Control system and control method of oil pumping unit
Through the moving average algorithm sensorless control system, the speed of the pumping machine is automatically adjusted, which solves the dry pumping problem of oil wells with rods and achieves low-cost and efficient oil pumping machine control.
Patent Information
- Application Number
- CN202211215356.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-09-30
- Publication Date
- 2025-09-02
- Estimated Expiration
- 2042-09-30
AI Technical Summary
The existing oil well pump control system relies on expensive sensors and a large amount of manual intervention, resulting in frequent dry pumping of rod pumps, and it is difficult to optimize the operating speed in a timely manner, resulting in waste of resources and equipment damage.
The moving average algorithm sensorless control system is adopted to obtain the operating speed of the oil pump with a rod, and to automatically adjust the speed of the oil pump with a judgment module and iterative algorithm to prevent dry pumping and optimize operation.
Accurate control without sensors is achieved, manual intervention and maintenance costs are reduced, dry pumping and breaking of the rod pump, and the operation efficiency and life of the oil pump are optimized.
Smart Images
Figure CN115949374B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of control of oil well pumping units, and in particular to a control system and a control method for preventing the pumping unit from dry pumping. Background Art
[0002] Oil is a fluid mineral buried deep underground. Oil extraction refers to the process of digging for and extracting oil from reservoirs. During the extraction process, oil and gas flow from the reservoir into the wellbore and then rise to the wellhead.
[0003] Currently, oilfield production is typically accomplished using a pumping unit, a motor that uses a rocker arm connecting rod to drive a lever that reciprocates to pull a rod pump. This unit is commonly known as a "bowing unit" or "walking beam pump." This unit is typically driven directly by a conventional AC asynchronous motor, which pumps oil through the oil pipeline to bring the oil downhole to the surface. Due to its mature technology, the "bowing unit" is widely used in the oil production field and is a key piece of equipment at oil production sites in the petroleum industry. Existing monitoring mechanisms for oil production sites primarily rely on on-site staff measuring relevant well parameters or remote monitoring via cameras. While remote monitoring can reduce some manpower and material resources, it still requires a significant amount of human resources to frequently check the cameras to ensure normal operation of the production site.
[0004] Currently, monitoring the health of oil wells typically involves regular on-site inspections, either visually inspecting or measuring relevant parameters to determine if the well has been shut down. In oilfield pumping areas, when a pumping unit no longer pumps sufficient oil, the well is considered "dry." If no action is taken to address this issue, the sucker rod pump may become damaged. Some damage, such as a broken sucker rod pump, can be extremely costly. Oil wells can reach depths of up to 3,500 meters, making the cost of extracting and replacing broken rods prohibitive, and the cost of the sucker rod pumps themselves is also extremely high.
[0005] Currently, in actual oil fields, the pump's rotational speed is set by the operator based on personal experience after several weeks of operation. This control method may not accurately and timely control the pump's optimal speed, resulting in significant kilowatt-hour waste, which incurs significant costs for the oilfield owner.
[0006] In the area of controlling oilfield pumping units, although some solutions have been proposed, these rely on very expensive load sensors and require extensive service, installation work, and maintenance. Summary of the Invention
[0007] In view of this, the present invention proposes a control system and a control method for a pumping unit, which realizes the control of the sucker rod pump of the kowtow machine through a moving average algorithm, thereby preventing the dry pumping of the sucker rod pump without the need for a sensor.
[0008] According to one aspect of the present invention, a control system for an oil pumping unit is provided, characterized in that it includes: a speed acquisition module, which acquires the operating speed of a rod pump of the oil pumping unit and generates a speed signal representing the operating speed; a first determination module, which receives the speed signal from the speed acquisition module, and the first determination module generates a first determination signal based on the speed signal, the first determination signal representing whether the acquired operating speed of the rod pumping unit is within a predetermined operating speed range; a sampling and averaging module, which receives the first determination signal from the first determination module, and if the first determination signal represents that the acquired operating speed of the rod pumping unit is within the predetermined operating speed range, the sampling and averaging module samples the most recent N strokes of the oil pumping unit and generates an average value signal, the average value signal representing the average value of the downstroke torque of the N strokes, wherein N is an integer greater than 1; a recording module, which generates a record a recording signal representing a down-stroke torque of each M-th stroke of the pumping unit, wherein the M-th stroke occurs after the N strokes, and M is an integer greater than 1; a second determination module receiving the average value signal from the sampling and averaging module and the recorded signal from the recording module, and generating a second determination signal based on the average value signal and the recorded signal, the second determination signal indicating whether the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torques of the N strokes; a control module receiving the second determination signal from the second determination module, and if the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torques of the N strokes, the control module generating a control signal and sending the control signal to a driver of the pumping unit to reduce the operating speed of the sucker rod pump of the pumping unit;A feedback module receives the second determination signal from the second determination module, and if the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torques of the N strokes, the feedback module generates an iterative signal and sends the iterative signal to the sampling and averaging module, the recording module, the second determination module, and the control module, so that the sampling and averaging module, the recording module, the second determination module, and the control module iteratively perform the following operations until the second determination signal indicates that the down-stroke torque of each M-th stroke is not less than the average value of the down-stroke torques of the N strokes: 1) causing the sampling and averaging module to resample the latest N strokes of the pumping unit and generate a new average value signal, the new average value signal representing the calculated average value of the resampled down-stroke torques of the N strokes, wherein N is an integer greater than 1; 2) causing the recording module to generate a new recording signal, the new recording signal representing the down-stroke torque of each M-th stroke of the pumping unit, wherein the M strokes occur after the resampled N strokes, and M is an integer greater than 1; 3) the second determination module receives the new average signal from the sampling and averaging module in operation 1) and the new recorded signal from the recording module in operation 2), and the second determination module generates a new second determination signal based on the new average signal and the new recorded signal, the new second determination signal indicating whether the downstroke torque of each M-th stroke recorded in operation 2) is less than the average value of the downstroke torque of the N strokes calculated in operation 1); 4) the control module receives the new second determination signal from the second determination module, and if the new second determination signal indicates that the downstroke torque of each M-th stroke recorded in operation 2) is less than the average value of the downstroke torque of the N strokes calculated in operation 1), the control module generates a new control signal and sends the new control signal to the driver of the pumping unit to further reduce the current operating speed of the rod pump of the pumping unit.
