A method of speed control for a pumping unit and related devices

Abstract

The application discloses a speed control method of a pumping unit and related devices, and the application calculates the crank angular velocity of each time period in the current period by acquiring the crank angle corresponding to the liquid knock point in the previous period, so that fine adjustment of the speed of the pumping unit is realized, and higher pumping efficiency and longer equipment life can be realized.

Description

Technical Field

[0001] This invention relates to a speed control method and related device for an oil pumping unit, belonging to the field of oil pumping unit control. Background Technology

[0002] During the production process of pumping wells, different well conditions require different control strategies to improve pump efficiency and system efficiency. Traditional pumping unit speed control is divided into two types: "fast up, slow down" and "slow up, fast down." In "fast up, slow down," the "fast up" is to reduce leakage from the floating valve, while the "slow down" is to reduce the risk of liquid hammer and protect the pumping equipment. In "slow up, fast down," the "fast down" is for wells with fixed leakage and can reduce pump leakage. However, the precision of existing control methods is not high enough to achieve higher pumping efficiency and longer equipment life. Summary of the Invention

[0003] This invention provides a speed control method and related apparatus for an oil pumping unit, which solves the problems disclosed in the background art.

[0004] According to one aspect of this disclosure, a speed control method for a pumping unit is provided, comprising: obtaining the crank angle corresponding to the liquid slamming point of the previous cycle based on the indicator diagram of the previous cycle; obtaining the crank angular velocity of each time period of the current cycle based on the initial crank angular velocity of each time period of the current cycle and the crank angle corresponding to the liquid slamming point of the previous cycle, under stroke constraints, speed regulation ratio constraints and frequency regulation point constraints; and controlling the speed of the pumping unit based on the crank angular velocity of each time period of the current cycle.

[0005] In some embodiments of this disclosure, the stroke constraint is: the stroke rate remains constant, and the time it takes for the crank to rotate one revolution is constant. T Unchanged; Speed ​​regulation ratio constraint: The ratio of crank angular velocity in the first time period to that in the second time period is... r 1. The ratio of the crank angular velocity in the third time period to that in the second time period is 1. r 2; among which, r 1 and r 2. Set according to the leakage of the moving valve and the fixed valve; the first time period is from the bottom dead center to the top dead center, the second time period is from the top dead center to the liquid hammer point, and the third time period is from the liquid hammer point to the bottom dead center; frequency adjustment point constraint: the first frequency adjustment point is the bottom dead center, the second frequency adjustment point is the top dead center, and the third frequency adjustment point is the liquid hammer point.

[0006] In some embodiments of this disclosure, based on the initial crank angular velocity of each time period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle, the crank angular velocity of each time period in the current cycle is obtained under the constraints of stroke rate, speed regulation ratio, and frequency regulation point, including: 1) Based on the frequency tuning point constraint, calculate the end time of the first period, the end time of the second period, and the end time of the third period in sequence according to the initial crank angular velocity of each period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle. 2) Response | △ t - T |If the initial crank angular velocity is not less than the threshold, adjust the initial crank angular velocity under the speed regulation ratio constraint, and use the adjusted initial crank angular velocity as the new initial crank angular velocity, then go to step 1); otherwise, obtain the crank angular velocity for each time period of the current cycle; where, △ t It is the difference between the end time of the third period and the start time of the first period.

[0007] In some embodiments of this disclosure, the end time of the first time period, the end time of the second time period, and the end time of the third time period are calculated using the following formula: t 2= t 1+( oh 1- oh 3) / α +( i T - i B -△ i 1-c ) / oh 1 t 3= t 2+( oh 2- oh 1) / β +( i L - i T -△ i 2-c ) / oh 2 t 4= t 3+( oh 3- oh 2) / α +( i B +2π- i L -△ i 3-c ) / oh 3 In the formula, t 1. t 2. t 3. t 4 represents the start time of the first period, the end time of the first period, the end time of the second period, and the end time of the third period, respectively. oh1. oh 2. oh 3 represents the initial crank angular velocity in the first time period, the initial crank angular velocity in the second time period, and the initial crank angular velocity in the third time period, respectively. α The angular acceleration is the result of frequency adjustment and uniform crank acceleration. β The angular acceleration is the result of frequency adjustment and uniform crank deceleration. i B This represents the crank angle corresponding to the bottom dead center. i T This represents the crank angle corresponding to the top dead center. i L Δ is the crank angle corresponding to the liquid impact point in the previous cycle. i 1-c From oh 3 Accelerate to oh 1. The crank angle Δ i 2-c From oh 1. Decelerate to oh 2. The crank angle Δ i 3-c From oh 2 Accelerate to oh 3. The crank angles traversed.

