Energy-saving hydraulic pumping unit and system with energy recycling function

Abstract

The invention belongs to the technical field of oilfield exploitation equipment, and particularly relates to an energy-saving hydraulic pumping unit with an energy recycling function, the energy-saving hydraulic pumping unit comprises a working oil cylinder and an energy-saving driving part, the working oil cylinder is fixedly mounted on a foundation platform, and the energy-saving driving part is arranged on the foundation platform on one side of the working oil cylinder; the energy-saving driving part comprises a hydraulic control system, the hydraulic control system is communicated with the working oil cylinder based on an intelligent reversing valve, and the intelligent reversing valve is further communicated with a two-way variable hydraulic motor and an energy storage part; the two-way variable hydraulic motor is in transmission connection with the synchronous generator based on a coupler mounted at the bottom; through dynamic oil way switching of the intelligent reversing valve, pressure buffering of the energy storage system and secondary utilization of mechanical potential energy, the vicious circle of'waste of down stroke energy and overload of an up stroke motor 'of a traditional system is thoroughly broken through, space-time matching optimization of energy supply and load requirements is achieved, and the overall energy consumption level of the system is fundamentally reduced.

Description

Technical Field

[0001] This invention belongs to the technical field of oilfield extraction equipment, specifically relating to an energy-saving hydraulic pumping unit and system with energy recovery and recycling function. Background Technology

[0002] In the oilfield development sector, pumping units, as the core equipment for lifting crude oil from underground to the surface, directly impact the development costs and energy utilization levels of oil and gas fields. Traditional hydraulic pumping unit systems are built upon crank-connecting rod mechanisms and hydraulic drive technology. An electric motor drives a hydraulic pump to generate high-pressure oil, which in turn drives the piston in the cylinder to reciprocate, thus propelling the sucker rod string to complete the periodic operation of lifting the liquid column from the tubing. However, as oilfield development enters its later stages, problems such as declining formation fluid supply capacity and increasingly complex well conditions become more prominent. Traditional hydraulic pumping units exhibit significant systemic deficiencies in energy utilization efficiency, becoming a key bottleneck restricting cost reduction and efficiency improvement in oilfields.

[0003] Current hydraulic pumping unit systems suffer from severe energy waste. In the hydraulic drive stage, the closed loop formed by the hydraulic pump and cylinder experiences significant pressure loss due to throttling effects when the oil flows through various control valves. Simultaneously, internal leakage in hydraulic components further exacerbates energy attenuation. More critically, traditional systems fail to effectively utilize the inherent potential difference during pumping unit operation. The motor, as the sole power source, must output power covering the entire reciprocating motion of the sucker rod string, failing to utilize energy recovery during the downstroke to compensate for the upstroke demand, resulting in an imbalance in the spatial and temporal distribution of energy supply. Specifically: during the downstroke, the potential energy released by the sucker rod string accelerating downwards due to gravity is not recovered and utilized; instead, it forces the motor to reverse work to maintain system pressure stability, forming a double-loss closed loop of "wasted gravitational potential energy and additional electrical energy consumption." During the upstroke, the motor needs to continuously output high power to drive the rodless chamber of the cylinder to establish pressure, causing instantaneous power demand to far exceed actual load demand, resulting in the motor operating in an uneconomical range for extended periods. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention provides an energy-saving hydraulic pumping unit and system with energy recovery and recycling functions. This addresses the problem that in current hydraulic pumping units, significant pressure loss occurs due to throttling effects when the oil flows through various control valves in the closed loop composed of the hydraulic pump and cylinder during the hydraulic drive stage. At the same time, internal leakage of hydraulic components further exacerbates energy attenuation.

[0005] One embodiment of the present invention discloses an energy-saving hydraulic pumping unit with energy recovery and recycling function, including a working cylinder and an energy-saving drive unit. The working cylinder, which is connected to an underground oil field, is fixedly installed on a foundation platform. An upper platform is fixedly installed above the working cylinder. A base is slidably installed on the foundation platform. The energy-saving drive unit for energy recovery and recycling is provided on one side of the working cylinder at the top of the base.

