An intelligent intermittent pumping control system and control method for an oilfield beam pumping unit

Abstract

The present invention provides an intelligent intermittent pumping control system and a control method for an oilfield beam pumping unit. Based on the monitoring and analysis of the crank position, motor speed and electrical parameters of the beam pumping unit, the intermittent pumping system that can ensure the efficient operation of a low-liquid-volume oil well is calculated through the inversion of the light-rod indicator diagram from the electric power diagram and the comprehensive analysis of the controller, and the controller outputs the intermittent pumping system to the motor for execution, thereby realizing the intelligent intermittent pumping control of the beam pumping unit. In addition, the electric power diagram is mainly corrected through the light-rod indicator diagram, and the fullness of the corrected electric power diagram reaches a certain lower limit value. At the same time, the number of electric power diagrams that reach the lower limit value accounts for a specific target value in the number of all electric power diagrams in the intermittent pumping cycle, indicating that the intermittent pumping system / cycle is reasonable. Furthermore, the low-liquid-volume oil well can be intermittently pumped according to this intermittent pumping cycle to realize the efficient operation of the pumping unit, and at the same time, the problems of production decline and low efficiency of the machine production system are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of oil field production, and in particular relates to an intelligent intermittent pumping control system and a control method thereof for an oil field beam pumping unit. Background Art

[0002] During the oil production process, when the permeability of the oil well is lower than the designed pumping capacity of the pumping unit, the oil well is in a state of insufficient fluid supply. In order to save electricity, reduce mechanical wear of the pumping unit, and improve the efficiency of the equipment, the control method currently generally used is to automatically intermittently control the pumping unit, that is, when it is detected that the oil well is in a state of insufficient fluid supply, the pumping unit is controlled to stop running and enter a countdown state, waiting for the oil well dynamic fluid level to recover naturally; when the predetermined downtime is over, the pumping unit is controlled to start working again; and this is repeated.

[0003] However, compared with high-liquid-yield oil wells, the unscientific artificial intermittent pumping system has caused a certain degree of decline in production or low efficiency of the mechanical production system. In addition, the existing various intermittent pumping control optimization systems cannot guarantee the efficient operation of low-liquid-yield oil wells "both stabilizing production and reducing energy consumption." Summary of the invention

[0004] The embodiment of the present invention provides an intelligent intermittent pumping control system and a control method for an oilfield walking beam pumping unit, the first purpose of which is to ensure that low-liquid-volume oil wells cannot achieve efficient operation during intermittent pumping; the second purpose is to solve the problem of production decline and low efficiency of the machine production system caused by intermittent pumping of low-liquid-volume oil wells.

[0005] In order to solve the above technical problems, the present invention provides an intelligent inter-pumping control system for an oilfield beam pumping unit, comprising a database server, a host computer, a well site RTU and a controller which are electrically connected in sequence, the controller is electrically connected to a display and a motor, the motor is connected to and drives the beam pumping unit, the donkey head of the beam pumping unit is connected to a polished rod, a speed sensor and an electric parameter sensor are installed on the motor, a crank position sensor is installed on the crank of the beam pumping unit, and a load displacement sensor is installed on the polished rod;

[0006] The rotation speed sensor, the electric parameter sensor, the crank position sensor and the load displacement sensor are respectively connected to the controller.

[0007] Furthermore, the electrical parameter sensor includes a voltage sensor for measuring the motor voltage, a current sensor for measuring the motor current, and a power factor sensor for measuring the motor power factor.

[0008] Preferably, the database server stores the following data: the allowable value P for intermittent pumping, the daily production of oil wells V 日产液 , crude oil volume water content n w , the density of water ρw , the density of crude oil without water ρ o , casing inner diameter ф 套 , oil pipe outer diameter ф 油 , oil pump diameter D p , stroke S, sprint n 冲 , stroke loss λ, oil pump leakage Q 漏 , pump suction gas-liquid ratio R, pump clearance volume coefficient K, oil well pump submersion pressure P s , oil pump outlet pressure P d , multivariable process index n.