[0008] In some embodiments of this disclosure, controlling the pumping unit speed based on the crank angular velocity of each time period in the current cycle includes obtaining a function of crank angular velocity versus time based on the crank angular velocity of each time period in the current cycle, and converting the function of crank angular velocity versus time into a function of crank angle versus time; obtaining the start time and crank angular velocity of each time period in the subsequent cycle starting from the time corresponding to the trigger point based on the function of crank angle versus time, and the crank angle and time corresponding to the trigger point; and controlling the pumping unit speed based on the start time and crank angular velocity of each time period in the subsequent cycle starting from the time corresponding to the trigger point.

[0009] According to another aspect of this disclosure, a speed control device for an oil pumping unit is provided, comprising: The indicator diagram module obtains the crank angle corresponding to the liquid hammer point of the previous cycle based on the indicator diagram of the previous cycle. The crank angular velocity module obtains the crank angular velocity for each time period of the current cycle based on the initial crank angular velocity for each time period of the current cycle and the crank angle corresponding to the liquid hammer point of the previous cycle, under the constraints of stroke, speed regulation ratio and frequency regulation point. The control module controls the speed of the pumping unit based on the crank angular velocity at each time point in the current cycle.

[0010] In some embodiments of this disclosure, the crank angular velocity module has a stroke constraint: the stroke rate remains constant, and the time it takes for the crank to rotate one revolution is constant. T constant; Speed ​​regulation ratio constraint: The ratio of the crank angular velocity in the first time period to that in the second time period is... r 1. The ratio of the crank angular velocity in the third time period to that in the second time period is 1. r 2; among which, r 1 and r 2. The settings are based on the leakage of the moving valve and the fixed valve; the first time period is from the bottom dead center to the top dead center, the second time period is from the top dead center to the liquid hammer point, and the third time period is from the liquid hammer point to the bottom dead center. Frequency tuning point constraints: The first frequency tuning point is the bottom dead center, the second frequency tuning point is the top dead center, and the third frequency tuning point is the liquid hammer point.

[0011] In some embodiments of this disclosure, the crank angular velocity module is configured as follows: 1) Based on the frequency tuning point constraint, calculate the end time of the first period, the end time of the second period, and the end time of the third period in sequence according to the initial crank angular velocity of each period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle. 2) Response | △ t - T |If the initial crank angular velocity is not less than the threshold, adjust the initial crank angular velocity under the speed regulation ratio constraint, and use the adjusted initial crank angular velocity as the new initial crank angular velocity, then go to step 1); otherwise, obtain the crank angular velocity for each time period of the current cycle; where, △ t It is the difference between the end time of the third period and the start time of the first period.

[0012] According to another aspect of this disclosure, a computer-readable storage medium is provided that stores one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform a speed control method for an oil pumping unit.

[0013] According to another aspect of this disclosure, a computer device is provided, including one or more processors and one or more memories, wherein one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for performing a speed control method for an oil pumping unit.

[0014] The beneficial effects achieved by this invention are as follows: By obtaining the crank angle corresponding to the liquid hammer point of the previous cycle, this invention calculates the crank angular velocity of each time period in the current cycle, thereby achieving fine adjustment of the pumping unit speed, which can achieve higher pumping efficiency and longer equipment life. Attached Figure Description

[0015] Figure 1 A flowchart of the speed control method for an oil pumping unit; Figure 2The graph shows the relationship between crank angular velocity and time. Figure 3 This is a structural block diagram of the speed control device for an oil pumping unit. Detailed Implementation

[0016] The technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0017] Unless otherwise stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure.

