A method and system for regulating and controlling oil extraction of a beam pumping unit without stopping the unit

Abstract

The present invention relates to a method and system for regulating and controlling oil extraction of a beam pumping unit without stopping the unit, which at least comprises a pumping mechanism (1) capable of receiving control information to perform oil extraction work, wherein the pumping mechanism (1) adjusts its working strategy according to the control instructions of a measurement and control terminal (2), and a parameter acquisition module (3) arranged on the pumping mechanism (1) can acquire three-phase electrical parameters and sensor parameters of the pumping mechanism (1) during operation; the measurement and control terminal (2) completes the calculation and processing of the indicator diagram data according to the acquisition information uploaded by the parameter acquisition module (3), thereby outputting a control strategy that satisfies the real-time working conditions of the pumping mechanism (1). In addition, the present invention also relates to a method for regulating and controlling oil extraction of a beam pumping unit without stopping the unit.

Description

Technical Field

[0001] The present invention relates to the technical field of beam pumping equipment, and in particular to a method and system for regulating and controlling oil extraction of a beam pumping unit without stopping the unit. Background Art

[0002] With the rapid development of automation, digitalization and intelligence, major oil fields are also moving towards smart oil fields in line with the times. At the same time, with the accelerated exploitation of crude oil in oil fields, some oil wells have entered the middle and late stages of exploitation. Among them, beam pumping units account for a large proportion of oil production equipment in major oil fields. Due to the different working parameters of each well in the oil field, there will be a mismatch in counterweights. When various types of pumping units are equipped for actual work, a certain power threshold will be reserved. In addition, in actual production, the pump fullness of the pumping unit will be affected by the change of the dynamic liquid level, the pumping unit suspension load will also change with the pump fullness, and the balance of the pumping unit will also be affected. The balance of the beam pumping unit is one of the key factors affecting its energy consumption. Therefore, the energy-saving and consumption-reducing needs can be met by balancing the beam pumping unit and effectively monitoring the balance of the pumping unit and the current stroke in real time.

[0003] The patent document with the publication number CN113445969A discloses a pumping unit that realizes intermittent pumping by using the non-integer-cycle motion of the crank, which relates to the technical field of oilfield production equipment, including a base, a bracket, a walking beam, a donkey head, a connecting rod, a crank, a reducer and a motor, and also includes a mechanical intermittent pumping transmission mechanism. The invention sets a mechanical intermittent pumping transmission mechanism, and by using the mechanical intermittent pumping transmission mechanism to provide the crank with a non-integer-cycle driving force, the stroke of the pumping unit is adjusted to be less than the elastic static deformation range of the rod column, thereby eliminating the safety hazards and freezing hazards caused by the shutdown of the pumping unit. Compared with the technical solution of realizing the non-integer-cycle motion of the crank by electrical means in the prior art, the use of a mechanical intermittent pumping transmission mechanism can effectively eliminate the electrical system impact caused by the frequent reversal of the motor, thereby extending the service life of the electrical system including the motor and the frequency converter, and thus improving the reliability of the pumping unit. However, the patent cannot adjust the balance of the pumping unit under different working conditions, nor can it adjust the working state and change the working strategy of the pumping unit according to the real-time data of the oil stored in the oil field monitored.

[0004] At present, the operating mode of beam pumping units worldwide is always that the motor drives the crank to perform continuous unidirectional rotational motion, and then drives the bare rod to complete the full stroke up and down reciprocating linear motion through the four-bar linkage and the transmission of the donkey head. That is to say, under the existing operating mode, as long as it enters the operating state, the bare rod of the beam pumping unit can only run at the full stroke. If the pumping well is to have no pumping effect, it can only be achieved by shutting down the pump or keeping the actual operating stroke of the pump less than the elastic static deformation range of the rod string; and under the existing operating mode, it is impossible for the beam pumping well to adjust the stroke of the pump to be less than the elastic static deformation range of the rod string during the shutdown period, so the only way to achieve no pumping effect is to shut down completely. However, the complete shutdown of the pumping well will cause the following two fatal problems that cannot be solved:

[0005] First, when restarting the machine from a shutdown state, there must be someone on duty, otherwise it is very easy to cause casualties;

[0006] Second, since the bare rod at the wellhead is in a completely static state during the shutdown waiting process, the liquid in the oil pipe near the wellhead is in a completely static state, lacking flow or agitation, which can easily cause the wellhead to freeze in winter.

[0007] In addition, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the inventor studied a large number of documents and patents when making the present invention, but due to space limitations, not all details and contents are listed in detail. However, this does not mean that the present invention does not have the characteristics of these prior arts. On the contrary, the present invention already has all the characteristics of the prior art, and the applicant reserves the right to add relevant prior art to the background technology. Summary of the invention

[0008] In view of the shortcomings of the prior art, the technical solution of the present invention provides a non-stop pumping and oil production control system for a beam pumping unit, which at least includes a pumping mechanism capable of receiving control information to perform oil pumping work, the pumping mechanism adjusts its operating parameters according to the control instructions of the measurement and control terminal, and the parameter acquisition module arranged on the pumping mechanism can collect the three-phase electrical parameters and sensor parameters of the pumping mechanism during the working process; the measurement and control terminal completes the calculation and processing of the indicator diagram data according to the acquisition information uploaded by the parameter acquisition module, thereby outputting a control strategy that meets the real-time working conditions of the pumping mechanism. Its advantage is that the operating parameters of the pumping mechanism are dynamically adjusted by the measurement and control terminal, so that the pumping mechanism can adjust the state according to the crude oil reserves and crude oil penetration in the oil field, so that the pumping mechanism can perform pumping work according to different operating parameters at different time points, so that the pumping mechanism parameters can always be adapted to the oil field parameters, avoiding the occurrence of undesirable phenomena such as liquid surface collision and empty pumping in the oil pump, reducing the defect that the work of the pumping mechanism does not correspond to the actual extraction effect, greatly improving the crude oil pumping efficiency, and avoiding the ineffective power consumption of the pumping mechanism. In addition, the measurement and control terminal can establish a performance diagram that continuously changes on the time axis based on historical data, and adjust the pumping process of the pumping mechanism in the next intermittent pumping cycle through the performance diagram data, so that the pumping unit and the oil well parameters are dynamically matched, ensuring that the pumping unit is always in the best operating state.

