Beam-pumping unit balance adjusting method and balance testing device

Abstract

The invention relates to a beam-pumping unit balance adjusting method and a balance testing device. The problem that an existing pumping unit balance adjusting method is inaccurate in calculation is mainly solved. The method is characterized by comprising the following steps: testing power data of the oil pumping unit in one period; carrying out filtering processing on the power data by adopting a fast Fourier transform method; the balance degree of the beam-pumping unit is calculated, and whether balance needs to be adjusted or not is analyzed according to the balance degree; and substituting the power data into a balance block adjustment amount formula, and calculating the balance block adjustment amount. The balance adjustment method of the beam-pumping unit solves the problems of false balance and unreasonable balance adjustment caused by inaccurate balance test of the pumping unit due to negative work of the pumping unit under a frequency conversion condition.

Description

Technical Field

[0001] The invention relates to the field of oil field pumping units, in particular to a balance adjustment method and a balance testing device for a beam pumping unit. Background Art

[0002] The imbalance of the pumping well can easily cause the oil well to be overloaded. Long-term imbalance can cause a variety of adverse consequences such as broken belts, broken sucker rods, and burned motors. Therefore, the balance of the pumping unit is directly related to the service life and system efficiency of the pumping unit. At present, the main method for testing the balance of the pumping unit in China is to use a clamp ammeter to measure the current peak value in the upper and lower strokes of the motor, and use the smaller of the two to compare with the larger one, and the ratio is used as the balance rate. This method is quite different from the definition of the actual balance of the pumping unit. For some seriously unbalanced wells, the current in the lower stroke (or upper stroke) has reversed in phase to become a current that does negative work, but the clamp ammeter cannot distinguish the phase of the current and still treats it as a current that does positive work, resulting in a false balance problem. Moreover, with the popularization and promotion of frequency converters in oil fields, more and more frequency conversion control cabinets are used in beam pumping units. Due to the influence of the frequency converter, the current value measured by the clamp ammeter at the input end under the condition of negative work of the pumping unit is zero, and the actual current of the pumping unit cannot be tested, which will also lead to problems such as inaccurate balance calculation. Summary of the invention

[0003] In order to overcome the shortcomings of inaccurate calculation of existing pumping unit balance adjustment methods, the present invention provides a beam pumping unit balance adjustment method and a balance testing device, which solves the problem of false balance and unreasonable balance adjustment caused by inaccurate balance test of the pumping unit due to negative work of the pumping unit under variable frequency conditions.

[0004] The technical solution of the present invention is: a method for balancing a beam pumping unit, comprising:

[0005] S1. Test the power data of the oil pump in one cycle;

[0006] S2, filtering the power data using the fast Fourier transform method;

[0007] S3. Calculate the balance of the beam pumping unit and analyze whether the balance needs to be adjusted based on the balance;

[0008] S4. Substitute the power data into the balance block adjustment formula to calculate the balance block adjustment.

[0009] Further, the power P(t) after filtering in step S2 is:

[0010]

[0011] Where: ω is the angular velocity of the crankshaft; a 0is the average power value of one cycle of the power curve; a n is the cosine component of each harmonic of the power curve; b n It is the sinusoidal component of each harmonic of the power curve.

[0012] Furthermore, the angular velocity ω of the crankshaft and the average power value a of one cycle of the power curve are 0 , the cosine component a of each harmonic of the power curve n , the sinusoidal component b of each harmonic of the power curve n They are:

[0013]

[0014]

[0015]

[0016]

[0017] Where: T is the stroke period, s; ​​N is the stroke frequency, 1 / min; ω is in rad / s; a 0 、a n 、b n The unit is kW.

[0018] Further, in step S3, the balance formula of the beam pumping unit is:

[0019]

[0020] Where, η is the balance degree of the beam pumping unit, %; W 下 is the work done by the motor in the down stroke, kN; W 上 is the work done by the motor on the upstroke, kN.

[0021] Furthermore, when the balance degree η of the oil pump is between 90% and 110%, no balance adjustment is required.