[0009] The control system controls the sucker rod pump of the kowtow machine through a moving average algorithm, without the need to install sensors or manual intervention, and can provide a time-saving and low-cost solution for the maintenance and control of the kowtow machine.
[0010] Preferably, the control system further includes a counter which receives the second determination signal from the second determination module, and the value of the counter is incremented by 1 whenever the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes.
[0011] The above structure can avoid the influence of random fluctuations and achieve accurate control of the kowtow machine.
[0012] Preferably, if the second judgment signal generated by the second judgment module indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes, and the value of the counter is greater than a predetermined threshold, the control module generates the control signal and sends the control signal to the driver of the pumping unit to reduce the operating speed of the rod pump of the pumping unit.
[0013] The above structure can optimize the operation of the sucker rod pump of the kowtow machine and extend the service life of the kowtow machine.
[0014] Preferably, the control system also includes a sleep module, which receives the second judgment signal from the second judgment module, and when the second judgment signal indicates that the down-stroke torque of each M-th stroke is less than a predetermined down-stroke torque threshold, the sleep module generates a sleep signal and sends the sleep signal to the driver of the pumping unit, causing the pumping unit to enter a sleep state for a predetermined time.
[0015] The above structure can ensure that the dry pumping of the kowtow machine is avoided and the breakage of the sucker rod oil pump is avoided.
[0016] Preferably, the control system also includes a timer, the feedback module receives the second judgment signal from the second judgment module, and if the second judgment signal indicates that the down-stroke torque of each M-th stroke is not less than the average value of the down-stroke torque of the N strokes, the feedback module generates a feedback signal, and the feedback signal indicates that the pumping unit is in a non-dry pumping state, the timer receives the feedback signal from the feedback module, and based on the feedback signal, times the duration of the pumping unit in the non-dry pumping state and generates a timing signal.
[0017] The above structure can avoid the influence of random fluctuations and achieve accurate control of the kowtow machine.
[0018] Preferably, the control module receives a timing signal from the timer, and if the timing signal indicates that the duration of the pumping unit in the non-dry pumping state is greater than a predetermined duration threshold, the control module generates a control signal and sends the control signal to the driver of the pumping unit to increase the operating speed of the pumping rod pump of the pumping unit.
[0019] The above structure can optimize the working efficiency of the oil pumping unit.
[0020] Preferably, the control module receives a timing signal from the timer, and if the timing signal indicates that the duration of the pumping unit in the non-dry pumping state is greater than a predetermined duration threshold, the control module generates a control signal and sends the control signal to the sampling and averaging module to increase the average value of the downstroke torque.
[0021] Preferably, the control module receives a timing signal from the timer, and if the timing signal indicates that the duration of the pumping unit in the non-dry pumping state is less than a predetermined duration threshold, the control module generates a control signal and sends the control signal to the driver of the pumping unit, so that the rod pump of the pumping unit maintains the current operating speed for a predetermined time.
[0022] Preferably, the control system further comprises a third determination module which receives the second determination signal from the second determination module and generates a third determination signal based on the second determination signal, wherein the third determination signal indicates the water content or gas content in the oil well where the pumping unit is located.
[0023] Preferably, when the control module generates a control signal to reduce the operating speed of the sucker rod pump of the pumping unit, the value of the counter is cleared to zero.