[0009] According to a preferred embodiment, the pumping mechanism at least includes a pumping motor, a frequency converter unit and a balancing motor, wherein the frequency converter unit can adjust the working state of the pumping motor according to the latest control strategy output by the measurement and control terminal, thereby completing the automatic adjustment of the pumping frequency, intelligent inter-pumping control and automatic adjustment of the balance of the pumping mechanism. Its advantage is that the measurement and control terminal generates a control strategy after predicting the matching of the operating parameters of the pumping mechanism and the oil well parameters in the next inter-pumping cycle based on the historical data of multiple continuous dynamometer diagrams on the time axis, and verifies the predicted control strategy based on the sensor monitoring data acquired in real time by the parameter acquisition module in this inter-pumping cycle, updates the control strategy based on the verification result, and adjusts the operating parameters of the pumping mechanism in the subsequent pumping time period of the same inter-pumping cycle according to the updated control strategy. The measurement and control terminal will predict the indicator diagram of the next pumping cycle based on historical data, and can pre-adjust the control strategy of the operating parameters of the pumping mechanism at different time points during this pumping cycle based on the predicted indicator diagram output, thereby establishing a pumping process that is continuously iteratively updated based on historical data. During the pumping process, the measurement and control terminal can also generate a real-time indicator diagram based on the actual collected oilfield parameters and the actual operating parameters of the pumping mechanism, and compare and verify the real-time indicator diagram with the predicted indicator diagram, thereby outputting an updated control strategy based on the difference between the real-time indicator diagram and the predicted indicator diagram, thereby adjusting the operating parameters of the pumping mechanism for the remaining time period of this pumping cycle based on the control strategy.

[0010] According to a preferred embodiment, the measurement and control terminal can create fuzzy rules that can control the balance of the pumping mechanism according to the collected information uploaded by the parameter collection module, so that the pumping mechanism can complete the self-balancing pumping work according to the control instructions of the measurement and control terminal. Its advantage is that the rotation of the balance arm of the pumping unit is relatively complicated, which makes it difficult to establish an accurate mathematical model and requires high robustness of the system. Fuzzy control can meet the use requirements of the above-mentioned pumping unit. As a branch of intelligent control, fuzzy control does not need to establish an accurate mathematical model, simplifies the complexity of the control system, and has strong robustness. Therefore, the use of fuzzy control algorithm can better solve the complexity of nonlinear control systems.

[0011] According to a preferred embodiment, the measurement and control terminal also generates a real-time updated indicator diagram based on the collected information uploaded by the parameter collection module, so as to adjust the working state of the pumping mechanism in the next stage according to the area of ​​the indicator diagram. Its advantage is that the indicator diagram representing the pumping work of the pumping mechanism and the change of crude oil reserves in the oil field within an inter-pumping cycle is updated by setting a threshold, so as to define the parameters such as the constantly changing stop pumping area according to the changing indicator diagram, so that the operating parameters of the pumping mechanism can maintain a high degree of matching with the oil field parameters, so as to facilitate faster and more efficient completion of crude oil pumping.

[0012] According to a preferred embodiment, during the process of calculating the area of ​​the dynamometer diagram, the measurement and control terminal also updates the pumping stop area according to whether the area difference of the dynamometer diagram calculated on both sides is within a set range.

[0013] According to a preferred embodiment, when the crank of the pumping mechanism runs a full cycle, the pumping motor works normally and runs at the rated speed; when the pumping time is reached, the crank swing operation stage is entered, the pumping motor stops working, the pumping rod moves up and down with a preset stroke, and the crank swings back and forth flexibly without impact within a specified range. The energy consumption of the motor during the swinging period is 10% of that of normal operation. When the swinging time is reached, the cycle is recycled and enters the full cycle operation stage.

[0014] According to a preferred implementation, during the crank full cycle operation stage, the frequency converter unit controls the pumping motor to operate at the rated speed; during the crank swing operation stage, the control target is to minimize energy consumption, while at the same time satisfying the requirement that the crank shows signs of swinging; for the swing angle, the stroke loss of the oil well is first calculated based on the bare rod indicator diagram, and the bare rod movement length is less than the stroke loss, satisfying the up and down movement of the pumping rod and the oil pump stops working; one rotation of the crank is 360 degrees, and the bare rod completes a cycle of reciprocating operation, and the crank swing angle is calculated based on the bare rod movement length; for the optimal swing position, since the balance state of each well is different, the minimum power value point during the swing process is not necessarily at the upper dead center of the bare rod, and therefore the optimal drive position is determined by comparing the minimum power value point during the swing process with the real-time collected electric power curve.

[0015] According to a preferred embodiment, after the measurement and control terminal obtains the corresponding balance control data through analysis and calculation based on the fuzzy control algorithm, it controls the balancing motor to adjust the balance degree of the oil pumping mechanism in a manner of adjusting the position of the swing-arm type balancing arm.