[0022] Further, in step S4, the balancing block adjustment amount is

[0023]

[0024] Where, ΔL is the displacement of the balance block, m; ω is the crank angular velocity, rad / s; G is the total weight of the balance block, kN; b 1 is the first-order sinusoidal component of each harmonic of the power curve, kW;

[0025] When the sign is positive, it means that the balance weight needs to be moved away from the crankshaft, and when the sign is negative, it means that the balance weight needs to be moved closer to the crankshaft;

[0026] in

[0027]

[0028] A beam pumping unit balance test device comprises a current transformer, a voltage transformer, an electric parameter data acquisition module, a data processing module and a display module; the current transformer and the voltage transformer are connected to the electric parameter data acquisition module, the electric parameter data acquisition module is connected to the data processing module, and the data processing module is connected to the display module.

[0029] Furthermore, the current transformer includes a current transformer A and a current transformer B, wherein the current transformer A is used to test the single-phase current at the input end of the inverter, and the current transformer B is used to test the single-phase current at the output end of the inverter; the voltage transformer includes a voltage transformer A and a voltage transformer B, wherein the voltage transformer A is used to test the voltage at the input end of the inverter, and the voltage transformer B is used to test the voltage at the output end of the inverter.

[0030] Furthermore, the data processing module includes a filtering unit, a balance calculation unit, a balance adjustment unit and a communication unit, and the communication mode of the communication unit is Bluetooth transmission or WiFi transmission.

[0031] The present invention has the following beneficial effects: due to the adoption of the above scheme, it is possible to effectively test the complete power curve data when the walking beam oil pumping unit has negative work under the working frequency and variable frequency conditions, and use the upper and lower stroke work to calculate the balance degree, so that the balance degree calculation is more accurate, and the problem of false balance caused by using the current method balance degree is avoided; the balance adjustment method of the present invention is based on the minimum root mean square power principle of the oil pumping unit, and the adjustment position of the balance block of the oil pumping unit is calculated, and the accurate balance weight adjustment position size can be given; the present invention can be applicable to conventional walking beam oil pumping units, out-of-phase oil pumping units, downward-biased barbell oil pumping units, double donkey head oil pumping units, low-profile oil pumping units and other models. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a flow chart of the balance adjustment method of the present invention;

[0033] Figure 2 is a schematic diagram of a balance test device in the present invention;

[0034] Figure 3 It is a power curve diagram tested in the embodiment. DETAILED DESCRIPTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings:

[0036] Depend on Figure 1 As shown, a method for balancing a beam pumping unit includes:

[0037] S1. Test the complete power data P of the oil pump in one cycle 0 (t).

[0038] S2. Power data P 0 (t) is filtered using the fast Fourier transform method, and the processed power data P(t) is:

[0039]

[0040] Where: ω is the angular velocity of the crankshaft; a 0 is the average power value of one cycle of the power curve; a n is the cosine component of each harmonic of the power curve; b n It is the sinusoidal component of each harmonic of the power curve.

[0041] The angular velocity ω of the crankshaft and the average power value a of one cycle of the power curve 0 , the cosine component a of each harmonic of the power curve n , the sinusoidal component b of each harmonic of the power curve n They are:

[0042]

[0043]

[0044]

[0045]

[0046] Where: T is the stroke period, s; ​​N is the stroke frequency, 1 / min; ω is in rad / s; a 0 、a n 、b n The unit is kW.

[0047] S3. Calculate the balance of the beam pumping unit and analyze whether the balance needs to be adjusted based on the balance. The balance formula of the beam pumping unit is:

[0048]

[0049] Where, η is the balance degree of the beam pumping unit, %; W 下 is the work done by the motor in the down stroke, kN; W 上 is the work done by the motor on the upstroke, kN.

[0050] When the balance degree η of the oil pump is between 90% and 110%, no balance adjustment is required.

[0051] S4. Substitute the power data into the balance block adjustment formula to calculate the balance block adjustment.

[0052] The balance block adjustment amount is

[0053]

[0054] Where, ω is the crank angular velocity, rad / s; G is the total weight of the balance block, kN; b 1 is the first-order sinusoidal component of each harmonic of the power curve, kW; ΔL is the movement of the balance block, m; a positive sign indicates an outward movement, that is, the balance block needs to move away from the crankshaft, and a negative sign indicates an inward movement, that is, the balance block needs to move closer to the crankshaft.

[0055] in:

[0056]

[0057] Depend on Figure 2 As shown, a beam pumping unit balance test device includes a current transformer, a voltage transformer, an electric parameter data acquisition module, a data processing module and a display module; the current transformer and the voltage transformer are connected to the electric parameter data acquisition module, the electric parameter data acquisition module is connected to the data processing module, and the data processing module is connected to the display module.

