Pumping unit effective stroke determination method based on indicator diagram characteristic analysis and application

Abstract

The invention provides a method for determining the effective stroke of an oil pumping unit based on indicator diagram feature analysis. The method mainly solves the problems that an existing method is sensitive to noise interference, large in calculation result deviation and poor in applicability. Comprising the following steps: S1, obtaining an effective indicator diagram data set; S2, obtaining a dimensionless indicator diagram data set; s3, calculating the top dead center of the plunger stroke; s4, on the basis of the normalized suspension center displacement sampling value and suspension center load sampling value, a plunger stroke bottom dead center, a fixed valve opening point and a traveling valve opening point are obtained; s5, the actual suspension point displacement and loads of the plunger stroke bottom dead center, the fixed valve opening point and the traveling valve opening point are reversely deduced respectively; s6, the effective stroke of the plunger is obtained; the effective stroke of the plunger can be used for calculating the liquid production capacity, the parameter adjustment coefficient and the stroke frequency after parameter adjustment of the oil pumping unit. According to the method, the indicator diagram valve opening and closing point of the oil pumping unit is detected in real time through indicator diagram feature analysis, and therefore the effective stroke of a plunger is determined.

Description

Technical Field

[0001] The present invention relates to the technical field of oil well oil measurement, and particularly to a method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of a dynamometer card and its application. Background Technique

[0002] With the vigorous development of digital oilfield construction in domestic oilfields, the requirements for the automatic acquisition and management of oil well production parameters are getting higher and higher. Through the real-time monitoring of parameters such as the load, stroke, and pumping frequency of the pumping unit, the real-time testing and acquisition of the dynamometer card are realized. At present, the traditional measurement methods at home and abroad are to transport the oil produced at each wellhead to the metering station for centralized metering. This measurement method has problems such as a large number of installed devices, a cumbersome technological process, and low real-time performance, and it is difficult to meet the development needs of intelligent oilfields. Under this demand, online oil measurement based on real-time tested dynamometer cards has become the main means to replace the oil measurement in the form of a metering station.

[0003] Whether the effective stroke of the plunger can be accurately determined is the key to the dynamometer card oil measurement technology. During the plunger stroke, due to the influence of various factors, part of the stroke is ineffective. The effective stroke of the plunger is determined by the opening and closing of the fixed valve and the traveling valve of the pumping unit at four key points. For the solution of the opening and closing points of the four valves, the curvature method is generally used in the industry at present. The curvature method has the advantages of simple calculation and good real-time performance in engineering applications, but at the same time, it also has the disadvantages of being sensitive to noise interference and having high requirements for the integrity of the dynamometer card. During the actual oilfield exploitation process, complex downhole conditions will lead to various forms of dynamometer cards. For some dynamometer cards with relatively severe load fluctuations and even the phenomenon of buckling, the calculation results of the curvature method have large deviations, and some cannot even be realized. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the problems in the background technique that the existing methods are sensitive to noise interference, have large calculation result deviations, and poor applicability, and to provide a method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of a dynamometer card. This method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of a dynamometer card can detect the characteristic points of the dynamometer card of the pumping unit in real time through the analysis of the characteristics of the dynamometer card, so as to determine the effective stroke of the plunger, which is not sensitive to noise interference, has small calculation result deviations, and has a wider range of applicable working conditions.

[0005] The present invention can achieve the above object through the following technical solutions: This method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of a dynamometer card includes the following steps:

[0006] S1: Collect the load and displacement data of the sucker rod of the pumping well to obtain an effective dynamometer card data set; S2: Normalize the effective dynamometer card data set and draw a closed polished rod dynamometer card image to obtain a dimensionless dynamometer card data set;

[0007] S3: Obtain the top dead center of the plunger stroke from the displacement change curve x of the effective dynamometer card dataset; S4: Based on the normalized polished rod displacement sampling values and polished rod load sampling values in the dimensionless dynamometer card dataset, obtain the bottom dead center of the plunger stroke, the fixed valve opening point, and the traveling valve opening point respectively;

[0008] S5: Denormalize the bottom dead center of the plunger stroke, the fixed valve opening point, and the traveling valve opening point calculated in step 4, and respectively reverse-deduce the actual polished rod displacement and load of the three points;

[0009] S6: Calculate the effective stroke of the plunger according to the top dead center of the plunger stroke in step 3 and the actual polished rod displacement and load values of the four points: the bottom dead center of the plunger stroke, the fixed valve opening point, and the traveling valve opening point in step 5.