[0018] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0019] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0020] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0021] It should be noted that similar symbols and letters in the following figures represent similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0022] To address the issue of precision in existing methods, this disclosure proposes a speed control method and related apparatus for an oil pumping unit. By analyzing data from the previous cycle, the method enables precise adjustment of the oil pumping unit speed for the current cycle.

[0023] Figure 1 This is a schematic diagram of one embodiment of the speed control method for the pumping unit disclosed herein. Figure 1 The implementation can be executed by the controller of the oil pumping unit.

[0024] like Figure 1 As shown, in step 1 of the embodiment, the crank angle corresponding to the liquid hammer point of the previous cycle is obtained based on the indicator diagram of the previous cycle.

[0025] It should be noted that the cycle here refers to the pumping unit's cycle from top dead center to bottom dead center, and then from bottom dead center to top dead center. After one cycle of the pumping unit's operation, the corresponding dynamometer card can be obtained. Using the method mentioned in "SY_T 7492-2020 Technical Specification for Calculation of Fluid Production by Dynamometer Card Method for Pumping Unit Wells", the effective stroke corresponding to the dynamometer card can be diagnosed, and then the crank angle corresponding to the liquid hammer point of the previous cycle can be further calculated. The crank angle calculation process can be referred to Section 5.2 of "Rod Pumping: Modern Methods of Design, Diagnosis and Surveillance".

[0026] During the cyclical motion of the pumping unit, the cyclical liquid slugging point changes slowly. That is to say, although the liquid slugging point of the current cycle changes compared to the liquid slugging point of the previous cycle, the change is not significant. Therefore, in the current cycle speed control method, the crank angle corresponding to the liquid slugging point of the previous cycle is used as the crank angle corresponding to the liquid slugging point of the current cycle, and similarly, the crank angle corresponding to the liquid slugging point of the current cycle is used as the crank angle corresponding to the liquid slugging point of the next cycle, and so on, layer by layer.

[0027] Step 2 of the embodiment involves obtaining the crank angular velocity for each time period of the current cycle based on the initial crank angular velocity for each time period of the current cycle and the crank angle corresponding to the liquid impact point of the previous cycle, under the constraints of stroke, speed regulation ratio, and frequency regulation point.

[0028] It should be noted that the time intervals of the cycle can be divided according to the actual situation. Some points can be set, and the time between two adjacent points can be considered as a time interval. Of course, for the convenience of measurement and calculation, the top dead center, bottom dead center, etc., will be used as the points for dividing the time intervals.

[0029] In some embodiments, a cycle can be specifically divided into three segments; wherein, the first segment is the segment from the bottom dead center to the top dead center, and the corresponding crank angle range can be used i B and i T The crank angular velocity is expressed as... oh 1 indicates that the second time period is from top dead center to liquid hammer point, and the corresponding crank angle range can be used. i T and i L The crank angular velocity is expressed as... oh 2 indicates that the third time period is from the liquid hammer point to the bottom dead center, and the corresponding crank angle range can be used. i L and i B The crank angular velocity is expressed as... ohThe number 3 indicates that this segmentation considers not only the upper and lower limits but also the liquid impact point, allowing for fine-tuning based on the location of the liquid impact point.

[0030] It should be noted that the stroke constraint, speed regulation ratio constraint, and frequency tuning point constraint need to be preset. Among them, the stroke constraint mainly limits the time for the crank to rotate one revolution, the speed regulation ratio constraint mainly limits the ratio of the crank angular velocity corresponding to different time periods, and the frequency tuning point constraint mainly limits the order of tuning points. These constraints can be set according to the actual situation.

