WO2009111970A1

WO2009111970A1 - Hydraulic cylinder, oil pumping unit, oil pumping module and oil pumping system

Info

Publication number: WO2009111970A1
Application number: PCT/CN2009/070688
Authority: WO
Inventors: 郝双晖; 郝明晖
Original assignee: Hao Shuanghui; Hao Minghui
Priority date: 2008-03-11
Filing date: 2009-03-09
Publication date: 2009-09-17
Also published as: CN101532486B; CN101532486A; EP2280174A1; EP2280174A4

Abstract

A hydraulic cylinder, an oil pumping unit, an oil pumping module and an oil pumping system, the hydraulic cylinder has a hydraulic cylinder body(330), a piston(331), and a first piston rod(333), a second piston rod(332); the two piston rods(332,333) are both connected with the piston(331) and reversely extended from the hydraulic cylinder body(330); the oil pumping unit has a hydraulic cylinder and a first oil well pump connected with the first piston rod(333); the oil pumping module has a control mechanism, a hydraulic power drive mechanism and the oil pumping unit; the oil pumping system has at least one oil pumping module, the oil outlet of every oil pumping module is connected with the total oil outlet of an oil pumping system through a pipe. The pump has simple transmission, high transmission efficiency, simple structure, and high reliability.

Description

Hydraulic cylinder, oil pumping unit, oil pumping module and oil pumping system

The invention relates to an oil field production machine, in particular to a pumping system and a pumping module, a pumping unit and a hydraulic cylinder applied to the oil pumping system.

Background technique

Oilfield oil production methods are divided into spray production oil and artificial lift production. The rod pumping system is the most important artificial lift production method in domestic and foreign oil fields. It is mainly composed of pumping unit, sucker rod and pumping pump. The oil machine is the most important lifting device for the rod pumping system.

Depending on whether there is a beam or not, the pumping unit can be divided into a beam pumping unit and a beamless pumping unit. For the beam pumping unit, such as the most widely used "head machine", the motor is pumped by the lever of the rocker arm to reciprocate the sucker rod. This structure satisfies the industry to some extent. Requirements, but with the advancement of machinery, electrical appliances and other technologies, it has many defects in the structure, such as the need to use heavy hammer to balance pumping, inevitably there will be defects of heavy and expensive steel; The weight is sharply increased, and the manufacturing process is long and the installation work is complicated. The up and down reciprocating stroke of the pumping unit is shorter than that of the existing pump, and the efficiency of the existing pump cannot be fully utilized. To match it, the volume and The power will be greatly increased; in addition, there are other shortcomings in the structure of the beam pumping unit, which is mainly reflected in the low efficiency of converting the rotary motion of the motor into linear reciprocating motion. The main reason is the loss of belt transmission efficiency and the transmission of the reduction box. Loss of efficiency, loss of three-bearing transmission efficiency of the four-bar linkage mechanism; the torque of the reduction gearbox increases proportionally when the stroke is increased, Need to replace larger and heavier gearboxes and so on.

In order to solve these problems, different technical solutions have been proposed. For example, the patent application No. 89217947.3 proposes to use a tubing string as a balancing system; or as proposed in the patent application No. 200620166023.0, the installation method is improved; or No. 92201875.8, the application of the hydraulic cylinder is improved; or the hydraulic cylinder structure is improved as in the patent application No. 200620020553.4; or the pumping power transmission mechanism is made in the patent application No. 02155159.6 The improvement of the pumping unit in the patent application of the application No. 200620119484.2 200420031970. X, 200710052554.6, and the like.

Furthermore, the sucker rod is too long, and it is prone to instantaneous stretching and compression. The deformation of the sucker rod not only reduces the efficiency of the pump, but also causes the sucker rod and the oil pipe to collide and rub frequently, in order to solve the problem. A corresponding technical solution is also proposed, such as the signal feedback type oil pumping device disclosed in the patent application No. 02237843.X, the hydraulic oil pumping device disclosed in the patent application No. 200610068939.7, and the like. Among them, no beam pumping unit, such as patent number 99234396.8, 99250803.7, etc., no beam pumping unit has higher mechanical transmission efficiency than beam pumping unit, but its structure is complex and its reliability is not high. Currently, there are still not many applications.

Whether it is a beam type or a beamless pumping unit, there is friction loss between the sucker rod and the oil pipe, and each time the pumping oil needs to lift the sucker rods of hundreds to thousands of kilometers, lift The sucker rod also consumes a lot of energy.

In the current oil pumping system, including the oil pumping system disclosed in the above patent applications, in order to realize the reciprocating motion of the piston in the hydraulic cylinder, the power transmission mechanism needs a fuel tank, a relief valve and a matching component thereof. The reservoir is used to replenish the liquid in the hydraulic cylinder, while the relief valve is used to define the maximum pressure of the liquid in the line. These components not only increase the complexity and power consumption of the system, but also reduce the reliability and safety of the system.

Moreover, at present, China's major oil fields have entered the high water cut development period. In order to ensure the stable production and high production of crude oil, it is necessary to increase the oil discharge volume of the oil wells, so that the energy consumption cost of the oil production system will increase sharply, and the energy consumption cost has become an impact on the oil production cost. One of the main factors, but there is currently no effective solution to the problem.