[0010] Furthermore, the method for obtaining the effective dynamometer card dataset is as follows:

[0011] Collect the polished rod load and displacement data of the pumping well through the load sensor and displacement sensor installed on the pumping well; and perform abnormal data filtering processing on the collected data to obtain the effective dynamometer card dataset;

[0012] The effective dynamometer card dataset D:

[0013] D = {d i = (x i，j , y i，j )|i = 1, 2, 3,..., n; j = 1, 2, 3,..., m}

[0014] Where: d i represents the i-th group of pumping well dynamometer sampling data, with a total of n groups; each group of data contains m pairs of polished rod displacement and load sampling values (x i，j , y i，j ), x i，j represents the j-th polished rod displacement sampling value, and y i，j represents the j-th polished rod load sampling value.

[0015] Furthermore, the obtained dimensionless dynamometer card dataset D norm is:

[0016]

[0017] Where: represents the dynamometer card sample drawn from the i-th group of normalized pumping well dynamometer sampling data d, with a total of n; where x norm and y norm are the normalized polished rod displacement sampling value and polished rod load sampling value respectively.

[0018] Further, the method for obtaining the top dead center of the plunger stroke in step S3 is as follows:

[0019] For the displacement change curve x of the effective indicator diagram dataset, find the first derivative of the displacement with respect to time respectively to obtain the first derivative curve of the displacement with respect to time. Locate the intersection point of the first derivative and the time axis on the first derivative curve, that is, the point where the first derivative is 0. This point is the top dead center of the plunger stroke, which is also the vertex of the upward stroke. Denote this time point as t C , and denote the load and displacement at this time point as (x C , y C ).

[0020] Further, the method for separately obtaining the bottom dead center of the plunger stroke, the opening point of the fixed valve, and the opening point of the traveling valve in step S4 is as follows:

[0021] For the normalized polished rod displacement sampling values and polished rod load sampling values (x norm , y norm ), denote the load and displacement at the starting time point t 0 as which is the bottom dead center of the plunger stroke;

[0022] For the normalized polished rod displacement sampling sequence and polished rod load sampling sequence (x norm , y norm ), record the load and displacement at the starting sampling time point t 0 as which is the bottom dead center of the plunger stroke;

[0023] In the part where t 0 < t < t C , calculate and find the minimum value point from (xnoem, y norm ) to (0, y norm ). Denote the sampling point position of this point in the dimensionless displacement sequence as t B , and denote the load and displacement at this point as which is the opening point of the fixed valve; where: t C is the time series position corresponding to the point where the first derivative of the displacement change curve is 0.

[0024] In the part where t C < t < t Max , calculate and find the minimum value point from (x norm , y norm ) to (x norm , 0). Denote the sampling point position of this point in the dimensionless displacement sequence as t D , and denote the load and displacement at this point as which is the opening point of the traveling valve; where: t Max is the end point of the dimensionless displacement sequence.

[0025] Further, the formula for calculating the effective stroke S of the plunger in step S6 is as follows:

[0026] S pe = min{(x C - x B ), (x D - x A )}.

[0027] The present invention also provides an application of a method for determining the effective stroke of a pumping unit based on the analysis of the indicator diagram characteristics. The effective stroke of the plunger can be used to calculate the liquid production volume, the parameter adjustment coefficient, and the stroke frequency after parameter adjustment of the pumping unit.

[0028] Further, the formula for calculating the liquid production volume based on the effective stroke of the plunger is as follows:

[0029] Q = 1440N s A p S pe

[0030] In the formula, Ns is the actual stroke frequency of the pumping unit, min -1 ; Ap is the cross-sectional area of the plunger, m 2 ; Spe is the effective stroke of the plunger, m.