[0009] The present invention also provides a control method using an intelligent intermittent pumping control system of an oil field beam pumping unit, comprising the following steps:

[0010] Step S1, the host computer retrieves the data stored in the database server and calculates the initial value of the sampling system according to the retrieved data;

[0011] Step S2, the initial value of the intermittent pumping system is sent by the host computer to the well site RTU, and the controller retrieves the initial value of the intermittent pumping system from the well site RTU;

[0012] Step S3, the controller draws a polished rod indicator diagram according to the load displacement data transmitted by the load displacement sensor, and displays it on the display;

[0013] Step S4, the controller draws a motor power diagram according to the data transmitted by the speed sensor, the electric parameter sensor, and the crank position sensor, and reflects it on the display;

[0014] Step S5, correcting the motor electrical power diagram according to the polished rod indicator diagram;

[0015] Step S6, customize the electric power diagram compliance rate and target value. If the electric power diagram compliance rate is within the threshold range of the target value, it indicates that the intermittent pumping system is reasonable, and the walking beam oil pumping unit can use the initial value of the intermittent pumping system as the intermittent pumping cycle for intermittent pumping. If the electric power diagram compliance rate is outside the threshold range of the target value, it indicates that the intermittent pumping system is unreasonable, and the initial value of the intermittent pumping system is adjusted. Repeat steps 2 to 6 until the electric power diagram compliance rate finally reaches the target value.

[0016] Furthermore, the initial value of the intermittent pumping system in step S1 includes the initial value of the well stopping time t and the initial value of the well opening time t', which are jointly obtained according to the following formula:

[0017]

[0018] Where: P is the allowable value of the pumping stop well, which is 0.5×105Pa; V 日产液 —Daily fluid production of oil wells, m 3 / d; t—upper limit of well stopping time, h; nw —Volume water content of crude oil; ρ w —Density of water, kg / m 3 ρ o —Density of crude oil without water, kg / m 3 ;ф 套 —Inner diameter of casing, m; ф 油 —Outer diameter of the oil pipe, m;

[0019]

[0020] Where: D p —Oil pump diameter, m; S—stroke, m; n 冲 — stroke times, min -1 ;λ—stroke loss, m; Q 漏 —Oil pump leakage, m 3 / d;η 充 —Oil pump filling coefficient;

[0021]

[0022] Where: R—gas-liquid ratio at pump suction port, m 3 / m 3 ; K—pump clearance volume coefficient; P s —Submergence pressure of the oil well pump, Pa; P d —Oil pump outlet pressure, Pa; n—variable process index, n≈1.1.

[0023] Preferably, step S3 of drawing a polished rod dynamometer diagram includes:

[0024] S301. The load displacement sensor collects different polished rod positions and loads during the pumping process and sends them to the controller;

[0025] S302. The controller plots the position of the polished rod S θ With polished rod load N θ The relationship diagram, i.e. the bare rod indicator diagram, is reflected on the display.

[0026] Furthermore, step S4 of drawing the motor electrical power diagram includes:

[0027] S401. The crank position sensor collects different crank positions θ, and the speed sensor collects the motor speed distribution ω at different crank positions θ. θ , the electric parameter sensor collects the current distribution I of the motor at different crank positions θ θ 、The voltage distribution U of the motor at different crank positions θ θ and the power factor distribution cosθ of the motor at different crank positions θ;

[0028] S402. Calculate the motor torque distribution T according to the following formulaθ :

[0029]

[0030] Where: U θ — Voltage distribution of the motor at different crank positions θ; I θ —Current distribution of the motor at different crank positions θ; cosθ —Power factor distribution of the motor at different crank positions θ; ω θ —Motor speed distribution at different crank positions θ;

[0031] S403. Check the table of pumping unit polished rod position factor and torque factor in the instruction manual of the beam pumping unit, and record the pumping unit polished rod position factor γ θ According to formula 5, different crank positions θ and polished rod positions S are established θ The relationship between them is as follows:

[0032] S θ =S×γ θ Formula 5

[0033] Where: S θ —Position of the polished rod, m; S—Stroke, m; γ θ — polished rod position factor;

[0034] S404. Establish motor torque distribution T θ With the position of the polished rod S θ The corresponding relationship between the light rod position S θ With motor torque T θ The relationship diagram, that is, the motor electrical power diagram, is reflected on the display.

[0035] Preferably, step S5 of correcting the motor electrical power diagram according to the polished rod dynamometer diagram is specifically as follows:

[0036] Check the display and observe the relative positions of the bare rod indicator diagram and the motor electric power diagram in the display. Taking the bare rod indicator diagram as the standard, adjust the stroke S of the motor electric power diagram so that the boundary points of the bare rod indicator diagram and the motor electric power diagram coincide. Then remove the load displacement sensor to complete the correction of the motor electric power diagram.