[0031] In some embodiments, the stroke constraint includes: a constant stroke rate and the time required for one revolution of the crank. T Unchanged; taking the above 3 segments as an example, then △ T 1+△ T 2+△ T 3= T Among them, △ T 1. △ T 2. △ T 3 represents the time periods corresponding to the first, second, and third time periods, respectively. The speed regulation ratio constraint includes: the ratio of the crank angular velocity between the first and second time periods is... r 1. The ratio of the crank angular velocity in the third time period to that in the second time period is 1. r 2. This can be expressed by the formula: oh 1 / oh 2= r 1, oh 3 / oh 2= r 2; among which, r 1 and r 2. The control method is set according to the leakage of both the moving and fixed valves; this method is applicable to wells with leakage from both the moving and fixed valves. To adapt to the three-stage control, the frequency tuning point constraints include: the first frequency tuning point is the bottom dead center, the second frequency tuning point is the top dead center, and the third frequency tuning point is the liquid hammer point.

[0032] It should be noted that frequency regulation here refers to the adjustment of the inverter frequency, that is, adjusting the inverter frequency at appropriate times to achieve different crank angular velocities, such as in... i B , i T , i L Adjust the inverter frequency at the corresponding points respectively. f 1. f 2. f 3, to achieve oh 1. oh 2. oh 3.

[0033] It should be noted that the initial crank angular velocity for each period of the current cycle can be set based on experience, and the specific setting can be based on historical data.

[0034] In some embodiments, the specific process of obtaining the crank angular velocity for each time period of the current cycle can be as follows: 1) Based on the frequency tuning point constraint, calculate the end time of the first period, the end time of the second period, and the end time of the third period in sequence according to the initial crank angular velocity of each period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle.

[0035] It should be noted that, due to the frequency tuning point constraint, i.e., the frequency tuning points have an order, the end time of the second period can be calculated based on the end time of the first period, and the end time of the third period can be calculated based on the end time of the second period.

[0036] When a frequency inverter adjusts from one frequency to another, it requires acceleration time. t α or deceleration time t β Yes. Acceleration time t α or deceleration time t β Based on reference frequency f b In other words, reference frequency f b This corresponds to the crank's reference angular velocity. oh b Acceleration time t α This refers to accelerating from 0 to the base frequency. f b Time; deceleration time t β Refers to the reference frequency f b The time required to decelerate to 0. Both the acceleration and deceleration processes are uniform acceleration and deceleration processes; the acceleration time... t α Deceleration time t β and reference frequency f b All of these can be set manually. Reference angular velocity. oh b and reference frequency f b A linear relationship exists: oh b = f b R ;in,R The transmission ratio is the crank angular velocity; therefore, the angular acceleration during crank acceleration is... α = oh b / t α The angular acceleration during deceleration is β = oh b / t β The unit of angular acceleration is rad / s². 2 .

[0037] The transmission ratio of the crank angular velocity can be calculated by running the crank at a constant speed, i.e., by first running the crank at a constant speed and recording the current number of pumping unit strokes. S The unit is revolutions per minute (rpm), which, when converted to the angular velocity of the crank, is... oh = S ×π / 30, converted to the crank period T =60 / S The frequency of the inverter is f The unit is Hz, so the transmission ratio can be calculated by converting the frequency into crank angular velocity. R = oh / f .

[0038] Because of the existence of acceleration and deceleration times, each period can be divided into two parts: the first part is the acceleration or deceleration period, and the second part is the period of stable speed.

[0039] See Figure 2 Assuming the acceleration phase ends at time 1 t 1-c It can be expressed by the formula as follows: t 1-c = t 1+( oh 1- oh 3) / α ;in, t 1 represents the start time of the first time period, which is also the end time of the third time period of the previous cycle. Within a cycle, this time is marked as 0. oh 1. oh 3 represents the initial crank angular velocity in the first time period and the initial crank angular velocity in the third time period, respectively. α The angular acceleration when the frequency is adjusted and the crank is uniformly accelerated, from oh 3 Accelerate to oh 1. The crank angle Δ i 1-c =( oh 1+ oh 3)×( t1-c - t 1) / 2. Definition t 2 represents the end time of the first time period, until... t At time 2, the angle that needs to be traversed is i T - i B Therefore, from t 1-c arrive t The angles that need to be traversed are: i T - i B -△ i 1-c , t 2- t 1-c =( i T - i B -△ i 1-c ) / oh 1. t 1-c Substituting, we can obtain t 2= t 1+( oh 1- oh 3) / α +( i T - i B -△ i 1-c ) / oh 1.