[0006] In one embodiment, the energy-saving drive unit includes a hydraulic control system connected to an oil tank. The hydraulic control system is connected to the working cylinder based on an intelligent directional valve. The intelligent directional valve is also connected to a bidirectional variable hydraulic motor and an energy storage unit. The bidirectional variable hydraulic motor is connected to a synchronous generator via a coupling mounted at the bottom.

[0007] In one embodiment, a movable pulley assembly is fixedly installed on the top of the cylinder piston rod. One end of the upstroke rope and the downstroke rope are respectively fixedly connected to corresponding rope tensioners. The other end of the upstroke rope passes over the movable pulley assembly and the transmission box and is fixedly connected to the bottom of the balance box. The other end of the downstroke rope passes over the movable pulley assembly and the downstroke fixed pulley assembly on the top of the upper platform and is fixedly connected to the top of the balance box. One end of the transmission belt fixedly connected to the top of the balance box is fixedly connected to the suspension rope device that moves in coordination with the cylinder piston rod based on the fixed pulley assembly of the balance part on the top of the upper platform.

[0008] In one embodiment, the bottom of the bidirectional variable hydraulic motor is fixedly mounted on a coupling, which is fixedly mounted on the top of the base on one side of the working cylinder. A synchronous generator is also mounted on the coupling. The bidirectional variable hydraulic motor is driven by the synchronous generator through the coupling, and the bidirectional variable hydraulic motor can realize bidirectional switching between forward and reverse rotation. An energy storage unit is fixedly mounted on the side of the base platform away from the working cylinder. The energy storage unit is used to realize energy storage and release.

[0009] In one embodiment, the hydraulic control system of the energy-saving drive unit is connected to the oil tank, the intelligent directional valve and the energy storage unit to form a hydraulic oil circuit, and the intelligent directional valve is connected to the rod chamber at the top and the rodless chamber at the bottom of the working cylinder to form a hydraulic oil circuit, and the bidirectional variable hydraulic motor is connected to the energy storage unit to form a hydraulic oil circuit.

[0010] In one embodiment, the upstroke rope tensioner located on one side of the working cylinder is fixedly connected to one end of the upstroke rope. Two upstroke pulley sets are provided in the transmission box at the top of the base. The other end of the upstroke rope passes over the upper end face of the first movable pulley of the movable pulley set, and then passes over the lower end face of the two upstroke pulley sets. The other end of the upstroke rope is then fixedly connected to the bottom of the balance box.

[0011] In one embodiment, the downstroke fixed pulley assembly fixedly installed on the top of the upper platform includes a first downstroke fixed pulley and a second downstroke fixed pulley. The first downstroke fixed pulley is fixedly installed on one side of the top of the upper platform, and the second downstroke fixed pulley is fixedly installed on the top of the upper platform at the corresponding position of the movable pulley assembly. One end of the downstroke rope is fixedly connected to a downstroke rope tensioner located at the bottom of the upper platform, and the other end of the downstroke rope passes around the second movable pulley of the movable pulley assembly, and then passes around the second downstroke fixed pulley and is fixedly connected to the top of the balance box with the first downstroke fixed pulley.

[0012] In one embodiment, the balancing pulley assembly includes a first balancing pulley and a second balancing pulley respectively disposed on both sides of the top of the upper platform. The other end of the transmission belt passes over the upper surfaces of the first and second balancing pulleys and is fixedly connected to the top of the suspension device.

[0013] In one embodiment, horizontally movable push-pull devices are respectively provided on both sides of the top of the base platform, and the horizontally movable push-pull devices are respectively fixedly connected to one side of the base.

[0014] In one embodiment, a protective stand is provided on the top of the base, and the upper platform is fixedly connected to the top of the protective stand. The protective stands are respectively provided on both sides of the bottom of the upper platform. The protective stand near the end of the energy-saving drive unit is provided with a slot for storing the hydraulic oil circuit pipeline. The intelligent reversing valve is fixedly installed on the inner side of the protective stand at the top of the slot.

