Energy-saving pumping unit

Abstract

The invention provides an energy-saving oil pumping unit, which belongs to the technical field of oil exploitation equipment and comprises a support frame, a winding wheel body, a motor, a first traction piece, a second traction piece, an oil pumping rod and an adjustable counterweight assembly. The winding wheel body is rotationally arranged on the supporting frame; the motor is arranged on the supporting frame, is in transmission connection with the winding wheel body and is used for driving the winding wheel body to rotate; the first traction piece and the second traction piece are respectively wound on two opposite sides of the winding wheel body; the sucker rod is connected to the free end of the first traction piece; the adjustable counterweight assembly is connected to the free end of the second traction piece and used for balancing the total gravity of the sucker rod and the sucker rod underground load by adjusting the gravity of the counterweight of the adjustable counterweight assembly. According to the energy-saving oil pumping unit, the total gravity of the oil pumping rod and the load of the oil pumping rod is matched in real time, so that the driving motor only needs to provide a small amount of power for overcoming the friction force of the system to complete lifting operation, and the energy consumption in the lifting process of the oil pumping unit is reduced.

Description

Technical Field

[0001] This invention belongs to the field of oil extraction equipment technology, and more specifically, relates to an energy-saving oil pumping unit. Background Technology

[0002] In oil extraction, the walking beam pumping unit is the most widely used lifting equipment. The process of lifting the sucker rod and downhole fluid column is the main power-consuming stage, requiring an electric motor to overcome a load of several tons, resulting in enormous energy consumption. Traditional pumping units typically use fixed counterweights (such as the counterweight at the tail of the walking beam) to balance part of the load, but the balancing effect is static and coarse, unable to be precisely adjusted according to changes in downhole load (fluid column height, density, etc.).

[0003] In actual production, the load conditions of oil wells fluctuate over time, and a fixed balancing method often leads to the system being in a state of "underbalance" or "overbalance" for a long time. In an underbalanced state, the motor still needs to output huge power, resulting in high energy consumption; in an overbalanced state, although the energy consumption for lifting is reduced, it will lead to additional power consumption for braking during lowering and may cause equipment shock. Summary of the Invention

[0004] The purpose of this invention is to provide an energy-saving pumping unit that can match the gravity of the counterweight with the total gravity of the sucker rod and its load in real time, thereby forming a nearly balanced system during the lifting phase. This allows the drive motor to complete the lifting operation with only a small amount of power to overcome the system's friction, fundamentally reducing the energy consumption of the pumping unit during the lifting process.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: to provide an energy-saving oil pumping unit, comprising: Supporting framework; The winch reel is rotatably mounted on the support frame; An electric motor is mounted on the support frame and is connected to the winch wheel body for driving the winch wheel body to rotate. The first traction component and the second traction component are respectively wound around opposite sides of the winch wheel body; The sucker rod is connected to the free end of the first traction member; An adjustable counterweight assembly is connected to the free end of the second traction member. The adjustable counterweight assembly is used to balance the total weight of the sucker rod and the downhole load of the sucker rod by adjusting the weight of its counterweight.

[0006] In one possible implementation, the adjustable reconfigurable component includes: The counterweight box is connected to the free end of the second traction component; The liquid storage tank contains a counterweight liquid; An infusion line connects the counterweight box and the storage tank; An infusion pump, located on the infusion pipeline, is used to drive the counterweight liquid to transfer between the counterweight box and the storage tank, so as to adjust the total weight of the adjustable counterweight assembly.

[0007] In one possible implementation, the adjustable counterweight assembly further includes a controller and a gravity sensor, the gravity sensor being used to detect the load on the sucker rod side, and the controller controlling the operation of the infusion pump based on the signal from the gravity sensor to automatically adjust the total gravity of the adjustable counterweight assembly.

[0008] In one possible implementation, the electric motor is optionally connected to the winch body via a first clutch, and the system further includes: The generator is mounted on the support frame and is optionally connected to the winch wheel via a second clutch. An energy storage device is electrically connected to the generator; The descent and return phase of the sucker rod is the power generation phase. During this phase, the electric motor is disconnected from the winch body via a first clutch, and the generator is connected to the winch body via a second clutch. The weight of the adjustable counterweight assembly is adjusted to be less than the total weight of the sucker rod and its downhole load. Under the influence of gravity, the sucker rod drives the winch body to rotate via the first traction component, thereby driving the generator to generate electricity. The generated electrical energy is stored in the energy storage device.