[0058] The current transformer includes a current transformer A and a current transformer B, wherein the current transformer A is used to test the single-phase current at the input end of the inverter, and the current transformer B is used to test the single-phase current at the output end of the inverter; the voltage transformer includes a voltage transformer A and a voltage transformer B, wherein the voltage transformer A is used to test the voltage at the input end of the inverter, and the voltage transformer B is used to test the voltage at the output end of the inverter.

[0059] The data processing module includes a filtering unit, a balance calculation unit, a balance adjustment unit and a communication unit, and the communication mode of the communication unit is Bluetooth transmission or WiFi transmission.

[0060] Embodiment 1:

[0061] Take X1 well as an example. This well is a beam pumping well. There are 4 balancing blocks, each weighing 1000Kg. The stroke cycle is 8.32s, and the stroke frequency is 7.21 times / min. The average center of gravity is at 1.30m. The power curve is as follows: Figure 3 As shown, the power curve data is calculated according to the balance calculation formula to obtain a balance degree of 125% for the pumping unit, and the movement amount of the balance block is calculated by the balance block adjustment amount formula to obtain a balance amount of ΔL=-0.28m.

Claims

1. A method for balancing a beam pumping unit, characterized in that: S1. Test the power data of the oil pump in one cycle; S2, filtering the power data using the fast Fourier transform method; S3. Calculate the balance of the beam pumping unit and analyze whether the balance needs to be adjusted based on the balance; S4. Substitute the power data into the balance block adjustment formula to calculate the balance block adjustment.

2. The beam pumping unit balancing adjustment method according to claim 1, characterized in that: The power P(t) after filtering in step S2 is: Where: ω is the angular velocity of the crankshaft; a0 is the average power value of one cycle of the power curve; a n is the cosine component of each harmonic of the power curve; b n It is the sinusoidal component of each harmonic of the power curve.

3. The beam pumping unit balancing adjustment method according to claim 2, characterized in that: The angular velocity ω of the crankshaft, the average power value a0 of one cycle of the power curve, the cosine component a of each harmonic of the power curve n , the sinusoidal component b of each harmonic of the power curve n They are: Where: T is the stroke period, s; ​​N is the stroke frequency, 1 / min; ω is in rad / s; a0, a n , b n The unit is kW.

4. The beam pumping unit balancing adjustment method according to claim 1, characterized in that: In step S3, the balance formula of the beam pumping unit is: Where, η is the balance degree of the beam pumping unit, %; W 下 is the work done by the motor in the down stroke, kN; W 上 is the work done by the motor on the upstroke, kN.

5. The beam pumping unit balancing adjustment method according to claim 6, characterized in that: When the balance degree η of the oil pump is between 90% and 110%, no balance adjustment is required.

6. The beam pumping unit balance adjustment method according to claim 5, characterized in that: In step S4, the balance block adjustment amount is Where, ΔL is the movement of the balance block, m; ω is the crank angular velocity, rad / s; G is the total weight of the balance block, kN; b1 is the first-order sinusoidal component of each harmonic of the power curve, kW; When the sign is positive, it means that the balance weight needs to be moved away from the crankshaft, and when the sign is negative, it means that the balance weight needs to be moved closer to the crankshaft; in 7. A beam pumping unit balance test device, characterized in that: It includes a current transformer, a voltage transformer, an electric parameter data acquisition module, a data processing module and a display module; the current transformer and the voltage transformer are connected to the electric parameter data acquisition module, the electric parameter data acquisition module is connected to the data processing module, and the data processing module is connected to the display module.

8. The beam pumping unit balance test device according to claim 7, characterized in that: The current transformer includes a current transformer A and a current transformer B, wherein the current transformer A is used to test the single-phase current at the input end of the inverter, and the current transformer B is used to test the single-phase current at the output end of the inverter; the voltage transformer includes a voltage transformer A and a voltage transformer B, wherein the voltage transformer A is used to test the voltage at the input end of the inverter, and the voltage transformer B is used to test the voltage at the output end of the inverter.

9. The beam pumping unit balance test device according to claim 8, characterized in that: The data processing module includes a filtering unit, a balance calculation unit, a balance adjustment unit and a communication unit, and the communication mode of the communication unit is Bluetooth transmission or WiFi transmission.

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