Oil well intelligent management system for oil field and oil well pump production parameter control method

Abstract

The oil well production intelligent management system for the oil field comprises the steps that the ratio of the current liquid production capacity of an oil well under the current frequency of the oil well pump to the liquid production capacity of the oil well under the power frequency state is obtained, and a comprehensive evaluation index under the current frequency is obtained in combination with the current efficiency of the oil well pump; and comparing the comprehensive evaluation index under the current frequency with the comprehensive evaluation index under the previous frequency, and adjusting the control parameters of the oil well pump according to the comparison result. The method is simple in principle, small in data size and rapid in calculation, the system can automatically find the optimal working parameters, manual input is not needed, automatic and accurate adjustment of the oil well stroke frequency in the true sense is achieved, and the oil well production efficiency is effectively improved.

Description

Technical Field

[0001] This invention relates to the field of oilfield automation control technology, and in particular to an intelligent management system for oil wells and a method for controlling the production parameters of oil pumps in oilfields. Background Technology

[0002] Currently, various automatic frequency conversion speed regulation technologies for pumping units are widely used in oilfields. However, due to factors such as the complexity of oil production systems, imperfect well conditions, and incomplete evaluation models, the optimal production parameters for oil wells are often difficult to determine, and parameter adjustments can be somewhat arbitrary.

[0003] The operating status of an oil pumping unit is generally measured using indicators such as well production, pump efficiency, and power consumption, depending on the different measurement principles and methods used. The lack of uniformity in these principles and methods makes it difficult to determine the appropriate number of pumping cycles.

[0004] Existing technology discloses an automatic adjustment method for pumping unit stroke frequency based on the continuous fluid production at the pumping unit wellhead. This method involves continuously collecting fluid production data for each pumping unit stroke using a fluid production metering device; calculating the average fluid production per unit time under the current well conditions based on the acquired data; calculating the average pump efficiency under the current fluid production conditions based on the average fluid production and the theoretical pump displacement; comparing the average pump efficiency with a preset pump efficiency to obtain a comparison result; and sending a speed control command to the frequency converter based on the result to adjust the pumping unit stroke frequency. While this method is simple in principle and easy to implement, it still has the following shortcomings in practice:

[0005] 1) This method requires manual input of a preset value for pump efficiency before use, and it is difficult to determine whether the manually input value is reasonable. In field application, only one value can be used for a batch of wells in a block. However, the optimal operating parameters of the equipment are closely related to factors such as the model of the equipment used, the type and quantity of downhole tools, and formation conditions. The optimal value is different for each well in the field. Using a uniform value will obviously affect the application effect of the system.

[0006] 2) The oil pumping unit production system is a complex nonlinear system. This method uses a simple linear model to replace the calculation, which results in a very large error.

[0007] Existing technology also includes an intelligent management system for oilfield pump efficiency adjustment, which discloses an intelligent adjustment system for oilfield pumping units based on pump efficiency. Its basic principle is that the system generates a baseline dynamometer diagram based on manually input pump efficiency values. Data obtained from on-site measurements generates the current dynamometer diagram; the two are compared to determine whether frequency conversion parameter adjustment is necessary. The shortcomings of this method are:

[0008] 1) Similar to the aforementioned existing technology solutions, it requires manual input of preset values, but it is difficult to determine whether the input values ​​are reasonable;

[0009] 2) This method requires on-site acquisition of dynamometer diagrams, which cannot be applied to oil wells without dynamometer diagram data sensors, thus hindering the promotion of automated control systems.

[0010] Existing technology employs an optimal pumping frequency process for digital pumping units suitable for ultra-low permeability reservoirs. This method discloses a mechanism for determining and adjusting the pumping frequency, which, while ensuring production, automatically identifies the optimal pumping frequency based on the well's production rate, thus achieving optimal operating conditions. This method achieves automatic adjustment of the pumping frequency, avoiding the problem of unreasonable manually input target preset values. While theoretically feasible, it still has the following shortcomings in field applications:

[0011] 1) This method relies on the collected dynamometer diagrams for data processing, but it cannot be guaranteed that a dynamometer diagram can be generated for every stroke on site, and the error in the dynamometer diagram measurement has not been eliminated.

