4, the open end of which corresponds to the open end of the lower groove 8. Pins 5 are provided through the two free ends of the protective cover 4. When the lower support component is installed on the smooth rod sealer, the upper end cover 6 of the smooth rod sealer is located inside the protective cover 4. After the pins 5 are installed on the protective cover 4, the upper end cover 6 of the smooth rod sealer is restricted between the pins 5 of the protective cover 4.

[0040] After the lower plate 2 is placed on the upper end cover 6 of the smooth rod seal, the upper end cover 6 of the smooth rod seal is located inside the protective cover 4. Then, the pin 5 is installed on the protective cover 4, so that the upper end cover 6 of the smooth rod seal is located between the protective cover 4 and the pin 5. At this time, the lower support assembly and the upper support assembly are stabilized on the upper end cover 6 of the smooth rod seal, which can improve the stability of the device.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A downhole load unloading device for a pumping unit, comprising a lower support assembly and an upper support assembly, characterized in that, The lower end of the upper support component is slidably inserted into the lower support component. The upper and lower support components are concentric and elastically connected. A lower groove (8) is provided on one side of the upper support component. The length direction of the lower groove (8) is parallel to the radial direction of the lower support component. The closed end of the lower groove (8) is arc-shaped and concentric with the lower support component. An upper groove (16) is provided on the upper support component. The length direction of the upper groove (16) is parallel to the radial direction of the upper support component. The closed end of the upper groove (16) is arc-shaped and concentric with the upper support component. The upper groove (16) and the lower groove (8) are concentrically offset. A slider (11) is slidably provided on the outer side of the upper support component along its axial direction. The slider (11) is slidably engaged in the opening end of the lower groove (8). After the slider (11) exits from the opening end of the lower groove (8), the upper support component can rotate in the lower support component. A stabilizing component is provided at the lower end of the lower support component. The lower support component is installed on the upper end of the smooth rod seal. The stabilizing component cooperates with the upper end cover (6) of the smooth rod seal to position the lower support component and the upper support component. The smooth rod (7) passes through the closed ends of the lower groove (8) and the upper groove (16).

2. The downhole load unloading device for an oil pumping unit according to claim 1, characterized in that, The lower support assembly includes a lower plate (2), and a lower cylinder (1) is concentrically fixed at the upper end of the lower plate (2). The upper end of the lower cylinder (1) is machined with a protruding edge (3) that protrudes outward.

3. The downhole load unloading device for a pumping unit according to claim 2, characterized in that, The upper support assembly includes an upper cylinder (10), with an upper plate (14) fixed concentrically at the upper end of the upper cylinder (10). The lower end of the upper cylinder (10) is slidably inserted into the lower cylinder (1). Multiple inner springs (9) are evenly distributed and fixed on the upper end of the lower plate (2) inside the lower cylinder (1). The upper end of the inner springs (9) is in contact with the lower end of the upper cylinder (10).

4. The downhole load unloading device for a pumping unit according to claim 3, characterized in that, Multiple outer springs (13) are evenly distributed and fixed on the lower circumference of the upper plate (14) on the outer side of the upper cylinder (10). The upper end of the outer spring (13) is fixedly connected to the lower end of the upper plate (14), and the lower end of the outer spring (13) is in contact with the upper end of the protrusion (3).

5. The downhole load unloading device for a pumping unit according to claim 3, characterized in that, The upper cylinder (10) has a sliding groove (12) on its outer edge that corresponds to the lower groove (8). The length direction of the sliding groove (12) is parallel to the axial direction of the upper cylinder (10). A locking block is slidably arranged in the sliding groove (12), and the slider (11) is fixedly connected to the locking block.

6. The downhole load unloading device for a pumping unit according to claim 2, characterized in that, The stabilizing component includes an inverted U-shaped shield (4), the opening of which corresponds to the opening of the lower groove (8). Pins (5) are provided through the two free ends of the shield (4). When the lower support component is installed on the smooth rod sealer, the upper end cover (6) of the smooth rod sealer is located inside the shield (4). After the pins (5) are installed on the shield (4), the upper end cover (6) of the smooth rod sealer is restricted between the shield (4) and the pins (5).

7. The downhole load unloading device for a pumping unit according to claim 3, characterized in that, A handle (15) is fixed to the outer edge of the upper plate (14).

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