Implementation method for constructing electrical indicator diagram based on electrical parameter data of oil pumping unit

Abstract

The invention relates to the technical field of oil exploitation equipment, in particular to an implementation method for constructing an electrical indicator diagram based on electrical parameter data of a pumping unit. The technical problems are as follows: an actual measurement indicator diagram device in the prior art is under the action of periodic alternating load for a long time and is easy to break down; according to the technical scheme, the implementation method for constructing the electrical indicator diagram based on the electrical parameter data of the oil pumping unit comprises the steps that collected power and angular displacement data are substituted into a fitted torque curve formula for calculation, and an indicator diagram is obtained; compared with an actual measurement indicator diagram device in the prior art, which is under the action of periodic alternating load for a long time and is easy to generate faults, the suspension point indicator diagram is indirectly calculated by measuring the electrical parameters of the pumping unit motor and walking beam rotation angle data acquired by the attitude instrument, direct use of the actual measurement device is avoided, and the cost is reduced. Therefore, the efficiency and the accuracy of obtaining the indicator diagram are obviously improved; as the measurement of the electrical parameters and the rotation angle data is relatively stable and reliable, the repeatability of the indicator diagram is also improved.

Description

Technical Field

[0001] The invention relates to the technical field of oil production equipment, and in particular to a method for implementing an electric power diagram based on electrical parameter data of an oil pumping unit. Background Art

[0002] The dynamometer diagram of a well pumping unit is an important representation of the working status of the well pumping unit. It can fully reflect the operation of the well pump and the working status of the well. However, since the dynamometer diagram device is under the effect of periodic alternating load for a long time, it is easy to cause failure, which in turn affects the field operation.

[0003] Therefore, in response to the above problems, a method for indirectly obtaining the suspension point dynamometer diagram from the measured motor power and attitude meter data is proposed. The suspension point dynamometer diagram is indirectly calculated by measuring the electrical parameters of the pumping unit motor and the walking beam angle data obtained by the attitude meter, avoiding the direct use of the actual measuring device, thereby significantly improving the efficiency and accuracy of obtaining the dynamometer diagram. At the same time, since the measurement of the electrical parameters and the angle data is relatively stable and reliable, the repeatability of the dynamometer diagram is also improved. Summary of the invention

[0004] In order to overcome the problem that the actual measuring indicator diagram device under the existing technology is under the action of periodic alternating load for a long time, it is easy to cause failure, which in turn affects the on-site operation.

[0005] The technical solution of the present invention is: a method for constructing an electric power diagram based on electrical parameter data of an oil pump, comprising the following steps:

[0006] S1: Measure the input and output electrical parameters of the pumping unit motor to obtain the motor loss and input power;

[0007] S2: Obtain the beam angle data of the pumping unit through the attitude meter and convert it into corresponding crank angle and displacement data;

[0008] S3: Analyze the relationship between crank angle and suspension point load according to the relevant parameters of the pumping unit.

[0009] S4: fitting and analyzing the acquired electrical parameters, crank angle and displacement data, and the torque relationship between the suspension point load and the crank shaft to obtain a torque curve representing the current well;

[0010] S5: When new power and angular displacement data are collected, they are substituted into the fitted torque curve formula for calculation to obtain the power diagram.

[0011] Preferably, the step of measuring the electrical parameters of the input and output ends of the pumping unit motor further includes measuring the loss of the motor during the energy conversion process using a special electrical parameter measuring device, and the loss is only related to the input power; the specific steps are as follows:

[0012] S101: Start the electrical parameter measuring device and ensure that it is correctly connected to the input and output terminals of the pumping unit motor;

[0013] S102: Setting parameters of the measuring device, including sampling frequency and measuring range;

[0014] S103: starting the motor and making it run in a normal working state, and at the same time using a measuring device to collect the input voltage, input current, output voltage, and output current parameters of the motor in real time;

[0015] S104: Calculating the input power and output power of the motor and the loss of the motor during energy conversion according to the collected electrical parameters; wherein the loss calculation can be derived according to the working principle of the motor and the law of conservation of energy, and the loss is only related to the input power;

[0016] S105: storing and recording the calculated loss value and input power value.

[0017] Preferably, in step S104, the input power and output power of the motor, as well as the loss of the motor during energy conversion are calculated based on the collected electrical parameters; wherein the motor input power is P 1 When the motor is running, the energy loss of the motor stator copper loss, exciter iron loss, rotor copper loss and no-load loss is η 1 , the power output by the motor and input to the transmission belt is P 1 η 1 The energy loss of the belt bending loss and elastic sliding loss of the transmission belt is η 2 The power output from the transmission belt and input to the reduction box is P 1 η 1 η 2 , the energy loss of the reduction gearbox bearing friction loss and gear meshing loss is η 3 The power output from the reduction gearbox and input to the four-bar linkage is P 1 η 1 η 2 η 3 , the energy loss of the potential energy change of the four-bar linkage, the bearing friction loss and the wire rope deformation loss is η 4 , the suspension power output of the four-bar linkage is P 1 η 1 η 2 η 3 η 4 -P 1 .