Summary of the invention

In view of the deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a hydraulic cylinder, a pumping unit, a pumping module and a pumping system for simplifying the structure, improving efficiency, and reducing energy consumption.

In order to solve the above technical problem, the present invention provides a hydraulic cylinder including a hydraulic cylinder, a piston and a first piston rod connected to the piston, a second piston rod, the second piston rod and the first piston rod The cylinder block is extended backwards, the piston divides the hydraulic cylinder into two upper and lower chambers, and a liquid inlet and outlet is provided on the hydraulic cylinders corresponding to the upper and lower chambers.

The present invention also provides a pumping unit comprising the above-mentioned hydraulic cylinder and a first oil pump, the first piston rod of the hydraulic cylinder being connected with the sucker rod of the first oil pump, the first oil pump It has an oil outlet.

As a modification of the oil pumping unit, a second oil pump is further included, the second piston rod of the hydraulic cylinder is connected to the sucker rod of the second oil pump; the second oil pump is also provided Oil port.

The present invention also provides a pumping module comprising a control mechanism, a hydraulic drive mechanism and the above-mentioned oil pumping unit, wherein the oil pumping unit is connected to the hydraulic drive mechanism via a hydraulic oil pipe, the hydraulic drive mechanism and the The control mechanism is connected, and the hydraulic drive mechanism is controlled by the control mechanism, and the hydraulic drive mechanism drives the piston in the hydraulic cylinder of the oil pumping unit to reciprocate up and down, thereby driving the sucker rod of the oil pump to reciprocate Pumping work.

Wherein the hydraulic drive mechanism in the above-mentioned oil pumping module comprises a bidirectional pump and an electric motor, the electric motor The bidirectional pump is connected to the two-way pump through a coupling, and the two-way pump is connected to the first and second hydraulic oil pipes of the hydraulic cylinder in the oil pumping unit. More specifically, the bidirectional pump is a gear pump; the electric motor is an AC servo motor.

The control mechanism is a control circuit designed according to a control task, including a central processing unit, a servo control unit, an information acquisition unit, and the like, wherein the servo control unit is matched with an AC servo motor for controlling an AC servo motor. For servo controllers, encoders, etc., the information acquisition unit generally includes various sensors such as a current sensor, a position sensor, a travel switch, and the like. Since the design of the control mechanism is conventional, it will not be described here.

The present invention also provides a pumping system comprising one or more oil pumping modules as described above, each of the oil pumping modules being connected to a total oil outlet through a pipe connected to the oil outlet thereof, when the pumping When there are a plurality of oil modules, they are connected to each other by a connecting member.

Compared with the prior art, the oil pumping system provided by the invention has simple transmission and high transmission efficiency. Moreover, the system does not have hundreds of kilometers of sucker rods, and there is no friction loss between the sucker rod and the oil pipe. There is also no increase in the energy consumption of the sucker rod, so the energy consumption will be an order of magnitude lower than in existing rod pumping systems.

The oil pumping system provided by the invention has the advantages of simple structure, few parts, and the whole system works underground, is not affected by the ground environment, and therefore has high reliability; and, since the whole system works underground, the ground staff is not given. Personal injury is caused. At present, the staff often encounters safety accidents when operating the existing pumping unit equipment, and is injured or even killed by the pumping unit. This pumping system fundamentally eliminates safety hazards and has good safety.

The system adopts a modular design, which can install different numbers of components according to the requirements of each well displacement, and the displacement of each component can be adjusted, so the installation and configuration are flexible and convenient.

The oil pumping system provided by the invention has good flexibility and flexible control strategy. Because the servo system is used, the control strategy can be flexibly adopted according to the needs of each well. If some oil wells have low oil production, letting the pumping system work intermittently is conducive to saving energy. However, due to the safety hazard of the existing pumping system, intermittent pumping will bring more safety hazards to the staff, and this system does not have this problem, so the method of pumping can be adopted.

The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

DRAWINGS

1 is a schematic structural view of Embodiment 1 of the oil pumping system of the present invention;

2 is a schematic view showing the overall structure installation and assembly of an oil pumping system according to an embodiment of the present invention; FIG. 3 is a schematic structural view of a second embodiment of the oil pumping system according to the present invention;

4 is a schematic structural view of a pumping module in a third embodiment of the oil pumping system of the present invention;

Figure 5 is a schematic structural view of a total oil outlet in the third embodiment of the oil pumping system of the present invention; Figure 6 is a schematic view showing the overall structure of a third embodiment of the oil pumping system of the present invention;

Figure 7 is a schematic view showing the position of a limit switch of a hydraulic cylinder in the oil pumping system of the present invention;

Figure 8 is a schematic structural view of the oil pump of the present invention when it is in an upstroke;

Figure 9 is a schematic view showing the structure of the oil pump of the present invention when it is in the down stroke;

Figure 10 is a schematic view showing the structure of the oil pump outlet pipe and the hydraulic cylinder outlet pipe in the oil pumping system of the present invention;

Figure 11 is a schematic structural view of the oil pumping system of the present invention in a main pipe;

Figure 12 is a schematic view showing another structure of the oil pumping system of the present invention in the main pipe;

Figure 13 is a schematic view showing the manner of fixing the oil pumping system in the main pipe according to the present invention;

Figure 14 is a schematic view showing another fixing manner of the oil pumping system of the present invention in the main pipe.