[0016] The present application also provides a method for controlling oil extraction of a beam pumping unit without stopping, which at least includes the following steps: a parameter acquisition module acquires three-phase electrical parameters and various sensor signals of the pumping mechanism, and uploads the acquired data to a measurement and control terminal through a wireless communication module; the measurement and control terminal analyzes the received data, and sends the obtained data and control signals to the corresponding module to realize the pumping mechanism's stroke adjustment, self-balancing adjustment, and display of the control panel. Its advantage is that the measurement and control terminal dynamically adjusts the operating parameters of the pumping mechanism, so that the pumping mechanism can adjust its state according to the crude oil reserves and crude oil penetration in the oil field, so that the pumping mechanism can perform pumping work according to different operating parameters at different time points, so that the pumping mechanism parameters can always be adapted to the oil field parameters, avoiding the occurrence of adverse phenomena such as liquid surface collision and empty pumping in the oil pump, reducing the defect that the work of the pumping mechanism does not correspond to the actual extraction effect, greatly improving the crude oil extraction efficiency, and avoiding the ineffective power consumption of the pumping mechanism. In addition, the measurement and control terminal can establish a continuously changing indicator diagram on the time axis based on historical data, and adjust the pumping process of the pumping mechanism in the next pumping cycle through the indicator diagram data, so that the pumping unit and the oil well parameters maintain dynamic matching, and the pumping unit is always in the best operating state. The measurement and control terminal generates a control strategy after predicting the matching of the operating parameters of the pumping mechanism and the oil well parameters in the next pumping cycle based on the historical data of multiple indicator diagrams continuously on the time axis, and verifies the predicted control strategy based on the sensor monitoring data obtained in real time by the parameter acquisition module in this pumping cycle, updates the control strategy based on the verification results, and adjusts the operating parameters of the pumping mechanism in the subsequent pumping time period of the same pumping cycle based on the updated control strategy. The measurement and control terminal will predict the indicator diagram of the next pumping cycle based on historical data, and can pre-adjust the control strategy of the operating parameters of the pumping mechanism at different time points during this pumping cycle based on the predicted indicator diagram output, thereby establishing a pumping process that is continuously iteratively updated based on historical data. During the pumping process, the measurement and control terminal can also generate a real-time indicator diagram based on the actual collected oilfield parameters and the actual operating parameters of the pumping mechanism, and compare and verify the real-time indicator diagram with the predicted indicator diagram, thereby outputting an updated control strategy based on the difference between the real-time indicator diagram and the predicted indicator diagram, thereby adjusting the operating parameters of the pumping mechanism for the remaining time period of this pumping cycle based on the control strategy.

[0017] According to a preferred embodiment, the measurement and control terminal transmits data and sends control signals through a wireless communication module. The advantage is that by using the same communication module to complete the transmission of data and signals, the real-time processing efficiency of the system can be improved to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1The present invention is a schematic diagram of the working process of a non-stop oil extraction and control system for a beam pumping unit.

[0019] Reference numerals list

[0020] 1: Pumping mechanism; 2: Measurement and control terminal; 3: Parameter acquisition module; 4: Wireless communication module; 5: Control panel; 11: Pumping motor; 12: Frequency converter unit; 13: Register unit; 14: Balancing motor. DETAILED DESCRIPTION

[0021] The following is a detailed description with reference to the accompanying drawings.

[0022] Example 1

[0023] The present application provides a non-stop oil extraction control system for a beam pumping unit, which includes an oil pumping mechanism 1, a measurement and control terminal 2 and a parameter acquisition module 3.

[0024] according to Figure 1 A specific implementation method is shown. Before the initial acquisition work is performed, the measurement and control terminal 2 calculates the working strategy of the pumping mechanism 1 according to the pre-acquired underground oil field parameters. After the acquisition work starts, the frequency converter unit 12 of the pumping mechanism 1 receives the optimal operating frequency value of the pumping motor 11 of the pumping mechanism 1 from the measurement and control terminal 2 and updates it to the corresponding block in the register unit 13 of the pumping mechanism 1, and then drives the pumping motor 11 to operate with this frequency value. The pumping motor 11 drives the four-bar structure of the pumping mechanism 1 to perform periodic mechanical movement, and the four-bar structure drives the pumping pump to complete the pumping cycle and pump the crude oil to the ground. During the operation of the pumping mechanism 1, the parameter acquisition module 3 converts the various physical signals sensed into electrical signals and transmits them back to the measurement and control terminal 2. The measurement and control terminal 2 completes the acquisition and processing of the indicator diagram data by analyzing the suspension point displacement signal and the load signal, calculates the optimal stroke or intermittent pumping control strategy of the pumping mechanism 1 through the energy-saving control algorithm, and then drives the pumping motor 11 to work according to the latest operating frequency through the frequency converter unit 12. The measurement and control terminal 2 can also calculate the balance of the oil pumping mechanism 1 by analyzing the electrical parameters of the oil pumping motor 11 , and then adjust the balance of the oil pumping mechanism 1 by controlling the balancing motor 14 .