[0024] According to another aspect of the present invention, a control method for an oil pumping unit is provided, which is characterized in that it includes the following steps: a speed acquisition step, acquiring the operating speed of the rod pump of the oil pumping unit and generating a speed signal representing the operating speed; a first judgment step, generating a first judgment signal based on the speed signal generated in the speed acquisition step, the first judgment signal indicating whether the acquired operating speed of the rod pumping unit is within a predetermined operating speed range; a sampling and averaging step, receiving the first judgment signal generated in the first judgment step, and if the first judgment signal indicates that the acquired operating speed of the rod pumping unit is within the predetermined operating speed range, the sampling and averaging step samples the most recent N strokes, and generating an average value signal, the average value signal represents the average value of the down-stroke torque of the N strokes, wherein N is an integer greater than 1; a recording step, generating a recording signal, the recording signal represents the down-stroke torque of each M-th stroke of the pumping unit, wherein the M-th stroke occurs after the N strokes, and M is an integer greater than 1; a second determination step, receiving the average value signal from the sampling and averaging step and the recording signal from the recording step, and in the second determination step, generating a second determination signal based on the average value signal and the recording signal, the second determination signal representing whether the down-stroke torque of each M-th stroke is less than the down-stroke torque of the N strokes. the average value of the torque; a control step, receiving the second determination signal from the second determination step, and if the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes, generating a control signal in the control step, and sending the control signal to the driver of the pumping unit to reduce the operating speed of the rod pump of the pumping unit; a feedback step, receiving the second determination signal from the second determination step, and if the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes, generating an iterative signal in the feedback step, so as to In the second determination step and the control step, the following operations are iteratively performed until the second determination signal indicates that the downstroke torque of each M-th stroke is not less than the average value of the downstroke torques of the N strokes: 1) in the sampling and averaging step, the most recent N strokes of the pumping unit are resampled and a new average value signal is generated, wherein the new average value signal represents the average value of the downstroke torques of the resampled N strokes, wherein N is an integer greater than 1; 2) in the recording step, a new recording signal is generated, wherein the new recording signal represents the downstroke torque of each M-th stroke of the pumping unit, wherein the M-th stroke occurs after the resampled N strokes, and M is an integer greater than 1;3) In the second determination step, the new average value signal from the sampling and averaging step in operation 1) and the new recorded signal from the recording step in operation 2) are received, and the second determination step generates a new second determination signal based on the new average value signal and the new recorded signal, wherein the new second determination signal indicates whether the downstroke torque of each M-th stroke recorded in operation 2) is less than the average value of the downstroke torque of the N strokes calculated in operation 1). 4) In the control step, the new second determination signal from the second determination step is received, and if the new second determination signal indicates that the downstroke torque of each M-th stroke recorded in operation 2) is less than the average value of the downstroke torque of the N strokes calculated in operation 1), the control step generates a new control signal and transmits the new control signal to the driver of the pumping unit to further reduce the current operating speed of the rod pump of the pumping unit.
[0025] Preferably, the control method also includes: a counting step, receiving the second determination signal from the second determination step, and whenever the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes, in the counting step, the counting value is incremented by 1.
[0026] Preferably, in the control method, if the second judgment signal generated by the second judgment step indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes, and the count value in the counting step is greater than a predetermined threshold, then the control step generates the control signal and sends the control signal to the driver of the pumping unit to reduce the operating speed of the rod pump of the pumping unit.
[0027] Preferably, the control method also includes: a sleep step, receiving the second determination signal from the second determination step, and when the second determination signal indicates that the down-stroke torque of each M-th stroke is less than a predetermined down-stroke torque threshold, generating a sleep signal in the sleep step, and sending the sleep signal to the driver of the pumping unit, so that the pumping unit enters a sleep state for a predetermined time.
[0028] Preferably, the control method also includes a timing step, the feedback step receives the second determination signal from the second determination step, and if the second determination signal indicates that the down-stroke torque of each M-th stroke is not less than the average value of the down-stroke torque of the N strokes, the feedback step generates a feedback signal, and the feedback signal indicates that the pumping unit is in a non-dry pumping state, the timing step receives the feedback signal from the feedback step, and based on the feedback signal, times the duration of the pumping unit in the non-dry pumping state and generates a timing signal.
[0029] Preferably, the control step receives a timing signal from the timing step, and if the timing signal indicates that the duration of the pumping unit in the non-dry pumping state is greater than a predetermined duration threshold, the control step generates a control signal and sends the control signal to the driver of the pumping unit to increase the operating speed of the rod pump of the pumping unit.
[0030] Preferably, the control step receives a timing signal from the timing step, and if the timing signal indicates that the duration of the pumping unit in the non-dry pumping state is greater than a predetermined duration threshold, the control step generates a control signal, and the control signal increases the average value of the downstroke torque in the sampling and averaging step.
[0031] Preferably, the control step receives a timing signal from the timing step, and if the timing signal indicates that the duration of the pumping unit in the non-dry pumping state is less than a predetermined duration threshold, the control step generates a control signal, which is sent to the driver of the pumping unit to keep the sucker rod pump of the pumping unit at the current operating speed for a predetermined time.
[0032] Preferably, the control method also includes: a third determination step, receiving the second determination signal from the second determination step, and the third determination step generates a third determination signal based on the second determination signal, and the third determination signal indicates the water content or gas content in the oil well where the pumping unit is located.
[0033] Preferably, when the control step generates a control signal to reduce the operating speed of the sucker rod pump of the pumping unit, the count value in the counting step is cleared to zero.
[0034] As can be seen from the above scheme, since the present invention uses a moving average algorithm to control the sucker rod pump of the kowtow machine, it can prevent the sucker rod pump from drying out without the need for sensors. When the well oil is sufficient, the sucker rod pump (SRP) speed is 100% of the rated speed. When the well oil is 50% full, the sucker rod pump speed automatically changes to 50% speed. If the oil level falls below the lower limit, the sucker rod pump will sleep for a set time. After the sleep time, the sucker rod pump will restart at the lowest speed. Therefore, the optimal match between the oil level of the following oil wells and the sucker rod pump speed can be automatically achieved:
[0035] • 100% Fill - 100% Speed
[0036] • 50% fill - 50% speed
[0037] • < 50% fill - Motor goes to sleep.
[0038] Therefore, the control system for the pumping unit proposed in this invention can save significant time and manpower, and by maintaining the SRP speed within the optimized range, it also saves significant energy. Furthermore, the SRP speed automatically operates within the appropriate speed range, eliminating the need for manual on-site adjustment. This optimized operation of the pumping rod extends the overall service life of the unit. BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art will understand the above and other features and advantages of the present invention more clearly. In the accompanying drawings:
[0040] Figure 1 Schematic diagram of a control system of an oil pumping unit according to an embodiment of the present invention.
[0041] Figure 2 4 is a flowchart of a control method for an oil pumping unit according to an embodiment of the present invention.