[0015] Beneficial effects Compared with the prior art, the embodiments of the present invention have the following beneficial effects: By coordinating the bidirectional variable hydraulic motor and the energy storage unit, efficient recovery of potential energy during the downstroke and precise release of energy during the upstroke are achieved. Specifically, during the downstroke, the high-pressure hydraulic fluid released from the rod chamber of the working cylinder drives the bidirectional variable hydraulic motor to reverse, switching to generator mode via an intelligent directional valve, converting mechanical energy into electrical energy and storing it. Simultaneously, the high-pressure hydraulic fluid enters the energy storage unit to compress inert gas, forming a dual storage of hydraulic energy and compression potential energy. During the upstroke, the hydraulic fluid released from the energy storage unit drives the bidirectional variable hydraulic motor to switch to pump mode via the intelligent directional valve, converting the stored energy into hydraulic energy to drive the cylinder piston rod. Combined with the auxiliary power supply of the synchronous generator, this significantly reduces the instantaneous power demand of the motor. This design, through the dynamic oil circuit switching of the intelligent directional valve, the pressure buffering of the energy storage system, and the secondary utilization of mechanical potential energy, completely breaks the vicious cycle of "energy waste during the downstroke and motor overload during the upstroke" in traditional systems, achieving optimized spatiotemporal matching between energy supply and load demand, fundamentally reducing the overall energy consumption level of the system. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, 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 the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of an energy-saving hydraulic pumping unit with energy recovery and circulation function according to an embodiment of the present invention; the dotted line in the figure represents the hydraulic oil circuit.

[0018] The components include: 1. Basic platform; 2. Base; 3. Horizontal moving push-pull device; 4. Transmission box; 5. Protective frame; 6. Hydraulic control system; 7. Oil tank; 8. Intelligent reversing valve; 9. Bidirectional variable hydraulic motor; 10. Coupling; 11. Synchronous generator; 12. Energy storage unit; 13. Working cylinder; 14. Cylinder piston rod; 15. Moving pulley block; 16. Upper platform; 17. Upstroke pulley block; 18. Upstroke rope; 19. Balance box; 20. First fixed pulley of the balance section; 21. Transmission belt; 22. Second fixed pulley of the balance section; 23. Suspension rope device; 24. Downstroke rope; 25. First fixed pulley of the downstroke; 26. Second fixed pulley of the downstroke. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this invention are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or end that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or ends.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] refer to Figure 1 As shown, one embodiment of the present invention discloses an energy-saving hydraulic pumping unit with energy recovery and recycling function, characterized in that: it includes a working cylinder 13 and an energy-saving drive unit. The working cylinder 13, which is connected to an underground oil field, is fixedly installed on a base platform 1. An upper platform 16 is fixedly installed above the working cylinder 13. A base 2 is slidably installed on the base platform 1. The energy-saving drive unit for energy recovery and recycling is provided on one side of the working cylinder 13 at the top of the base 2. The energy-saving drive unit includes a hydraulic control system 6 connected to the oil tank 7. The hydraulic control system 6 is connected to the working cylinder 13 based on the intelligent reversing valve 8. The intelligent reversing valve 8 is also connected to the bidirectional variable hydraulic motor 9 and the energy storage unit 12. The bidirectional variable hydraulic motor 9 is connected to the synchronous generator 11 based on the coupling 10 installed at the bottom. A movable pulley assembly 15 is fixedly installed on the top of the cylinder piston rod 14. One end of the upper stroke rope 18 and the lower stroke rope 24 are respectively fixedly connected to the corresponding rope tensioners. The other end of the upper stroke rope 18 passes through the movable pulley assembly 15 and the transmission box 4 and is fixedly connected to the bottom of the balance box 19. The other end of the lower stroke rope 24 passes through the movable pulley assembly 15 and the lower stroke fixed pulley assembly on the top of the upper platform 16 and is fixedly connected to the top of the balance box 19. One end is fixedly connected to the transmission belt 21 on the top of the balance box 19 and is fixedly connected to the suspension rope device 23 that moves in coordination with the cylinder piston rod 14 based on the fixed pulley assembly of the balance part on the top of the upper platform 16.