[0025] Preferably, the measurement and control terminal 2 can control the parameter acquisition module 3 to complete the acquisition of the three-phase electrical parameters of the pumping mechanism 1, the current data of the pumping motor 11 and the balancing motor 14, the dynamometer diagram data and other sensor parameters. Preferably, the sensor parameters can include real-time data information monitored by sensors such as angular displacement sensors, load sensors, and pressure sensors, as well as data such as the wellhead temperature and flow rate of the oil field, so as to calculate important production data such as the number of strokes, inter-pumping time, balance, power factor, power consumption per ton of oil, and active power saving rate of a single well of the pumping unit based on the above data information. In addition, by using sensors to monitor the oil field in real time, data information that can be used to calculate the dynamometer diagram and sinking degree, etc., which can characterize the permeability of the oil field, can also be obtained. Specifically, the pumping mechanism 1 can also include an intelligent controller that can work in conjunction with the frequency converter unit 12 to control the pumping unit. The intelligent controller can manually adjust the operation of the pumping unit when the frequency converter 12 does not receive the control command of the measurement and control terminal 2. Preferably, the control strategy calculated by the measurement and control terminal 2 refers to judging whether there is a mismatch between the pumping unit parameters and the oil field parameters or whether the set pumping unit parameters and the oil field parameters will be mismatched in the next pumping cycle based on the monitoring data such as the dynamometer data collected in real time and the operating parameters of the pumping unit (for example: the number of strokes, the interval pumping time, the balance, the power factor, the power consumption per ton of oil and the active power saving rate of a single well), so as to output the operating parameters of the pumping unit in the next pumping cycle according to the real-time monitored pumping unit parameters and the oil field parameters. Preferably, the control strategy output by the measurement and control terminal 2 refers to the pumping process that characterizes the continuous change of the operating parameters of the pumping unit in an interval pumping cycle, and the operating parameters of the pumping unit include adjusting and setting the number of strokes, the interval pumping time and the balance of the pumping unit in a pumping cycle. Preferably, the existing oil fields are generally in a low permeability state, therefore, it is necessary to stop the pumping operation after the pumping unit continues to pump for a certain period of time, so that the crude oil in the oil field can slowly seep out from the formation to restore the oil volume of the oil field. In addition, the pumping unit needs to adjust the stroke of the bare rod according to demand during the pumping process, so that the pumping unit can adjust the stroke of the bare rod during each full cycle of the crank movement as the oil storage in the oil field decreases within a cycle time period, avoiding inefficient operation such as empty pumping. Specifically, the stroke of the bare rod gradually shortens as the oil storage in the oil field decreases. The measurement and control terminal 2 can intelligently analyze the collected dynamometer data and control the operating parameters of the pumping unit, so that the pumping unit and the oil well parameters are dynamically matched, and the pumping unit is always in the best operating state. It can also cooperate with the host computer monitoring configuration software and the dynamometer intelligent working condition diagnosis and dynamometer oil measuring system of the Oil and Gas Technology Research Institute to realize oil metering, fault diagnosis and intelligent control.

[0026] The measurement and control terminal 2 can also process the working condition data collected in real time through the on-chip DSP engine of its main control chip and control the parameters of external devices such as the frequency converter unit 12 through the on-chip MCU unit, and finally realize the automatic adjustment of the stroke frequency, intelligent inter-pumping control and automatic adjustment of the balance degree of the pumping mechanism 1. Preferably, the measurement and control terminal 2 calculates the indicator diagram of multiple continuous inter-pumping cycles based on the data information collected by the load sensor and the angular displacement sensor for multiple times, and predicts the above parameters of the next inter-pumping cycle based on multiple groups of gradually changing full pumping area, stop pumping area, stop pumping time and pumping time parameters obtained from the indicator diagram, so as to adjust the operating parameters of the pumping unit according to the predicted full pumping area, stop pumping area, stop pumping time and pumping time, and generate the latest control strategy, and then the pumping mechanism 1 adjusts the working state of the pumping motor 11 according to the control strategy containing its operating parameters issued by the measurement and control terminal 2, so that the pumping mechanism 1 can always keep its pumping parameters matching the oil parameters of the oil field, and avoid the phenomenon of empty pumping. Preferably, the automatic adjustment of the stroke frequency, intelligent inter-pumping control and automatic adjustment of the balance degree of the pumping mechanism 1 is to adjust the stroke of the light rod, the swing angle of the crank and the operation of the balancing motor in real time in different time periods according to the operating parameter data of the pumping mechanism 1 in the control strategy. The measurement and control terminal 2 generates a control strategy after predicting the matching of the operating parameters of the pumping mechanism and the oil well parameters in the next inter-pumping cycle based on the historical data of multiple continuous dynamometer diagrams on the time axis, and verifies the predicted control strategy based on the sensor monitoring data obtained in real time by the parameter acquisition module 3 in this inter-pumping cycle, updates the control strategy based on the verification result, and adjusts the operating parameters of the pumping mechanism in the subsequent pumping time period of the same inter-pumping cycle according to the updated control strategy. The measurement and control terminal will predict the indicator diagram of the next pumping cycle based on historical data, and can pre-adjust the control strategy of the operating parameters of the pumping mechanism at different time points during this pumping cycle based on the predicted indicator diagram output, thereby establishing a pumping process that is continuously iteratively updated based on historical data. During the pumping process, the measurement and control terminal can also generate a real-time indicator diagram based on the actual collected oilfield parameters and the actual operating parameters of the pumping mechanism, and compare and verify the real-time indicator diagram with the predicted indicator diagram, thereby outputting an updated control strategy based on the difference between the real-time indicator diagram and the predicted indicator diagram, thereby adjusting the operating parameters of the pumping mechanism for the remaining time period of this pumping cycle based on the control strategy.

[0027] Preferably, the balance of the pumping mechanism 1 is a key parameter for the stable operation of the pumping unit, and a good control strategy can stably control the balance of the self-balancing pumping mechanism. Due to the different geological characteristics and the formation fluid supply capacity, the pumping mechanism 1 is driven by the high speed of the driving motor, and the energy is converted by the reduction box, so that its energy is transferred to the donkey head, so that the oil rod reciprocates up and down. During the normal operation of the walking beam self-balancing pumping unit, when the balancing motor is working, the changes in various parameters of the pumping unit are nonlinear changes, and the rotation of the balance arm of the pumping unit is also relatively complex. It is difficult to establish an accurate mathematical model, and the robustness of the system is required to be high. Fuzzy control can meet the use requirements of the above-mentioned pumping unit. As a branch of intelligent control, fuzzy control has the following main characteristics: (1) It does not need to establish an accurate mathematical model; (2) It can simplify the complexity of the control system; (3) It has strong robustness. Therefore, the use of fuzzy control algorithm can better solve the complexity of nonlinear control systems.