[0018] Preferably, the step of obtaining the walking beam angle data of the pumping unit through the attitude meter further includes using a high-precision attitude meter to obtain the walking beam angle data in real time, and converting the walking beam angle and crank angle data into crank angle and displacement data through a mathematical model between the walking beam angle and the crank angle; the specific steps are as follows:

[0019] S201: Correctly install the high-precision attitude meter on the walking beam of the pumping unit or the position that can accurately reflect the walking beam rotation angle;

[0020] S202: Start the attitude meter and perform initialization calibration;

[0021] S203: The attitude instrument will output the angle data of the walking beam at the current moment in real time, record the angle data, and add a time stamp;

[0022] S204: Filter the acquired beam angle data to remove noise and abnormal values;

[0023] S205: establishing a mathematical model between a beam angle and a crank angle according to the mechanical structure and kinematics principle of the pumping unit;

[0024] S206: Substituting the pre-processed beam angle data into the mathematical model to calculate the corresponding crank angle;

[0025] S207: Calculate the displacement of the crank by using the crank length and the crank angle, and calculate the displacement components of the crank on the x-axis and the y-axis according to the crank angle using trigonometric functions and the crank length;

[0026] S208: Compare the calculation result with the actual operating state of the pumping unit. If a large error is found, return to step S205 to adjust the mathematical model and calculation parameters.

[0027] S209: Timestamp the calculated crank angle and displacement data and store them in a database.

[0028] Preferably, in step S205, a mathematical model between a beam angle and a crank angle is established according to the mechanical structure and kinematics principle of the pumping unit; wherein the beam angle is defined as the rotation angle of the beam relative to the vertical position of the frame, and the crank angle is defined as the rotation angle of the crank relative to its initial position. According to the kinematics principle of the four-bar linkage, the relationship between the beam angle and the crank angle can be established by the following steps:

[0029] S2051: Determine the dimensions of the connecting rod mechanism, including the crank length, connecting rod length, beam length, and the locations of the connection points between them;

[0030] S2052: Based on the geometric constraints of the four-bar linkage to maintain a closed quadrilateral during movement, the mathematical relationship between the beam angle and the crank angle is established through the constraint conditions;

[0031] S2053: Through geometric analysis and trigonometric calculation, the mathematical relationship between the beam angle and the crank angle is derived; the specific formula is as follows:

[0032] θ L =n×θ C +θ 0 ;

[0033] Among them, θ L is the beam rotation angle, θ C is the crank angle, θ 0 is the initial offset angle, and n is the proportional coefficient between the beam angle and the crank angle.

[0034] Preferably, the step of analyzing the relationship between the crank angle and the suspension point load further includes analyzing using a mathematical model according to structural characteristics of the oil pump to obtain an accurate relationship between the crank angle and the suspension point load.

[0035] As a preferred method, a mathematical model is used to analyze and obtain the precise relationship between the crank angle and the suspension point load; wherein the suspension point load generates a polished rod load torque T on the crankshaft. rod The torque T of the reducer output reducer , beam balance torque T balance And the unbalanced torque T of the pumping unit itself imbalance The sum is equal; the specific steps are as follows:

[0036] S301: Define torque factor: Torque factor K torque Defined as the polished rod torque and the suspension point load F suspension The ratio is:

[0037] K torque =T rod / F suspension ;

[0038] Among them, this factor is used to reflect the linear relationship between the suspension point load and the polished rod torque;

[0039] S302: Establish the relationship between displacement and torque factor, suspension point displacement x and torque factor K torque The specific relationship formula is as follows:

[0040] K torque =f(x);

[0041] S303: Analyze the relationship between the crank angle and the displacement. There is a one-to-one correspondence between the crank angle and the suspension point displacement. This relationship is specifically expressed as follows:

[0042] x=g(θ C );

[0043] Among them, g(θ C ) is a function of the crank angle, and its specific form depends on the geometric structure and kinematic parameters of the pumping unit;

[0044] S304: Solve the simultaneous equations to obtain the relationship between the crank angle and the suspension point load.

[0045] Preferably, the specific steps of solving the simultaneous equations in step S304 to obtain the relationship between the crank angle and the suspension point load are as follows:

[0046] S3041: Combine the relationship formulas in S301 and S302 to obtain the relationship between the crank angle and the suspension point load; the relationship formula is as follows:

[0047] K torque =f(g(θ C ));

[0048] S3042: Due to K torque =T rod / F suspension , thus further obtaining the following formula:

[0049] T rod =F suspension ×f(g(θ C )), the precise relationship between the crank angle and the suspension point load is obtained.

[0050] Preferably, in step S4, the acquired electrical parameters, crank angle and displacement data, and the torque relationship between the suspension point load and the crankshaft are fitted and analyzed to obtain a torque curve representing the current well; the steps are as follows:

[0051] S401: Establishing a mathematical model between electrical parameters, crank angle and displacement, suspension point load and torque; the model includes a motor energy conversion model, a four-bar linkage kinematic model, and a torque factor and displacement relationship model;

[0052] S402: fitting the preprocessed data into the established mathematical model using a least squares fitting method;

[0053] S403: Calculating a torque curve according to the model parameters obtained by fitting and the input data; wherein the torque curve is a curve representing the relationship between the crank angle and the torque, and is used to reflect the torque change of the pumping unit during operation;

[0054] S404: Output torque curve.