Figure 15 is a schematic diagram of the operating speed of the oil pump;

Figure 16 is a schematic view showing the force of the main oil pipe in the first embodiment of the present invention;

Figure 17 is a schematic view showing the force of the main oil pipe in the second embodiment of the present invention;

Figure 18 is a schematic view showing the force of the main oil pipe in the third embodiment of the present invention;

Figure 19 is a schematic view showing the installation of the fourth embodiment of the oil pumping system of the present invention;

20 is a schematic external view of a pumping module according to Embodiment 4 of the present invention;

21 is a schematic view showing the removal of the outer casing of the oil pumping module according to the fourth embodiment of the present invention;

Figure 22 is a partial cross-sectional view showing the oil pumping module of the fourth embodiment of the present invention;

23 is a schematic view showing the removal of the outer casing of the oil pumping module according to the fifth embodiment of the present invention;

Figure 24 is a partial cross-sectional view showing the oil pumping module of the fifth embodiment of the present invention;

Figure 25 is a partial cross-sectional view showing the oil pumping module of the sixth embodiment of the present invention;

26 is a schematic diagram of an oil passage inside a pumping module according to Embodiment 7 of the present invention;

27 is a schematic diagram of an internal oil circuit of a pumping module according to Embodiment 8 of the present invention;

28 is a schematic structural view of a cable joint of the present invention;

Figure 29 is a schematic view showing the connection of the motor and the bidirectional pump of the present invention;

Figure 30 is a structural view showing the use of a magnetic induction element to control the stroke of the hydraulic cylinder;

31 is a structural diagram for controlling the stroke of the hydraulic cylinder by using a contact switch.

detailed description

The hydraulic cylinder provided by the present invention comprises a hydraulic cylinder, a piston and a first piston rod and a second piston rod connected to the piston, and the second piston rod and the first piston rod are oppositely extended from the hydraulic cylinder, The piston will be the hydraulic cylinder Divided into two upper and lower chambers. A liquid inlet and outlet are provided at upper and lower ends of the hydraulic cylinder body, and are respectively connected to the hydraulic power drive mechanism through the first and second hydraulic oil pipes.

Since the hydraulic cylinder of the present invention has two piston rods extending from the cylinder block, the total volume of the hydraulic chamber remains unchanged during the hydraulic circulation, and the amount of liquid for circulation remains unchanged, omitting the prior art for The liquid tank for replenishing the liquid, and the pressure of the liquid can be controlled by the control mechanism, omitting components such as a relief valve for balancing the pressure of the liquid, thereby simplifying the structure of the pumping system, and the transmission is simple; and each hydraulic rod is A pump can be connected to increase pumping efficiency.

A hydraulic cylinder and one or two oil pump constitute a pumping unit, a pumping unit plus a control mechanism and a hydraulic drive mechanism form a pumping module, and one or more pumping modules constitute a pumping system, The pumping system is a modular structure with simple structure, convenient installation and maintenance, high efficiency, low energy consumption and good safety.

Embodiment 1

Referring to Fig. 1 is a schematic structural view of a first embodiment of the oil pumping system of the present invention. The oil pumping system in the present embodiment is located in a main pipe A, and the bottom of the main pipe A has underground oil B entering through the oil well. The oil pumping system mainly comprises a pumping module, that is, a control mechanism, a hydraulic driving mechanism and a pumping unit. The pumping unit in this embodiment is composed of a hydraulic cylinder and an oil pump, and the control mechanism includes a CPU and a servo motor controller. The encoder and some sensors (such as current sensor, position sensor) and corresponding peripheral circuits, the hydraulic drive mechanism includes a bidirectional pump and an AC servo motor, where the AC servo motor corresponds to the servo motor controller in the control mechanism. The main pipe A is a fixed support component of the whole system. The components of the whole system are fixed on the main pipe, and the main pipe connection is fixed at the lower end of the main oil pipe, as shown in Fig. 1.