[0028] Preferably, the balance of the pumping mechanism 1 is affected by many factors, and the use of fuzzy control can well realize the control of the balance of the walking beam pump. Fuzzy control requires a total of three important steps, namely fuzzification, fuzzy rule design and reasoning, and defuzzification. When designing the fuzzy rules, two input quantities are usually used, namely deviation and deviation change rate. The balance of the walking beam pump is adjusted according to the two input quantities, and the intelligent control system can have better and stable dynamic performance. According to the characteristics of the control of the balance in the intelligent control system of the digital walking beam self-balancing pump, the input quantities of the system are the balance deviation e and the balance deviation change rate ec. The two are analyzed and calculated to obtain the corresponding control output u of the self-balancing pump, which constitutes the total control query table of the balance.

[0029] Preferably, the two input quantities of fuzzy control are balance deviation e and balance deviation change rate ec, and the fuzzy control output u1 is output after passing through the proportional factor G. The deviation e, the deviation change rate ec and the control signal m all select isosceles triangle membership functions, and the deviation level of balance is X, X={-6, -5, -4, -3, -2, -1, 0, +1, +2, +3, +4, +5, +6}.

[0030] The basic domain of the balance deviation e is {-50, 50}, the quantization factor Ge=0.12, and the linguistic variables are: NB (negative large), NNl (negative medium), NS (negative small), NO (zero), PS (positive small), PM (positive medium), PB (positive large).

[0031] The basic domain of the balance deviation change rate ec is {-10, 10}, the quantization factor Gee=0.6, and the linguistic variables are: NB (negative large), NM (negative medium), NS (negative small), NO (zero), PS (positive small), PM (positive medium), PB (positive large).

[0032] The basic domain of the fuzzy control output u1 of the balance degree is {-6, 6}, the amplification factor G=1, and the linguistic variables are: NB (negative large), NM (negative medium), NS (negative small), NO (zero), PS (positive small), PM (positive medium), and PB (positive large).

[0033] Specifically, the measurement and control terminal 2 obtains the corresponding balance control signal m after analysis and calculation by the fuzzy control algorithm, and sends it to the well site pumping mechanism 1. The measurement and control terminal 2 converts the balance control signal m into a control signal of the motor, controls the balance adjustment circuit of the self-balancing pumping mechanism 1 by controlling the pull-in of the control relay, and then controls the balance adjustment motor 14 to adjust the position of the swing arm balance arm, and adjusts the balance degree of the digital walking beam self-balancing pumping unit, so that the digital walking beam self-balancing pumping unit reaches an ideal balance state.

[0034] Preferably, when the system is initialized, it receives data such as the balance degree from the upper monitoring platform and the control signal of the balance degree of the self-balancing oil pump, and judges the balance degree. If the balance degree is not within the set range, the function is called to convert the control signal value into a pulse control signal output, and the Forward and Reverse functions are called to control the solid-state relay to operate, thereby controlling the balancing motor to operate. The balancing motor is reversed as needed to control the balance degree between 85% and 115%.

[0035] During the crank full-cycle operation stage, the oil pump works normally and the motor runs at the rated speed; when the pumping time is reached, the crank swing operation stage is entered, the oil pump stops working, the sucker rod moves up and down with a preset stroke, and the crank swings back and forth flexibly without impact within the specified range. The energy consumption of the motor during the swinging period is 10% of that in normal operation. When the swinging time is reached, the cycle enters the full-cycle operation stage.

[0036] During the crank full cycle operation stage, the control system controls the motor to operate at the rated speed.

[0037] During the crank swing operation stage, the control target is to minimize energy consumption, while at the same time satisfying the requirement that the crank shows signs of swinging, that is, during the crank swing process, the swing amplitude of the crank is a gradually changing process, and the swing amplitude of the crank can be close to 0° or 360°.

[0038] For the swing angle, the stroke loss of the oil well is first calculated based on the polished rod indicator diagram. The movement length of the polished rod is less than the stroke loss, which satisfies the up and down movement of the sucker rod and the oil pump stops working. One rotation of the crank is 360 degrees, and the polished rod completes a cycle of reciprocating operation. The crank swing angle is calculated based on the movement length of the polished rod.

[0039] For the best swing position, since the balance state of each well is different, the minimum power value point during the swing process is not necessarily at the top dead center of the polished rod. Therefore, the best driving position is determined by comparing the minimum power value point during the swing process with the real-time collected electric power curve.

[0040] The calculation principle of the actual motor speed n is:

[0041] n=(1-s)60f / p.

[0042] Among them, s is the slip rate of the three-phase asynchronous motor, p is the number of poles of the motor, and f is the stator power supply frequency of the motor. When p is constant, f is adjusted under the condition that the fluctuation of the slip rate is not large, and the changes of n and f are positively correlated. Among them, the function of the frequency converter is mainly to use the on-off semiconductor devices to act on the fixed-frequency AC power to convert the fixed-frequency AC power into the adjustable-frequency AC power.

[0043] The period from 0 to t1 is the crank full cycle operation stage of the oil pumping mechanism 1. The motor accelerates to the rated speed and then starts to decelerate to 0. The period from t1 to t2 is the crank swing operation stage of the oil pumping mechanism 1. The motor starts to accelerate until it reaches a certain set value and then decelerates. The motor accelerates in the reverse direction until it reaches a certain set value and then decelerates, and this is repeated. When the next operation cycle begins at time t2.

[0044] The crank of the beam pumping unit performs regular or irregular reciprocating motion in a non-full cycle. Regular motion means that the crank performs forward and reverse bidirectional reciprocating motion according to a fixed swing amplitude and swing period. Irregular motion means that the swing amplitude of the crank changes within the allowable range or the swing period of the crank changes.

[0045] The above-mentioned movement mode of the oil pumping mechanism 1 has the following advantages:

[0046] First, since the dead point is at or close to the minimum load point of the crank, the crank makes a non-full-circle regular or irregular motion around the dead point, which can reduce the load of the motor driving the crank;

[0047] Second, in this case, within the operating range of the suspension point, the swing amplitude of the crank is large, which can provide a striking reminder that the pumping unit is running;

[0048] Third, since the crank performs non-full-circle bidirectional reciprocating motion around the dead point, the shortest suspension point running length of the crank can be achieved under a unit rotation angle, which is more conducive to achieving precise control of the suspension point position.