[0023] In this embodiment of the invention, an energy-saving drive unit is provided on one side of the working cylinder 13 at the top of the base 2 to recover and recycle energy. The energy-saving drive unit includes a hydraulic control system 6, an intelligent reversing valve 8, a bidirectional variable hydraulic motor 9, and an energy storage unit 12. During the downstroke, the high-pressure oil at the bottom of the working cylinder 13 enters the bidirectional variable hydraulic motor 9, which is frequency-modulated to motor mode, after passing through the intelligent reversing valve 8. At this time, the bidirectional variable hydraulic motor 9 is pushed by the high-pressure oil to reverse, thereby driving the synchronous generator 11 through the coupling 10, so that the synchronous generator 11 generates electricity for storage, realizing the conversion of hydraulic energy into mechanical energy and then into electrical energy. Energy conversion; during the upstroke, the oil in the tank 7 enters the bidirectional variable hydraulic motor 9, which is frequency-modulated into pump mode, after passing through the intelligent reversing valve 8. At this time, the bidirectional variable hydraulic motor 9 works as a hydraulic pump, driven by the synchronous generator 11 based on the previously stored electrical energy. Thus, the bidirectional variable hydraulic motor 9 delivers high-pressure oil to the working cylinder 13 to provide upstroke power; thereby realizing a reasonable and efficient closed-loop energy cycle conversion between potential energy, electrical energy and hydraulic energy during the stroke of the hydraulic pumping unit, solving the problem of "energy waste during the downstroke and motor overload during the upstroke" mentioned in the background technology.

[0024] Traditional hydraulic pumping units have fundamental defects in energy utilization. They rely on crank connecting rods and closed hydraulic circuits, resulting in unidirectional and inefficient energy flow: the potential energy released by the downward stroke of the sucker rod is not captured and utilized, but instead forces the motor to do work in the opposite direction, consuming electrical energy; the motor needs to output full power throughout the upstroke to meet the load, resulting in a serious mismatch between energy supply and load demand in both time and space, causing a double loss of "wasted potential energy in the downstroke and redundant electrical energy in the upstroke". The core breakthrough of this solution lies in constructing a closed-loop energy cycle system of "potential energy - electrical energy - hydraulic energy," achieving innovation across the entire process from energy recovery, conversion to reuse: During the downstroke, the sucker rod column descends under gravity, driving the high-pressure hydraulic fluid in the rod chamber of the working cylinder 13. This fluid is then guided by the intelligent directional valve 8 to the bidirectional variable hydraulic motor 9 (switched to reverse mode), converting hydraulic energy into mechanical energy to drive the synchronous generator 11, completing the initial conversion from potential energy to electrical energy. After the generated electrical energy is stored, during the upstroke, the energy storage system releases energy to assist in driving the bidirectional variable hydraulic motor 9 (switched to pump mode), converting the electrical energy back into hydraulic energy and injecting it into the rodless chamber of the working cylinder 13 to provide power for the upstroke. This bidirectional energy scheduling based on stroke characteristics precisely matches the load characteristics of the downstroke ("surplus potential energy, low electrical energy demand") and the upstroke ("high electrical energy demand, insufficient potential energy"), fundamentally breaking the spatial and temporal mismatch dilemma of traditional systems. This allows energy to serve the oil extraction process at the right time and in the right form, completely reversing the situation of energy waste and supply-demand imbalance.

[0025] In terms of energy recovery and recycling technology, this solution further breaks through the technical constraints of traditional closed-loop circuits through the collaborative innovation of intelligent directional valve 8, bidirectional variable hydraulic motor 9, and energy storage unit 12. Traditional circuits, due to their rigid structure, cannot respond to the energy demands of stroke changes and suffer irreversible losses due to oil throttling and internal leakage of components. In this solution, intelligent directional valve 8 enables "on-demand switching" of the hydraulic circuit direction, while bidirectional variable hydraulic motor 9 flexibly switches between "motor (downstroke energy recovery) - pump (upstroke energy output)" modes. Combined with the energy storage unit 12's "peak shaving and valley filling" of energy (excess oil in the downstroke compresses inert gas to store energy for upstroke replenishment), energy forms a dynamically adjustable cycle between "hydraulic-mechanical-electrical-hydraulic". This design not only reduces throttling and internal leakage losses through energy form conversion, but also uses the energy storage unit 12 to accurately compensate for the load gap in the upstroke with the energy recovered during the downstroke. This upgrades the energy supply for the entire pumping cycle from "forced matching" to "flexible adaptation", significantly improving energy utilization efficiency while reducing the operating load of the motor under extreme conditions. It reshapes the energy flow logic of the pumping unit from the bottom of the technical architecture, achieving a leapfrog improvement in energy efficiency and stability.