[0012] 2) This method adjusts the number of strokes by using the production rate as a single parameter. Oil well production is a very complex system, and optimizing only a single parameter cannot guarantee that the entire system can reach its optimal state.

[0013] The existing technology employs a publicly disclosed method for adjusting the optimal pumping frequency of an oil pumping unit, and discloses a novel algorithm for adjusting the pumping frequency based on a digital oil pumping unit (RTU). The main steps are as follows: The maximum frequency of the oil pumping unit is set as the initial frequency, and the frequency is gradually reduced during operation. Then, the actual pump efficiency is calculated based on the collected data, and the product of the pump efficiency and the frequency is used as the equivalent liquid production rate to replace the actual liquid production rate for data storage. Next, a global search is performed on the time-series data of the equivalent liquid production rate to quickly find the optimal reasonable pumping frequency, and the motor frequency at this point is used as the optimal base frequency. Finally, the optimal base frequency of the oil pumping unit is fine-tuned to ensure that the optimal pumping frequency remains accurate over a long period. This method has adaptive capabilities; the system can automatically find the optimal pump efficiency point without manual input. However, it has the following shortcomings in field applications:

[0014] 1) The process is too time-consuming. This method requires starting from the maximum permissible frequency and gradually decreasing the frequency to run once as the base data. According to the application example, to ensure data accuracy, it needs to run stably for 3 hours at each frequency, and one pass generally takes more than 30 hours.

[0015] 2) This method requires that the data at each frequency be stored in the system during traversal. The amount of data is large and the subsequent calculations are complex, which puts high demands on the computing and storage equipment used on site.

[0016] 3) This method uses the product of pump efficiency and frequency as the equivalent liquid volume for evaluation, but it cannot be verified whether the actual liquid production volume changes proportionally with frequency and pump efficiency.

[0017] 4) This method still relies on a single parameter for optimization, and the optimality of a single parameter does not equate to the overall optimality of the system.

[0018] Therefore, existing technologies still need improvement. Summary of the Invention

[0019] To address the aforementioned technical problems, this invention proposes an intelligent management system for oil wells and a method for controlling the production parameters of oil pumps in oilfields, thereby resolving the technical issues existing in the control of production parameters of oil pumps in oilfields in the prior art.

[0020] To address the aforementioned technical problems, some embodiments of the present invention disclose a method for controlling the production parameters of an oil pump, comprising:

[0021] S1 obtains the ratio of the current production rate of the oil well at the current pump frequency to the production rate of the oil well at the power frequency. Combined with the current efficiency of the pump, a comprehensive evaluation index at the current frequency is obtained.

[0022] S2 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the previous frequency, and adjusts the control parameters of the oil pump based on the comparison results.

[0023] In some embodiments, the calculation of the comprehensive evaluation index at the previous frequency includes:

[0024] The ratio of the previous fluid production of the oil well at the previous pumping frequency to the previous fluid production at the power frequency is obtained. Combined with the previous efficiency of the pumping pump, a comprehensive evaluation index at the previous frequency is obtained.

[0025] In some embodiments, the formula for calculating the comprehensive evaluation index is as follows:

[0026]

[0027] In the formula, C is the comprehensive evaluation index, q is the actual fluid production of the oil well, Q is the fluid production of the oil well under power frequency conditions, e is the actual efficiency of the oil pump, and a and b are the weighting coefficients.

[0028] In some embodiments, the values ​​of a and b are determined according to different site conditions and oil well production needs, with production a being 1 to 1.8 and b being 1.

[0029] In some embodiments, the initial frequency of oil pump production is set to the power frequency; and when the current frequency of oil pump production is the initial frequency, the comprehensive evaluation index calculation uses the oil well production rate under the power frequency state as the current oil well production rate.

[0030] In some embodiments, it also includes:

[0031] After the oil pump has been running for a preset time, the current frequency is set to the initial frequency, the parameter adjustment is reset, and S1 and S2 are repeated to readjust the frequency of the oil pump.