[0042] In the above drawings, the reference numerals used are as follows:
[0043] 102: speed acquisition module;
[0044] 104: first determination module;
[0045] 106: sampling and averaging module;
[0046] 108: recording module;
[0047] 110: second determination module;
[0048] 112: counter;
[0049] 114: timer;
[0050] 116: control module;
[0051] 118: feedback module;
[0052] 120: third determination module;
[0053] 122: Sleep module. DETAILED DESCRIPTION
[0054] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail with reference to the following examples.
[0055] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.
[0056] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by ordinary technicians in the technical field to which this application belongs.
[0057] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity direction; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above directional words are not used to limit the present invention.
[0058] Figure 1 Schematic diagram of a control system of an oil pumping unit according to an embodiment of the present invention.
[0059] The control system of the pumping unit mainly includes: a speed acquisition module 102, which acquires the current operating speed of the rod pump of the pumping unit; a first determination module 104, which determines whether the current operating speed of the rod pump obtained by the speed acquisition module 102 is within a predetermined operating speed range, and if it is determined that the current operating speed of the rod pump is within the predetermined operating speed range, the current operating speed of the rod pump and the current speed command are stored in, for example, a memory; a sampling and averaging module 106, which samples the most recent N strokes of the pumping unit (for example, the most recent N strokes) if the first determination module 104 determines that the current operating speed of the rod pump is within the predetermined operating speed range. 10 strokes of the pumping unit), and calculate the average value of the down-stroke torque of the N strokes. For example, in the case of sampling the latest 10 strokes of the pumping unit, the down-stroke torques of the 10 strokes are added and the average value of the down-stroke torques of the 10 strokes is obtained, and the calculated average value of the down-stroke torque is used as the baseline used in the moving average algorithm; the recording module 108 records the down-stroke torque of every M-th stroke of the pumping unit, wherein the M-th stroke occurs after N strokes, and M is an integer greater than 1. For example, in the case of sampling and averaging module 106 sampling the latest 10 strokes of the pumping unit, the recording module 108 records every subsequent 5th stroke (for example, the 15th stroke, The second determination module 110 determines whether the down-stroke torque of each M-th stroke recorded by the recording module 108 is less than the average value of the down-stroke torque calculated by the sampling and averaging module 106. For example, the second determination module 110 determines whether the down-stroke torque of each 5th stroke recorded by the recording module 108 is less than the average value of the down-stroke torque calculated by the sampling and averaging module 106. The counter 112 is incremented by 1 whenever the second determination module 110 determines that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of N strokes. For example, whenever the second determination module 110 determines that the down-stroke torque of each 5th stroke is less than the average value of the down-stroke torque of N strokes, the value of the counter 112 is incremented by 1. When the average value of the downstroke torque of 10 strokes calculated by the sampling and averaging module 106 is reached, the value of the counter 112 is incremented by 1. If the second determination module 110 determines that the downstroke torque of every M-th stroke is not less than the average value of the downstroke torque of N strokes, the timer 114 determines that the pumping unit is in a non-dry pumping state. The timer 114 measures the duration of the pumping unit in the non-dry pumping state. For example, if the second determination module 110 determines that the downstroke torque of every fifth stroke is not less than the average value of the downstroke torque of 10 strokes calculated by the sampling and averaging module 106, the pumping unit is in a non-dry pumping state. The timer 114 measures the duration of the pumping unit in the non-dry pumping state.If the second determination module 110 determines that the downstroke torque of every M-th stroke is less than the average value of the downstroke torques of N strokes, the control module 116 controls the driver of the pumping unit to reduce the current operating speed of the rod pump of the pumping unit. For example, if the second determination module 110 determines that the downstroke torque of every fifth stroke is less than the average value of the downstroke torques of 10 strokes calculated by the sampling and averaging module 106, and the value of the counter 112 is greater than a predetermined threshold, the control module 116 controls the driver of the pumping unit to reduce the current operating speed of the rod pump of the pumping unit. In addition, if the count of the timer 114 indicates that the duration of the pumping unit in the non-dry pumping state is greater than a predetermined duration threshold, the control module 116 may gradually increase the current operating speed and the average value of the downstroke torque of the rod pump of the pumping unit (for example, increase the operating speed and the average value of the downstroke torque of the rod pump to the previously saved average values of the operating speed and the downstroke torque, respectively). The feedback module 118, if the second determination module 110 determines that the downstroke torque of each M-th stroke is less than the average value of the downstroke torque of the N strokes, then the feedback module 118 iteratively performs the following operations until the second determination module 110 determines that the downstroke torque of each M-th stroke is not less than the average value of the downstroke torque of the N strokes: 1) causes the sampling and averaging module 106 to resample the most recent N strokes of the pumping unit and calculate the average downstroke torque of the resampled N strokes; value, where N is an integer greater than 1; 2) causing the recording module 108 to record the downstroke torque of each M-th stroke of the pumping unit, where the M-th stroke occurs after the resampled N strokes and M is an integer greater than 1; 3) causing the second determination module 110 to determine whether the downstroke torque of each M-th stroke recorded in operation 2) is less than the average downstroke torque of the N strokes calculated in operation 1); and 4) causing the control module 116 to further reduce the current operating speed of the rod pump of the pumping unit. Furthermore, the control system may further include a third determination module 120 that, based on the determination result of the second determination module 110, determines the water content or gas content in the oil well where the pumping unit is located (for example, based on experimental data, the water content or gas content in the oil well where the pumping unit is located may be determined based on the relationship between the downstroke torque of each M-th stroke recorded by the second determination module 110 and a predetermined threshold). Furthermore, the control system may further include a sleep module 122. When the second determination module 110 determines that the downstroke torque of each M-th stroke is less than a predetermined downstroke torque threshold, the sleep module 122 causes the pumping unit to enter a sleep state for a predetermined time.