[0026] In one embodiment, the bottom of the bidirectional variable hydraulic motor 9 is fixedly mounted on the coupling 10, which is fixedly mounted on the top of the base 2 on one side of the working cylinder 13. A synchronous generator 11 is also mounted on the coupling 10. The bidirectional variable hydraulic motor 9 is connected to the synchronous generator 11 via the coupling 10, and the bidirectional variable hydraulic motor 9 can realize bidirectional switching between forward and reverse rotation. An energy storage unit 12 is fixedly mounted on the side of the base platform 1 away from the working cylinder 13. The energy storage unit 12 is used to realize energy storage and release.

[0027] In this embodiment of the invention, the energy storage section 12 is filled with inert gas. Energy storage and release are achieved by utilizing the compressibility of the inert gas. Specifically, during the downstroke, the high-pressure oil from the working cylinder 13 enters the bidirectional variable hydraulic motor 9 through the intelligent reversing valve 8 to drive the synchronous generator 11 to generate electricity and store electrical energy. At the same time, the high-pressure oil will enter the energy storage section 12 to compress the inert gas inside after pushing the bidirectional variable hydraulic motor 9 to reverse. During this process, when the volume of the high-pressure oil involved exceeds the single stroke capacity of the working cylinder 13, the excess oil will be compressed and stored in the energy storage section 12. At the same time, the hydraulic energy will be converted into the compression potential energy in the energy storage section 12. During the upstroke, the inert gas in the energy storage section 12 expands, causing the oil stored inside to flow out to the intelligent reversing valve 8, or it can flow back directly to the bidirectional variable hydraulic motor 9 to supply oil. The electrical energy output by the synchronous generator 11 synchronously drives the bidirectional variable hydraulic motor 9, thereby providing power for the upstroke.

[0028] In one embodiment, the hydraulic control system 6 of the energy-saving drive unit is connected to the oil tank 7, the intelligent directional valve 8 and the energy storage unit 12 to form a hydraulic oil circuit, and the intelligent directional valve 8 is connected to the rod chamber at the top and the rodless chamber at the bottom of the working cylinder 13 to form a hydraulic oil circuit, and the bidirectional variable hydraulic motor 9 is connected to the energy storage unit 12 to form a hydraulic oil circuit.

[0029] In this embodiment of the invention, the hydraulic oil circuit is specifically as follows: during the downstroke, the working cylinder 13 rod chamber → intelligent directional valve 8 → bidirectional variable hydraulic motor 9 (motor mode is in reverse) → energy storage unit 12 → oil tank 7; specifically, high-pressure oil enters the bidirectional variable hydraulic motor 9 from the intelligent directional valve 8, causing the bidirectional variable hydraulic motor 9 to reverse and drive the synchronous generator 11 to generate electrical energy storage, and continues to flow to the energy storage unit 12 to compress the internal inert gas to store energy. If the energy storage unit 12 reaches the full load state, it flows back to the oil tank 7 through the overflow valve of the energy storage unit 12.

[0030] During the upstroke, the energy storage unit 12 → intelligent directional valve 8 → bidirectional variable hydraulic pump (pump mode is in forward rotation state) → rodless chamber of working cylinder 13 → oil tank 7; specifically, the expansion of the inert gas pushes the oil out through the high-pressure hose into the intelligent directional valve, and then through the intelligent directional valve 8 to the bidirectional variable hydraulic motor 9 to assist in powering the bidirectional variable hydraulic motor 9, thereby providing power for the upstroke of working cylinder 13, and finally flowing back to the oil tank 7.

[0031] In one embodiment, the upstroke rope tensioner located on one side of the working cylinder 13 is fixedly connected to one end of the upstroke rope 18. Two upstroke pulley sets 17 are provided in the transmission box 4 at the top of the base 2. The other end of the upstroke rope 18 passes over the upper end face of the first movable pulley of the movable pulley set 15, and then passes over the lower end faces of the two upstroke pulley sets 17. The other end of the upstroke rope 18 is then fixedly connected to the bottom of the balance box 19.