[0032] In some embodiments, comparing the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the previous frequency, and adjusting the control parameters of the oil pump based on the comparison results includes:

[0033] If the comprehensive evaluation index at the current frequency is greater than that at the previous frequency, it indicates that the parameter adjustment is reasonable, and the frequency of the oil pump should continue to be adjusted in the current direction.

[0034] If the comprehensive evaluation index at the current frequency is less than or equal to the comprehensive evaluation index at the previous frequency, it indicates that the parameter adjustment is unreasonable. The next parameter adjustment will be carried out in the opposite direction to the current parameter adjustment.

[0035] In some embodiments, if the initial parameter tuning result or two adjacent parameter tuning results are both reasonable, or if the initial parameter tuning result is unreasonable, then the next parameter tuning is performed at twice the predetermined step size.

[0036] In some embodiments, if the results of two consecutive parameter tunings are different, the tuning step size is reduced in the next parameter tuning.

[0037] In some embodiments, the oil pump operates for a predetermined time at each frequency.

[0038] In some embodiments, the following are included:

[0039] S0 starts the oil pump at the power frequency and runs for a predetermined time. The actual liquid production under the power frequency state is assigned as the current liquid production state. Combined with the current efficiency of the oil pump, a comprehensive evaluation index under the power frequency state is obtained.

[0040] S1 sends a command to the frequency converter of the oil pump to adjust the frequency of the oil pump upward by a predetermined step size and run for a predetermined time, or to adjust the frequency of the oil pump downward by a predetermined step size and run for a predetermined time, and calculates the comprehensive evaluation index at the current frequency.

[0041] S2 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the power frequency. If the comprehensive evaluation index at the current frequency is greater than the comprehensive evaluation index at the power frequency, it indicates that the parameter adjustment is reasonable. Continue to adjust the frequency of the oil pump in the current parameter adjustment direction with a predetermined step size.

[0042] If the comprehensive evaluation index at the current frequency is less than or equal to the comprehensive evaluation index at the power frequency, it indicates that the parameter adjustment is unreasonable. The next parameter adjustment will be carried out in the opposite direction of the current parameter adjustment and the frequency of the oil pump will be adjusted by twice the predetermined step size.

[0043] S3 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the previous frequency. If the comprehensive evaluation index at the current frequency is greater than the comprehensive evaluation index at the previous frequency, it indicates that the parameter adjustment is reasonable. Continue to adjust the frequency of the oil pump in the predetermined step size according to the current parameter adjustment direction.

[0044] S4 repeats S3 until the parameter adjustment results obtained from two adjacent parameter adjustments are different. Then, in the next parameter adjustment, the parameter adjustment step size is reduced, and the frequency of the oil pump is adjusted in the opposite direction of the previous parameter adjustment.

[0045] S5 repeats S3 and S4 until the oil pump runs for the preset time, then re-enters S0.

[0046] On the other hand, some embodiments of the present invention also disclose an intelligent management system for oil wells in oil fields, which includes the aforementioned method for controlling the production parameters of oil pumps.

[0047] By adopting the above technical solution, the present invention has at least the following beneficial effects:

[0048] The present invention provides an intelligent management system for oilfields and a method for controlling the production parameters of oil pumps. The system is simple in principle, requires little data, and is fast in calculation. The system can automatically find the optimal operating parameters without manual input, realizing true automatic and precise adjustment of oil well strokes and effectively improving oil well production efficiency. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1 This is a control flowchart of a method for controlling production parameters of an oil pump as disclosed in some embodiments of the present invention;

[0051] Figure 2 This is a structural block diagram of an oilfield intelligent management system disclosed in some embodiments of the present invention;

[0052] Figure 3 This is a diagram of a tubular structure used in rodless lifting as disclosed in some embodiments of the present invention. Detailed Implementation

[0053] The embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings and examples. The detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of this disclosure by way of example, but should not be used to limit the scope of this disclosure. This disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0054] These embodiments are provided to make the disclosure thorough and complete, and to fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0055] It should be noted that, in the description of this disclosure, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationship, are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0056] Furthermore, the terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. "Vertical" is not strictly vertical, but within the permissible margin of error. "Parallel" is not strictly parallel, but within the permissible margin of error. Terms such as "including" or "contains" mean that the element preceding the word encompasses the element listed after the word, and do not exclude the possibility of encompassing other elements as well.