[0060] Next, we will refer to Figure 2 , further described Figure 1The working principle of the control system shown in . In the control system disclosed in the present invention, a moving average algorithm is used to implement a sensorless anti-dry pumping control method for a rod pump of a kowtow machine. As understood by those skilled in the art, the moving average algorithm is a common method of using a set of recent actual data values to predict data values within a certain period of time in the future. The moving average algorithm can effectively eliminate random fluctuations in the prediction and is a simple smoothing prediction technology. The basic idea of the moving average algorithm is: based on time series data, item by item, a time-series average value containing a certain number of items is calculated in sequence to reflect the long-term trend. Therefore, when the numerical value fluctuates greatly due to the influence of periodic changes and random fluctuations, and it is not easy to show the development trend of the event, the use of the moving average algorithm can eliminate the influence of these factors, show the development direction of the event, and then analyze the prediction sequence according to the trend line.
[0061] Figure 2 FIG. 1 is a flowchart of a control method for an oil pumping unit according to an embodiment of the present invention. Figure 2As shown in , the control method includes the following steps: Step 202, the speed acquisition module 102 acquires the current operating speed of the sucker rod pump of the pumping unit and generates a speed signal representing the operating speed; Step 204, the first determination module 104 determines whether the current operating speed of the sucker rod pump acquired in Step 202 is within a predetermined operating speed range, that is, determines whether the current operating speed state of the sucker rod pump acquired in Step 202 is true (if Step 204 determines that the current operating speed of the sucker rod pump acquired in Step 202 is not within the predetermined operating speed range, a notification can be issued to the operator); Step 206, when it is determined in Step 204 that the current operating speed of the sucker rod pump is within the predetermined operating speed range, The current operating speed of the sucker rod pump and the current speed command are stored in, for example, a memory. In step 208, if it is determined in step 204 that the current operating speed of the sucker rod pump is within a predetermined operating speed range, then in step 208, the sampling and averaging module 106 samples the most recent N strokes (for example, the most recent 10 strokes) of the pumping unit. In step 210, the average value of the downstroke torque of the N strokes sampled in step 208 is calculated. For example, in the case of sampling the most recent 10 strokes of the pumping unit, the downstroke torques of the 10 strokes are added together and the average value of the downstroke torques of the 10 strokes is calculated. The calculated average value of the downstroke torque is used as a baseline for use in a moving average algorithm. In step 212 , record the down-stroke torque of every M-th stroke of the pumping unit, wherein the M-th stroke occurs after N strokes, and M is an integer greater than 1. For example, in the case of sampling the most recent 10 strokes of the pumping unit in step 208, in step 212, the recording module 108 records the down-stroke torque of every subsequent fifth stroke (for example, the 15th stroke, the 20th stroke, and so on); in step 214, the second determination module 110 determines whether the down-stroke torque of every M-th stroke recorded in step 212 is less than the average value of the down-stroke torque calculated in step 210. For example, the down-stroke torque of every fifth stroke recorded in step 212 is compared with the average value of the down-stroke torque calculated in step 210 to determine whether the down-stroke torque of step 214 is less than the average value of the down-stroke torque calculated in step 210. In step 216, the second determination module 110 further determines whether the down-stroke torque of every fifth stroke recorded in step 212 is less than the average value of the down-stroke torque calculated in step 210. In step 216, the second determination module 110 further determines whether the down-stroke torque of every M-th stroke recorded in step 212 is less than a predetermined torque threshold. For example, the down-stroke torque of every fifth stroke recorded in step 212 is compared with the predetermined torque threshold to determine whether the down-stroke torque of every fifth stroke recorded in step 212 is less than the predetermined torque threshold. In step 220, if it is determined in step 216 that the down-stroke torque of every fifth stroke recorded in step 212 is less than the predetermined torque threshold, the sleep module 122 causes the pumping unit to enter a sleep state for a predetermined time and may issue a notification to the operator.In step 218, whenever it is determined in step 214 that the downstroke torque of each M-th stroke recorded in step 212 is less than the average value of the downstroke torque calculated in step 210, and in step 216 that the downstroke torque of each M-th stroke recorded in step 212 is greater than the predetermined torque threshold, the value of the counter 112 is incremented by 1. For example, whenever it is determined in step 214 that the downstroke torque of each fifth stroke is less than the average value of the downstroke torque of ten strokes calculated in step 210, the value of the counter 112 is incremented by 1. In step 218, it is further determined whether the value of the counter 112 is greater than or equal to a specific value (for example, 2). In step 222, if the value of the counter 112 in the counting step 218 is greater than or equal to a specific value, the control module 116 controls the driver of the pumping unit to reduce the current operating speed of the sucker rod pump of the pumping unit. For example, the current operating speed of the sucker rod pump may be reduced to 80% of the original operating speed, and the counter 112 is incremented. The value is reset to zero; in a timing step 224, the timer measures the duration of time during which the value of the counter 112 in step 218 is less than a specific value, and determines whether the measured duration is greater than a predetermined duration; in step 228, if the measured duration in step 224 is greater than a predetermined duration, the current operating speed of the rod pump of the pumping unit and the average value of the downstroke torque are gradually increased. For example, the current operating speed of the rod pump can be increased to the previously saved operating speed, and the average value of the downstroke torque can be increased to the previously saved average value; in step 230, if the measured duration in step 224 is not greater than a predetermined duration, the current operating speed and the current average value of the downstroke torque are maintained unchanged; in step 226, if the value of the counter 112 in step 218 is greater than or equal to a specific value, the operator can control the driver of the pumping unit to reduce the current operating speed of the rod pump of the pumping unit. In this case, the process continues to jump to step 202.