[0031] Further, the method for calculating the parameter adjustment coefficient:

[0032] Calculate the displacements between the lower dead point of the plunger stroke and the opening point of the traveling valve, and between the opening point of the fixed valve and the upper dead point of the plunger stroke respectively. The ratio of the two is the parameter adjustment coefficient I; the calculation formula is as follows:

[0033]

[0034] Further, the calculation method for the stroke frequency after parameter adjustment is: change the output stroke frequency of the pumping unit according to the parameter adjustment coefficient, and the calculation formula is as follows:

[0035] N x = I · N y

[0036] In the formula, Ny is the original stroke frequency, min -1 ; Nx is the stroke frequency after parameter adjustment, min -1 .

[0037] The present invention can have the following beneficial effects compared with the above background technology:

[0038] The present invention discloses an innovative method for determining the effective stroke of an oil pump, which is based on the characteristic analysis of the indicator diagram and aims to solve the challenges brought by the complexity and diversity of the actual downhole conditions in the oil field. It is not only applicable to the power diagram situation where the curvature method can normally determine the effective stroke, but also can accurately calculate the effective stroke of the oil pump well when facing the power diagram with various downhole conditions, different shapes and severe load fluctuations in the oil field. The uniqueness of this method lies in its versatility and wide applicability. Regardless of the power diagram form, the method can reliably perform characteristic analysis and accurately calculate the effective stroke. Its calculation process is simple and easy to operate, and can be applied in real time in oilfield engineering practice. This makes this method a reliable tool that provides solid technical support for power diagram oil measurement. Through the application of the present invention, oilfield engineers and researchers can more accurately understand the performance of oil wells, optimize production strategies, increase production, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Attached Figure 1 is a system flow chart of the method of the present invention;

[0040] Attached Figure 2 It is a dynamometer diagram after data preprocessing of a specific embodiment of the present invention;

[0041] Attached Figure 3 It is a normalized dynamometer diagram of a specific embodiment of the present invention;

[0042] Attached Figure 4 It is a schematic diagram of determining the top dead center of the plunger stroke by the first-order derivative in a specific embodiment of the present invention;

[0043] Attached Figure 5 This is a diagram of the valve opening and closing point search process according to a specific embodiment of the present invention;

[0044] Attached Figure 6 The result diagram of determining the opening and closing points of four valves for a specific embodiment of the present invention. Specific implementation method:

[0045] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0046] As attached Figure 1 As shown, the present invention discloses a method for determining the effective stroke of an oil pump based on characteristic analysis of an indicator diagram, comprising the following steps:

[0047] Step 1: The load sensor and displacement sensor installed on the pumping well are used to collect the load and displacement data of the pumping rod of the pumping well, and the abnormal data are filtered to obtain the effective dynamometer data set D:

[0048] D={d i =(x i，j ,yi，j )|i=1, 2, 3, ..., n; j=1, 2, 3, ..., m}

[0049] Where: d i represents the i-th group of pumping unit dynamometer sampling data, a total of n groups; each group of data contains m pairs of pumping unit suspension point displacement and load sampling values ​​(x i，j ,y i，j ), x i，j represents the jth suspension point displacement sampling value, y i，j Represents the jth suspension point load sampling value.

[0050] Step 2: Normalize the effective dynamometer data set and draw a closed bare rod dynamometer image to obtain the dimensionless dynamometer data set D norm :

[0051]

[0052] in: represents the sample of the dynamometer diagram drawn by the normalized sampling data d of the pumping unit dynamometer of the ith group, a total of n; where x norm and norm are the normalized suspension point displacement sampling values ​​and suspension point load sampling values ​​respectively.

[0053] Step 3: Calculate the first-order derivative of displacement with respect to time for the displacement change curve x of the effective dynamometer data set, and obtain the first-order derivative curve of displacement with respect to time. Find the intersection of the first-order derivative and the time axis on the first-order derivative curve, that is, the point where the first-order derivative is 0. This point is the top dead center of the plunger stroke, that is, the top of the upper punch. The point is at the t position of the time series position in x. C , the load and displacement of this point are recorded as (x C ,y C ).

[0054] Step 4: Normalize the suspension point displacement sampling value and suspension point load sampling value (x norm ,y norm ), record the starting time t 0 The load and displacement are It is the bottom dead center of the plunger stroke.