For ease of installation, the present invention integrates the CPU, servo motor controller and peripheral circuits in the control mechanism into a control box, that is, the servo control box 310, and the power of the entire system is input from the ground through the cable inlet A1 of the main pipe through the cable. Into the system, used to provide electrical energy. The motor encoder signal line 311 and the motor power supply line 312 of the AC servo motor 320 are connected to the servo control box 310, and the power source is connected to the servo control box from the ground through the cable inlet A1 of the main pipe through the cable, and the power of the AC servo motor 320 is supplied. The end is connected to the three-phase power supply output from the servo control box. The CPU detects the position and current of the motor at regular intervals (such as 60 microseconds) according to the set control strategy (such as the motor rotates at a constant speed), detects the position signal of the motor through the motor encoder, and rotates the angle of the motor. The signal is converted into a corresponding electric signal, transmitted to the CPU in the servo control box via the signal line 311, and the three-phase current value of the motor is detected by the current sensor, and the appropriate voltage value is calculated by the calculation of the CPU to control the voltage applied to the motor. The voltage magnitude forms a closed loop control of the motor. The AC servo motor 320 is connected to the bidirectional pump shaft 323 through the coupling 321 to drive the bidirectional pump 324. The gear pump is a typical double. To the pump. The two-way pump 324 is connected to the hydraulic cylinder 330 through the first hydraulic oil pipe 334 and the second hydraulic oil pipe 335. When the AC servo motor 320 drives the bidirectional pump 324 to rotate in one direction, the hydraulic oil flows in one direction, thereby pushing the hydraulic piston 331 to move in one direction; when the AC servo motor 320 drives the bidirectional pump 324 to rotate in the other direction, the hydraulic oil Flowing in the other direction pushes the hydraulic piston 33 1 to move in the other direction. The second piston rod 332 and the first piston rod 333 are connected to the hydraulic piston 331 and repeatedly move with the hydraulic piston 33 1 . The first piston rod 333 is connected to the sucker rod 341 to drive the sucker rod 341 to reciprocate. The oil pump 340 is pumped, and the oil in the oil pump 340 is sent to the main oil outlet 350 of the oil pumping system through the oil pump outlet pipe 342.

FIG. 2 is a schematic diagram showing the overall structure installation and assembly of the system of the present invention, wherein the main oil outlet 350 and the main oil pipe 360 are fixedly connected by a connecting member 361, and the main oil pipe 360 extends from the ground to the ground D, The ground fixed equipment C is fixed, the main oil pipe 360 and the main pipe A are located in the oil well, the inner layer of the oil well is the protective steel pipe E, and the outer layer is the cement layer F.

In the present embodiment, the second piston rod 332 and the first piston rod 333 extend out of the hydraulic cylinder. When the two-way pump 324 rotates in one direction, the hydraulic oil in the two-way pump 324 flows from one direction to the other, such as the flow direction. The first hydraulic pipe 334, the hydraulic oil in the two-way pump 324 flows from the first hydraulic pipe 334 to the upper hydraulic chamber of the hydraulic cylinder (the space in the upper portion of the hydraulic piston 331), thereby pushing the hydraulic piston 331 downward; at this time, the hydraulic pressure The hydraulic oil in the lower hydraulic chamber of the cylinder (the space in the lower portion of the hydraulic piston 33 1 ) flows from the second hydraulic pipe 335 to the two-way pump 324, thus forming a circulating flow of hydraulic oil; when the two-way pump 324 is rotated in the other direction , forming a circulating flow of hydraulic oil in the opposite direction. It can be seen that the present invention does not require the rehydration system and the pipeline pressure balance system in the prior art, reduces the components, simplifies the control object, and the hydraulic cylinder and the AC servo motor used in the embodiment are highly efficient, and The transmission is simple, so the efficiency is much higher than the prior art; and, the system does not have hundreds of kilometers of sucker rods, no friction loss between the sucker rod and the oil pipe, and no energy loss of the sucker rod. Therefore, compared to existing rod pumping systems, energy consumption will be an order of magnitude reduction.

Embodiment 2

3 is a schematic structural view of a second embodiment of the oil pumping system according to the present invention. Different from the first embodiment, the oil pumping unit of the present invention has two oil pumping pumps, as shown in the figure 340'. In the present embodiment, the oil pumping oil pipes 342, 342' of the two oil pumping pumps are combined in Together, they are sent to the main oil outlet 350 of the oil pumping system.

Compared with the first embodiment, the hydraulic cylinder 324 is fully utilized in this embodiment, and the first piston rod 332 is connected to the second oil pump 340'. Thus, when the hydraulic piston 33 1 of the hydraulic cylinder 330 reciprocates, The first and second pumping pumps 340' work in time division, which doubles the pumping efficiency.

Embodiment 3 Referring to FIG. 4 and FIG. 6, FIG. 6 is a schematic structural diagram of Embodiment 3 of the oil pumping system according to the present invention. In the present invention, a plurality of pumping modules may be combined to form a pumping system. In an embodiment, the pumping system is composed of three pumping modules. 4 is a schematic structural view of the oil pumping module in the third embodiment of the oil pumping system of the present invention. The oil pumping module is substantially the same as the first embodiment or/and the second embodiment, and is not described herein again; The structure of the total oil outlet is shown. The total oil outlet is composed of the main oil outlet 350 and the oil inlets 351 and 352. The oil inlet can be 1, 2, 3, etc. imported oil. Figure 6 is a schematic diagram of the installation of the total oil outlet and each oil pumping module. The total oil outlet and the oil pumping module and the oil pumping modules are connected by connecting parts. The connecting parts can be threaded or flanged. Connect and so on. The oil drawn from the pumping pump of each pumping module is sent to the main oil outlet 350 through the oil outlet pipe, and the main oil outlet 350 is in communication with the main oil pipe, and the oil is delivered to the ground through the main oil pipe, see FIG.

In addition, in order to control the stroke of the hydraulic cylinder, limit switches are set at the highest and lowest points of the hydraulic cylinder respectively.