[0037] Furthermore, step S6 specifically includes:

[0038] S601. The compliance rate of the electric power diagram is defined as the number of electric power diagrams with a fullness of ≥70% in the most recent intermittent period and the proportion of all electric power diagrams in the intermittent period. The fullness of the electric power diagram refers to the proportion of the electric power diagram and the bare rod indicator diagram in the same intermittent period;

[0039] S602. 90% ≥ ≥ 70% of the electric power diagram compliance rate in the most recent intermittent pumping cycle is taken as the target value. If the electric power diagram compliance rate is within the threshold range of the target value, it indicates that the intermittent pumping system is reasonable, and the beam pumping unit can use the initial value of the intermittent pumping system as the intermittent pumping cycle for intermittent pumping oil production;

[0040] S603. If the compliance rate of the electric power diagram is outside the threshold range of the target value, it indicates that the intermittent extraction system is unreasonable. Adjust the initial value of the intermittent extraction system within a floating range of ±5%, and repeat steps 2 to 6 continuously to make the compliance rate of the electric power diagram fluctuate within the range of ±5% until the compliance rate of the electric power diagram finally reaches the target value.

[0041] The beneficial effects of the present invention are as follows:

[0042] The intelligent intermittent pumping control system and control method of the oil field walking beam pumping unit protected by the present invention mainly corrects the electric power diagram through the light rod indicator diagram, and makes the fullness of the corrected electric power diagram reach a certain lower limit value. At the same time, the proportion of the number of electric power diagrams that reach the lower limit value in the number of all electric power diagrams in the intermittent pumping cycle reaches a specific target value, which indicates that the intermittent pumping system / cycle is reasonable. Furthermore, low liquid volume oil wells can carry out intermittent pumping according to this intermittent pumping cycle to achieve efficient operation of the pumping unit, while also solving the problems of reduced production and low efficiency of the machine production system.

[0043] In order to make the above contents of the present invention more clearly understood, preferred embodiments are given below and described in detail in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a structural diagram of the intelligent intermittent pumping control system of the oil field beam pumping unit.

[0045] Figure 2 It is a schematic diagram of the bare rod dynamometer diagram and electric dynamometer diagram before correction in the same coordinate system.

[0046] Figure 3 It is a schematic diagram of the corrected bare rod dynamometer diagram and electric dynamometer diagram in the same coordinate system.

[0047] Figure 4 It is a schematic diagram of the optimization logic algorithm of step S6.

[0048] Description of reference numerals:

[0049] 1. Electric motor; 2. Pumping unit; 3. Bare rod; 4. Speed ​​sensor; 5. Electrical parameter sensor; 6. Crank position sensor; 7. Load displacement sensor; 8. Controller; 9. Display; 10. Database server; 11. Host computer; 12. Well site RTU. DETAILED DESCRIPTION

[0050] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0051] The exemplary embodiments of the present invention are now described with reference to the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to disclose the present invention in detail and completely and to fully convey the scope of the present invention to those skilled in the art. The terms used in the exemplary embodiments shown in the accompanying drawings are not intended to limit the present invention. In the accompanying drawings, the same units / elements are marked with the same reference numerals.

[0052] Unless otherwise specified, the terms (including technical terms) used herein have the commonly understood meanings to those skilled in the art. In addition, it is understood that the terms defined in commonly used dictionaries should be understood to have the same meanings as those in the context of the relevant fields, and should not be understood as idealized or overly formal meanings.

[0053] First embodiment

[0054] The first embodiment of the present invention relates to an intelligent intermittent pumping control system for an oil field beam pumping unit, such as Figure 1 As shown, it includes a database server 10, a host computer 11, a well site RTU 12 and a controller 8 which are electrically connected in sequence, the controller 8 is electrically connected to a display 9 and a motor 1, the motor 1 is connected to and drives a beam pumping unit 2, the donkey head of the beam pumping unit 2 is connected to a polished rod 3, a speed sensor 4 and an electric parameter sensor 5 are installed on the motor 1, a crank position sensor 6 is installed on the crank of the beam pumping unit 2, and a load displacement sensor 7 is installed on the polished rod 3;

[0055] The rotation speed sensor 4 , the electric parameter sensor 5 , the crank position sensor 6 and the load displacement sensor 7 are respectively connected to the controller 8 .