[0009] In one possible implementation, a braking device is also included, which is disposed on the winch wheel body and is used to brake the winch wheel body.

[0010] In one possible implementation, the first traction member and the second traction member are two free ends formed after the same continuous rope is wound around the winch body.

[0011] In one possible implementation, the winch wheel body includes a rim and a hub arranged coaxially, and spokes connecting the two; the winch wheel body is rotatably connected to the support frame by means of a bearing through a shaft that passes through and is fixed to the hub; the outer circumferential surface of the rim is provided with an annular groove extending circumferentially, and the first traction member and the second traction member are accommodated in the annular groove and wound around the rim.

[0012] In one possible implementation, an internal gear ring is coaxially fixed to the inner side of the wheel rim; the electric motor is selectively connected to a transmission gear meshing with the internal gear ring via a first clutch and the generator is connected to a second clutch via a second clutch.

[0013] In one possible implementation, a speed detector is also included, which is used to detect the rotational speed of the winch wheel; when the speed detector detects that the speed of the winch wheel exceeds a preset value, the braking device applies braking to the winch wheel.

[0014] In one possible implementation, the counterweight box has a liquid inlet at the top and a liquid outlet at the bottom; The infusion pipeline includes a first pipeline connecting the inlet and the infusion pump, and a second pipeline connecting the outlet and the infusion pump. The first pipeline is equipped with a first control valve, and the second pipeline is equipped with a second control valve.

[0015] The beneficial effects of the energy-saving pumping unit provided by this invention are as follows: Compared with the prior art, the energy-saving pumping unit of this invention, through the setting of an adjustable counterweight assembly consisting of a fluid pump, fluid pipeline, counterweight box and storage tank, and the structural design of the winch body driving the sucker rod and counterweight box to move in opposite directions, drives the counterweight fluid to transfer bidirectionally between the counterweight box and the storage tank, realizing the real-time dynamic adjustment of the counterweight gravity on the sucker rod and the total weight of the downhole load. This not only solves the static coarse balance problem of traditional fixed balance blocks being unable to cope with load fluctuations such as changes in liquid column height and density, but also forms a near-balanced system during the lifting stage, allowing the motor to provide only a small amount of power to overcome the system friction to complete the lifting operation. This fundamentally solves the problem of high energy consumption in the underbalanced state and significantly reduces the energy consumption of the pumping unit during the lifting process.

[0016] With the increasing maturity of wind and solar power technologies, coupled with the significant reduction in the electricity required for operation of the energy-saving pumping unit of this invention, using wind and solar power to provide power for the pumping unit has become a practical and feasible solution. This directly eliminates the need for laying power cables and other power supply facilities in remote, uninhabited oilfield areas. Wind and solar power generation equipment of corresponding power can be matched and installed according to the actual installed power of the pumping unit to supply the power required for its operation, fundamentally solving the problem of power supply in the field. Oilfield extraction areas are usually located in remote wilderness areas, and drilling rigs generally rely on their own diesel engines as a power source. Laying power cables for the pumping unit after well completion is difficult and costly. For decades, the global oilfield industry has generally used cable laying to provide power to pumping units. The low-energy consumption characteristics of this invention break the limitations of this traditional power supply mode. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the main structure of an energy-saving oil pumping unit provided in an embodiment of the present invention; Figure 2 This is a top view of an energy-saving oil pumping unit provided in an embodiment of the present invention; Figure 3 This is a left-side structural schematic diagram of an energy-saving oil pumping unit provided in an embodiment of the present invention; Figure 4 This is a cross-sectional structural diagram of the winch wheel body provided in an embodiment of the present invention.