313, 3 14, as shown in FIG. 7, the limit signal is transmitted to the servo control box 310, and the servo control box 310 controls the AC servo motor 320 to rotate forward or reverse according to the limit signal, thereby implementing the hydraulic cylinder 330 and the oil pump 340. Reciprocating motion. It is also possible to replace the limit switch with a non-contact type sensor such as Hall or infrared, or to use a limit switch. When the hydraulic piston reaches the highest or lowest point of the hydraulic cylinder, the current of the servo motor suddenly increases, according to this signal. To control the forward and reverse of the servo motor; the stroke of the hydraulic cylinder piston can also be calculated from the angle that the servo motor rotates to determine when to change the steering of the servo motor.

A specific embodiment of controlling the stroke of the hydraulic cylinder is shown in Figs. 30 and 31, wherein Fig. 30 is a structural view in which the magnetic induction element is used to control the stroke of the control cylinder. Among them, the oil pumping module shown in Fig. 22 is taken as an example. A magnetic steel is disposed on the sucker rod 451, and a magnetic induction element 492 is disposed at a lower end of the flange to which the hydraulic cylinder 440 and the oil pump 450 are connected, and a protective cover 498 is disposed outside, and the magnetic induction element 492 is controlled by a signal line 493 and servo. The units 410 are connected. When the sucker rod 451 moves downward, the magnet 491 also moves downward with the sucker rod 451. When the magnet 491 approaches the magnetic sensing element 492, the magnetic sensing element 492 transmits the sensing signal to the servo controller through the signal line 493. 410, the servo controller 410 controls the servo motor 420 to reverse, and the sucker rod moves upward. When the sucker rod 451 moves upward, the servo motor 420 is positionally controlled, that is, after the motor is turned to the set number of turns, and then the servo motor 420 is controlled to rotate forward, the sucker rod 451 moves downward to realize the pumping. The reciprocating motion of the rod 451.

Of course, the magnetic sensing element 492 can also be mounted on the upper end of the flange, or a magnetic sensing element can be placed on the upper and lower sides of the flange for limiting the stroke.

Fig. 31 is a structural view showing the control of the stroke of the control cylinder by the contact type switch. The following figure shows the structure of the contact switch. The lower end of the sucker rod 451 is provided with a magnetic steel 491 ', and a protective cover 498 ' is provided at the lower end of the flange. An elastic piece 494 is fixed on the protective cover 498', and a magnetic steel 492' having a polarity opposite to that of the magnetic steel 49 is disposed on the elastic piece 494, and a contact 495 is provided on the protective cover 498', and the free end thereof is The free ends of the resilient tabs 494 are opposite and spaced apart, and the resilient tabs 494 and contacts 495 are coupled to the servo controller 410 via signal lines 495, 496, respectively. When the sucker rod 451 moves downward, the magnetic steel 49 on the sucker rod 451 also moves downward, and when the two oppositely opposite magnetic steels 49 and 492 ' are close, an attractive force is generated, causing the elastic piece 494 to bend, The free end is in contact with the contact 495, and the signal lines 495, 496 are electrically conducted through the elastic piece and the contact. When the signal lines 495 and 496 are turned on, the servo controller 410 controls the servo motor 420 to reverse, and the sucker rod 451 moves upward. When the sucker rod 451 moves upward, the position of the servo motor 420 is controlled, that is, when the motor is turned to the set number of turns, and then the servo motor 420 is rotated forward, the sucker rod 451 moves downward to realize pumping. The reciprocating motion of the oil rod 451.

Of course, the contact switch can also be mounted on the upper end of the flange or one on top of the flange for limiting the stroke.

In the above embodiment, the oil pump can adopt a conventional structure, as shown in Figs. 8 and 9, which is a typical schematic diagram of the oil pump, wherein, in the upper stroke, as shown in Fig. 8, when in the downstroke, 9 is shown. The sucker rod 341 is connected to the swimming valve cover 3441, the swimming valve cover 3441 is fixed on the swimming valve seat 3461, the swimming valve seat 3461 is connected to the piston 347, and the swimming valve ball 3451 is located at the swimming valve seat 3461 and the swimming valve. Within the space between the covers 3441. The fixed valve ball 3452 is located in the space between the fixed valve seat 3462 and the fixed valve cover 3442. The oil enters the pump from the fixed valve and flows out of the oil pump outlet 342. The oil pump outlet pipe delivers oil to the main oil outlet, and the main oil outlet is connected to the main oil pipe, and the oil is delivered to the ground through the main oil pipe.

In addition, there may be various ways for placing the oil pumping system of the present invention in the main pipe. FIG. 10-14 is an example of the oil pumping system of FIG. 1 to illustrate other things in the main pipe (except for the first embodiment). The way the placement is shown). Of course, the same applies to other pumping systems described in the present invention.

Figure 10 is a schematic view showing the structure of the oil pump outlet pipe and the hydraulic cylinder outlet pipe all placed inside the main pipe. This is a compact design with all components in the main pipe and main pipe protection. However, it is required that the components in the main pipe are arranged reasonably and cannot interfere with each other.

