Effective stroke determination method and device based on equivalent area of indicator diagram

Abstract

The invention relates to the technical field of oil production engineering, in particular to an effective stroke determining method and device based on an indicator diagram equivalent area. The method comprises the following steps: determining down-stroke data points on an obtained indicator diagram; determining the area of a rectangle formed between each lower stroke data point and the zero point of the indicator diagram coordinate axis, and determining the area of a graph formed between a curve formed by each lower stroke data point and lower stroke data points behind the lower stroke data point and the zero point of the indicator diagram coordinate axis; determining a difference value change rate between the area of the rectangle and the area of the graph; if the difference value change rate is smaller than or equal to the preset value, the displacement value of the down stroke data point corresponding to the difference value change rate is the effective stroke. The problems that in an existing method, a manual recognition mode is low in efficiency, nonstandard in recognition standard, large in human factor influence and low in recognition precision; the problem that the effective stroke calculation result is inaccurate due to the fact that the judgment boundary of an indicator diagram with a frequently fluctuating curve is easy to be inaccurate and errors are easy to exist in selection of intercept and density is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil production engineering, and particularly to a method and device for determining an effective stroke based on the equivalent area of a dynamometer card. Background Art

[0002] The dynamometer card is a key and important means for diagnosing the working conditions of pumping wells. It is a closed curve composed of the suspension point displacement and load data within a reciprocating motion cycle. The dynamometer card curve is generally composed of 60 - 250 load-displacement point data. Currently, the digital load sensors in each oilfield are mostly unified into a format of 200 load-displacement points. As Figure 1 shown, that is, the abscissa of the dynamometer card is displacement, with a total of 200 displacement data, and the ordinate of the dynamometer card is load, also 200 load data. Moreover, the displacement and load correspond one by one in sequence, thus forming the dynamometer card curve.

[0003] The dynamometer card curve is divided into two parts: the upstroke and the downstroke. The upstroke of the dynamometer card is the liquid lifting process, and the downstroke of the dynamometer card is the liquid intake process. This cycle repeats to lift the well fluid from the underground to the wellhead. At the beginning of the downstroke, when the plunger touches the liquid level in the pump barrel, the traveling valve is pushed open, and the well fluid enters above the plunger. At this time, it is manifested that the liquid column load is unloaded, and the load drops rapidly, and then it continues to descend stably. When reaching the bottom dead center, the traveling valve closes and the upstroke begins. At the beginning of the upstroke, the well fluid entering above the plunger is lifted to the wellhead. At this time, the dynamometer card shows that the liquid column load is loaded, and the load rises rapidly, and then it continues to ascend stably. The effective stroke of the pump refers to the effective stroke of the liquid intake of the plunger during the period when the traveling valve is opened and then closed during the downstroke of the pumping well, that is, the effective stroke.

[0004] There is currently no clear quantitative standard for the effective stroke. It mainly relies on experience for judgment. By observing the downstroke unloading curve of the dynamometer card, when the load near the top dead center drops rapidly to near the minimum load and starts to stabilize, the displacement at this point is the effective stroke. However, the manual identification workload of this method is large, the identification standard is not standardized, and the influence of human factors is significant, resulting in low identification efficiency and accuracy.

[0005] Currently, the commonly used methods for calculating the effective stroke include the curvature method, the slope method, and the projection interception method. As Figure 2 shown, in Figure 2In Figure (a), the five-point curvature method is shown; in Figure (b), the slope discrimination method is shown; and in Figure (c), the projection interception method is shown. The curvature method calculates the curvature of several adjacent data points on the indicator diagram. After the maximum curvature reaches the set limit (maximum), it is considered that the traveling valve has completed the opening and closing actions. Then, the displacement between the two maximum curvature points during the downward stroke is the effective stroke. The slope method calculates the slope of each data point relative to the starting point of the indicator diagram during the downward stroke. When the set slope limit (which is 0) is reached, the displacement of this data point is considered the effective stroke. The above two methods are more applicable to wells with smooth and stable indicator diagram curves. However, for wells with indicator diagram curves that fluctuate frequently, due to the frequent fluctuations of curvature and slope, it is easy to reach the discrimination limit prematurely or lag, resulting in large fluctuations in the calculation of the effective stroke. The projection interception method scans the indicator diagram from top to bottom by selecting an appropriate intercept rectangular frame to find the interval with the maximum density of load-displacement points during the downward stroke of the indicator diagram. The difference between the maximum displacement and the minimum displacement in this interval is the effective stroke. This method avoids the problem of curve fluctuations, but the selection of the intercept and density requires high precision. Improper selection is prone to errors, and for wells with working conditions such as bottom bumping, the calculation result of the effective stroke is severely underestimated, and it also has limitations. Summary of the Invention