[0057] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this disclosure depending on the specific circumstances. When a particular device is described as being located between a first device and a second device, an intermediary device may or may not be present between the particular device and the first or second device.

[0058] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0059] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0060] In oilfield management systems, controlling and adjusting oil well production parameters is crucial for maximizing well productivity and improving production efficiency. Among these parameters, fluid production is the most direct indicator of a well's production status; however, solely pursuing high fluid production may reduce the overall operational efficiency of the oil production system. Pump efficiency is an indicator of well production efficiency, but simply increasing pump efficiency may negatively impact production and profitability. Therefore, a comprehensive evaluation combining fluid production and pump efficiency, balancing both production and efficiency, plays a vital role in maximizing well productivity and achieving optimal production benefits.

[0061] like Figure 1 As shown, some embodiments of the present invention disclose a method for controlling the production parameters of an oil pump, including:

[0062] S1 obtains the ratio of the current production rate of the oil well at the current pump frequency to the production rate of the oil well at the power frequency. Combined with the current efficiency of the pump, a comprehensive evaluation index at the current frequency is obtained.

[0063] S2 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the previous frequency, and adjusts the frequency of the oil pump based on the comparison results.

[0064] In this embodiment, the operating time of the pumping unit at each frequency is generally a predetermined time, such as 30 minutes. This embodiment integrates production rate and pump efficiency into a comprehensive evaluation index through an algorithm, balancing both production rate and pump efficiency for on-site parameter adjustment evaluation. This achieves automatic target finding and automatic adjustment of operating parameters without unmanned intervention of the pumping unit, improving the system efficiency of the oil well and significantly reducing its production cost.

[0065] In the above embodiments, the calculation of the comprehensive evaluation index at the previous frequency may include:

[0066] The ratio of the well's previous fluid production at the previous pumping frequency to its production at the previous power frequency is obtained. Combined with the previous pumping efficiency, a comprehensive evaluation index at the previous frequency is derived. The formula for calculating the comprehensive evaluation index is as follows:

[0067]

[0068] In the formula, C is the comprehensive evaluation index, q is the actual fluid production of the oil well, Q is the fluid production of the oil well under power frequency conditions, e is the actual efficiency of the pumping unit, and a and b are weighting coefficients. a and b are determined manually according to the oil well conditions and operating objectives; typically, a is chosen between 1.0 and 1.8, and b is 1. The pumping unit efficiency e (hereinafter referred to as pump efficiency) is calculated using the following formula:

[0069] e = Current liquid production / Theoretical output of the oil pump under current parameters

[0070] Depending on the operating principle of the oil pump, the theoretical production capacity is generally calculated using a standard theoretical formula or obtained by consulting relevant technical manuals.

[0071] The oil pump production parameter control method disclosed in this embodiment generally sets the initial frequency of the oil pump to the power frequency. Furthermore, when the current frequency of the oil pump is the initial frequency, the comprehensive evaluation index calculation uses the well production rate at the power frequency as the current production rate of the well. To avoid the impact of changes in formation, reservoir, and other objective conditions on the parameter adjustment effect, after a preset operating time, the current frequency is set back to the initial frequency, and parameter adjustment is reset. Steps S1 and S2 are repeated to readjust the oil pump frequency. This preset time can be a clearly defined time length, such as resetting the parameter adjustment every 24 hours; or it can be a predetermined number of parameter adjustment cycles, such as resetting the parameter adjustment after 50 cycles.

[0072] In this embodiment, comparing the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the previous frequency, and adjusting the frequency of the oil pump based on the comparison result includes:

[0073] If the comprehensive evaluation index at the current frequency is greater than that at the previous frequency, it indicates that the parameter adjustment is reasonable, and the frequency of the oil pump should continue to be adjusted in the current direction.