[0056] Specifically, the database server 10 stores basic data collected from the oil field. The host computer 11 retrieves the data stored in the database server 10 and calculates the initial value of the intermittent pumping system based on the retrieved data. The initial value of the intermittent pumping system is sent by the host computer 11 to the well site RTU 12. The controller 8 retrieves the initial value of the intermittent pumping system from the well site RTU 12. The controller 8 draws the bare rod power diagram based on the load displacement data transmitted by the load displacement sensor 7, and reflects it on the display 9. At the same time, the controller 8 draws the motor power diagram based on the data transmitted by the speed sensor 4, the electrical parameter sensor 5, and the crank position sensor 6, and reflects it on the display 9.

[0057] Preferably, the controller 8 in the present invention is a controller of the SFC rope pumping unit system optimization operation integrated controller model produced by Harbin Sophie Electric Technology Co., Ltd.

[0058] Therefore, the intelligent intermittent pumping control system of the oil field walking beam pumping unit is mainly used to collect, transmit and store data. In addition, there is an important function, which is to calculate and draw the bare rod indicator diagram and the motor electrical power diagram, and use the bare rod indicator diagram to correct the motor electrical power diagram, so as to achieve a reasonable intermittent pumping system.

[0059] Second embodiment

[0060] Different from the first embodiment, in this embodiment, the electric parameter sensor 5 includes a voltage sensor for measuring the voltage of the motor 1 , a current sensor for measuring the current of the motor 1 , and a power factor sensor for measuring the power factor of the motor 1 .

[0061] In addition, the database server 10 further stores the following data: the allowable value P for intermittent pumping, the daily production of oil wells V 日产液 , crude oil volume water content n w , the density of water ρ w , the density of crude oil without water ρ o , casing inner diameter ф 套 , oil pipe outer diameter ф 油 , oil pump diameter D p , stroke S, sprint n 冲 , stroke loss λ, oil pump leakage Q 漏 , pump suction gas-liquid ratio R, pump clearance volume coefficient K, oil well pump submersion pressure P s , oil pump outlet pressure P d , multivariable process index n.

[0062] The above data can all be measured, assigned values ​​or obtained by looking up tables, and are basic data commonly used by technicians in this field in their work, so they can all be used as known data.

[0063] Third embodiment

[0064] On the basis of the intelligent inter-pumping control system of the oil field beam pumping unit, the present invention also protects a control method using the intelligent inter-pumping control system of the oil field beam pumping unit, which specifically includes the following steps:

[0065] Step S1, the host computer 11 retrieves the data stored in the database server 10, and calculates the initial value of the sampling system according to the retrieved data;

[0066] Step S2, the initial value of the intermittent pumping system is sent by the host computer 11 to the well site RTU 12, and the controller 8 retrieves the initial value of the intermittent pumping system from the well site RTU 12;

[0067] Step S3, the controller 8 draws a polished rod indicator diagram according to the load displacement data transmitted by the load displacement sensor 7, and displays it on the display 9;

[0068] Step S4, the controller 8 draws a motor power diagram according to the data transmitted by the speed sensor 4, the electric parameter sensor 5, and the crank position sensor 6, and reflects it on the display 9;

[0069] Step S5, correcting the motor electrical power diagram according to the polished rod indicator diagram;

[0070] Step S6, customize the electric power diagram compliance rate and target value. If the electric power diagram compliance rate is within the threshold range of the target value, it indicates that the intermittent pumping system is reasonable, and the walking beam pumping unit 2 can use the initial value of the intermittent pumping system as the intermittent pumping cycle to perform intermittent pumping. If the electric power diagram compliance rate is outside the threshold range of the target value, it indicates that the intermittent pumping system is unreasonable, and the initial value of the intermittent pumping system is adjusted. Repeat steps 2 to 6 until the electric power diagram compliance rate finally reaches the target value.

[0071] The present embodiment is different from the conventional intermittent pumping control method in that after the bare rod indicator diagram and the motor electric power diagram are drawn, they are not used directly, but the bare rod indicator diagram is used to correct (also called calibrate) the motor electric power diagram. The principle of correction is that if the electric power diagram compliance rate is within the threshold range of the target value, it indicates that the intermittent pumping system is reasonable, and the walking beam pumping unit 2 can use the initial value of the intermittent pumping system as the intermittent pumping cycle to perform intermittent pumping; if the electric power diagram compliance rate is outside the threshold range of the target value, it indicates that the intermittent pumping system is unreasonable, and the initial value of the intermittent pumping system is adjusted, and steps two to six are repeated continuously until the electric power diagram compliance rate finally reaches the target value.