[0055] Preferably, in step S401, a mathematical model between electrical parameters, crank angle and displacement, suspension point load and torque is established; specifically, the following steps are included:

[0056] S4011: Build a motor energy conversion model, including:

[0057] Through the input voltage V in and input current I in Calculate the motor input power P in ; The calculation formula is as follows:

[0058] P in =V in ×I in ;

[0059] Calculate the motor output power P based on the motor efficiency η out ; The calculation formula is as follows:

[0060] P out =η×P in ;

[0061] The motor loss is calculated based on the motor output power and the motor input power as the difference between the input power and the output power; the specific expression is as follows:

[0062] P loss =P in -P out ;

[0063] S4012: Establish a kinematic model of a four-bar linkage, including:

[0064] According to the crank angle θ C , determine the position of the crank; determine the position of the connecting rod and the walking beam through geometric relationships;

[0065] In a four-bar linkage, multiple triangles are formed between the bars. Apply the cosine theorem, sine theorem and trigonometric function relationships to establish equations that describe the lengths and angles of the sides of these triangles.

[0066] Through the above equations, a set of nonlinear equations are established to describe the kinematic characteristics of the four-bar linkage; these equations will include the rocker angle θ yb As the unknown variable; use the numerical iteration method to solve the nonlinear equation, for each given crank angle θ C , iterative solution to obtain the corresponding beam angle θ yb ;

[0067] By numerically solving the C and θyb The corresponding value of θ is obtained by curve fitting to obtain an approximate polynomial function to describe θ C and θ yb The specific relationship formula is as follows:

[0068]

[0069] Among them, a 0 , a 1 , a 2 , a 3 , ... are the coefficients obtained by fitting;

[0070] S4013: Establish a torque factor and displacement relationship model, including:

[0071] Through the torque factor k t Indicates the suspension load F δ The torque T generated by the crankshaft C The specific relationship formula is as follows:

[0072] T C =k t ×F δ ;

[0073] Torque factor k t It may vary with the suspension point displacement x, expressed as: k t =f(x); where f(x) is a function of the suspension point displacement x;

[0074] In step S403, torque curve calculation is performed; the specific steps are as follows:

[0075] S4031: Acquire input data, including power data and angular displacement data;

[0076] S4032: Calculate the suspension load F using the four-bar linkage kinematic model and input data δ ;

[0077] S4033: Calculate the torque factor k based on the torque factor and displacement relationship model t ;

[0078] S4034: Use torque factor k t and the suspension load F δ Calculate the torque T generated by the crankshaft C ;

[0079] S4035: Plot the calculated torque value and the corresponding crank angle into a graph to obtain a torque curve.

[0080] Beneficial effects of the present invention:

[0081] 1. Compared with the actual measurement dynamometer device under the prior art, which is under the effect of periodic alternating load for a long time, it is easy to cause failure, which in turn affects the on-site operation; the present invention indirectly calculates the suspension point dynamometer by measuring the electrical parameters of the pumping unit motor and the beam angle data obtained by the attitude meter, avoiding the direct use of the actual measurement device, thereby significantly improving the acquisition efficiency and accuracy of the dynamometer; at the same time, since the measurement of the electrical parameters and the angle data is relatively stable and reliable, the repeatability of the dynamometer is also improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] Figure 1 What is shown is a schematic diagram of energy loss of a pumping unit system according to a method for implementing the present invention of constructing an electric power diagram based on the electrical parameter data of the pumping unit;

[0083] Figure 2 Shown is a schematic diagram of energy conversion of an oil pumping unit motor according to a method for implementing the electric power diagram based on the electric parameter data of the oil pumping unit of the present invention;

[0084] Figure 3 What is shown is a schematic diagram of the transmission efficiency of the mechanical part of the oil pumping unit according to the implementation method of the present invention for constructing an electric power diagram based on the electrical parameter data of the oil pumping unit;

[0085] Figure 4 Shown is a schematic diagram of the analysis of pumping unit data for realizing the method of constructing an electric power diagram based on the electrical parameter data of the pumping unit according to the present invention;

[0086] Figure 5 What is shown is a schematic diagram of the relationship between the crank angle and the displacement of the method for constructing an electric power diagram based on the electrical parameter data of the oil pumping unit according to the present invention;

[0087] Figure 6 The diagram shows the relationship between attitude meter data, crank angle and displacement of the method for constructing an electric power diagram based on the electrical parameter data of the oil pumping unit according to the present invention;

[0088] Figure 7 The diagram shows the relationship between displacement and torque factor in the method for constructing an electric power diagram based on the electrical parameter data of the oil pumping unit according to the present invention;

[0089] Figure 8 Shown is a schematic diagram of the relationship between the rotation angle and the torque factor of the method for constructing an electric power diagram based on the electrical parameter data of the oil pumping unit according to the present invention;

[0090] Fig. 9 The diagram shows a schematic flow chart of the steps of the method for constructing an electric power diagram based on the electrical parameter data of the oil pumping unit according to the present invention;

[0091] Fig.10 What is shown is a schematic diagram comparing the measured power diagram and the calculated power diagram of an implementation method of the present invention for constructing an electric power diagram based on electrical parameter data of an oil pumping unit. DETAILED DESCRIPTION

[0092] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0093] See also Figure 1-10 The present invention provides an embodiment: a method for constructing an electric power diagram based on electrical parameter data of a pumping unit, comprising the following steps:

[0094] S1: Measure the input and output electrical parameters of the pumping unit motor to obtain the motor loss and input power;

[0095] S2: Obtain the beam angle data of the pumping unit through the attitude meter and convert it into corresponding crank angle and displacement data;

[0096] S3: Analyze the relationship between crank angle and suspension point load according to the relevant parameters of the pumping unit.