[0074] If the comprehensive evaluation index at the current frequency is less than or equal to the comprehensive evaluation index at the previous frequency, it indicates that the parameter adjustment is unreasonable. The frequency of the oil pump should be adjusted in the opposite direction to the current parameter adjustment in the next adjustment.

[0075] If the initial parameter tuning result or the results of two consecutive parameter tunings are both reasonable, or if the initial parameter tuning result is unreasonable, then the next parameter tuning will be performed at twice the predetermined step size.

[0076] If the results of two consecutive parameter adjustments are different, the step size should be reduced in the next parameter adjustment.

[0077] Some embodiments of the present invention also disclose a method for controlling the production parameters of an oil pump, such as... Figure 1 As shown, it includes:

[0078] S0 starts the oil pump at the power frequency and runs for a predetermined time. The actual liquid production under the power frequency state is assigned as the current liquid production state. Combined with the current efficiency of the oil pump, a comprehensive evaluation index under the power frequency state is obtained.

[0079] S1 sends a command to the frequency converter of the oil pump to adjust the frequency of the oil pump upward by a predetermined step size and run for a predetermined time, or to adjust the frequency of the oil pump downward by a predetermined step size and run for a predetermined time, and calculates the comprehensive evaluation index at the current frequency.

[0080] S2 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the power frequency. If the comprehensive evaluation index at the current frequency is greater than the comprehensive evaluation index at the power frequency, it indicates that the parameter adjustment is reasonable. Continue to adjust the frequency of the oil pump in the current parameter adjustment direction with a predetermined step size.

[0081] If the comprehensive evaluation index at the current frequency is less than or equal to the comprehensive evaluation index at the power frequency, it indicates that the parameter adjustment is unreasonable. The next parameter adjustment will be carried out in the opposite direction of the current parameter adjustment and the frequency of the oil pump will be adjusted by twice the predetermined step size.

[0082] S3 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the previous frequency. If the comprehensive evaluation index at the current frequency is greater than the comprehensive evaluation index at the previous frequency, it indicates that the parameter adjustment is reasonable. Continue to adjust the frequency of the oil pump in the predetermined step size according to the current parameter adjustment direction.

[0083] S4 repeats S3 until the parameter adjustment results obtained from two adjacent parameter adjustments are different. Then, in the next parameter adjustment, the parameter adjustment step size is reduced, and the frequency of the oil pump is adjusted in the opposite direction of the previous parameter adjustment.

[0084] S5 repeats S3 and S4 until the oil pump runs for the preset time, then re-enters S0.

[0085] Some embodiments of the present invention also disclose an intelligent oilfield management system, employing the aforementioned method for controlling the production parameters of oil pumps. For example... Figure 2As shown, the system includes a continuous production fluid metering device, a control module, a frequency converter, a motor and pumping unit system, and a display module. The control module can be a microcontroller, PLC, RTU, or other computing, control, and storage module. It obtains the current production fluid volume through the surface production fluid metering device and transmits it to the surface computing and control unit (control module). The computing and control unit calculates the current pump efficiency and comprehensive evaluation indicators, and compares them with the indicator values ​​from the previous parameter adjustment. Based on the comparison results, it issues adjustment commands and displays the comparison results on the display module. The frequency converter or other speed control device changes the operating parameters of the motor or pumping unit system according to the commands. The adjustment and comparison results balance production and efficiency, ensuring the oil production system operates at its optimal state while fully utilizing the downhole fluid supply capacity, significantly reducing the production cost of the oil well and improving the economic benefits of oilfield production.

[0086] Example 1

[0087] This embodiment describes an automatic adjustment method for pumping unit stroke rate based on a dual balance of production volume and pump efficiency, applicable to conventional beam pumping units.

[0088] Well number: A1. This well is located in an oil production plant in Jilin Oilfield. The well has been using an intelligent lift system to achieve automated parameter adjustment control since December 21, 2023, and it is still operating smoothly as of May 10, 2024.