[0019] Explanation of reference numerals in the attached figures: 1. Support frame; 11. Rectangular frame; 12. Column; 13. Connecting beam; 14. Support frame; 2. Winch wheel body; 21. Wheel rim; 211. Annular groove; 22. Wheel hub; 23. Wheel spoke; 24. Shaft; 25. Internal gear ring; 3. Electric motor; 4. First traction component; 5. Second traction component; 6. Sucker rod; 7. Adjustable counterweight assembly; 71. Counterweight box; 72. Liquid storage tank; 73. Infusion pump; 74. Infusion pipeline; 741. First pipeline; 742. Second pipeline; 743. First control valve; 744. Second control valve; 8. Generator; 9. Braking device. Detailed Implementation

[0020] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0021] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0022] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0024] Please see Figures 1 to 4 The present invention will now describe an energy-saving oil pumping unit. The energy-saving oil pumping unit includes a support frame 1, a winch wheel 2, a motor 3, a first traction component 4, a second traction component 5, a sucker rod 6, and an adjustable counterweight assembly 7.

[0025] The support frame 1 is an H-beam welded frame structure, located next to the oil well in the oilfield. Specifically, the support frame 1 includes a horizontally placed rectangular frame 11 at its top. Each of the four corners of the rectangular frame 11 is supported by a column 12, and adjacent columns 12 are fixedly connected by connecting beams 13. Two support frames 14 are arranged opposite each other at the middle of the two long side beams of the rectangular frame 11. A winch wheel 2 is longitudinally positioned inside the rectangular frame 11, between the two support frames 14. A rotating shaft 24 is axially inserted and fixed in the middle of the winch wheel 24, with both ends supported on the support frames 14 on the same side, and rotatably connected to the support frames 14 via bearings.

[0026] In this example, the winch wheel 2 consists of a rim 21, a hub 22, and spokes 23. The hub 22 is coaxially disposed inside the rim 21, and multiple spokes 23 are evenly connected circumferentially between the hub 22 and the rim 21. The aforementioned shaft 24 passes through and is fixed to the hub 22. A circumferentially extending annular groove 211 is provided on the outer circumferential surface of the rim 21. The aforementioned first traction member 4 and second traction member 5 are accommodated within the annular groove 211 and wound around the rim 21.

[0027] In this embodiment, the aforementioned motor 3 is mounted on the aforementioned rectangular frame 11, and its output end is connected to the winch wheel 2 for transmission, providing power for the rotation of the winch wheel 2. The aforementioned first traction member 4 and second traction member 5 are two free ends formed after the same continuous rope is wound around the wheel rim 21, and the first traction member 4 and the second traction member 5 are located on opposite sides of the wheel rim 21. The aforementioned sucker rod 6 is connected to the free end of the first traction member 4, while the adjustable counterweight assembly 7 is connected to the free end of the second traction member 5. When the winch wheel 2 rotates, the sucker rod 6 and the adjustable counterweight assembly 7 move in opposite directions under the traction of the first traction member 4 and the second traction member 5, respectively.

[0028] In application, the aforementioned adjustable counterweight assembly 7 specifically includes a counterweight box 71, a liquid storage tank 72, an infusion pipeline 74, and an infusion pump 73. The counterweight box 71 is connected to the free end of the second traction member 5 as a counterweight bearing component, and has a accommodating chamber inside. The liquid storage tank 72 is located on the ground and stores counterweight liquid, which is the medium for adjusting the counterweight. The infusion pipeline 74 connects the counterweight box 71 and the liquid storage tank 72. The infusion pump 73 is connected in series on the infusion pipeline 74 and is configured as a bidirectional pump to drive the counterweight liquid to transfer between the counterweight box 71 and the liquid storage tank 72, thereby adjusting the total weight of the counterweight box 71.

[0029] This invention provides an energy-saving pumping unit. Compared with the prior art, it features an adjustable counterweight assembly 7 consisting of a pump 73, a pipeline 74, a counterweight box 71, and a storage tank 72. This assembly, combined with a winch wheel 2 driving the sucker rod 6 to move in opposite directions between the counterweight box 71 and the storage tank 72, enables bidirectional transfer of the counterweight fluid between the counterweight box 71 and the storage tank 72. This achieves real-time dynamic adjustment of the counterweight's gravity on the sucker rod 6 and the total downhole load. It solves the problem of static, coarse balancing that traditional fixed counterweights cannot handle with load fluctuations such as changes in liquid column height and density. Furthermore, it creates a near-balanced system during the lifting phase, allowing the motor 3 to provide only a small amount of power to overcome system friction to complete the lifting operation. This fundamentally solves the problem of high energy consumption in an underbalanced state, significantly reducing energy consumption during the pumping unit's lifting process.