[0040] By analogy, we can obtain: t 3= t 2+( oh 2- oh 1) / β +( i L - i T -△ i 2-c ) / oh 2 In the formula, t 3 represents the end time of the second period, △ i 2-c From oh 1. Decelerate to oh 2. The crank angle Δ i 2-c =( oh 1+ oh 2)×( t 2-c - t 2) / 2, t 2-c This is the end time of the second deceleration period; t 4= t 3+( oh 3- oh 2) / α +( i B +2π- i L -△ i 3-c ) / oh 3 In the formula, t 4 represents the end time of the third period, △ i 3-c From oh 2 Accelerate to oh The crank angles 3 pass through, △ i 3-c =( oh 2+ oh 3)×( t 3-c - t 3) / 2, t 3-c The third period ends at an accelerated pace.

[0041] 2) Response | △ t - T |If the initial crank angular velocity is not less than the threshold, adjust the initial crank angular velocity under the speed regulation ratio constraint, and use the adjusted initial crank angular velocity as the new initial crank angular velocity, then go to step 1); otherwise, obtain the crank angular velocity for each time period of the current cycle; where, △ t It is the difference between the end time of the third period and the start time of the first period.

[0042] It should be noted that, in addition to meeting the speed regulation ratio constraint, the initial crank angular velocity adjustment can be adjusted according to a certain percentage. This percentage should be set based on the amount of calculation and the adjustment accuracy. In some embodiments, it can be set to 10%, i.e., |Δ t - T |Not less than the threshold, and △ t > T Then you can oh 1. oh 2. oh 3. Increased by 10%; |△ t - T |Not less than the threshold, and △ t <T Then you can oh 1. oh 2. oh 3. Reduced by 10%.

[0043] Step 3 of the embodiment involves controlling the pumping unit speed based on the crank angular velocity at each time period of the current cycle.

[0044] It should be noted that after obtaining the crank angular velocity for each time period of the current cycle, the pumping unit speed can be controlled according to the time and the corresponding crank angular velocity during control. This control fully considers the dynamic conditions downhole, such as the location of the liquid hammer point, the interaction between the plunger and the pump barrel liquid surface, and the leakage of the floating and fixed valves. Through real-time monitoring and analysis, the pumping unit speed can be finely adjusted.

[0045] In some embodiments, since the trigger time of the speed control method cannot be set at the bottom dead center all the time, in general, in some embodiments, the crank angular velocity as a function of time can be obtained first based on the crank angular velocity of each time period in the current cycle, and the crank angular velocity as a function of time can be converted into a crank angle as a function of time. Based on the crank angle as a function of time, and the crank angle and time corresponding to the trigger point, the start time and crank angular velocity of each time period in the subsequent cycle starting from the time corresponding to the trigger point can be obtained. Based on the start time and crank angular velocity of each time period in the subsequent cycle starting from the time corresponding to the trigger point, the pumping unit speed can be controlled.

[0046] It should be noted that obtaining the function of crank angle versus time only requires time integration of the function of crank angular velocity versus time. Based on the function of crank angle versus time, the moment corresponding to the crank angle at the time of triggering can be calculated. t A , then t 1. t 2. t Level 3 is converted to a time starting from the trigger moment. t 11 , t 22 , t 33 The conversion method is to first subtract the time. t A If subtract t A If the result is negative, then add the crank rotation period.

[0047] Finally, event frequency pairs can be generated. t 11 , f 1) ( t 22 , f 2), (t 33 , f 3) indicates that starting from the proximity switch trigger point, at t 11 Adjust the frequency of the frequency converter at all times. f 1. In t 22 Adjust the frequency of the frequency converter at all times. f 2, in t 33 Adjust the frequency of the frequency converter at all times. f 3.

[0048] This disclosure discloses a speed control method for an oil pumping unit. By obtaining the crank angle corresponding to the liquid hammer point of the previous cycle, the crank angular velocity of each time period in the current cycle is calculated, thereby achieving fine adjustment of the oil pumping unit speed, which can achieve higher oil pumping efficiency and longer equipment life.