[0032] In this embodiment of the invention, before the cylinder piston rod 14 moves upward, the balance box 19 is in a high position and stores gravitational potential energy. When the servo electric cylinder drives the cylinder piston rod 14 to make an upstroke motion, the negative pressure in the working cylinder 13 draws the crude oil in the oil well into the working cylinder 13. At this time, the cylinder piston rod 14 makes an upstroke motion and moves upward. The balance box 19 moves downward and releases the stored potential energy, which is then converted into kinetic energy. This offsets part of the upward resistance of the cylinder piston rod 14 and reduces the load on the permanent magnet motor.

[0033] In one embodiment, the downstroke fixed pulley assembly fixedly installed on the top of the upper platform 16 includes a first downstroke fixed pulley 25 and a second downstroke fixed pulley 26. The first downstroke fixed pulley 25 is fixedly installed on one side of the top of the upper platform 16, and the second downstroke fixed pulley 26 is fixedly installed on the top of the upper platform 16 at the corresponding position of the movable pulley assembly 15. One end of the downstroke rope 24 is fixedly connected to the downstroke rope tensioner located at the bottom of the upper platform 16, and the other end of the downstroke rope 24 passes around the second movable pulley of the movable pulley assembly 15, and then passes around the second downstroke fixed pulley 26 and is fixedly connected to the top of the balance box 19 with the first downstroke fixed pulley 25.

[0034] In this embodiment of the invention, when the piston rod 14 of the oil cylinder makes a downward stroke, the crude oil in the working oil cylinder 13 is discharged from the oil outlet pipe for collection, and at the same time, the balance box 19 is pulled up to a high position to store gravitational potential energy, thereby reducing the output power of the motor through energy conversion.

[0035] In one embodiment, the balancing pulley assembly includes a first balancing pulley 20 and a second balancing pulley 22 respectively disposed on both sides of the top of the upper platform 16. The other end of the transmission belt 21 passes over the upper end surfaces of the first balancing pulley 20 and the second balancing pulley 22 and is then fixedly connected to the top of the suspension rope device 23.

[0036] In this embodiment of the invention, the suspension rope device 23 is mainly used to convert the up-and-down reciprocating motion of the pumping unit head into the linear motion of the downhole sucker rod via the transmission belt 21.

[0037] In one embodiment, horizontal moving push-pull devices 3 are respectively provided on both sides of the top of the base platform 1, and the horizontal moving push-pull devices 3 are respectively fixedly connected to one side of the base 2.

[0038] In this embodiment of the invention, the horizontally moving pusher-puller 3 is mainly used to balance lateral forces. When the piston rod 14 of the pumping unit's cylinder makes up-and-down strokes within the working cylinder 13, if it becomes deflected due to downhole conditions such as sand production or wax deposition, it will bear lateral forces. Prolonged uneven loading will accelerate the wear of the seals in the working cylinder 13, and in severe cases, may even cause the working cylinder 13 to deform or seize. By finely adjusting the horizontal direction using the horizontally moving pusher-puller 3, the axial position of the piston rod 14 is corrected in real time, ensuring that it coincides with the cylinder's centerline and preventing damage from lateral forces. Furthermore, it can also reduce joint wear and enhance the device's impact resistance.

[0039] In one embodiment, a protective frame 5 is provided on the top of the base 2. The upper platform 16 is fixedly connected to the top of the protective frame 5. The protective frames 5 are respectively provided on both sides of the bottom of the upper platform 16. The protective frame 5 near the end of the energy-saving drive unit is provided with a slot for storing the hydraulic oil circuit pipeline. The intelligent reversing valve 8 is fixedly installed on the inner side of the protective frame 5 at the top of the slot.

[0040] In this embodiment of the invention, the protective frame 5 is mainly used to support the upper platform 16 and provides a certain degree of protection for the entire device and external personnel.