[0030] In some embodiments, the adjustable counterweight assembly 7 further includes a controller and a gravity sensor. The gravity sensor is installed at the connection point between the sucker rod 6 and the first traction member 4 (or at the force-bearing part of the top of the sucker rod 6). This gravity sensor can collect the total load data of the sucker rod 6 and the downhole fluid column in real time (e.g., when the fluid column height increases, causing the load to increase from 5 tons to 6 tons, the gravity sensor synchronously outputs a corresponding electrical signal). The controller pre-stores a matching algorithm model between the load and the counterweight fluid volume. Its input terminal is connected to the gravity sensor signal, and its output terminal is electrically connected to the control module of the infusion pump 73. In actual oil production operations, when the well load fluctuates (e.g., changes in the reservoir's fluid supply capacity lead to an increase in the fluid column density), the gravity sensor immediately transmits the changed load signal to the controller. The controller calculates the required counterweight adjustment amount using an algorithm model and then automatically sends an operating command to the fluid pump 73. If the load increases, the controller controls the fluid pump 73 to start forward, pumping the counterweight fluid from the storage tank 72 into the counterweight box 71 through the fluid pipeline 74, increasing the total weight of the adjustable counterweight assembly 7. If the load decreases (e.g., the fluid column height decreases), the controller controls the fluid pump 73 to run in reverse, pumping some of the counterweight fluid from the counterweight box 71 back to the storage tank 72, reducing the total weight of the counterweight. The entire adjustment process requires no manual intervention, achieving dynamic synchronous matching between the counterweight and the load.

[0031] In some embodiments, please refer to Figures 1 to 4 The energy-saving oil pumping unit provided by the present invention also includes a generator 8 and a storage device. In application, the electric motor 3 is selectively connected to the winch body 2 via a first clutch (power is transmitted when the first clutch is engaged and cut off when it is disengaged); the generator 8 is mounted on the rectangular frame 11 and is selectively connected to the winch body 2 via a second clutch; the storage device is electrically connected to the generator 8 via a wire and is used to store the electrical energy generated by the generator.

[0032] In practical applications, actual oil production operations are divided into two stages: Firstly, during the lifting operation phase: at this time, the first clutch is engaged and the second clutch is disengaged. The controller controls the fluid pump 73 to adjust the gravity of the counterweight box 71 to a near-balanced state based on the total gravity of the sucker rod 6 detected by the gravity sensor and the downhole load. The motor 3 only needs to output a small amount of power to overcome the friction of the system, which can drive the sucker rod 6 to lift through the winch wheel 2, thus fundamentally reducing the lifting energy consumption. Secondly, the descent and return phase: After the sucker rod 6 is raised to the preset height, the first clutch disengages (cuts off the power connection of the motor 3 to avoid the motor 3 idling and consuming energy), and the second clutch engages (establishes the transmission relationship between the winch wheel 2 and the generator 8). At the same time, the controller sends a command to the fluid pump 73 to adjust the total weight of the counterweight box 71 to be less than the total weight of the sucker rod 6 and its load. At this time, the sucker rod 6 falls naturally under the gravity difference of itself and the downhole fluid column. The first traction component 4 pulls the winch wheel 2 to rotate in the opposite direction. The rotation of the winch wheel 2 is transmitted to the generator 8 through the second clutch, driving the generator 8 to cut magnetic field lines to generate electrical energy. The generated electrical energy is transmitted to the storage device in real time through the wire. When the subsequent lifting phase occurs, the storage device can directly power the motor 3 (or supplement the power grid), forming a cycle of "potential energy-electrical energy-kinetic energy".

[0033] In some embodiments, an internal gear ring 25 is coaxially fixed to the inner side of the wheel rim 21; the motor 3 is selectively connected to a transmission gear meshing with the internal gear ring 25 via a first clutch and the generator 8 is selectively connected via a second clutch.