[0097] S4: fitting and analyzing the acquired electrical parameters, crank angle and displacement data, and the torque relationship between the suspension point load and the crank shaft to obtain a torque curve representing the current well;

[0098] S5: When new power and angular displacement data are collected, they are substituted into the fitted torque curve formula for calculation to obtain the power diagram.

[0099] Preferably, the step of measuring the electrical parameters of the input and output ends of the pumping unit motor further includes measuring the loss of the motor during the energy conversion process using a special electrical parameter measuring device, and the loss is only related to the input power; the specific steps are as follows:

[0100] S101: Start the electrical parameter measuring device and ensure that it is correctly connected to the input and output terminals of the pumping unit motor;

[0101] S102: Setting parameters of the measuring device, including sampling frequency and measuring range;

[0102] S103: starting the motor and making it run in a normal working state, and at the same time using a measuring device to collect the input voltage, input current, output voltage, and output current parameters of the motor in real time;

[0103] S104: Calculating the input power and output power of the motor and the loss of the motor during energy conversion according to the collected electrical parameters; wherein the loss calculation can be derived according to the working principle of the motor and the law of conservation of energy, and the loss is only related to the input power;

[0104] S105: storing and recording the calculated loss value and input power value.

[0105] Preferably, in step S104, the input power and output power of the motor, as well as the loss of the motor during energy conversion are calculated based on the collected electrical parameters; wherein the motor input power is P 1 When the motor is running, the energy loss of the motor stator copper loss, exciter iron loss, rotor copper loss and no-load loss is η 1 , the power output by the motor and input to the transmission belt is P 1 η 1 The energy loss of the belt bending loss and elastic sliding loss of the transmission belt is η 2 The power output from the transmission belt and input to the reduction box is P 1 η 1 η 2 , the energy loss of the reduction gearbox bearing friction loss and gear meshing loss is η 3 The power output from the reduction gearbox and input to the four-bar linkage is P 1 η 1 η 2 η 3 , the energy loss of the potential energy change of the four-bar linkage, the bearing friction loss and the wire rope deformation loss is η 4 , the suspension power output of the four-bar linkage is P 1 η 1 η 2 η 3 η 4 -P 1 .

[0106] Preferably, the step of obtaining the walking beam angle data of the pumping unit through the attitude meter further includes using a high-precision attitude meter to obtain the walking beam angle data in real time, and converting the walking beam angle and crank angle data into crank angle and displacement data through a mathematical model between the walking beam angle and the crank angle; the specific steps are as follows:

[0107] S201: Correctly install the high-precision attitude meter on the walking beam of the pumping unit or the position that can accurately reflect the walking beam rotation angle;

[0108] S202: Start the attitude meter and perform initialization calibration;

[0109] S203: The attitude instrument will output the angle data of the walking beam at the current moment in real time, record the angle data, and add a time stamp;

[0110] S204: Filter the acquired beam angle data to remove noise and abnormal values;

[0111] S205: establishing a mathematical model between a beam angle and a crank angle according to the mechanical structure and kinematics principle of the pumping unit;

[0112] S206: Substituting the pre-processed beam angle data into the mathematical model to calculate the corresponding crank angle;

[0113] S207: Calculate the displacement of the crank by using the crank length and the crank angle, and calculate the displacement components of the crank on the x-axis and the y-axis according to the crank angle using trigonometric functions and the crank length;

[0114] S208: Compare the calculation result with the actual operating state of the pumping unit. If a large error is found, return to step S205 to adjust the mathematical model and calculation parameters.

[0115] S209: Timestamp the calculated crank angle and displacement data and store them in a database.

[0116] Preferably, in step S205, a mathematical model between a beam angle and a crank angle is established according to the mechanical structure and kinematics principle of the pumping unit; wherein the beam angle is defined as the rotation angle of the beam relative to the vertical position of the frame, and the crank angle is defined as the rotation angle of the crank relative to its initial position. According to the kinematics principle of the four-bar linkage, the relationship between the beam angle and the crank angle can be established by the following steps:

[0117] S2051: Determine the dimensions of the connecting rod mechanism, including the crank length, connecting rod length, beam length, and the locations of the connection points between them;

[0118] S2052: Based on the geometric constraints of the four-bar linkage to maintain a closed quadrilateral during movement, the mathematical relationship between the beam angle and the crank angle is established through the constraint conditions;

[0119] S2053: Through geometric analysis and trigonometric calculation, the mathematical relationship between the beam angle and the crank angle is derived; the specific formula is as follows:

[0120] θ L =n×θ C +θ 0 ;

[0121] Among them, θ L is the beam rotation angle, θ C is the crank angle, θ 0 is the initial offset angle, and n is the proportional coefficient between the beam angle and the crank angle.