[0049] Figure 3 This is a schematic diagram of one embodiment of the speed control device for the pumping unit of this disclosure, specifically a virtual device for the above method, such as software. Figure 3 The embodiment can be loaded by the pumping unit's controller and started when the pumping unit is running.

[0050] Figure 3 The embodiment includes an indicator diagram module, which obtains the crank angle corresponding to the liquid hammer point of the previous cycle based on the indicator diagram of the previous cycle.

[0051] Similar to the method, the cycle here refers to the pumping unit from top dead center to bottom dead center, and then from bottom dead center to top dead center. After the pumping unit has worked for one cycle, the corresponding indicator diagram can be obtained. Through the indicator diagram, the effective stroke corresponding to the indicator diagram can be diagnosed, and then the crank angle corresponding to the liquid hammer point of the previous cycle can be calculated.

[0052] During the cyclical motion of the pumping unit, the cyclical liquid slugging point changes slowly. That is to say, although the liquid slugging point of the current cycle changes compared to the liquid slugging point of the previous cycle, the change is not significant. Therefore, in the current cycle speed control method, the crank angle corresponding to the liquid slugging point of the previous cycle is used as the crank angle corresponding to the liquid slugging point of the current cycle, and similarly, the crank angle corresponding to the liquid slugging point of the current cycle is used as the crank angle corresponding to the liquid slugging point of the next cycle, and so on, layer by layer.

[0053] The embodiment also includes a crank angular velocity module, which obtains the crank angular velocity for each time period of the current cycle based on the initial crank angular velocity for each time period of the current cycle and the crank angle corresponding to the liquid hammer point of the previous cycle, under the constraints of stroke, speed regulation ratio and frequency regulation point.

[0054] Similarly, in some embodiments, for ease of measurement and calculation, and considering the liquid slam point, the top dead center, bottom dead center, and liquid slam point are used as points to divide time periods, specifically dividing one cycle into three segments; wherein, the first time period is the period from the bottom dead center to the top dead center, and the corresponding crank angle range can be used i B and i T The crank angular velocity is expressed as... oh 1 indicates that the second time period is from top dead center to liquid hammer point, and the corresponding crank angle range can be used. i T and i L The crank angular velocity is expressed as... oh 2 indicates that the third time period is from the liquid hammer point to the bottom dead center, and the corresponding crank angle range can be used. i L and i B The crank angular velocity is expressed as... oh The number 3 indicates that this segmentation considers not only the upper and lower limits but also the liquid impact point, allowing for fine-tuning based on the location of the liquid impact point.

[0055] The stroke constraint includes: with a constant stroke rate, the time it takes for the crank to complete one revolution. T Unchanged; taking the above 3 segments as an example, then △ T 1+△ T 2+△ T 3= T Among them, △ T 1. △ T 2. △ T 3 represents the time periods corresponding to the first, second, and third time periods, respectively. The speed regulation ratio constraint includes: the ratio of the crank angular velocity between the first and second time periods is... r 1. The ratio of the crank angular velocity in the third time period to that in the second time period is 1. r 2. This can be expressed by the formula: oh 1 / oh 2= r 1, oh 3 / oh 2= r 2; among which, r 1 and r 2. The control method is set according to the leakage of both the moving and fixed valves; this method is applicable to wells with leakage from both the moving and fixed valves. To adapt to the three-stage control, the frequency tuning point constraints include: the first frequency tuning point is the bottom dead center, the second frequency tuning point is the top dead center, and the third frequency tuning point is the liquid hammer point.

[0056] The crank angular velocity module is specifically configured as follows: 1) Based on the frequency tuning point constraint, calculate the end time of the first period, the end time of the second period, and the end time of the third period in sequence according to the initial crank angular velocity of each period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle. 2) Response | △ t - T |If the initial crank angular velocity is not less than the threshold, adjust the initial crank angular velocity under the speed regulation ratio constraint, and use the adjusted initial crank angular velocity as the new initial crank angular velocity, then go to step 1); otherwise, obtain the crank angular velocity for each time period of the current cycle; where, △ t It is the difference between the end time of the third period and the start time of the first period.