[0055] At time t 0 <t<t C Part, calculate and find (x norm ,y norm ) to (0, y norm ), and the sampling point position of this point in the dimensionless displacement sequence is t B , the load and displacement at this point are recorded as This is the fixed valve opening point.

[0056] At time t C <t<t Max Partial calculation to find (x norm ,y norm ) to (x norm , 0), and the sampling point position of this point in the dimensionless displacement sequence is t D , the load and displacement at this point are recorded as This is the opening point of the traveling valve.

[0057] Step 5: The plunger stroke bottom dead center and the two valve opening points calculated in step 4 are denormalized to invert the actual suspension point displacement and load (x A ,y A ), (x B ,y B ) and (x D ,y D ).

[0058] Step 6: According to the actual suspension point displacement and load value of the four characteristic points of the indicator diagram (the top dead center of the plunger stroke in step 3 and the bottom dead center of the plunger stroke in step 5 and the two valve opening points), the effective stroke S of the plunger is calculated as follows:

[0059] S pe =min{(x C -x B ), (x D -x A )}

[0060] The formula for calculating the liquid production based on the effective stroke of the plunger in step 6 is as follows:

[0061] Q=144N s A p S pe

[0062] Where Ns is the actual stroke frequency of the pumping unit, min -1 ; Ap is the plunger cross-sectional area, m 2 ; Spe is the effective stroke of the plunger, m.

[0063] Calculate the displacement between the bottom dead point of the plunger stroke and the opening point of the floating valve, and between the opening point of the fixed valve and the top dead point of the plunger stroke respectively. The ratio of the two is the parameter adjustment coefficient I. The calculation formula is as follows:

[0064]

[0065] According to the parameter adjustment coefficient, the pumping unit output stroke frequency is changed, and the calculation formula is as follows:

[0066] N x =I·Ny

[0067] Where Ny is the original impulse, min -1 ; Nx is the number of impulses after parameter adjustment, min -1 .

[0068] Example 1

[0069] The present invention is further described in detail below with reference to examples, and the implementation effect of the method on the effective stroke of a pumping well in the Daqing Oilfield Production Plant No. 1 is explained by a specific operation process. It should be understood that these embodiments are only used to illustrate the present invention and are not limited to the scope of the present invention.

[0070] The method for determining the effective stroke of an oil pumping unit based on the characteristic analysis of the indicator diagram of the present invention has the following specific implementation steps:

[0071] Step 1: The load sensor and displacement sensor installed on the pumping well are used to collect the load and displacement data of the pumping rod of the pumping well, and the abnormal data are filtered to obtain the effective dynamometer data set D, which is 4950 sets in total, and each set of data includes 200 sampling points:

[0072] D={d i =(x i，j ,y i，j )|i=1, 2, 3, ..., 4590; j=1, 2, 3, ..., 200}

[0073] Take the first set of valid data d of oil well No. 1 in the original data sample 1 For example, the original data function diagram is as follows Figure 2 shown.

[0074] d 1 =[(0, 23.0), (0, 23.3), (0.01, 25.0), ..., (0.01, 22.2), (0, 23.0)] 2×200

[0075] Step 2: Normalize the effective dynamometer data set and draw a closed bare rod dynamometer image to obtain the dimensionless dynamometer data set D norm , the normalized data work diagram is as follows Figure 3 shown.

[0076] Get the effective dynamometer data set D norm :

[0077]

[0078] First, the maximum load y of the pumping unit production parameters max =47.50kN is the maximum range of the longitudinal axis, with the maximum stroke xmax =2.33m is the maximum range of the horizontal axis to normalize the dynamometer data, converting the original data to the range of [0, 1]. The normalization results are as follows:

[0079]

[0080] d 1 and The conversion relationship is as follows:

[0081]

[0082] Step 3: Calculate the first-order derivative of displacement with respect to time for the displacement change curve x, and obtain the first-order derivative curve of displacement with respect to time, where the first-order derivative is represented by the following first-order derivative quotient difference:

[0083]

[0084] where f i represents the displacement of the ith point, and Δt represents the time interval.

[0085] Find the intersection of the first-order derivative and the time axis on the first-order derivative curve, that is, the point where the first-order derivative is 0, such as Figure 4 This point is the top dead center of the plunger stroke, that is, the top of the upward stroke. The time series position of this point in x is t C =100, the load and displacement at this point are recorded as (x C ,y C )=(2.33,45.10).