[0122] Preferably, the step of analyzing the relationship between the crank angle and the suspension point load further includes analyzing using a mathematical model according to structural characteristics of the oil pump to obtain an accurate relationship between the crank angle and the suspension point load.

[0123] As a preferred method, a mathematical model is used to analyze and obtain the precise relationship between the crank angle and the suspension point load; wherein the suspension point load generates a polished rod load torque T on the crankshaft. rod The torque T of the reducer output reducer , beam balance torque T balance And the unbalanced torque T of the pumping unit itself imbalance The sum is equal; the specific steps are as follows:

[0124] S301: Define torque factor: Torque factor K torque Defined as the polished rod torque and the suspension point load F suspension The ratio is:

[0125] K torque =T rod / F suspension ;

[0126] Among them, this factor is used to reflect the linear relationship between the suspension point load and the polished rod torque;

[0127] S302: Establish the relationship between displacement and torque factor, suspension point displacement x and torque factor K torque The specific relationship formula is as follows:

[0128] K torque =f(x);

[0129] S303: Analyze the relationship between the crank angle and the displacement. There is a one-to-one correspondence between the crank angle and the suspension point displacement. This relationship is specifically expressed as follows:

[0130] x=g(θ C );

[0131] Among them, g(θ C ) is a function of the crank angle, and its specific form depends on the geometric structure and kinematic parameters of the pumping unit;

[0132] S304: Solve the simultaneous equations to obtain the relationship between the crank angle and the suspension point load.

[0133] Preferably, the specific steps of solving the simultaneous equations in step S304 to obtain the relationship between the crank angle and the suspension point load are as follows:

[0134] S3041: Combine the relationship formulas in S301 and S302 to obtain the relationship between the crank angle and the suspension point load; the relationship formula is as follows:

[0135] K torque =f(g(θ C ));

[0136] S3042: Due to Ktorque =T rod / F suspension , thus further obtaining the following formula:

[0137] T rod =F suspension ×f(g(θ C )), the precise relationship between the crank angle and the suspension point load is obtained.

[0138] Preferably, in step S4, the acquired electrical parameters, crank angle and displacement data, and the torque relationship between the suspension point load and the crankshaft are fitted and analyzed to obtain a torque curve representing the current well; the steps are as follows:

[0139] S401: Establishing a mathematical model between electrical parameters, crank angle and displacement, suspension point load and torque; the model includes a motor energy conversion model, a four-bar linkage kinematic model, and a torque factor and displacement relationship model;

[0140] S402: fitting the preprocessed data into the established mathematical model using a least squares fitting method;

[0141] S403: Calculating a torque curve according to the model parameters obtained by fitting and the input data; wherein the torque curve is a curve representing the relationship between the crank angle and the torque, and is used to reflect the torque change of the pumping unit during operation;

[0142] S404: Output torque curve.

[0143] Preferably, in step S401, a mathematical model between electrical parameters, crank angle and displacement, suspension point load and torque is established; specifically, the following steps are included:

[0144] S4011: Build a motor energy conversion model, including:

[0145] Through the input voltage V in and input current I in Calculate the motor input power P in ; The calculation formula is as follows:

[0146] P in =V in ×I in ;

[0147] Calculate the motor output power P based on the motor efficiency η out ; The calculation formula is as follows:

[0148] P out =η×P in ;

[0149] The motor loss is calculated based on the motor output power and the motor input power as the difference between the input power and the output power; the specific expression is as follows:

[0150] P loss =P in -P out ;

[0151] S4012: Establish a kinematic model of a four-bar linkage, including:

[0152] According to the crank angle θ C , determine the position of the crank; determine the position of the connecting rod and the walking beam through geometric relationships;

[0153] In a four-bar linkage, multiple triangles are formed between the bars. Apply the cosine theorem, sine theorem and trigonometric function relationships to establish equations that describe the lengths and angles of the sides of these triangles.

[0154] Through the above equations, a set of nonlinear equations are established to describe the kinematic characteristics of the four-bar linkage; these equations will include the rocker angle θ yb As the unknown variable; use the numerical iteration method to solve the nonlinear equation, for each given crank angle θ C , iterative solution to obtain the corresponding beam angle θ yb ;

[0155] By numerically solving the C and θ yb The corresponding value of θ is obtained by curve fitting to obtain an approximate polynomial function to describe θ C and θ yb The specific relationship formula is as follows:

[0156]

[0157] Among them, a 0 , a 1 , a 2 , a 3 , ... are the coefficients obtained by fitting;

[0158] S4013: Establish a torque factor and displacement relationship model, including:

[0159] Through the torque factor k t Indicates the suspension load F δ The torque T generated by the crankshaft C The specific relationship formula is as follows:

[0160] T C =k t ×F δ ;

[0161] Torque factor k t It may vary with the suspension point displacement x, expressed as: k t =f(x); where f(x) is a function of the suspension point displacement x;

[0162] In step S403, torque curve calculation is performed; the specific steps are as follows:

[0163] S4031: Acquire input data, including power data and angular displacement data;

[0164] S4032: Calculate the suspension load F using the four-bar linkage kinematic model and input data δ ;

[0165] S4033: Calculate the torque factor k based on the torque factor and displacement relationship model t ;

[0166] S4034: Use torque factor k t and the suspension load F δ Calculate the torque T generated by the crankshaft C ;

[0167] S4035: Plot the calculated torque value and the corresponding crank angle into a graph to obtain a torque curve.