[0062] Here, if Figure 2 As shown, an iterative operation is performed to automatically adjust the operating speed of the sucker rod pump according to the specific oil conditions in the oil well. That is, if step 214 determines that the downstroke torque of each M-th stroke is less than the average value of the downstroke torque of N strokes, the feedback module 118 can iteratively perform the operations of steps 208 to 222 until step 214 determines that the downstroke torque of each M-th stroke is not less than the average value of the downstroke torque of N strokes, that is, as shown in FIG. Figure 2As shown in , for example, the feedback module 118 iteratively executes: 1) step 208, causing the sampling and averaging module 106 to resample the most recent 10 strokes of the pumping unit; 2) step 210, calculating the average value of the downstroke torque of the resampled 10 strokes; 3) step 212, recording the downstroke torque of every fifth stroke of the pumping unit, wherein every fifth stroke occurs after the resampled 10 strokes; 4) step 214, determining whether the downstroke torque of every fifth stroke recorded in step 212 is less than the average value of the downstroke torque calculated in step 210, for example, the downstroke torque recorded in step 212 is recorded. The down-stroke torque of each fifth stroke is compared with the average value of the down-stroke torque calculated in step 210 to determine whether the down-stroke torque of each fifth stroke recorded in step 212 is less than the average value of the down-stroke torque calculated in step 210; 5) Step 216, further determining whether the down-stroke torque of each fifth stroke recorded in step 212 is less than a predetermined torque threshold, for example, comparing the down-stroke torque of each fifth stroke recorded in step 212 with the predetermined torque threshold to determine whether the down-stroke torque of each fifth stroke recorded in step 212 is less than the predetermined torque threshold; 6) Step 220, in step In step 216, when it is determined that the down-stroke torque of every fifth stroke recorded in step 212 is less than the predetermined torque threshold, the sleep module 122 puts the pumping unit into a sleep state for a predetermined time and may issue a notification to the operator; 7) In step 218, whenever it is determined in step 214 that the down-stroke torque of every fifth stroke recorded in step 212 is less than the average value of the down-stroke torque calculated in step 210 and in step 216 that the down-stroke torque of every fifth stroke recorded in step 212 is greater than the predetermined torque threshold, the value of the counter 112 is incremented by 1. For example, whenever it is determined in step 214 that the down-stroke torque of every fifth stroke recorded in step 212 is less than the average value of the down-stroke torque calculated in step 210, the value of the counter 112 is incremented by 1. When the downstroke torque of the stroke is less than the average downstroke torque of the ten strokes calculated in step 210, the value of counter 112 is incremented by 1. In step 218, it is further determined whether the value of counter 112 is greater than or equal to a specific value (e.g., 2). In step 222, if the value of counter 112 is greater than or equal to the specific value in step 218, control module 116 controls the pumping unit driver to reduce the current operating speed of the sucker rod pump of the pumping unit. For example, the current operating speed of the sucker rod pump may be further reduced to 60% of the original operating speed, and the value of counter 112 is reset to zero. Therefore, sensorless anti-dry pumping control of the sucker rod pump of the kowtow unit can be implemented using a moving average algorithm.For example, by comparing the periodically sampled downstroke torque of the sucker-rod pump with the average value of the most recent set of downstroke torques, the oil condition of the oil well can be learned, thereby gradually adjusting the operating speed of the sucker-rod pump (for example, from 100% of the rated speed to 80%, and then to 60%, and so on), and then calculating the average value of the most recent set of downstroke torques at the adjusted operating speed of the sucker-rod pump, and then again comparing the periodically sampled downstroke torque of the sucker-rod pump with the average value of the most recent set of downstroke torques, so that according to the comparison result, the operating speed of the sucker-rod pump can be adaptively adjusted again (for example, SRP 60% can be gradually increased to 80%, and then to 100% of the rated speed).
[0063] As can be seen from the above scheme, the control system and control method of the pumping unit proposed in the present invention can save significant manpower and time, and by maintaining the SRP speed within the optimized range, it also saves a significant amount of energy. Furthermore, the SRP speed automatically operates within the appropriate speed range, eliminating the need for manual on-site adjustment. This optimized operation of the pumping rod extends the overall service life of the pumping unit.