[0086] Step 4: Normalize the suspension point displacement sampling value and suspension point load sampling value (x norm ,y norm ), record the time point t 0 The load and displacement are This is the bottom dead center of the plunger stroke. Figure 5 As shown, at time t 0 <t<t C (ie 0 <t<100)的部分计算寻找(x norm ,y norm ) to (0, y norm ), and the position of this point in the dimensionless displacement sequence is t B =22, the load and displacement of this point are recorded as This is the fixed valve opening point. C <t<t Max (i.e. 101 <t<200)的部分计算寻找(x norm ,y norm ) to (x norm, 0), and the position of this point in the dimensionless displacement sequence is t D =150, the load and displacement at this point are recorded as This is the opening point of the traveling valve.

[0087] Step 5: The calculated plunger stroke bottom dead point and the two valve opening and closing points are denormalized. The denormalized conversion relationship is as follows:

[0088] (x i，j ,y i，j )=(x norm ,y norm )×(x max ,y max )

[0089] The actual suspension point displacement and load (x B ,y B )=(0.19,44.0)和(x D ,y D )=(1.33,18.80).

[0090] Step 6: The actual suspension point displacement and load values ​​of the four valve opening and closing points are as follows: Figure 6 As shown in the figure, the effective stroke S of the plunger is calculated based on the actual suspension point displacement and load value of the four valve opening and closing points as follows:

[0091] S pe =min{(x C -x B ), (x D -x A )}=min{(2.33-0.19), (1.33-0)}=1.33m

[0092] Step 7: The formula for calculating the liquid production based on the effective stroke of the plunger is as follows:

[0093] Q=1440N s A p S pe =1440×2.76×0.0015×1.33=7.8t / d

[0094] Where Ns is the actual stroke frequency of the pumping unit, min-1; Ap is the cross-sectional area of ​​the plunger, m 2 ; Spe is the effective stroke of the plunger, m.

[0095] Step 8: Calculate the displacement between the bottom dead point of the plunger stroke and the opening point of the floating valve, and the displacement between the opening point of the fixed valve and the top dead point of the plunger stroke. The ratio of the two is the parameter adjustment coefficient I. The calculation formula is as follows:

[0096]

[0097] Step 9: Change the pumping unit output stroke frequency according to the parameter adjustment coefficient. The calculation formula is as follows:

[0098] N x =I·N y =1.61×2.76=4.44

[0099] Where Ny is the original impulse, min -1 ; Nx is the number of impulses after parameter adjustment, min -1 .

[0100] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Therefore, the content of the present invention is not limited to the examples listed, and any equivalent changes taken by ordinary technicians in the field of the present invention by reading the specification of the present invention to the technical solution of the present invention are all covered by the claims of the present invention.

Claims

1. A method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of the indicator diagram, characterized in that: It includes the following steps: S1: Collect the load and displacement data of the sucker rod of the pumping well, and filter the abnormal data of the collected data to obtain an effective indicator diagram data set; S2: Normalize the effective indicator diagram data set to obtain a dimensionless indicator diagram data set; S3: Obtain the top dead center of the plunger stroke through the displacement change curve x of the effective indicator diagram data set; S4: Based on the polished rod displacement sampling value and the polished rod load sampling value of the dimensionless indicator diagram data, obtain the bottom dead center of the plunger stroke, the opening point of the fixed valve, and the opening point of the traveling valve respectively; S5: Denormalize the bottom dead center of the plunger stroke, the opening point of the fixed valve, and the opening point of the traveling valve calculated in step 4, and respectively reverse-deduce the actual polished rod displacement and load of the three points; S6: Calculate the effective stroke of the plunger based on the actual polished rod displacements of the four indicator diagram characteristic points of the top dead center of the plunger stroke, the bottom dead center of the plunger stroke, the opening point of the fixed valve, and the opening point of the traveling valve.