[0168] Example

[0169] Optionally, the Zhao 41-46 well in the Zhaoxian work area of ​​the fifth plant is selected as the experimental object. The pumping unit model used in the well is CYJ14-4.8-73HF. The purpose of this experiment is to indirectly calculate the suspension point indicator diagram by measuring the electrical parameters of the pumping unit motor and the walking beam angle data obtained by the attitude instrument, and compare it with the measured indicator diagram to verify the accuracy and feasibility of the present invention;

[0170] When measuring the input and output electrical parameters of the pumping unit motor, the following steps are included:

[0171] A101: Start the electrical parameter measuring device and ensure that it is correctly connected to the input and output terminals of the pumping unit motor;

[0172] A102: Set the parameters of the measuring equipment, including the sampling frequency of 100 Hz, the measuring range of 0-500 V voltage and 0-100 A current;

[0173] A103: Start the motor and make it run under normal working conditions, and use the measuring equipment to collect the motor's input voltage 220V, input current 50A, output voltage 200V, and output current 45A in real time;

[0174] A104: Calculate the motor input power P based on the collected electrical parameters in =220V×50A=11000W and output power P out =200V×45A=9000W, and the loss of the motor during energy conversion P loss =P in -P out =2000W;

[0175] A105: storing and recording the calculated loss value and input power value;

[0176] When obtaining the walking beam angle data of the pumping unit through the attitude meter, the following steps are included:

[0177] A201: Correctly install the high-precision attitude meter on the walking beam of the pumping unit;

[0178] A202: Start the attitude indicator and perform initial calibration;

[0179] A203: The attitude instrument outputs the beam angle data in real time, such as the angle is 30 degrees at a certain moment, and records the timestamp;

[0180] A204: filtering the obtained beam angle data to remove noise and abnormal values;

[0181] A205: According to the mechanical structure and kinematics principle of the pumping unit, a mathematical model between the beam angle and the crank angle is established. 游梁 = k × θ 曲柄 +θ 0 , where k is the proportionality coefficient, θ 0 is the initial offset angle;

[0182] A206: Calculate the corresponding crank angle, θ 曲柄 =(θ 游梁 -θ 0 ) / k 0 ;

[0183] A207: Calculate the crank displacement by crank length and crank angle, x = L × cos(θ 曲柄 ), y = L × sin(θ 曲柄 ), where L is the crank length;

[0184] A208: Compare the calculation results with the actual operating status of the pumping unit, and adjust the mathematical model and calculation parameters until the error meets the requirements;

[0185] A209: storing the calculated crank angle and displacement data;

[0186] When analyzing the relationship between crank angle and suspension point load, the specific steps are as follows:

[0187] A301: Define the torque factor K = T / F; where T is the polished rod torque and F is the suspension point load;

[0188] A302: Establish the relationship between displacement and torque factor K = a × x + b; where a and b are coefficients;

[0189] A303: Analyze the relationship between crank angle and displacement x = f (θ 曲柄 );

[0190] A304: Solve the simultaneous equations to obtain the relationship between the crank angle and the suspension point load F = g(θ 曲柄 );

[0191] When fitting and analyzing to obtain the torque curve, the specific steps are as follows:

[0192] A401: Establish mathematical models between electrical parameters, crank angle and displacement, suspension point load and torque;

[0193] A402: Fit the preprocessed data to a mathematical model using the least squares fitting method;

[0194] A403: Calculate the torque curve according to the fitted model parameters and input data;

[0195] A404: Output torque curve and compare it with the measured torque curve;

[0196] When new power and angular displacement data are collected, they are substituted into the fitted torque curve formula for calculation to obtain the power diagram, and the measured power diagram is compared with the calculated power diagram. Fig.10 As shown;

[0197] By comparing the measured dynamometer diagram of Zhao 41-46 well with the dynamometer diagram calculated by the present invention, it is found that the two are highly consistent in shape and trend, with an average error of 97%. The remaining 3% error may come from the accuracy limitation of the measuring equipment, the error caused by the simplification of the mathematical model, and the uncertain factors in the actual operation process, thereby verifying the accuracy and feasibility of the present invention.

[0198] In summary, the present invention successfully indirectly calculates the suspension point dynamometer diagram by measuring the electrical parameters of the pumping unit motor and the walking beam angle data obtained by the attitude meter, and compares and verifies it with the measured dynamometer diagram; experimental results show that the present invention has high accuracy and feasibility, and provides a new and effective method for obtaining the dynamometer diagram of the pumping unit well.

[0199] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of those skilled in the art without departing from the spirit of the present invention.