[0041] The specific working principle of the energy-saving hydraulic pumping unit with energy recovery and recycling function of the present invention is as follows: During the downstroke, the piston rod 14 of the hydraulic cylinder moves downward under the action of gravity and downhole load. The high-pressure oil in the rod chamber of the working cylinder 13 switches the hydraulic circuit through the intelligent reversing valve 8 and enters the bidirectional variable hydraulic motor 9. At this time, the bidirectional variable hydraulic motor 9 switches to reverse mode under the drive of high-pressure oil, and its rotational motion is transmitted to the synchronous generator 11 through the bottom coupling 10, driving the synchronous generator 11 to generate electricity and store electrical energy externally. At the same time, the oil discharged from the bidirectional variable hydraulic motor 9 enters the energy storage unit 12 under continuous high pressure, driving the internal inert gas to compress and store energy. The energy storage unit 12 realizes the conversion of hydraulic energy into compression potential energy through gas volume compression. If the oil flow exceeds the full load limit of the energy storage unit 12, the overflow valve guides the excess oil back to the oil tank 7 to avoid system overload. During this process, the moving pulley block 15 and the balance box 19 are linked through the downstroke rope 24. The balance box 19 is pulled up to a high position to store gravitational potential energy, while the rope tensioner maintains the stability of the movement of the piston rod 14 of the hydraulic cylinder. The horizontally moving push-pull device 3 monitors the cylinder axis offset in real time and ensures that the piston rod coincides with the cylinder centerline through horizontal fine adjustment, eliminating the risk of lateral force wear on the seals.

[0042] During the upstroke, the compressed inert gas in the energy storage unit 12 expands, pushing the stored oil through the intelligent reversing valve 8 into the bidirectional variable hydraulic motor 9. At this time, the bidirectional variable hydraulic motor 9 switches to pump mode. Under the pressure of the oil released from the energy storage unit 12 and the auxiliary power supply of the synchronous generator 11, the oil is pressurized and delivered to the rodless chamber of the working cylinder 13, driving the piston rod upward. If the pressure in the energy storage unit 12 is insufficient, the external motor starts to drive the bidirectional variable hydraulic motor 9 to supplement the energy, ensuring sufficient power for the upstroke. The balance box 19 releases the stored gravitational potential energy at a high position, which is linked with the fixed pulley group through the transmission belt 21 to drive the suspension rope device 23 and the downhole sucker rod to move upward smoothly, offsetting part of the cylinder load. During the upward movement of the cylinder piston rod 14, a negative pressure is formed in the working cylinder 13, and crude oil is drawn from the oil tank 7 through the oil inlet pipe to replenish the cylinder. The movable pulley block 15 and the rope system amplify the lifting force through mechanical leverage; the horizontally moving push-pull device 3 continuously monitors and corrects the position of the cylinder axis to prevent mechanical losses caused by off-center loading. The entire process achieves a closed-loop energy cycle of "potential energy recovery during the downstroke → electrical energy storage → stored electrical energy release during the upstroke" through real-time switching of the intelligent reversing valve 8 and dynamic coordination with the energy storage system, significantly reducing system energy consumption and motor load fluctuations.

[0043] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0044] Finally, it should be noted that the energy-saving hydraulic pumping unit with energy recovery and recycling function disclosed in the embodiments of the present invention is only a preferred embodiment of the present invention and is only used to illustrate the technical solution of the present invention, not to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An energy-saving hydraulic pumping unit with energy recovery and recycling function, characterized in that, The utility oil cylinder (13) connected with the underground oil field is fixedly installed on the base platform (1), an upper platform (16) is fixedly arranged above the utility oil cylinder (13), a base (2) is slidingly installed on the base platform (1), and an energy-saving driving part for recycling energy is arranged on one side of the utility oil cylinder (13) at the top of the base (2).

2. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 1, characterized in that: The energy-saving driving part comprises a hydraulic control system (6) communicated with an oil tank (7), the hydraulic control system (6) is communicated with the utility oil cylinder (13) based on an intelligent reversing valve (8), the intelligent reversing valve (8) is further communicated with a bidirectional variable hydraulic motor (9) and an energy storage part (12), and the bidirectional variable hydraulic motor (9) is drivingly connected with a synchronous generator (11) based on a shaft coupling (10) installed at the bottom.

3. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 1, characterized in that: A dynamic pulley set (15) is fixedly installed at the top of the oil cylinder piston rod (14), one end of an upper stroke rope (18) and a lower stroke rope (24) is respectively fixedly connected with a corresponding rope tensioner, the other end of the upper stroke rope (18) is fixedly connected with the bottom of a balance tank (19) after passing through the dynamic pulley set (15) and a transmission box (4), the other end of the lower stroke rope (24) is fixedly connected with the top of the balance tank (19) after passing through the dynamic pulley set (15) and a lower stroke fixed pulley set at the top of the upper platform (16), and a transmission belt (21) fixedly connected with the top of the balance tank (19) is fixedly connected with a rope suspension device (23) moving in cooperation with the oil cylinder piston rod (14) based on a balance part fixed pulley set at the top of the upper platform (16).

4. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 2, characterized in that: The bottom of the bidirectional variable hydraulic motor (9) is fixedly installed on the shaft coupling (10), the shaft coupling (10) is fixedly installed on the top of the base (2) on one side of the utility oil cylinder (13), the synchronous generator (11) is further installed on the shaft coupling (10), the bidirectional variable hydraulic motor (9) is drivingly connected with the synchronous generator (11) based on the shaft coupling (10), and the bidirectional variable hydraulic motor (9) can realize bidirectional transformation of forward rotation and reverse rotation; the energy storage part (12) is fixedly installed on the side of the base platform (1) away from the utility oil cylinder (13), and the energy storage part (12) is used for realizing energy storage and release.

5. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 4, characterized in that: The hydraulic control system (6) of the energy-saving driving part is communicated with the oil tank (7), the intelligent reversing valve (8) and the energy storage part (12) respectively to form a hydraulic oil circuit, the intelligent reversing valve (8) is communicated with a rod cavity at the top of the utility oil cylinder (13) and a rodless cavity at the bottom respectively to form a hydraulic oil circuit, and the bidirectional variable hydraulic motor (9) is communicated with the energy storage part (12) to form a hydraulic oil circuit.

6. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 3, characterized in that: The upper stroke rope tensioner located on one side of the working oil cylinder (13) is fixedly connected with one end of the upper stroke rope (18), two upper stroke pulley blocks (17) are arranged in the transmission box (4) at the top of the base (2), the other end of the upper stroke rope (18) is wound around the upper end surface of the first movable pulley of the movable pulley block (15), then wound around the lower end surfaces of the two upper stroke pulley blocks (17), and then the other end of the upper stroke rope (18) is fixedly connected with the bottom of the balance box (19).

7. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 6, characterized in that: The lower stroke fixed pulley block fixedly installed at the top of the upper platform (16) comprises a lower stroke first fixed pulley (25) and a lower stroke second fixed pulley (26), the lower stroke first fixed pulley (25) is fixedly installed on one side of the top of the upper platform (16), the lower stroke second fixed pulley (26) is fixedly installed on the top of the upper platform (16) at the corresponding position of the movable pulley block (15), one end of the lower stroke rope (24) is fixedly connected with the lower stroke rope tensioner located at the bottom of the upper platform (16), and the other end of the lower stroke rope (24) is wound around the second movable pulley of the movable pulley block (15), then successively wound around the lower stroke second fixed pulley (26) and the lower stroke first fixed pulley (25), and fixedly connected with the top of the balance box (19).

8. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 7, characterized in that: The balance part fixed pulley block comprises a balance part first fixed pulley (20) and a balance part second fixed pulley (22) arranged on the top of the upper platform (16) on both sides respectively, and the other end of the transmission belt (21) is fixedly connected with the top of the rope suspension device (23) after being wound around the upper end surfaces of the balance part first fixed pulley (20) and the balance part second fixed pulley (22).

9. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 1, characterized in that: Horizontal movement push-pull devices (3) are arranged on both sides of the top of the base platform (1) respectively, and the horizontal movement push-pull devices (3) are fixedly connected with one side of the base (2) respectively.

10. The energy-saving hydraulic pumping unit with energy recovery cycle function according to claim 2, characterized in that: A protection stand (5) is arranged at the top of the base (2), the protection stand (5) is fixedly connected with the upper platform (16) at the top, the protection stand (5) is arranged on both sides of the bottom of the upper platform (16) respectively, the protection stand (5) close to the end of the energy-saving driving part is provided with a slot for accommodating a hydraulic oil circuit pipeline, and the inside of the protection stand (5) at the top of the slot is fixedly installed with the intelligent reversing valve (8).

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