[0089] Table 1 shows a record of the parameter adjustment process for a certain day in this well. The following section uses this record as an example to describe in detail the main steps of intelligent parameter adjustment using this system:

[0090] Step 1: Run the pumping unit at the power frequency for 30 minutes, set the current pump efficiency adjustment direction to decrease, and the step size is 10Hz. Obtain the oil well production rate Q = 11.011 at the power frequency, and calculate the current pump efficiency e = 26.76% and the current comprehensive evaluation index C0 = 26.76.

[0091]

[0092] In the formula, a and b are weighting coefficients, which are manually entered before the system runs.

[0093] Step 2: Send a command to the frequency converter to output a frequency of 40Hz and start timing;

[0094] Step 3: After running stably for 30 minutes, obtain the current well production rate q and other parameters, and use them to calculate the current comprehensive evaluation index C1 = 30.37;

[0095]

[0096] Step 4: 26.76 < 30.37, indicating that the parameter adjustment direction (reducing the frequency) is correct. The inverter outputs 30Hz. Assign the value of C1 to C0, return to step 3, and continue execution.

[0097] Step 5: When the frequency drops to 20Hz, the comprehensive evaluation index C1 = 31.41. At this time, C0 (37.72) > C1 (31.41), indicating that the current parameter adjustment direction is wrong. Change to increase the frequency, and at the same time change the frequency adjustment step size to 5Hz. The inverter outputs 25Hz, assign the value of C1 to C0, return to step 3, and continue to execute.

[0098] As can be seen from the table, the frequency of the well has been fluctuating between 20Hz and 25Hz since then, achieving intelligent frequency reduction control.

[0099] To avoid the impact of changes in objective conditions such as formation and reservoir on the parameter adjustment effect, the system is set to resume power frequency production every 50 parameter adjustments to reacquire the current oil well production Q at the current power frequency.

[0100] Compared with the system before application (i.e., operation under traditional power frequency), the pumping unit stroke rate decreased from 6 strokes / min to 2.78 strokes / min, the average daily power consumption decreased from 196.89 kWh to 123.1 kWh, and the average pump efficiency of the pumping unit increased from 11.36% to 40%–50%, showing significant application effects.

[0101] Table 1. Partial Intelligent Parameter Adjustment Records for Well A1

[0102]

[0103]

[0104] Example 2

[0105] This embodiment describes a method and system for applying a smart parameter adjustment method that balances both production volume and pump efficiency to a rodless lifting process. Figure 3 This is a system architecture diagram showing the application of this method in the field.

[0106] The system includes: a downhole submersible motor 1, a submersible screw pump 2, a submersible cable 3, tubing 4, a wellhead production metering device 5, and a surface control system 6. The downhole motor and submersible screw pump are lowered into the well together, supplying power to the well via the submersible cable. The production metering device is installed at the wellhead, and the acquired data is transmitted to the surface control system. The surface control system is divided into a calculation and processing module and a control output module. The control module controls the pump production by controlling the downhole motor speed through commands, while the calculation and processing module calculates the current pump efficiency and comprehensive evaluation indicators based on the acquired data.

[0107]

[0108] Where q is the current liquid production of the oil well, Q is the liquid production of the oil well at the motor speed of 100 rpm, e is the current efficiency of the submersible screw pump (abbreviated as pump efficiency), and a and b are the weight coefficients, which are manually set before the system is applied. The current pump efficiency = the current actual liquid production / the theoretical liquid production of the screw pump at the current speed. According to different downhole equipment, the theoretical liquid production of the screw pump at different speeds is different and can be obtained by referring to relevant technical manuals. The weight coefficients are input manually before the system runs.