Claims

1. A method for constructing an electric power diagram based on electrical parameter data of a pumping unit; characterized in that: The following steps are included: S1: Measure the input and output electrical parameters of the pumping unit motor to obtain the motor loss and input power; S2: Obtain the beam angle data of the pumping unit through the attitude meter and convert it into corresponding crank angle and displacement data; S3: Analyze the relationship between crank angle and suspension point load according to the relevant parameters of the pumping unit. S4: fitting and analyzing the acquired electrical parameters, crank angle and displacement data, and the torque relationship between the suspension point load and the crank shaft to obtain a torque curve representing the current well; S5: When new power and angular displacement data are collected, they are substituted into the fitted torque curve formula for calculation to obtain the power diagram.

2. The method for constructing an electric power diagram based on electrical parameter data of a pumping unit according to claim 1, characterized in that: The step of measuring the electrical parameters of the input and output ends of the pumping unit motor further includes using a special electrical parameter measuring device to measure the loss of the motor during the energy conversion process, and the loss is only related to the input power; the specific steps are as follows: S101: Start the electrical parameter measuring device and ensure that it is correctly connected to the input and output terminals of the pumping unit motor; S102: Setting parameters of the measuring device, including sampling frequency and measuring range; S103: starting the motor and making it run in a normal working state, and at the same time using a measuring device to collect the input voltage, input current, output voltage, and output current parameters of the motor in real time; S104: Calculating the input power and output power of the motor and the loss of the motor during energy conversion according to the collected electrical parameters; wherein the loss calculation can be derived according to the working principle of the motor and the law of conservation of energy, and the loss is only related to the input power; S105: storing and recording the calculated loss value and input power value.

3. The method for constructing an electric power diagram based on the electrical parameter data of a pumping unit according to claim 2, characterized in that: In the step S104, the input power and output power of the motor and the loss of the motor in the energy conversion process are calculated according to the collected electrical parameters; wherein, the motor input power is P1, when the motor is running, the energy loss of the motor stator copper loss, exciter iron loss, rotor copper loss and no-load loss is η1, the power output by the motor and input to the transmission belt is P1η1, the energy loss of the belt bending loss and elastic sliding loss of the transmission belt is η2, the power output by the transmission belt and input to the reduction box is P1η1η2, the energy loss of the reduction box bearing friction loss and gear meshing loss is η3, the power output by the reduction box and input to the four-bar linkage is P1η1η2η3, the energy loss of the potential energy change of the four-bar linkage, the bearing friction loss and the deformation loss of the wire rope is η4, and the suspension point power output by the four-bar linkage is P1η1η2η3η4-P1.

4. The method for constructing an electric power diagram based on electrical parameter data of a pumping unit according to claim 1, characterized in that: The step of obtaining the walking beam angle data of the pumping unit through the attitude meter further includes using a high-precision attitude meter to obtain the walking beam angle data in real time, and converting the walking beam angle and crank angle data into crank angle and displacement data through a mathematical model between the walking beam angle and the crank angle; the specific steps are as follows: S201: Correctly install the high-precision attitude meter on the walking beam of the pumping unit or the position that can accurately reflect the walking beam rotation angle; S202: Start the attitude meter and perform initialization calibration; S203: The attitude instrument will output the angle data of the walking beam at the current moment in real time, record the angle data, and add a time stamp; S204: Filter the acquired beam angle data to remove noise and abnormal values; S205: establishing a mathematical model between a beam angle and a crank angle according to the mechanical structure and kinematics principle of the pumping unit; S206: Substituting the pre-processed beam angle data into the mathematical model to calculate the corresponding crank angle; S207: Calculate the displacement of the crank by using the crank length and the crank angle, and calculate the displacement components of the crank on the x-axis and the y-axis according to the crank angle using trigonometric functions and the crank length; S208: Compare the calculation result with the actual operating state of the pumping unit. If a large error is found, return to step S205 to adjust the mathematical model and calculation parameters. S209: Timestamp the calculated crank angle and displacement data and store them in a database.

5. The method for constructing an electric power diagram based on the electrical parameter data of a pumping unit according to claim 4 is characterized in that: In step S205, a mathematical model between the rocker angle and the crank angle is established according to the mechanical structure and kinematic principle of the oil pumping unit; wherein the rocker angle is defined as the rotation angle of the rocker relative to the vertical position of the frame, and the crank angle is defined as the rotation angle of the crank relative to its initial position. According to the kinematic principle of the four-bar linkage, the relationship between the rocker angle and the crank angle can be established by the following steps: S2051: Determine the dimensions of the connecting rod mechanism, including the crank length, connecting rod length, beam length, and the locations of the connection points between them; S2052: Based on the geometric constraints of the four-bar linkage to maintain a closed quadrilateral during movement, the mathematical relationship between the beam angle and the crank angle is established through the constraint conditions; S2053: Through geometric analysis and trigonometric calculation, the mathematical relationship between the beam angle and the crank angle is derived; the specific formula is as follows: i L =n×θ C +θ0; Among them, θ L is the beam rotation angle, θ C is the crank angle, θ0 is the initial offset angle, and n is the proportional coefficient between the beam angle and the crank angle.

6. The method for constructing an electric power diagram based on electrical parameter data of a pumping unit according to claim 1, characterized in that: The step of analyzing the relationship between the crank angle and the suspension point load further includes analyzing using a mathematical model according to the structural characteristics of the oil pump to obtain an accurate relationship between the crank angle and the suspension point load.