2. The method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of the indicator diagram according to claim 1, characterized in that: The method for obtaining the effective indicator diagram data set is: Collect the load and displacement data of the sucker rod of the pumping well through the load sensor and displacement sensor installed on the pumping well; and filter the abnormal data of the collected data to obtain an effective indicator diagram data set; The effective indicator diagram data set D: D = {d i = (x i，j , y i，j ) | i = 1, 2, 3, ..., n; j = 1, 2, 3, ..., m} where: d i represents the sampling data of the dynamometer of the i-th group of pumping units, with a total of n groups; each group of data contains m pairs of sampling values of the polished rod displacement and load of the pumping unit (x i，j , y i，j ); x i，j represents the j-th sampling value of the polished rod displacement; y i，j represents the j-th sampling value of the polished rod load.

3. The method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of the indicator diagram according to claim 2, characterized in that: The obtained dimensionless indicator diagram dataset D norm is as follows: Wherein: represents the indicator diagram samples drawn from the sampled data d of the pumping unit dynamometer normalized by the i-th group, with a total of n; where x norm and y norm are respectively the sampled values of the polished rod displacement and the polished rod load after normalization.

4. The method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of the indicator diagram according to claim 3, characterized in that: The method for obtaining the top dead center of the plunger stroke in step S3 is: For the displacement change curve x of the effective indicator diagram dataset, the first derivative of the displacement with respect to time is calculated respectively to obtain the first derivative curve of the displacement with respect to time. The intersection point of the first derivative and the time axis is found on the first derivative curve, that is, the point where the first derivative is 0. This point is the top dead center of the plunger stroke, which is also the vertex of the upward stroke. The time series position of this point in x is denoted as t C , and the load and displacement at this time point are denoted as (x C , y C ).

5. The method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of the indicator diagram according to claim 4, characterized in that: The method for respectively obtaining the bottom dead center of the plunger stroke, the opening point of the fixed valve, and the opening point of the traveling valve in step S4 is: For the normalized sampling sequences of polished rod displacement and polished rod load (x norm , y norm ), record the load and displacement at the starting point t 0 of the sampling time, which is namely the bottom dead center of the plunger stroke; At time t 0 <t < t C For the part where, calculate and find the minimum point of (x norm , y norm ) to (0, y norm ). Denote the sampling point position of this point in the dimensionless displacement sequence as t B . Denote the load and displacement of this point as , which is the fixed valve opening point; where: t C is the time series position corresponding to the point where the first derivative of the displacement change curve is 0; At time t C <t < t Max For the partial calculation at this time, find the minimum point of (X norm , y norm ) to (x norm , 0). Denote the sampling point position of this point in the dimensionless displacement sequence as t D . Denote the load and displacement of this point as , which is the opening point of the traveling valve; where: t Max is the end point of the dimensionless displacement sequence.

6. The method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of the indicator diagram according to claim 5, characterized in that: The formula for calculating the effective stroke S of the plunger in the step S6 is: S pe = min{(x C - x B ), (x D - x A )}.

7. An application of the method for determining the effective stroke of a pumping unit based on the analysis of the characteristics of the indicator diagram according to any one of claims 1-6, characterized in that: The effective stroke of the plunger can be used to calculate the liquid production volume, the parameter adjustment coefficient, and the stroke frequency after parameter adjustment of the pumping unit.

8. An application according to claim 7, characterized in that: The formula for calculating the liquid production volume Q based on the effective stroke of the plunger is as follows: Q = 1440N s A p S pe where Ns is the actual stroke frequency of the pumping unit, min -1 ; Ap is the cross-sectional area of the plunger, m 2 ; Spe is the effective stroke of the plunger, m.

9. An application according to claim 8, characterized in that: The method for calculating the parameter adjustment coefficient: Calculate the displacements between the bottom dead center of the plunger stroke and the opening point of the traveling valve, and between the opening point of the fixed valve and the top dead center of the plunger stroke respectively, and the ratio of the two is the parameter adjustment coefficient I; the calculation formula is as follows:

10. An application according to claim 9, characterized in that: The calculation method of the stroke frequency after parameter adjustment is: change the output stroke frequency of the pumping unit according to the parameter adjustment coefficient, and the calculation formula is as follows: N x = I · N y where Ny is the original stroke frequency, min -1 ; Nx is the stroke frequency after parameter adjustment, min -1 .

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