[0109] Well number: A2. This well is located in an oil production plant of Jilin Oilfield. Due to the complex wellbore trajectory and frequent rod lifting operations, it has been changed to a rodless lifting process. Since March 71, 2024, this well has applied an intelligent lifting system to achieve automatic parameter adjustment control. Table 2 shows a record of a parameter adjustment process for this well on a certain day. Taking this record as an example, the main steps of applying the intelligent lifting system for parameter adjustment are described in detail below:

[0110] Step 1: The reasonable speed range of the submersible screw pump used in this well is 50 rpm to 250 rpm, corresponding to a liquid production of 0.2 m3 to 10.5 m3. Write the corresponding working characteristic curve of the screw pump into the control system in advance. Since the initial speed of this well is 200 rpm, the parameter adjustment direction is set to increase, the parameter adjustment interval is set to 30 minutes, and the step size is 20 rpm. Adjust the motor speed to 100 rpm. After running for 30 minutes, obtain the current liquid production Q of the oil well, calculate the current pump efficiency e and the current comprehensive evaluation index C0 = 94.76;

[0111] Step 2: Send a command to the downhole motor to adjust the speed to 120 rpm and start timing; [[ID=​​​​​​​​​​​​

[0116] As can be seen from the table, the motor speed of the well subsequently fluctuated between 170rpm and 175rpm, achieving intelligent control.

[0117] To avoid the impact of changes in objective conditions such as formation and reservoir on the parameter adjustment effect, the system is set to resume power frequency production every 7 days to reacquire the current oil well production Q at the current power frequency.

[0118] Compared with the system before its application (i.e., operating at a fixed speed of 200 rpm), the daily fluid production of the well increased from 7.39 t / day to 7.20 t / day, which is basically the same. The average daily power consumption decreased from 70.38 kWh to 59.35 kWh, and the average pump efficiency of the oil pump increased from 63.5% to 81%–85%. The application effect is obvious.

[0119] Table 2A2 Well Intelligent Parameter Adjustment Record (Partial)

[0120]

[0121] In summary, the intelligent management system for oil wells and the method for controlling the production parameters of pumping units disclosed in this invention achieve precise calibration of the automatic adjustment of pumping unit strokes, improving the system efficiency of the oil well. It is applicable not only to wells with sufficient fluid supply and a relatively stable production environment, but also to wells with unstable fluid supply and significant downhole environmental changes. This invention combines production rate and pump efficiency for comprehensive judgment, avoiding the shortcomings of traditional single-parameter adjustment of pumping unit parameters, which fails to achieve the optimal system state. The intelligent control method for oil wells based on this algorithm allows the system to automatically find the optimal parameters, avoiding the problem of unreasonable manually input target values. This invention requires less computation, greatly reducing memory usage and improving judgment speed, meeting the requirements of real-time on-site adjustment. Furthermore, the automatic control system using this method has been applied to multiple conventional pumping unit wells and downhole submersible pump wells in oil fields. Results show that this method significantly reduces the production cost of oil wells, improves the economic benefits of oil production in oil fields, and operates stably and reliably in the field.

[0122] The embodiments of this disclosure have now been described in detail. To avoid obscuring the concept of this disclosure, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions disclosed herein based on the above description.

[0123] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. In particular, as long as there is no structural conflict, the technical features mentioned in the various embodiments can be combined in any manner.

Claims

1. A method for controlling production parameters of an oil pump, characterized in that, include: S1 obtains the ratio of the current production rate of the oil well at the current pump frequency to the production rate of the oil well at the power frequency. Combined with the current efficiency of the pump, a comprehensive evaluation index at the current frequency is obtained. S2 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the previous frequency, and adjusts the control parameters of the oil pump based on the comparison results.

2. The method for controlling the production parameters of an oil pump according to claim 1, characterized in that, The calculation of the comprehensive evaluation index at the previous frequency includes: The ratio of the previous fluid production of the oil well at the previous pumping frequency to the previous fluid production at the power frequency is obtained. Combined with the previous efficiency of the pumping pump, a comprehensive evaluation index at the previous frequency is obtained.

3. The method for controlling the production parameters of an oil pump according to claim 1, characterized in that, The formula for calculating the comprehensive evaluation index is as follows: In the formula, C is the comprehensive evaluation index, q is the actual fluid production of the oil well, Q is the fluid production of the oil well under power frequency conditions, e is the actual efficiency of the oil pump, and a and b are the weighting coefficients.