In Figure 11, the oil from the pump directly enters the main pipe cavity. The oil is not sent to the main oil outlet by a separate oil pipe. The main pipe is connected to the main oil pipe. At this time, all the components are immersed in the oil of the main oil pipe, and the pressure of the main oil pipe oil is tolerated, and high requirements are imposed on the compressive performance of each component. The advantage is that the intermediate oil pipeline is missing, and the sealing problems associated with the intermediate oil pipeline are not considered.

Figure 12 is a special example of Figure 11, the outer wall of the oil pump is the main pipe, and the oil pump is integrated with the main pipe. Many of the pumping pumps of the existing pumping system are designed in this way. The advantages of this structure are: simple structure, can be straight The cost of using the existing common pump is relatively low. Disadvantages are: high requirements are placed on the compressive performance of the components, and it is not conducive to the connection between the modules in the third embodiment.

Figure 13 and Figure 14 show the two fixing methods for the inner parts of the pipe. Each part in Figure 13 is fixed on the main pipe, which is a conventional connection fixing method. In Figure 14, the components are first fixed on a long part, and then the long parts are fixed on the main pipe. This allows all the components to be fixed on the long part, put together in the main pipe, and then only It is necessary to fix the long strips and it is convenient to install and fix.

Embodiment 4

19 is a schematic view showing the installation of the fourth embodiment of the oil pumping system of the present invention, FIG. 20 is a schematic view showing the outer shape of the oil pumping module according to the fourth embodiment of the present invention, and FIG. FIG. 22 is a partial cross-sectional view showing the oil pumping module of the fourth embodiment of the present invention. In this embodiment, different from the foregoing embodiments, the fixing manner of the device is different. In the first, second, or third embodiment, the device fixing manner is as shown in FIG. 13 or FIG. In the embodiment, the oil pumping system is a module assembly 400 having a housing 401, which is fixed on the main oil pipe 460 via a flange 403, a servo control box 410, an AC servo motor 420, a bidirectional pump 430, and a hydraulic cylinder. 440, the oil pump 450 is sequentially connected through the flange, and the hydraulic oil is circulated between the two-way pump 430 and the hydraulic cylinder 440 through the hydraulic oil pipes 471 and 472, and the oil extracted by the oil pump 450 is sent through the intermediate oil pipes 461 and 462 through the flange 403. Go into the main oil pipe 460.

Referring to Fig. 22, the bidirectional pump 430 is a gear pump. The bidirectional pump shaft 43 1 of the bidirectional pump 430 is connected to a gear 432. The bidirectional pump shaft 431 is connected to the output shaft of the AC servo motor 420 through a coupling 481, and the bidirectional pump 430 passes The flange is connected to the hydraulic cylinder 440. The hydraulic cylinder 440 has a piston 442 therein. Two piston rods 441, 443 of the piston 442 respectively extend from both ends of the hydraulic cylinder 440, and the piston rod 443 is connected to the sucker rod 451 of the oil pump 450 through a coupling 482. In the present embodiment, the housing 401 is used to protect and support the internal components. The housing is provided with an oil inlet hole, and the function is to allow external oil to enter the module cavity to supply oil to the oil pump.

Embodiment 5

Referring to Figures 23-24, Figure 23 is a schematic view showing the removal of the outer casing of the oil pumping module according to the fifth embodiment of the present invention, and Figure 24 is a partial cross-sectional view of the oil pumping module of the fifth embodiment of the present invention. Different from the fourth embodiment, the hydraulic cylinder 440 in the fifth embodiment is connected to two pumping pumps 450, 450'.

Embodiment 6

Referring to FIG. 25, FIG. 25 is a partial cross-sectional view of the oil pumping module according to Embodiment 6 of the present invention. In the embodiment, the oil pumping system may be a plurality of pumping modules connected in series (shown in each of the broken lines in the figure) ), each of the oil pumping modules may be connected to the intermediate oil pipes of the respective oil pumping modules as in the fourth embodiment or the fifth embodiment, and together with the main oil pipe 460 Connected. By connecting multiple pumping modules in series, the pumping capacity can be increased to increase the output.

Example 7

Referring to FIG. 26, it is a schematic diagram of an oil circuit inside the oil pumping module according to Embodiment 7 of the present invention. In the present embodiment, the oil inlet 702 is opened in the casing 701, and the oil pump 750 is connected to the oil outside the casing 701 through an oil inlet pipe connected to the oil inlet 702. An oil outlet 751 is provided at an appropriate position of the oil pump 750 for discharging the extracted oil through the oil outlet 751 into the housing cavity. The housing cavity communicates with the main oil pipe through a passage in the flange 703. In this embodiment, since the inner cavity of the oil pumping module is sealed, the external oil enters the oil pump through the oil inlet pump of the oil pump, and the oil of the oil pump flows into the inner cavity of the oil pumping module, and the inner cavity is used as an intermediate oil pipe, and the oil is sent through the inner cavity. Enter the main oil pipe. The advantage is that the intermediate oil pipe is omitted, and the problem of the intermediate oil pipeline is not required to be filtered, such as sealing, assembly, etc. However, since all the components are immersed in the oil, the oil pressure of the main oil pipe is to be withstood, so each component should pay attention to the resistance. Pressure and sealing issues.