[0072] The reason why the bare rod indicator diagram is used to correct the motor electric power diagram is that the value of the bare rod indicator diagram is a theoretical value, and the indicator diagram obtained is also a diagram under ideal conditions, so it can be used as a standard diagram. However, since the electric power diagram is a value measured by the load displacement sensor 7, there is a certain error. If the error is corrected, the initial value of the intermittent pumping system obtained after correction is a reasonable value, which can further ensure that the walking beam pumping unit can fully exert its pumping performance after intermittent pumping.

[0073] Fourth embodiment

[0074] The present invention also protects a control method using an intelligent intermittent pumping control system of an oil field beam pumping unit, which specifically includes the following steps:

[0075] Step S1, the host computer 11 retrieves the data stored in the database server 10, and calculates the initial value of the intermittent pumping system based on the retrieved data. The initial value of the intermittent pumping system includes the initial value of the well stopping time t and the initial value of the well opening time t', which are jointly calculated according to the following formula:

[0076]

[0077] Where: P is the allowable value of the pumping stop well, which is 0.5×105Pa; V 日产液 —Daily fluid production of oil wells, m 3 / d; t—well stop time, h; n w —Volume water content of crude oil; ρ w —Density of water, kg / m 3 ρ o —Density of crude oil without water, kg / m 3 ;ф 套 —Inner diameter of casing, m; ф 油 —Outer diameter of the oil pipe, m;

[0078]

[0079] Where: D p —Oil pump diameter, m; S—stroke, m; n 冲 — stroke times, min -1 ;λ—stroke loss, m; Q 漏 —Oil pump leakage, m 3 / d;η 充 —Oil pump filling coefficient;

[0080]

[0081] Where: R—gas-liquid ratio at pump suction port, m 3 / m 3 ; K—pump clearance volume coefficient; P s —Submergence pressure of the oil well pump, Pa; P d —Oil pump outlet pressure, Pa; n—variable process index, n≈1.1.

[0082] Step S2, the initial value of the intermittent pumping system is sent by the host computer 11 to the well site RTU 12, and the controller 8 retrieves the initial value of the intermittent pumping system from the well site RTU 12;

[0083] Step S3, the controller 8 draws a polished rod indicator diagram according to the load displacement data transmitted by the load displacement sensor 7, and displays it on the display 9, which specifically includes:

[0084] S301. The load displacement sensor 7 collects different positions and loads of the polished rod 3 during the pumping process and sends them to the controller 8;

[0085] S302. The controller 8 plots the position of the polished rod S θ With polished rod load N θ The relationship diagram, i.e., the bare rod indicator diagram, is reflected on the display 9.

[0086] Step S4, the controller 8 draws the motor power diagram according to the data transmitted by the speed sensor 4, the electric parameter sensor 5, and the crank position sensor 6, and reflects it on the display 9, which specifically includes:

[0087] S401. The crank position sensor 6 collects different crank positions θ, and the speed sensor 4 collects the motor speed distribution ω at different crank positions θ. θ , the electric parameter sensor 5 collects the current distribution I of the motor 1 at different crank positions θ θ , the voltage distribution U of motor 1 at different crank positions θ θ and the power factor distribution cosθ of motor 1 at different crank positions θ;

[0088] S402. Calculate the motor torque distribution T according to the following formula θ :

[0089]

[0090] Where: U θ — Voltage distribution of motor 1 at different crank positions θ; I θ — current distribution of the motor 1 at different crank positions θ; cosθ — power factor distribution of the motor 1 at different crank positions θ; ω θ —Motor speed distribution at different crank positions θ;

[0091] S403. Check the table of pumping unit polished rod position factor and torque factor in the instruction manual of the beam pumping unit 2, and record the pumping unit polished rod position factor γ θ According to formula 5, different crank positions θ and polished rod positions S are established θ The relationship between them is as follows:

[0092] S θ =S×γ θ Formula 5

[0093] Where: S θ —Position of the polished rod, m; S—Stroke, m; γ θ — polished rod position factor;

[0094] S404. Establish motor torque distribution T θ With the position of the polished rod S θ The corresponding relationship between the light rod position and the

[0095] S θ With motor torque T θ The relationship diagram, i.e. the motor electrical power diagram, is reflected on the display 9.

[0096] Step S5, correcting the motor electrical power diagram according to the polished rod indicator diagram, specifically:

[0097] Check the display 9 and observe the relative position of the bare rod power diagram and the motor power diagram in the display 9. Figure 2 and Figure 3 , taking the bare rod indicator diagram as the standard, adjust the stroke S of the motor electric power diagram so that the boundary points of the bare rod indicator diagram and the motor electric power diagram coincide, and then remove the load displacement sensor 7 to complete the correction of the motor electric power diagram.