[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A control system for an oil pumping unit, characterized in that: include: a speed acquisition module for acquiring the operating speed of the sucker rod pump of the pumping unit and generating a speed signal representing the operating speed; a first determination module receiving the speed signal from the speed acquisition module and generating a first determination signal based on the speed signal, the first determination signal indicating whether the acquired operating speed of the sucker rod pump is within a predetermined operating speed range; a sampling and averaging module that receives the first determination signal from the first determination module, and if the first determination signal indicates that the acquired operating speed of the sucker rod pump is within the predetermined operating speed range, the sampling and averaging module samples the most recent N strokes of the pumping unit and generates an average value signal, the average value signal indicating an average value of downstroke torques of the N strokes, wherein N is an integer greater than 1; a recording module, generating a recording signal, wherein the recording signal represents a downstroke torque of each M-th stroke of the pumping unit, wherein the M-th stroke occurs after the N strokes, and M is an integer greater than 1; a second determination module receiving the average value signal from the sampling and averaging module and the recorded signal from the recording module, and generating a second determination signal based on the average value signal and the recorded signal, the second determination signal indicating whether the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torques of the N strokes; a control module that receives the second determination signal from the second determination module, and if the second determination signal indicates that the downstroke torque of each M-th stroke is less than an average value of the downstroke torques of the N strokes, the control module generates a control signal and sends the control signal to a driver of the pumping unit to reduce the operating speed of the rod pump of the pumping unit; a feedback module that receives the second determination signal from the second determination module, and if the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torques of the N strokes, the feedback module generates an iterative signal and sends the iterative signal to the sampling and averaging module, the recording module, the second determination module, and the control module, so that the sampling and averaging module, the recording module, the second determination module, and the control module iteratively perform the following operations until the second determination signal indicates that the down-stroke torque of each M-th stroke is not less than the average value of the down-stroke torques of the N strokes: 1) causing the sampling and averaging module to resample the latest N strokes of the pumping unit and generate a new average value signal, wherein the new average value signal represents the average value of the downstroke torque of the resampled N strokes, wherein N is an integer greater than 1; 2) enabling the recording module to generate a new recording signal, wherein the new recording signal represents the downstroke torque of every M-th stroke of the pumping unit, wherein the M-th stroke occurs after the resampled N strokes, and M is an integer greater than 1; 3) causing the second determination module to receive the new average value signal from the sampling and averaging module in operation 1) and the new recorded signal from the recording module in operation 2), and generating a new second determination signal based on the new average value signal and the new recorded signal, wherein the new second determination signal indicates whether the down-stroke torque of each M-th stroke recorded in operation 2) is less than the average value of the down-stroke torques of the N strokes calculated in operation 1); 4) The control module receives the new second determination signal from the second determination module, and if the new second determination signal indicates that the down-stroke torque of each M-th stroke recorded in operation 2) is less than the average value of the down-stroke torque of the N strokes calculated in operation 1), the control module generates a new control signal and sends the new control signal to the driver of the pumping unit to further reduce the current operating speed of the rod pump of the pumping unit.
2. The control system of the oil pumping unit according to claim 1, characterized in that: The control system further includes a counter that receives the second determination signal from the second determination module, and increments a value of the counter by 1 whenever the second determination signal indicates that the down-stroke torque of each M-th stroke is less than an average value of the down-stroke torques of the N strokes.
3. The control system of the oil pumping unit according to claim 2, characterized in that: If the second judgment signal generated by the second judgment module indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes, and the value of the counter is greater than a predetermined threshold, the control module generates the control signal and sends the control signal to the driver of the pumping unit to reduce the operating speed of the rod pump of the pumping unit.
4. The control system of the oil pumping unit according to claim 1, characterized in that: The control system also includes a sleep module that receives the second judgment signal from the second judgment module, and when the second judgment signal indicates that the down-stroke torque of each M-th stroke is less than a predetermined down-stroke torque threshold, the sleep module generates a sleep signal and sends the sleep signal to the driver of the pumping unit, causing the pumping unit to enter a sleep state for a predetermined time.
5. The control system of the oil pumping unit according to claim 1, characterized in that: The control system also includes a timer, the feedback module receives the second judgment signal from the second judgment module, and if the second judgment signal indicates that the down-stroke torque of each M-th stroke is not less than the average value of the down-stroke torque of the N strokes, the feedback module generates a feedback signal, and the feedback signal indicates that the pumping unit is in a non-dry pumping state, the timer receives the feedback signal from the feedback module, and based on the feedback signal, times the duration of the pumping unit in the non-dry pumping state and generates a timing signal.
6. The control system of the oil pumping unit according to claim 5, characterized in that: The control module receives a timing signal from the timer, and if the timing signal indicates that the duration of the pumping unit in the non-dry pumping state is greater than a predetermined duration threshold, the control module generates a control signal and sends the control signal to the driver of the pumping unit to increase the operating speed of the rod pump of the pumping unit.
7. The control system of the oil pumping unit according to claim 5, characterized in that: The control module receives a timing signal from the timer, and if the timing signal indicates that the duration of the pumping unit in the non-dry pumping state is greater than a predetermined duration threshold, the control module generates a control signal and sends the control signal to the sampling and averaging module to increase the average value of the downstroke torque.
8. The control system of the oil pumping unit according to claim 5, characterized in that: The control module receives a timing signal from the timer, and if the timing signal indicates that the duration of the pumping unit being in the non-dry pumping state is less than a predetermined duration threshold, the control module generates a control signal and sends the control signal to the driver of the pumping unit, so that the rod pump of the pumping unit maintains the current operating speed for a predetermined time.
9. The control system of the oil pumping unit according to claim 1, characterized in that: The control system further includes a third determination module that receives the second determination signal from the second determination module and generates a third determination signal based on the second determination signal, wherein the third determination signal indicates the water content or gas content in the oil well where the pumping unit is located.
10. The control system of the oil pumping unit according to claim 2, characterized in that: When the control module generates a control signal to reduce the operating speed of the sucker rod pump of the pumping unit, the value of the counter is cleared to zero.