Example eight

Referring to FIG. 27, it is a schematic diagram of the internal oil circuit of the oil pumping module according to the eighth embodiment of the present invention. Unlike the seventh embodiment, the oil pump 850 passes through an oil inlet pipe connected to the oil inlet hole 802 and oil outside the casing 801. Liquid phase pass. An intermediate oil pipe 861 connected to the main oil pipe is provided at an appropriate position of the oil pump 850. In this embodiment, since the inner cavity of the pumping module is sealed, the external oil enters the oil pump through the oil feed pump inlet pipe, and the oil pumped by the oil pump enters the main oil pipe through the intermediate oil pipe. The advantage is that the oil flows completely in the pipeline, and there is no oil in the inner cavity of the oil pumping module, and it is not necessary to filter various components, such as the pressure resistance and sealing of the motor, the controller, etc., and only the pressure resistance of the filter oil pipe is required. Sealing problem.

In addition, the control mechanism is connected to the ground device through a cable, and the sealing at the connection between the cable and the servo motor controller is critical. In the present invention, a cable connector as shown in FIG. 28 is used, and one end of the cable connector is a cable end 91. The other end is a control wire end 93, the cable is connected to the cable end 91, and is glued at the joint. The wiring of the control mechanism is inserted into the wiring hole 94 of the control wire end 93, and is sealed and fixed by the flange 92. Control agency. In this way, the sealing effect can be ensured and the installation on site is convenient.

In the above embodiments, the output end of the servo motor is connected with a protector. As shown in FIG. 29, the structure of the first embodiment is taken as an example, and the connection between the motor 320 and the bidirectional pump 324 is shown. The protector 380 is in communication with the interior of the motor 320 and is filled with insulating oil. The external liquid needs to pass through the protector 380 to enter the inside of the motor from the output end of the motor. Thus, the protector 380 plays a protective role in the middle, and the protector 380 can balance the internal and external pressures, so that the pressure inside and outside the motor 320 is uniform, preventing internal and external pressures. The imbalance causes the motor 320 to fail to seal.

During the pumping process, due to the acceleration and deceleration of the pump during reciprocating motion, this movement will cause the main oil When the force is changed, the vibration is generated. The greater the vibration, the more easily the main oil pipe is fatigued, and the loss is increased. The invention can solve the problem well, and the main oil pipe is evenly stressed to effectively reduce the oil pipe loss. For the above three examples, the force of the main oil pipe is analyzed as follows - the mass of the liquid in the main oil pipe is - m = pV = pSh where m - the quality of the liquid in the oil pipe

„—The density of liquid in the tubing

S-—the cross-sectional area of the tubing

h----the height of the oil in the oil pipe

Take p = lxl0 ³ A: g/w ³ , = 60x10 - ⁴ m ² , h = 2000m

Bay U = lxl0 ³ x 60x10 - ⁴ x 2000 = 1200 (1⁄2g When the pump is reciprocating up and down, the sucker rod is accelerating at the beginning of the upstroke and downstroke, setting the acceleration to "=

For the above three embodiments, the speed change curve of the sucker rod is as shown in Fig. 15.

For the first embodiment, take the piston pump cross-sectional area:

^{54xl (r4 2} , sucker rod cross-sectional area - S = 5xl0-W When the upper stroke sucker rod is accelerated, the acceleration of the liquid in the tubing is:

^A S 60xl0- ⁴

The increased pulling force of the tubing is -

_{_{AF A = ma A = 0.9ma =}} 0.9 x 12000 x 1 = 10800N when the rod stroke acceleration, the acceleration of the liquid within the tubing _{^{- α = α¾1 = a 5x10 =}} 0.083α

S 60xl0- ⁴ tubing under tension is increased:

A ^下 = m = 0.083m = 0.083 χ 12000 χ 1 = 996Ν Then, the force curve of the main oil pipe in the first embodiment is shown in Fig. 16. For the second embodiment, since the system has two oil pumping pumps, the cross-sectional area of the pump piston is taken in the same case as the total displacement of the fuel pipe: to ^{= 27xl (r4w2} , the cross-sectional area of the sucker rod: <5^ =2'5><10-^ ² .

When the sucker rod 1 is stroked, the sucker rod 2 is the down stroke.

When the sucker rod 1 is down stroked, the sucker rod 2 is on the upstroke, then

11 Replacement page (Article 26) When the sucker rod is accelerated, the acceleration of the liquid in the tubing is:

^Piston β + β 27xl0— ⁴ +2.5xl0— ⁴

a a α- 0.492α

S 60x10

The increased pulling force of the tubing is:

AF _B = ma _B = 0A92ma = 0.492 x 12000 x 1 = 5904N Shell 1J, the force curve of the main oil pipe in the second embodiment is shown in Fig. 17.

For the third embodiment, since there are three oil pumpes in the system (for the versatility of the description, n is set), in the case that the total displacement of the oil pipe is the same as in the first embodiment, the displacement of each oil pump is implemented. Example 1 / n of the displacement of the pump;

By controlling the acceleration of each pump in different time periods by the servo control system, the increased tension of the tubing can be significantly reduced, that is, the magnitude of the change of the tubing tension is significantly reduced;

2

AF _r , -AF _B

n

2

5904/2 -2952N

When =4, the force of the main oil pipe is as shown in Fig. 18.