[0034] Among them, the clutch, transmission gear, and internal gear ring 25 are all existing technologies. Clutch: A mechanical component in the prior art used for selectively transmitting power, which has the function of transmitting torque when engaged and cutting off power when disengaged, and can be controlled by electronic or mechanical means; Transmission gear: A toothed power transmission component in the prior art, which realizes torque transmission through tooth surface meshing, and has the characteristics of high transmission efficiency and strong stability; Internal gear ring 25: A ring transmission component with teeth on the inner side in the prior art, which can realize coaxial reverse or same-direction power transmission when meshing with external transmission gear, and has a better load-bearing capacity than external meshing transmission.

[0035] In specific applications, an internal gear ring 25 is coaxially mounted on the inner side of the rim 21 of the winch wheel body 2 by welding or bolting; the output shaft of the motor 3 is fixedly connected to the input end of the first clutch via a coupling, and the output end of the first clutch is fixedly connected to the first transmission gear; the input shaft of the generator 8 is fixedly connected to the input end of the second clutch via a coupling, and the output end of the second clutch is fixedly connected to the second transmission gear; both the first transmission gear and the second transmission gear mesh with the inner teeth of the internal gear ring 25; and both the first clutch and the second clutch are electrically connected to the aforementioned controller.

[0036] During the lifting operation, the controller, based on the total weight of the sucker rod 6 and the downhole load (e.g., 7 tons) detected by the gravity sensor, controls the adjustable counterweight assembly 7 to adjust the weight of the counterweight box 71 to 6.8 tons (close to the load weight); at the same time, it sends an "engage" command to the first clutch and an "disengage" command to the second clutch. After the first clutch engages, the power of the motor 3 is transmitted to the internal gear ring 25 through the first transmission gear, driving the winch wheel 2 to rotate in the forward direction, and pulling the sucker rod 6 upward through the first traction component 4. At this time, the motor 3 only needs to output power to overcome the system friction to complete the operation, and the battery can simultaneously supplement the power supply to the motor 3. During the return trip to generate electricity, after the sucker rod 6 is raised to the preset height, the controller automatically switches modes, sending a "disengage" command to the first clutch (cutting off the power of the motor 3 to avoid idling and energy consumption) and a "engage" command to the second clutch (establishing the transmission link between the winch wheel 2 and the generator 8). At the same time, the controller controls the fluid pump 73 to adjust the weight of the counterweight box 71 to 6.2 tons (less than the total load weight of 7 tons). The sucker rod 6 falls naturally under the gravity difference of itself and the downhole fluid column, pulling the winch wheel 2 to rotate in the opposite direction through the first traction component 4. The internal gear ring 25 rotates in the opposite direction synchronously with the wheel ring 21, thereby meshing and driving the second transmission gear to rotate. The second transmission gear transmits torque to the generator 8 through the second clutch, driving the generator 8 to generate electricity. The generated electrical energy is processed by the rectifier module and stored in the storage device to provide supplementary energy for the next lifting stage or to input electrical energy into the power grid.

[0037] In some embodiments, please refer to Figures 1 to 4 The energy-saving pumping unit provided by this invention also includes a braking device 9 and a speed detector. The braking device 9 is a brake, disc brake, or drum brake mechanism suitable for braking the rotating shaft 24 / rotating wheel in the prior art, which can decelerate and stop the rotating parts through friction. The speed detector is a speed sensor in the prior art, used to collect the rotation speed of the rotating parts in real time and output an electrical signal.

[0038] In practical applications, the braking device 9 is mounted on the rectangular frame 11, located on one side of the wheel rim 21, and directly acts on the wheel rim 21 to achieve braking. The speed detector is correspondingly arranged on the side of the shaft 24 or the winch wheel 2 to detect the actual rotation speed of the winch wheel 2 in real time and transmit the speed signal to the controller in real time.