11. A method for controlling an oil pumping unit, characterized in that: The following steps are involved: a speed acquisition step of acquiring the operating speed of the sucker rod pump of the pumping unit and generating a speed signal representing the operating speed; a first determination step of generating a first determination signal based on the speed signal generated in the speed acquisition step, wherein the first determination signal indicates whether the acquired operating speed of the sucker rod pump is within a predetermined operating speed range; a sampling and averaging step, receiving the first determination signal generated in the first determination step, and if the first determination signal indicates that the acquired operating speed of the pumping rod pump is within the predetermined operating speed range, sampling the most recent N strokes of the pumping unit and generating an average value signal, wherein the average value signal represents an average value of the downstroke torque of the N strokes, wherein N is an integer greater than 1; a recording step of generating a recording signal, wherein the recording signal represents a downstroke torque of each M-th stroke of the pumping unit, wherein the M-th stroke occurs after the N strokes, and M is an integer greater than 1; a second determination step of receiving the average value signal from the sampling and averaging step and the recorded signal from the recording step, and generating a second determination signal based on the average value signal and the recorded signal in the second determination step, the second determination signal indicating whether the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torques of the N strokes; a control step of receiving the second determination signal from the second determination step, and if the second determination signal indicates that the downstroke torque of each M-th stroke is less than an average value of the downstroke torques of the N strokes, generating a control signal in the control step and sending the control signal to a driver of the pumping unit to reduce the operating speed of the rod pump of the pumping unit; a feedback step of receiving the second determination signal from the second determination step, and if the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torques of the N strokes, generating an iterative signal in the feedback step, thereby iteratively performing the following operations in the sampling and averaging step, the recording step, the second determination step, and the control step until the second determination signal indicates that the down-stroke torque of each M-th stroke is not less than the average value of the down-stroke torques of the N strokes: 1) In the sampling and averaging step, the most recent N strokes of the pumping unit are resampled and a new average value signal is generated, wherein the new average value signal represents the average value of the downstroke torque of the resampled N strokes, wherein N is an integer greater than 1; 2) in the recording step, generating a new recording signal, wherein the new recording signal represents the downstroke torque of each M-th stroke of the pumping unit, wherein the M-th stroke occurs after the resampled N strokes, and M is an integer greater than 1; 3) in the second determination step, receiving the new average value signal from the sampling and averaging step in operation 1) and the new recorded signal from the recording step in operation 2), and generating a new second determination signal based on the new average value signal and the new recorded signal, the new second determination signal indicating whether the down-stroke torque of each M-th stroke recorded in operation 2) is less than the average value of the down-stroke torques of the N strokes calculated in operation 1); 4) In the control step, the new second determination signal from the second determination step is received, and if the new second determination signal indicates that the down-stroke torque of each M-th stroke recorded in operation 2) is less than the average value of the down-stroke torque of the N strokes calculated in operation 1), the control step generates a new control signal and sends the new control signal to the driver of the pumping unit to further reduce the current operating speed of the rod pump of the pumping unit.
12. The control method of the oil pumping unit according to claim 11, characterized in that: The control method also includes: a counting step, receiving the second determination signal from the second determination step, and whenever the second determination signal indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes, in the counting step, the counting value is incremented by 1.
13. The control method of the oil pumping unit according to claim 12, characterized in that: If the second judgment signal generated in the second judgment step indicates that the down-stroke torque of each M-th stroke is less than the average value of the down-stroke torque of the N strokes, and the count value in the counting step is greater than the predetermined threshold, the control step generates the control signal and sends the control signal to the driver of the pumping unit to reduce the operating speed of the rod pump of the pumping unit.
14. The control method of the oil pumping unit according to claim 11, characterized in that: The control method also includes: a sleep step, receiving the second determination signal from the second determination step, and when the second determination signal indicates that the down-stroke torque of each M-th stroke is less than a predetermined down-stroke torque threshold, generating a sleep signal in the sleep step, and sending the sleep signal to the driver of the pumping unit, so that the pumping unit enters a sleep state for a predetermined time.
15. The control method of the oil pumping unit according to claim 11, characterized in that: The control method also includes a timing step, the feedback step receives the second determination signal from the second determination step, and if the second determination signal indicates that the down-stroke torque of each M-th stroke is not less than the average value of the down-stroke torque of the N strokes, the feedback step generates a feedback signal, and the feedback signal indicates that the pumping unit is in a non-dry pumping state, the timing step receives the feedback signal from the feedback step, and based on the feedback signal, times the duration of the pumping unit in the non-dry pumping state and generates a timing signal.
16. The control method of the oil pumping unit according to claim 15, characterized in that: The control step receives a timing signal from the timing step, and if the timing signal indicates that the duration of the pumping unit being in a non-dry pumping state is greater than a predetermined duration threshold, the control step generates a control signal and sends the control signal to a driver of the pumping unit to increase the operating speed of the rod pump of the pumping unit.
17. The control method of the oil pumping unit according to claim 15, characterized in that: The control step receives a timing signal from the timing step, and if the timing signal indicates that the duration of the pumping unit being in a non-dry pumping state is greater than a predetermined duration threshold, the control step generates a control signal, which increases the average value of the downstroke torque in the sampling and averaging step.
18. The control method of the oil pumping unit according to claim 15, characterized in that: The controlling step receives a timing signal from the timing step, and if the timing signal indicates that the duration of the pumping unit being in the non-dry pumping state is less than a predetermined duration threshold, the controlling step generates a control signal, which is sent to a driver of the pumping unit to keep the sucker rod pump of the pumping unit at a current operating speed for a predetermined time.
19. The control method of the oil pumping unit according to claim 11, characterized in that: The control method further includes: a third determination step, receiving the second determination signal from the second determination step, and generating a third determination signal based on the second determination signal, wherein the third determination signal indicates the water content or gas content in the oil well where the pumping unit is located.
20. The control method of the oil pumping unit according to claim 12, wherein: When the control step generates a control signal to reduce the operating speed of the sucker rod pump of the pumping unit, the count value in the counting step is cleared to zero.
Citation Information
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