It can be seen from the above three force diagrams that in the acceleration phase of the up and down stroke, the force change of the second embodiment is smaller than that of the first embodiment, and the force change of the third embodiment is 2/ of the second embodiment. η, when η takes a larger value, the force variation of the third embodiment will be small.

The elastic modulus of steel is taken as follows: E = 2QQGPci The cross-sectional area of the tube is taken as:

AFxL

AL

ExS^

The change in length of the tubing due to the change in tensile force is: Example 1:

AF xL _ 5904 :2000

AL 0.05904w

Ex <10x10- ⁴

Embodiment 2: Tube 200 xlO ⁹ )

AF xL _ 2952 > :2000

AL 0.02952w

Ex 200 xlO ⁹⁾ <10x10- ⁴

Embodiment 3:

It can be seen from the above comparison that the minimum of the third embodiment, the vibration of the main oil pipe - the longest service life; In the third embodiment, it is also easier to increase the displacement of the entire system. It should be noted that the above embodiments are only intended to illustrate the invention and are not to be construed as limiting the scope of the invention. Modifications or equivalents of the invention are intended to be included within the scope of the appended claims.

Claims

Claim

What is claimed is: 1. A hydraulic cylinder comprising a hydraulic cylinder, a piston, and a first piston rod connected to the piston, the piston dividing the hydraulic cylinder into upper and lower chambers, and further comprising a second piston a rod connected to the piston, extending from the first piston rod to the hydraulic cylinder body, and a liquid inlet and outlet on the hydraulic cylinder corresponding to the upper and lower chambers.

2. The hydraulic cylinder according to claim 1, wherein the liquid inlet and outlet are connected to the hydraulic power drive mechanism through the first and second hydraulic oil pipes, respectively.

An oil pumping unit, comprising: the hydraulic cylinder according to claim 1 or 2, and a first oil pump, a first piston rod of the hydraulic cylinder and a sucker rod of the first oil pump Connected, the first oil pump is provided with an oil outlet.

4. The oil pumping unit according to claim 3, further comprising a second oil pump, the second piston rod of the hydraulic cylinder being connected to the sucker rod of the second oil pump, the second The pump has an oil outlet.

The oil pumping unit according to claim 3 or 4, further comprising a position sensor disposed at a maximum of the up and down stroke of the cylinder rod for restricting the upper and lower strokes of the hydraulic cylinder.

6. The oil pumping unit according to claim 5, wherein the position sensor comprises a contact sensor and/or a non-contact sensor.

7. The oil pumping unit according to claim 6, wherein the touch sensor is a limit switch.

8. The oil pumping unit according to claim 6, wherein the non-contact sensor is a Hall switch or an infrared switch.

An oil pumping module, comprising: a control mechanism, a hydraulic drive mechanism, and the oil pumping unit according to any one of claims 3 to 8, wherein the oil pumping unit is driven by the hydraulic oil pipe and the hydraulic pump The hydraulic drive mechanism is connected to the control mechanism, and the hydraulic drive mechanism is controlled by the control mechanism, and the hydraulic drive mechanism drives the piston in the hydraulic cylinder of the oil pumping unit to reciprocate up and down, thereby The sucker rod of the oil pump is driven to perform the reciprocating pumping work.

10. The oil pumping module according to claim 9, wherein the hydraulic drive mechanism comprises a two-way pump and an electric motor, the electric motor is connected to the two-way pump through a coupling, the two-way pump and the pumping The first and second hydraulic oil pipes of the hydraulic cylinder in the oil unit are connected.

11. The oil pumping module according to claim 10, wherein a protector is connected to an output end of the motor, and the protector communicates with the inside of the motor and is filled with insulating oil.

The oil pumping module according to claim 9, wherein the two-way pump is a gear pump, and the motor is an AC servo motor.

The oil pumping module according to claim 9, wherein the control mechanism is connected to the ground device through a cable, and the end of the cable connected to the control mechanism is a pressure-resistant sealed cable joint.

The oil pumping module according to claim 13, wherein one end of the cable joint is a cable end, and the other end is a control wire end, and the cable is connected to the cable end, and is sealed with glue at the joint, and is controlled. The wiring of the mechanism is inserted into the wiring hole of the control line end and fixed to the control mechanism by a flange seal.

15. The oil pumping module according to claim 9, further comprising a sealed casing provided with an oil inlet hole, the oil pump passing through an oil inlet pipe connected to the oil inlet hole and oil outside the casing The same.

16. The oil pumping module according to claim 15, wherein the oil pump delivers oil through an intermediate oil pipe connected to the oil outlet.

17. The oil pumping module according to claim 15, wherein an oil outlet is provided at an appropriate position of the casing for discharging oil inside the casing from the oil pump outlet. Delivered out.

18. A pumping system, comprising: one or more oil pumping modules according to any one of claims 9-17, each of said oil pumping modules being connected to a main pipe through a fuel outlet thereof The ports are connected.

19. The oil pumping system according to claim 18, wherein each of the oil sucking modules is connected to each other by a connecting member, and the connecting member is connected by a screw connection or/and a flange connection.