4. The method for controlling the production parameters of an oil pump according to claim 3, characterized in that, Depending on the site conditions and the production needs of the oil well, a and b take different values, with a ranging from 1 to 1.8 and b being 1.

5. The method for controlling the production parameters of an oil pump according to claim 1, characterized in that, The initial frequency of oil pump production is set to the power frequency; and when the current frequency of oil pump production is the initial frequency, the comprehensive evaluation index calculation uses the oil well production rate under the power frequency state as the current oil well production rate.

6. The method for controlling the production parameters of an oil pump according to claim 5, characterized in that, Also includes: After the oil pump has been running for a preset time, the current frequency is set to the initial frequency, the parameter adjustment is reset, and S1 and S2 are repeated to readjust the frequency of the oil pump.

7. The method for controlling production parameters of an oil pump according to claim 1, characterized in that, The comprehensive evaluation index at the current frequency is compared with that at the previous frequency, and the control parameters of the oil pump are adjusted based on the comparison results, including: If the comprehensive evaluation index at the current frequency is greater than that at the previous frequency, it indicates that the parameter adjustment is reasonable, and the frequency of the oil pump should continue to be adjusted in the current direction. If the comprehensive evaluation index at the current frequency is less than or equal to the comprehensive evaluation index at the previous frequency, it indicates that the parameter adjustment is unreasonable. The next parameter adjustment will be carried out in the opposite direction to the current parameter adjustment.

8. The method for controlling production parameters of an oil pump according to claim 7, characterized in that, If the initial parameter tuning result or the results of two adjacent parameter tunings are both reasonable, or if the initial parameter tuning result is unreasonable, then the next parameter tuning will be performed at twice the predetermined step size.

9. A method for controlling production parameters of an oil pump according to claim 7 or 8, characterized in that, If the results of two consecutive parameter adjustments are different, the step size should be reduced in the next parameter adjustment.

10. The method for controlling production parameters of an oil pump according to claim 1, characterized in that, The operating time of the oil pump at each frequency is the preset time.

11. The method for controlling the production parameters of an oil pump according to claim 1, characterized in that, include: S0 starts the oil pump at the power frequency and runs for a predetermined time. The actual liquid production under the power frequency state is assigned as the current liquid production state. Combined with the current efficiency of the oil pump, a comprehensive evaluation index under the power frequency state is obtained. S1 sends a command to the frequency converter of the oil pump to adjust the frequency of the oil pump upward by a predetermined step size and run for a predetermined time, or to adjust the frequency of the oil pump downward by a predetermined step size and run for a predetermined time, and calculates the comprehensive evaluation index at the current frequency. S2 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the power frequency. If the comprehensive evaluation index at the current frequency is greater than the comprehensive evaluation index at the power frequency, it indicates that the parameter adjustment is reasonable. Continue to adjust the frequency of the oil pump in the current parameter adjustment direction with a predetermined step size. If the comprehensive evaluation index at the current frequency is less than the comprehensive evaluation index at the power frequency, it indicates that the parameter adjustment is unreasonable. The next parameter adjustment will be carried out in the opposite direction of the current parameter adjustment and the frequency of the oil pump will be adjusted by twice the predetermined step size. S3 compares the comprehensive evaluation index at the current frequency with the comprehensive evaluation index at the previous frequency. If the comprehensive evaluation index at the current frequency is greater than the comprehensive evaluation index at the previous frequency, it indicates that the parameter adjustment is reasonable. Continue to adjust the frequency of the oil pump in the current parameter adjustment direction with a predetermined step size. S4 repeats S3 until the parameter adjustment results obtained from two adjacent parameter adjustments are different. Then, in the next parameter adjustment, the parameter adjustment step size is reduced, and the frequency of the oil pump is adjusted in the opposite direction of the previous parameter adjustment. S5 repeats S3 and S4 until the oil pump runs for the preset time, then re-enters S0.

12. An intelligent management system for oil well production in oilfields, characterized in that, The method for controlling the production parameters of an oil pump as described in any one of claims 1-11.

Images