[0057] The embodiment also includes a control module that controls the pumping unit speed based on the crank angular velocity at each time period of the current cycle.

[0058] In some embodiments, since the trigger time of the speed control method cannot be set at the bottom dead center all the time, in general, in some embodiments, the crank angular velocity as a function of time can be obtained first based on the crank angular velocity of each time period in the current cycle, and the crank angular velocity as a function of time can be converted into a crank angle as a function of time. Based on the crank angle as a function of time, and the crank angle and time corresponding to the trigger point, the start time and crank angular velocity of each time period in the subsequent cycle starting from the time corresponding to the trigger point can be obtained. Based on the start time and crank angular velocity of each time period in the subsequent cycle starting from the time corresponding to the trigger point, the pumping unit speed can be controlled.

[0059] The speed control device for the pumping unit disclosed herein calculates the crank angular velocity for each time period of the current cycle by acquiring the crank angle corresponding to the liquid hammer point of the previous cycle, thereby achieving fine adjustment of the pumping unit speed and enabling higher pumping efficiency and longer equipment life.

[0060] Based on the same technical solution, this disclosure further relates to a computer-readable storage medium that stores one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform a speed control method for an oil pumping unit.

[0061] Based on the same technical solution, this disclosure further relates to a computer device, including one or more processors and one or more memories, wherein one or more programs are stored in the one or more memories and configured to be executed by the one or more processors, and the one or more programs include instructions for performing a speed control method for an oil pumping unit.

[0062] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0063] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure one One or more processes and / or boxes Figure one A device that provides the functions specified in one or more boxes.

[0064] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure one One or more processes and / or boxes Figure one The function specified in one or more boxes.

[0065] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure one One or more processes and / or boxes Figure one The steps of the function specified in one or more boxes.

[0066] The above are merely embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of the claims of the present invention pending approval.

Claims

1. A speed control method for an oil pumping unit, characterized in that, include: Based on the indicator diagram of the previous cycle, obtain the crank angle corresponding to the liquid hammer point of the previous cycle; Based on the initial crank angular velocity of each time period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle, the crank angular velocity of each time period in the current cycle is obtained under the constraints of stroke, speed regulation ratio, and frequency regulation point. The stroke constraint is defined as the time it takes for the crank to rotate one revolution while maintaining a constant stroke rate. T Unchanged; Speed ​​regulation ratio constraint: The ratio of crank angular velocity in the first time period to that in the second time period is... r 1. The ratio of the crank angular velocity in the third time period to that in the second time period is 1. r 2; r 1 and r 2. Based on the leakage of the moving valve and the fixed valve, the settings are as follows: the first time period is from the bottom dead center to the top dead center, the second time period is from the top dead center to the liquid hammer point, and the third time period is from the liquid hammer point to the bottom dead center; frequency adjustment point constraints: the first frequency adjustment point is the bottom dead center, the second frequency adjustment point is the top dead center, and the third frequency adjustment point is the liquid hammer point. The pumping unit speed is controlled based on the crank angular velocity at each time point in the current cycle.

2. The speed control method for an oil pumping unit according to claim 1, characterized in that, Based on the initial crank angular velocity of each time period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle, under the constraints of stroke rate, speed regulation ratio, and frequency regulation point, the crank angular velocity of each time period in the current cycle is obtained, including: 1) Based on the frequency tuning point constraint, calculate the end time of the first period, the end time of the second period, and the end time of the third period in sequence according to the initial crank angular velocity of each period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle. 2) Response | △ t - T |If the initial crank angular velocity is not less than the threshold, adjust the initial crank angular velocity under the speed regulation ratio constraint, and use the adjusted initial crank angular velocity as the new initial crank angular velocity, then go to step 1); otherwise, obtain the crank angular velocity for each time period of the current cycle; where, △ t It is the difference between the end time of the third period and the start time of the first period.