[0049] In the present application, the final position where the pumping unit system can stably stop under completely free sliding conditions without driving or braking is regarded as a stable equilibrium position. When the pumping unit deviates from this position, any external force disturbance will cause the pumping unit to return to the stable equilibrium position. When the pumping unit is in a stable equilibrium position, the sum of the gravitational potential energy of the ground mechanical part, the gravitational potential energy of the downhole liquid column, and the elastic potential energy of the downhole rod and tubing string is minimal. The above-mentioned limitation on the stable equilibrium position of the crank can minimize the driving power consumption required for the reciprocating motion of the crank, minimize the probability of providing a reverse braking torque to ensure that the crank and the suspension point movement do not exceed the specified range, and reduce the energy consumption of the motor and the fatigue and impact of the mechanical transmission components.

[0050] Further limiting the crank to have regular or irregular motion: the crank to have regular or irregular motion includes pauses with intermittent characteristics. This limitation on the working state of the crank can further reduce the drive energy consumption, the energy consumption of the motor and the mechanical loss.

[0051] The elastic static deformation length value changes with the change of the downhole sinking pressure. Under the existing production equipment conditions, since the downhole sinking pressure cannot be collected in real time, in the production practice, the elastic static deformation length of the downhole rod string needs to be obtained according to the empirical value of the sinking pressure, that is, the elastic static deformation length of the downhole rod string is the elastic static deformation length value of the downhole rod string corresponding to the empirical value of the sinking pressure.

[0052] For the regular motion of the crank: the most typical motion mode is to make forward and reverse bidirectional reciprocating motion according to relatively fixed swing amplitude and swing frequency. For the irregular motion of the crank: it includes the situation that the swing amplitude changes within the allowed range and the swing frequency changes, and also includes the situation that the swing process is mixed with a short shutdown, because the shutdown state is a special motion with a speed of 0.

[0053] Example 2

[0054] This embodiment is a further improvement on Embodiment 1, and the repeated contents will not be repeated here.

[0055] There is a limit to the reduction of pumping strokes. For oil wells with serious "empty pumping", it is necessary to consider using intermittent pumping control, that is, "pumping when there is oil, and stopping when there is no oil". For such intermittent pumping wells, when pumping is restarted after stopping pumping for a sufficient period of time, the dynamic liquid level is high and the pump efficiency is high, which is reflected in the indicator diagram, showing that the area of ​​the indicator diagram is full and close to the theoretical indicator diagram, so the area of ​​the indicator diagram is large. As the pumping time continues, the downhole fluid supply speed cannot keep up with the pumping speed of the pumping unit, the dynamic liquid level gradually decreases, the pump efficiency gradually decreases, the indicator diagram becomes shriveled, and the area decreases. When the area of ​​the indicator diagram decreases to a certain extent and does not change much, the oil well fluid supply is seriously insufficient and the "empty pumping" phenomenon begins to occur. At this time, the machine should be shut down in time and restarted when the well fluid seeps back to a higher dynamic liquid level. The key to achieving the above process is when to stop pumping and how long to stop pumping, that is, the determination of the stop point and stop time.

[0056] Due to the influence of geological conditions and other factors, the uncertainty of downhole working conditions is relatively large. If the four parameters of full pumping area, stop pumping area, stop pumping time and pumping time are fixed, then as the pumping time continues (for example, half a year), these parameters may no longer be suitable for the oil well working conditions. Therefore, these four parameters must be dynamically changed according to the oil well working conditions. Here: full pumping area (Sm) refers to the average value of the area of ​​the dynamometer diagram within the first 10 minutes after the system is turned on after the pumping is stopped for a long period of time so that the downhole liquid replenishment volume is sufficient. Stop pumping area (St) refers to when the area of ​​the dynamometer diagram is lower than the stop pumping area (St) defined in the previous cycle for a long period of time, the pumping starts to stop. Stop pumping time (Ts) refers to the length of time the pumping is stopped. Pumping time (Cs) refers to the length of time from restarting the pumping to stopping pumping again after the pumping is stopped.

[0057] When the control system is put into production for the first time, four parameters, namely, full pumping area Sm, stop pumping area St, stop pumping time Ts and pumping time Cs, are set manually according to the actual production data of the oil field. For example, the full pumping area is set to 50KN*m, the stop pumping area is set to 18KN*m, the stop pumping time is set to 2 hours, and the pumping time is set to 1 hour. After pumping, the average area S of the indicator diagram within the first 10 minutes is calculated. AV Compared with the full pumping area, if the average area of ​​the indicator diagram within the first 10 minutes is S AV If the average area of ​​the indicator diagram within the first 10 minutes is greater than 70% of the full pumping area, the pumping time will be increased by △t and the pumping stop time will be reduced by △t in the next intermittent pumping cycle; AV If the area of ​​the dynamometer is less than 70% of the full pumping area, the pumping time will be reduced by △t and the pumping stop time will be increased by △t in the next intermittent pumping cycle; if the average area of ​​the dynamometer diagram S in the first 10 minutes is AVIf it is equal to 70% of the full pumping area, the original parameters are maintained unchanged. Thereafter, the average area of ​​the dynamometer is calculated every 10 minutes as the actual measured dynamometer area S. When S ≤ St*(1+10%), the pumping is stopped and the pumping is restarted after the intermittent pumping cycle is over.