[0039] During normal operation of the pumping unit, during the lifting phase, the controller adjusts the adjustable counterweight to match the load based on the gravity sensor signal. The motor 3 drives the winch wheel 2 to rotate at a constant speed through the first clutch, transmission gear, and internal gear ring 25, with the speed within the preset safety value. During the return generation phase, the controller adjusts the counterweight to be less than the total weight of the sucker rod 6 and the downhole load. The sucker rod 6 falls, causing the winch wheel 2 to rotate and drive the generator 8 to generate electricity. At this time, the speed is also maintained within a reasonable range.

[0040] When abnormal conditions occur, such as lag in adjustable counterweight adjustment, sudden large fluctuations in downhole load, jamming of transmission components, or abnormal reduction in the falling resistance of sucker rod 6, causing the speed of winch wheel 2 to exceed the preset safety value, the speed detector will immediately feed back the overspeed signal to the controller. The controller will then trigger the braking device 9 to start. The braking device 9 will quickly decelerate and brake the winch wheel 2 through friction braking, bringing the speed back to the safe range and preventing the equipment from going out of control.

[0041] In some embodiments, please refer to Figure 1 A liquid inlet is pre-set at the top of the counterweight box 71, and a liquid outlet is pre-set at the bottom (near the lowest point of the bottom of the counterweight box 71 to ensure that the counterweight liquid inside the box can be completely discharged). Both the liquid inlet and the liquid outlet are equipped with sealing joints to prevent liquid leakage. The infusion pipeline 74 is divided into two branches: one end of the first pipeline 741 is fixedly connected to the liquid inlet at the top of the counterweight box 71 through a sealing joint, and the other end is connected to the liquid outlet of the bidirectional infusion pump 73; one end of the second pipeline 742 is fixedly connected to the liquid outlet at the bottom of the counterweight box 71 through a sealing joint, and the other end is connected to the liquid inlet of the bidirectional infusion pump 73; a first control valve 743 is connected in series on the first pipeline 741, and a second control valve 744 is connected in series on the second pipeline 742. Both control valves are electrically connected to the controller through wires to realize the automatic control of the on / off state.

[0042] In practical applications, the counterweight adjustment process during the lifting operation phase is as follows: When the gravity sensor detects an increase in the total weight of the sucker rod 6 and the downhole load, for example, from 6.5 tons to 7.2 tons, the controller calculates through an algorithm that 0.7 tons of counterweight fluid needs to be added to the counterweight tank 71. It then sends a linkage command to open the first control valve 743 and close the second control valve 744. Simultaneously, the bidirectional pump 73 starts running in the forward direction. The counterweight fluid in the storage tank 72, after being pressurized by the pump 73, flows through the first pipeline 741 and the opened first control valve 743 from the counterweight tank 72. Liquid is injected into the tank through the top inlet of the counterweight tank 71 until the total weight of the counterweight tank 71 reaches 7.1 tons (close to the load weight). The controller then closes the first control valve 743 and the infusion pump 73 to complete the counterweight lifting adjustment. If the load subsequently drops to 6.8 tons, the controller controls the second control valve 744 to open and the first control valve 743 to close, and starts the bidirectional infusion pump 73 to run in reverse. 0.3 tons of counterweight liquid in the counterweight tank 71 flows out from the bottom outlet and is drawn back into the storage tank 72 through the second pipeline 742 and the opened second control valve 744, achieving precise reduction of the counterweight.

[0043] The counterweight adjustment process during the descent and return power generation phase is as follows: After the sucker rod 6 is raised to the preset height, the controller switches to the power generation mode, and the weight of the counterweight box 71 needs to be adjusted from 7.1 tons to 6.5 tons (less than the 7.2-ton load). At this time, the controller controls the second control valve 744 to open and the first control valve 743 to close, and the bidirectional liquid pump 73 runs in reverse to quickly extract 0.6 tons of counterweight liquid, ensuring that the sucker rod 6 falls smoothly under the action of gravity difference, driving the winch wheel 2 to rotate and generate electricity; when switching back to the lifting mode after power generation, the counterweight liquid is replenished to the value matching the load through the logic of opening the first control valve 743 and closing the second control valve 744.