3. The speed control method for an oil pumping unit according to claim 2, characterized in that, The formula for calculating the end time of the first time period, the end time of the second time period, and the end time of the third time period is: t 2= t 1+( ω 1- ω 3) / α +( θ T - θ B -△ θ 1-c ) / ω 1 t 3= t 2+( ω 2- ω 1) / β +( θ L - θ T -△ θ 2-c ) / ω 2 t 4= t 3+( ω 3- ω 2) / α +( θ B +2π- θ L -△ θ 3-c ) / ω 3 In the formula, t 1. t 2. t 3. t 4 represents the start time of the first period, the end time of the first period, the end time of the second period, and the end time of the third period, respectively. ω 1. ω 2. ω 3 represents the initial crank angular velocity in the first time period, the initial crank angular velocity in the second time period, and the initial crank angular velocity in the third time period, respectively. α The angular acceleration is the result of frequency adjustment and uniform crank acceleration. β The angular acceleration is the result of frequency adjustment and uniform crank deceleration. θ B This represents the crank angle corresponding to the bottom dead center. θ T This represents the crank angle corresponding to the top dead center. θ L Δ is the crank angle corresponding to the liquid impact point in the previous cycle. θ 1-c From ω 3 Accelerate to ω 1. The crank angle Δ θ 2-c From ω 1. Decelerate to ω 2. The crank angle Δ θ 3-c From ω 2 Accelerate to ω 3. The crank angles traversed.

4. The speed control method for an oil pumping unit according to claim 1, characterized in that, Based on the crank angular velocity at each time point in the current cycle, control the pumping unit speed, including: Based on the crank angular velocity at each time point of the current cycle, obtain the function of crank angular velocity versus time, and convert the function of crank angular velocity versus time into a function of crank angle versus time; Based on the function of crank angle and time, and the crank angle and time corresponding to the trigger point, obtain the start time and crank angular velocity of each time period in the subsequent cycle starting from the time corresponding to the trigger point. The pumping unit speed is controlled based on the start time and crank angular velocity of each time period in the subsequent cycle starting from the time corresponding to the trigger point.

5. A speed control device for an oil pumping unit, characterized in that, include: The indicator diagram module obtains the crank angle corresponding to the liquid hammer point of the previous cycle based on the indicator diagram of the previous cycle. The crank angular velocity module, based on the initial crank angular velocity of each time period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle, obtains the crank angular velocity of each time period in the current cycle under the constraints of stroke, speed regulation ratio, and frequency regulation point. The stroke constraint refers to the time it takes for the crank to rotate one revolution while maintaining a constant stroke rate. T Unchanged; Speed ​​regulation ratio constraint: The ratio of crank angular velocity in the first time period to that in the second time period is... r 1. The ratio of the crank angular velocity in the third time period to that in the second time period is 1. r 2; r 1 and r 2. Based on the leakage of the moving valve and the fixed valve, the settings are as follows: the first time period is from the bottom dead center to the top dead center, the second time period is from the top dead center to the liquid hammer point, and the third time period is from the liquid hammer point to the bottom dead center; frequency adjustment point constraints: the first frequency adjustment point is the bottom dead center, the second frequency adjustment point is the top dead center, and the third frequency adjustment point is the liquid hammer point. The control module controls the speed of the pumping unit based on the crank angular velocity at each time point in the current cycle.

6. The speed control device for an oil pumping unit according to claim 5, characterized in that, The crank angular velocity module is configured as follows: 1) Based on the frequency tuning point constraint, calculate the end time of the first period, the end time of the second period, and the end time of the third period in sequence according to the initial crank angular velocity of each period in the current cycle and the crank angle corresponding to the liquid hammer point in the previous cycle. 2) Response | △ t - T |If the initial crank angular velocity is not less than the threshold, adjust the initial crank angular velocity under the speed regulation ratio constraint, and use the adjusted initial crank angular velocity as the new initial crank angular velocity, then go to step 1); otherwise, obtain the crank angular velocity for each time period of the current cycle; where, △ t It is the difference between the end time of the third period and the start time of the first period.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform the method of any one of claims 1 to 4.

8. A computer device, characterized in that, include: One or more processors and one or more memories, one or more programs stored in the one or more memories and configured to be executed by the one or more processors, the one or more programs including instructions for performing the method of any one of claims 1 to 4.

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