[0058] In the process of calculating the area of ​​the dynamometer diagram every 10 minutes, if the difference of the stop-pumping area St of the actual stop working changes within 10% for more than 2 consecutive hours, it is considered that a new stop-pumping area has been found, and the data St is updated accordingly. If the average value of the dynamometer diagram area within the initial 10 minutes of each startup is greater than or equal to 110% of the full pumping area for more than two consecutive hours, it is considered that a new full pumping area has been found, and the data Sm is updated accordingly. At this point, the data Sm, St, Ts and Cs are dynamically updated.

[0059] Example 3

[0060] There are three main control aspects in the oil production process, namely remote monitoring of the beam pumping unit, self-balancing adjustment and automatic adjustment of the stroke frequency.

[0061] The intelligent control system of the digital beam self-balancing pumping unit is mainly composed of a digital self-balancing pumping unit, a digital intelligent pumping unit control cabinet and upper background monitoring equipment.

[0062] Firstly, the load signal, displacement signal and three-phase electrical parameter data of the beam pumping unit are collected through the load, angular displacement sensor and three-phase electrical parameter acquisition module, and the collected data are stored in the external memory of the intelligent controller, which is then uploaded to the monitoring platform and analyzed and calculated by the algorithm to obtain the balance degree, current stroke number and other data of the beam self-balancing pumping unit, and the data is stored in the database. Then the data and control signal are sent to the digital intelligent controller to adjust the balance degree of the beam self-balancing pumping unit.

[0063] 1. Remote monitoring of oil pumps, which can remotely start and stop the oil pumps, and display the background data in real time.

[0064] 2. Stroke frequency control: calculate the pump efficiency of the beam pumping unit based on the collected load data, and then judge the operating status of the pumping unit and adjust its stroke frequency in real time.

[0065] 3. Self-balancing control requires the use of intelligent control algorithms combined with intelligent control systems to ensure that the pump always operates within the most ideal balance range.

[0066] Example 4

[0067] The present application also provides a method for regulating oil production of a beam pumping unit without stopping the unit. When the pumping unit starts to operate, the method for regulating oil production may include the following steps:

[0068] The parameter acquisition module 3 acquires the three-phase electrical parameters and various sensor signals of the pumping mechanism 1, and uploads the acquired data to the measurement and control terminal 2 through the wireless communication module 4;

[0069] The measurement and control terminal 2 analyzes the received data and sends the obtained data and control signals to the corresponding modules to realize the stroke adjustment and self-balancing adjustment of the pumping mechanism 1 and the display of the control panel 5 .

[0070] Preferably, the measurement and control terminal 2 transmits data and sends control signals through the wireless communication module 4 .

[0071] The above-mentioned method for regulating and controlling oil production of a beam pumping unit without stopping the unit can have the following functions and advantages:

[0072] (1) It has the function of real-time collection and transmission of oil well parameters and electrical parameters;

[0073] (2) It has the function of receiving commands from the host computer to realize remote start and stop of the pumping unit, voice prompt and alarm;

[0074] (3) It has the function of automatically determining and adjusting the balance of the oil pump. It automatically monitors and displays the balance of the oil pump in real time, and can manually or automatically adjust the oil pump to the best balance, reduce the peak current, and achieve the purpose of protecting the reducer and saving energy;

[0075] (4) It has the function of automatically determining and adjusting the optimal working stroke frequency of the pumping unit. The stroke frequency of the pumping unit is displayed in real time. The stroke frequency can be adjusted steplessly manually, or the optimal stroke frequency can be automatically determined according to the amount of liquid produced by the oil well. While ensuring the amount of liquid produced, the stroke frequency can be adjusted to the minimum to achieve the best energy-saving effect;

[0076] (5) It has an intelligent intermittent pumping function for the pumping unit. For intermittent pumping wells, the intermittent pumping system can be set manually, or the optimal intermittent pumping system can be automatically formulated according to the trend of the oil well liquid production, realizing the "pump when there is oil, stop when there is no oil" function, while ensuring the liquid production, and achieving effective energy saving for intermittent pumping wells;

[0077] (6) It has the function of automatic switching between industrial frequency and variable frequency. When the inverter fails, it can automatically switch to industrial frequency mode;

[0078] (7) It has soft start and overload protection functions. It can effectively reduce the starting inertia load, and combined with the best balance determination and adjustment technology, it can reduce the installed power of the pumping unit by one level, greatly reducing the well site power grid capacity.

[0079] It should be noted that the above specific embodiments are exemplary, and those skilled in the art can come up with various solutions inspired by the disclosure of the present invention, and these solutions also belong to the disclosure scope of the present invention and fall within the protection scope of the present invention. Those skilled in the art should understand that the present specification and its drawings are illustrative and do not constitute a limitation on the claims. The scope of protection of the present invention is defined by the claims and their equivalents. Throughout the text, the features guided by "preferably" are only an optional method and should not be understood as having to be set, so the applicant reserves the right to abandon or delete the relevant preferred features at any time.