[0098] Step S6, customize the electric power diagram compliance rate and target value. If the electric power diagram compliance rate is within the threshold range of the target value, it indicates that the intermittent pumping system is reasonable, and the walking beam pumping unit 2 can use the initial value of the intermittent pumping system as the intermittent pumping cycle to perform intermittent pumping. If the electric power diagram compliance rate is outside the threshold range of the target value, it indicates that the intermittent pumping system is unreasonable, and the initial value of the intermittent pumping system is adjusted. Steps 2 to 6 are repeated until the electric power diagram compliance rate finally reaches the target value. Figure 4 As shown, specifically including:

[0099] S601. The compliance rate of the electric power diagram is defined as the number of electric power diagrams with a fullness of ≥70% in the most recent intermittent period and the proportion of all electric power diagrams in the intermittent period. The fullness of the electric power diagram refers to the proportion of the electric power diagram and the bare rod indicator diagram in the same intermittent period;

[0100] S602. Take 90% ≥ the electric power diagram compliance rate ≥ 70% in the most recent intermittent pumping cycle as the target value. If the electric power diagram compliance rate is within the threshold range of the target value, it indicates that the intermittent pumping system is reasonable, and the beam pumping unit 2 can use the initial value of the intermittent pumping system as the intermittent pumping cycle for intermittent pumping oil production;

[0101] S603. If the compliance rate of the electric power diagram is outside the threshold range of the target value, it indicates that the intermittent extraction system is unreasonable. Adjust the initial value of the intermittent extraction system within a floating range of ±5%, and repeat steps 2 to 6 continuously to make the compliance rate of the electric power diagram fluctuate within the range of ±5% until the compliance rate of the electric power diagram finally reaches the target value.

[0102] It should be noted that in step 4, both the bare rod dynamometer diagram and the electric dynamometer diagram are based on S θ As the horizontal axis, the displacement of the light rod under different crank positions θ is collected. The difference is that the S of the light rod indicator diagram θ is calculated by formula 5, and S of the electric power diagram θ is detected by the load displacement sensor 7. The biggest difference between the two is that the position factor of the polished rod in formula 5 is obtained by looking up the table, and the calculated S θis a theoretical value, that is, a value under an ideal state. However, the position information collected by the load displacement sensor 7 must have a certain error due to the problem of installation position and detection accuracy, and the error cannot be directly eliminated physically. Therefore, the present invention uses the light rod indicator diagram to correct the electric power diagram. While correcting the electric power diagram, the initial value of the intermittent pumping system, that is, the well stopping time t and the well opening time t', is also adjusted. Specifically, the following example will be used to explain in detail how to correct the electric power diagram and obtain a reasonable initial value of the intermittent pumping system. The detailed process is as follows:

[0103] Intermittent pumping cycle = well stopping time t and well opening time t'. Assuming that an electric power diagram is drawn every 10 minutes, and there are 100 electric power diagrams in the most recent (last) intermittent pumping cycle, of which 80 have an electric power diagram fullness ≥ 70%. The electric power diagram fullness refers to the area ratio of the electric power diagram and the bare rod indicator diagram that are produced at the same time and at the same position. This means that the electric power diagram compliance rate is 80 / 100×100%=80%. Obviously, 90%≥electric power diagram compliance rate 80%≥70%, that is, the electric power diagram compliance rate is within the threshold range of the target value, indicating that the intermittent pumping system is reasonable. The walking beam pumping unit 2 can use the initial value of the intermittent pumping system as the intermittent pumping cycle for intermittent pumping oil production.

[0104] Assume that an electric power diagram is drawn every 10 minutes, and there are 100 electric power diagrams in the most recent (previous) intermittent pumping cycle, of which 65 have a fullness of ≥70%. The fullness of the electric power diagram refers to the area ratio of the electric power diagram and the bare rod indicator diagram at the same time and at the same position. This means that the electric power diagram compliance rate is 65 / 100×100%=65%. Obviously, 65% is less than 70%, that is, the electric power diagram compliance rate is outside the threshold range of the target value, indicating that the intermittent pumping system is unreasonable. At this time, adjust the well stop time t and the well start time t', and gradually optimize them within the range of ±5%, such as Figure 4 As shown, the well stopping time t is adjusted to t×1.05, and the well opening time t' is adjusted to t'×0.95. Steps 2 to 6 are repeated continuously, and the intermittent pumping system finally reaches the target value requirement through self-learning.