7. The method for constructing an electric power diagram based on the electrical parameter data of a pumping unit according to claim 6 is characterized in that: The mathematical model is used to analyze and obtain the precise relationship between the crank angle and the suspension point load. The suspension point load generates a rod load torque T on the crankshaft. rod The torque T of the reducer output reducer , beam balance torque T balance And the unbalanced torque T of the pumping unit itself imbalance The sum is equal; the specific steps are as follows: S301: Define torque factor: Torque factor K torque Defined as the polished rod torque and the suspension point load F suspension The ratio is: K torque =T rod / F suspension ; Among them, this factor is used to reflect the linear relationship between the suspension point load and the polished rod torque; S302: Establish the relationship between displacement and torque factor, suspension point displacement x and torque factor K torque The specific relationship formula is as follows: K torque =f(x); S303: Analyze the relationship between the crank angle and the displacement. There is a one-to-one correspondence between the crank angle and the suspension point displacement. This relationship is specifically expressed as follows: x=g(θ C ); Among them, g(θ C ) is a function of the crank angle, and its specific form depends on the geometric structure and kinematic parameters of the pumping unit; S304: Solve the simultaneous equations to obtain the relationship between the crank angle and the suspension point load.

8. The method for constructing an electric power diagram based on the electrical parameter data of a pumping unit according to claim 7, characterized in that: The specific steps of solving the simultaneous equations in step S304 to obtain the relationship between the crank angle and the suspension point load are as follows: S3041: Combine the relationship formulas in S301 and S302 to obtain the relationship between the crank angle and the suspension point load; the relationship formula is as follows: K torque =f(g(θ C )); S3042: Due to K torque =T rod / F suspension , thus further obtaining the following formula: T rod =F suspension ×f(g(θ C )), the precise relationship between the crank angle and the suspension point load is obtained.

9. The method for constructing an electrical work diagram based on electrical parameter data of a pumping unit according to claim 1, characterized in that: In step S4, the acquired electrical parameters, crank angle and displacement data, and the torque relationship between the suspension point load and the crankshaft are fitted and analyzed to obtain a torque curve representing the current well; the steps are as follows: S401: Establishing a mathematical model between electrical parameters, crank angle and displacement, suspension point load and torque; the model includes a motor energy conversion model, a four-bar linkage kinematic model, and a torque factor and displacement relationship model; S402: fitting the preprocessed data into the established mathematical model using a least squares fitting method; S403: Calculating a torque curve according to the model parameters obtained by fitting and the input data; wherein the torque curve is a curve representing the relationship between the crank angle and the torque, and is used to reflect the torque change of the pumping unit during operation; S404: Output torque curve.

10. The method for constructing an electric power diagram based on electrical parameter data of a pumping unit according to claim 9, characterized in that: In the step S401, a mathematical model between electrical parameters, crank angle and displacement, suspension point load and torque is established; specifically, the following steps are included: S4011: Build a motor energy conversion model, including: Through the input voltage V in and input current I in Calculate the motor input power P in ; The calculation formula is as follows: P in =V in ×I in ; Calculate the motor output power P based on the motor efficiency η out ; The calculation formula is as follows: P out =η×P in ; The motor loss is calculated based on the motor output power and the motor input power as the difference between the input power and the output power; the specific expression is as follows: P loss =P in -P out ; S4012: Establish a kinematic model of a four-bar linkage, including: According to the crank angle θ C , determine the position of the crank; determine the position of the connecting rod and the walking beam through geometric relationships; In a four-bar linkage, multiple triangles are formed between the bars. Apply the cosine theorem, sine theorem and trigonometric function relationships to establish equations that describe the lengths and angles of the sides of these triangles. Through the above equations, a set of nonlinear equations are established to describe the kinematic characteristics of the four-bar linkage; these equations will include the rocker angle θ yb As the unknown variable; use the numerical iteration method to solve the nonlinear equation, for each given crank angle θ C , iterative solution to obtain the corresponding beam angle θ yb ; By numerically solving the C and θ yb The corresponding value of θ is obtained by curve fitting to obtain an approximate polynomial function to describe θ C and θ yb The specific relationship formula is as follows: Among them, a0, a1, a2, a3, ... are the coefficients obtained by fitting; S4013: Establish a torque factor and displacement relationship model, including: Through the torque factor k t Indicates the suspension load F δ The torque T generated by the crankshaft C The specific relationship formula is as follows: T C =k t ×F δ ; Torque factor k t It may vary with the suspension point displacement x, expressed as: k t =f(x); where f(x) is a function of the suspension point displacement x; In step S403, torque curve calculation is performed; the specific steps are as follows: S4031: Acquire input data, including power data and angular displacement data; S4032: Calculate the suspension load F using the four-bar linkage kinematic model and input data δ ; S4033: Calculate the torque factor k based on the torque factor and displacement relationship model t ; S4034: Use torque factor k t and the suspension load F δ Calculate the torque T generated by the crankshaft C ; S4035: Plot the calculated torque value and the corresponding crank angle into a graph to obtain a torque curve.

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