[0044] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An energy-saving oil pumping unit, characterized in that, include: Supporting framework (1); The winch wheel (2) is rotatably mounted on the support frame (1); An electric motor (3) is located on the support frame (1) and is connected to the winch wheel body (2) for driving the winch wheel body (2) to rotate. The first traction member (4) and the second traction member (5) are respectively wound around opposite sides of the winch wheel body (2); The sucker rod (6) is connected to the free end of the first traction member (4); An adjustable counterweight assembly (7) is connected to the free end of the second traction member (5). The adjustable counterweight assembly (7) is used to balance the total weight of the sucker rod (6) and the downhole load of the sucker rod (6) by adjusting the weight of its counterweight.

2. The energy-saving oil pumping unit as described in claim 1, characterized in that, The adjustable counterweight assembly (7) includes: The counterweight box (71) is connected to the free end of the second traction member (5); Storage tank (72) contains counterweight liquid; An infusion line (74) connects the counterweight box (71) and the storage tank (72); An infusion pump (73) is installed on the infusion pipeline (74) to drive the counterweight liquid to transfer between the counterweight box (71) and the storage tank (72) to adjust the total weight of the adjustable counterweight assembly (7).

3. The energy-saving oil pumping unit as described in claim 2, characterized in that, The adjustable counterweight assembly (7) also includes a controller and a gravity sensor. The gravity sensor is used to detect the load on the sucker rod (6) side. The controller controls the operation of the infusion pump (73) according to the signal from the gravity sensor to automatically adjust the total gravity of the adjustable counterweight assembly (7).

4. The energy-saving oil pumping unit as described in claim 1, characterized in that, The electric motor (3) is optionally connected to the winch wheel (2) via a first clutch, and further includes: The generator (8) is mounted on the support frame (1) and is optionally connected to the winch wheel body (2) via a second clutch; An energy storage device is electrically connected to the generator (8); The descent return phase of the sucker rod (6) is the power generation phase. During the power generation phase, the motor (3) is disconnected from the winch body (2) via the first clutch, and the generator (8) is connected to the winch body (2) via the second clutch. The weight of the adjustable counterweight assembly (7) is adjusted to be less than the total weight of the sucker rod (6) and its downhole load. Under the action of gravity, the sucker rod (6) drives the winch body (2) to rotate via the first traction member (4), thereby driving the generator (8) to generate electricity. The generated electrical energy is stored in the storage device.

5. An energy-saving oil pumping unit as described in claim 1, characterized in that, It also includes a braking device (9), which is disposed on the winch wheel body (2) and is used to brake the winch wheel body (2).

6. An energy-saving oil pumping unit as described in claim 1, characterized in that, The first traction member (4) and the second traction member (5) are two free ends formed by the same continuous rope wound around the winch body (2).

7. An energy-saving oil pumping unit as described in claim 4, characterized in that, The winch wheel body (2) includes a wheel rim (21) and a hub (22) arranged coaxially, and a spoke (23) connecting the two. The winch wheel body (2) is rotatably connected to the support frame (1) by means of a bearing through a rotating shaft (24) that passes through and is fixed to the hub (22). The outer circumferential surface of the wheel rim (21) is provided with an annular groove (211) extending in the circumferential direction. The first traction member (4) and the second traction member (5) are accommodated in the annular groove (211) and wound around the wheel rim (21).

8. An energy-saving oil pumping unit as described in claim 7, characterized in that, An internal gear ring (25) is coaxially fixed on the inner side of the wheel rim (21); the motor (3) is selectively connected to a transmission gear that meshes with the internal gear ring (25) through a first clutch and the generator (8) is connected to a second clutch through a first clutch.

9. An energy-saving oil pumping unit as described in claim 5, characterized in that, It also includes a speed detector, which is used to detect the rotational speed of the winch wheel (2); when the speed detector detects that the speed of the winch wheel (2) exceeds a preset value, the braking device (9) applies braking to the winch wheel (2).

10. An energy-saving oil pumping unit as described in claim 2, characterized in that, The counterweight box (71) has a liquid inlet at the top and a liquid outlet at the bottom; The infusion line (74) includes a first line (741) connecting the inlet and the infusion pump (73), and a second line (742) connecting the outlet and the infusion pump (73). The first pipeline (741) is provided with a first control valve (743), and the second pipeline (742) is provided with a second control valve (744).

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