[0105] In summary, the intelligent intermittent pumping control method for oil field beam pumping units provided by the present invention is based on the monitoring and analysis of the crank position, motor speed and electrical parameters of the beam pumping units, and calculates the intermittent pumping system that can ensure the efficient operation of low-liquid oil wells through the inversion of the light rod indicator diagram through the electric power diagram and the comprehensive analysis of the controller. The intermittent pumping system is output by the controller to the motor for execution, thereby realizing the intelligent intermittent pumping control of the beam pumping units and the efficient operation of the pumping units, while also solving the problems of reduced production and low efficiency of the machine production system.

[0106] Those skilled in the art will appreciate that the above-mentioned embodiments are specific examples for implementing the present invention, and in actual applications, various changes may be made thereto in form and detail without departing from the spirit and scope of the present invention.

Claims

1. A control method using an intelligent intermittent pumping control system for an oil field beam pumping unit, characterized in that: An intelligent intermittent pumping control system for an oilfield beam pumping unit comprises a database server (10), a host computer (11), a well site RTU (12) and a controller (8) which are electrically connected in sequence, the controller (8) being electrically connected to a display (9) and a motor (1), the motor (1) being connected to and driving a beam pumping unit (2), the donkey head of the beam pumping unit (2) being connected to a bare rod (3), a speed sensor (4) and an electric parameter sensor (5) being installed on the motor (1), a crank position sensor (6) being installed on the crank of the beam pumping unit (2), and a load displacement sensor (7) being installed on the bare rod (3); The rotation speed sensor (4), the electrical parameter sensor (5), the crank position sensor (6) and the load displacement sensor (7) are respectively connected to the controller (8); The electric parameter sensor (5) comprises a voltage sensor for measuring the voltage of the motor (1), a current sensor for measuring the current of the motor (1), and a power factor sensor for measuring the power factor of the motor (1); The database server (10) stores the following data: the allowable value P for intermittent pumping, the daily production of oil wells V 日产液 , crude oil volume water content n w , the density of water ρ w , the density of crude oil without water ρ o , casing inner diameter ф 套 , oil pipe outer diameter ф 油 , oil pump diameter Dp, stroke S, sprint n 冲 , stroke loss λ, oil pump leakage Q 漏 , pump suction gas-liquid ratio R, pump clearance volume coefficient K, oil pump submersion pressure Ps, oil pump discharge pressure P d , multivariable process index n; The control method comprises the following steps: Step S1, the host computer (11) retrieves the data stored in the database server (10), and calculates the initial value of the intermittent pumping system based on the retrieved data. The initial value of the intermittent pumping system includes the initial value of the well stopping time t and the initial value of the well opening time t', which are jointly calculated according to the following formula: Formula 1 Where: P is the allowable value of the pumping stop well, which is 0.5×105Pa; V 日产液 —Daily fluid production of oil wells, m 3 / d; t—well stop time, h; n w —Volume water content of crude oil; ρ w —Density of water, kg / m 3 ; ρ o —Density of crude oil without water, kg / m 3 ;ф 套 —Inner diameter of casing, m; ф 油 —Outer diameter of the oil pipe, m; Formula 2 Where: D p —Oil pump diameter, m; S—stroke, m; n 冲 — stroke times, min -1 ;λ—stroke loss, m; Q 漏 —Oil pump leakage, m 3 / d;η 充 —Oil pump filling coefficient; Formula 3 Where: R—gas-liquid ratio at pump suction port, m 3 / m 3 ; K—pump clearance volume coefficient; P s —Submergence pressure of the oil well pump, Pa; P d —Outlet pressure of the oil pump, Pa; n—variable process index, n≈1.1; Step S2, the initial value of the intermittent pumping system is sent by the host computer (11) to the well site RTU (12), and the controller (8) retrieves the initial value of the intermittent pumping system from the well site RTU (12); Step S3, the controller (8) draws a polished rod indicator diagram according to the load displacement data transmitted by the load displacement sensor (7), and drawing the polished rod indicator diagram includes: S301. The load displacement sensor (7) collects the positions and loads of different polished rods (3) during the pumping process and sends them to the controller (8); S302. The controller (8) plots the position of the polished rod S θ With polished rod load N θ The relationship diagram, i.e., the bare rod indicator diagram, is reflected on the display (9); Step S4, the controller (8) draws a motor power diagram according to the data transmitted by the speed sensor (4), the electric parameter sensor (5), and the crank position sensor (6), and drawing the motor power diagram includes: S401. The crank position sensor (6) collects different crank positions θ, and the speed sensor (4) collects the motor speed distribution ω at different crank positions θ θ The electric parameter sensor (5) collects the current distribution I of the motor (1) at different crank positions θ. θ 、The voltage distribution U of the motor (1) at different crank positions θ θ and the power factor distribution cosθ of the motor (1) at different crank positions θ; S402. Calculate the motor torque distribution T according to the following formula θ : Formula 4 Where: U θ —voltage distribution of the motor (1) at different crank positions θ; I θ — current distribution of the motor (1) at different crank positions θ; cosθ — power factor distribution of the motor (1) at different crank positions θ; ω θ —Motor speed distribution at different crank positions θ; S403. Use the rod position factor and torque factor of the beam pumping unit (2) to record the rod position factor γ θ According to formula 5, different crank positions θ and polished rod positions S are established θ The relationship between them is as follows: S θ =S×γ θ Formula 5 Where: S θ —Position of the polished rod, m; S —Stroke, m; S θ — polished rod position factor; S404. Establish motor torque distribution T θ With the position of the polished rod S θ The corresponding relationship between the light rod position S θ With motor torque T θ The relationship diagram, i.e., the motor electrical power diagram, is reflected on the display (9); In step S4, both the bare rod power diagram and the motor power diagram are based on S θ As the horizontal axis, the displacement of the light rod under different crank positions θ is collected. The difference is that the S of the light rod indicator diagram θ is calculated by formula 5, and S of the motor power diagram θ is detected by the load displacement sensor (7). The biggest difference between the two is that the calculated S θ is a theoretical value, that is, a value under ideal conditions. However, the position information collected by the load displacement sensor (7) will inevitably have a certain error due to the problem of installation position and detection accuracy. This error cannot be directly eliminated physically. Therefore, the bare rod indicator diagram is used to correct the motor power diagram. While correcting the power diagram, the initial value of the intermittent pumping system, that is, the well stopping time t and the well opening time t', is also adjusted. Step S5, correcting the motor electrical power diagram according to the polished rod indicator diagram; Step S6, customizing the electric power diagram standard-reaching rate and the target value. If the electric power diagram standard-reaching rate is within the threshold range of the target value, it indicates that the intermittent pumping system is reasonable, and the beam pumping unit (2) can use the initial value of the intermittent pumping system as the intermittent pumping cycle to perform intermittent pumping. If the electric power diagram standard-reaching rate is outside the threshold range of the target value, it indicates that the intermittent pumping system is unreasonable, and the initial value of the intermittent pumping system is adjusted. Steps 2 to 6 are continuously repeated until the electric power diagram standard-reaching rate finally reaches the target value.