Claims

1. A non-stop oil extraction control system for a beam pumping unit, comprising at least an oil extraction mechanism (1) capable of receiving control information to perform oil extraction, characterized in that: The oil pumping mechanism (1) adjusts its operating parameters according to the control instructions of the measurement and control terminal (2), and the parameter acquisition module (3) arranged on the oil pumping mechanism (1) is capable of acquiring three-phase electrical parameters and sensor parameters of the oil pumping mechanism (1) during operation; The measurement and control terminal (2) can create a fuzzy rule capable of controlling the working balance of the pumping mechanism (1) according to the collected information uploaded by the parameter collection module (3), so that the pumping mechanism (1) can complete the self-balancing pumping work according to the control instructions of the measurement and control terminal (2); The measurement and control terminal (2) generates a control strategy after predicting the matching of the operating parameters of the pumping mechanism and the oil well parameters in the next pumping cycle based on the historical data of a plurality of continuous indicator diagrams on the time axis, and verifies and updates the predicted control strategy based on the sensor monitoring data acquired in real time by the parameter acquisition module (3) in this pumping cycle, so as to adjust the operating parameters of the pumping mechanism (1) in the subsequent pumping time period of the same pumping cycle, thereby outputting a control strategy that conforms to the real-time working condition of the pumping mechanism (1); The pumping mechanism (1) adjusts the stroke of the bare rod according to demand during the pumping process, so that the pumping mechanism (1) can gradually shorten the stroke of the bare rod during each full-circle movement of the crank as the oil reserve in the oil field decreases within a period of time, wherein four parameters, namely, full pumping area, stop pumping area, stop pumping duration and pumping duration, are dynamically changed according to the working conditions of the oil well, wherein the full pumping area (Sm) refers to the average value of the area of ​​the dynamometer diagram within the first 10 minutes after the system is started after the pumping is stopped for a long period of time so that the amount of downhole fluid replenishment is sufficient; the stop pumping area (St) refers to the start of pumping when the area of ​​the dynamometer diagram is lower than the stop pumping area (St) for a long period of time; the stop pumping duration (Ts) refers to the length of time of pumping stop; and the pumping duration (Cs) refers to the length of time from restarting the pumping to stopping pumping again after the pumping is stopped; When the control system is put into production for the first time, four parameters are set manually based on the actual production data of the oil field: full pumping area (Sm), stop pumping area (St), stop pumping time (Ts) and pumping time (Cs); after pumping starts, the average area of ​​the indicator diagram within the first 10 minutes (S AV ) is compared with the full pumping area (Sm). If the average area of ​​the indicator diagram within the first 10 minutes (S AV ) is greater than 70% of the full pumping area (Sm), the pumping time will be increased by △t and the stop pumping time will be reduced by △t in the next intermittent pumping cycle; if the average area of ​​the indicator diagram within the first 10 minutes (S AV ) is less than 70% of the full pumping area (Sm), then in the next intermittent pumping cycle, the pumping time will be reduced by △t and the stop pumping time will be increased by △t; if the average area of ​​the indicator diagram within the first 10 minutes (S AV ) is equal to 70% of the full pumping area (Sm), the original parameters are maintained unchanged; thereafter, the average area of ​​the dynamometer is calculated every 10 minutes as the measured dynamometer area (S). When S≤St*(1+10%), the pumping is stopped, and after the stop period is over, the pumping is restarted; In the process of calculating the area of ​​the dynamometer diagram every 10 minutes, if the area difference changes within 10% for more than 2 consecutive hours, the data of the stop pumping area (St) is updated; if the average value of the dynamometer diagram area within the initial 10 minutes of each startup is greater than or equal to 110% of the full pumping area for more than two consecutive hours, the data of the full pumping area (Sm) is updated.

2. The non-stop oil extraction control system for beam pumping units according to claim 1, characterized in that: The oil pumping mechanism (1) comprises at least an oil pumping motor (11), a frequency converter unit (12) and a balancing motor (14), wherein: The frequency converter unit (12) can adjust the working state of the oil pumping motor (11) according to the latest control strategy output by the measurement and control terminal (2).

3. The non-stop oil extraction control system for beam pumping units according to claim 2, characterized in that: The measurement and control terminal (2) also generates a real-time updated performance diagram based on the collected information uploaded by the parameter collection module (3), thereby adjusting the working strategy of the oil pumping mechanism (1) in the next stage according to the area of ​​the performance diagram.

4. The non-stop oil extraction control system for beam pumping units as claimed in claim 3, characterized in that: During the process of calculating the area of ​​the indicator diagram, the measurement and control terminal (2) also updates the pumping stop area by judging whether the area difference of the indicator diagram obtained by two consecutive calculations is within a set range.

5. The non-stop oil extraction control system for beam pumping units according to claim 4, characterized in that: When the pumping mechanism (1) performs a full crank operation, the pumping motor (11) operates normally and runs at a rated speed; when the pumping time is reached, the pumping motor (11) enters a crank swing operation stage, the pumping motor (11) stops working, the pumping rod moves up and down with a preset stroke, the crank flexibly swings back and forth without impact within a specified range, and the motor energy consumption during the swing period is 10% of that in normal operation; when the swing time is reached, the crank recycles and enters a full cycle operation stage.

6. The non-stop oil extraction control system for beam pumping units according to claim 5, characterized in that: During the crank full cycle operation stage, the frequency converter unit (12) controls the oil pumping motor (11) to operate at a rated speed; The stroke loss of the oil well is calculated according to the polished rod dynamometer diagram. When the polished rod movement length is less than the stroke loss, the oil pump stops working. When the crank rotates one circle and the polished rod completes one cycle of reciprocating motion, the crank swing angle is calculated based on the motion length of the polished rod; The point of minimum power during the swinging process is monitored based on the real-time collected electric power curve to determine the optimal driving position.

7. The non-stop oil extraction control system for beam pumping units according to any one of the preceding claims, characterized in that: After the measurement and control terminal (2) obtains the balance control data by calculation according to the fuzzy control algorithm, it controls the balancing motor (14) to adjust the balance degree of the oil pumping mechanism (1) in a manner of adjusting the position of the swing-arm type balancing arm.

8. A method for controlling oil production of a beam pumping unit without stopping the unit according to any one of claims 1 to 7, characterized in that: At least the following steps are included: The parameter acquisition module (3) is used to acquire the three-phase electrical parameters and various sensor signals of the oil pumping mechanism (1), and the acquired data is uploaded to the measurement and control terminal (2) through the wireless communication module (4); The measurement and control terminal (2) is used to analyze the received data, and the obtained data and control signals are sent to the corresponding modules to achieve the stroke adjustment and self-balancing adjustment of the pumping mechanism (1) and display through the control panel (5).

9. The method according to claim 8, characterized in that The measurement and control terminal (2) performs data transmission and sends control signals through the wireless communication module (4).

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