2. The control method of the intelligent intermittent pumping control system of an oil field beam pumping unit according to claim 1, characterized in that: The step S5 of correcting the motor electrical power diagram according to the polished rod indicator diagram is specifically as follows: Check the display (9), observe the relative positions of the bare rod indicator diagram and the motor electric power diagram in the display (9), and adjust the stroke S of the motor electric power diagram based on the bare rod indicator diagram so that the boundary points of the bare rod indicator diagram and the motor electric power diagram coincide with each other, and then remove the load displacement sensor (7) to complete the correction of the motor electric power diagram.

3. The control method of the intelligent intermittent pumping control system of an oil field beam pumping unit according to claim 1, characterized in that: Step S6 specifically includes: S601. The compliance rate of the electric power diagram is defined as the number of electric power diagrams with a fullness of ≥70% in the most recent intermittent period and the proportion of all electric power diagrams in the intermittent period. The fullness of the electric power diagram refers to the proportion of the electric power diagram and the bare rod indicator diagram in the same intermittent period; S602. The target value is 90% or more than the electric power diagram compliance rate or more than 70% in the most recent intermittent pumping cycle. If the electric power diagram compliance rate is within the threshold range of the target value, it indicates that the intermittent pumping system is reasonable, and the beam pumping unit (2) can use the initial value of the intermittent pumping system as the intermittent pumping cycle for intermittent pumping oil production; S603. If the compliance rate of the electric power diagram is outside the threshold range of the target value, it indicates that the intermittent extraction system is unreasonable. Adjust the initial value of the intermittent extraction system within a floating range of ±5%, and repeat steps 2 to 6 continuously to make the compliance rate of the electric power diagram fluctuate within the range of ±5% until the compliance rate of the electric power diagram finally reaches the target value.

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