[0006] The present invention provides a method and device for determining the effective stroke based on the equivalent area of the indicator diagram, aiming to solve the problems in the existing methods for determining the effective stroke through the indicator diagram, such as low efficiency, non-standard recognition criteria, large influence of human factors, and low recognition accuracy in the manual recognition method; and inaccurate discrimination limits and easy errors in the selection of intercept and density in the calculation method for indicator diagrams with frequently fluctuating curves, resulting in inaccurate calculation results of the effective stroke.

[0007] According to one aspect of the present invention, a method for determining the effective stroke based on the equivalent area of the indicator diagram is provided, including:

[0008] Obtain the indicator diagram for which the effective stroke is to be determined, and determine the downward stroke data points on the indicator diagram;

[0009] Respectively determine the area of the rectangle formed between each downward stroke data point and the zero point of the indicator diagram coordinate axis, and respectively determine the area of the figure formed between the curve composed of each downward stroke data point and the subsequent downward stroke data points and the zero point of the indicator diagram coordinate axis;

[0010] Determine the difference change rate between the area of the rectangle corresponding to each downward stroke data point and the area of the corresponding figure;

[0011] Judge that if the difference change rate is less than or equal to a predetermined value, then the displacement value of the downward stroke data point corresponding to this difference change rate is the effective stroke.

[0012] Preferably, the method for determining the downward stroke data points on the indicator diagram includes:

[0013] Screen all the data points on the indicator diagram and find the data point with the largest corresponding displacement value among them;

[0014] Take the data point immediately following the data point with the largest displacement value as the starting point of the downstroke;

[0015] Among the two curves formed by the data points between the starting point of the downstroke and the starting point of the indicator diagram curve, the data points on the curve below are the downstroke data points.

[0016] Preferably, if there are multiple data points with the largest displacement value, select the first-occurring data point among them as the data point with the largest displacement value;

[0017] Among them, the first-occurring data point is: starting from the starting point of the indicator diagram curve, along the upper half of the indicator diagram curve towards the lower half, the first data point found with the largest displacement value.

[0018] Preferably, the method for determining the area of the rectangle formed between each downstroke data point and the zero point of the indicator diagram coordinate axis includes:

[0019] Use formula (1) to determine the area of the rectangle formed between each downstroke data point and the zero point of the indicator diagram coordinate axis;

[0020] JXMJ i =S i P i (1);

[0021] In the formula: S i is the displacement value corresponding to the downstroke data point i, and P i is the load value corresponding to the downstroke data point i.

[0022] Preferably, the method for respectively determining the area of the figure formed between the curve composed of each downstroke data point and the downstroke data points after it and the zero point of the indicator diagram coordinate axis includes:

[0023] Use formula (2) to determine the area of the figure formed between the curve composed of each downstroke data point and the downstroke data points after it and the zero point of the indicator diagram coordinate axis;

[0024]

[0025] In the formula: m is the starting point of the downstroke, n is the number of downstroke data points, S i is the displacement value corresponding to the downstroke data point i, and P i is the load value corresponding to the downstroke data point i.

[0026] Preferably, the method for determining the change rate of the difference between the area of the rectangle corresponding to each downstroke data point and the area of the corresponding graph includes:

[0027] Using formula (3), determine the change rate of the difference between the area of the rectangle corresponding to each downstroke data point and the area of the corresponding graph;

[0028] MJCZL i =(JXMJ i -QXMJ i ) / JXMJ i (3);

[0029] In the formula: JXMJ i is the area of the rectangle corresponding to the downstroke data point i, and QXMJ i is the area of the graph corresponding to the downstroke data point i.

[0030] Preferably, the predetermined value is: 0.02.

[0031] According to one aspect of the present invention, there is provided an effective stroke determination device based on the equivalent area of the indicator diagram, including:

[0032] An acquisition unit for acquiring the indicator diagram of the effective stroke to be determined and determining the downstroke data points on the indicator diagram;

[0033] An area determination unit for respectively determining the area of the rectangle formed between each downstroke data point and the zero point of the indicator diagram coordinate axis and the area of the graph formed between the curve composed of each downstroke data point and the subsequent downstroke data points and the zero point of the indicator diagram coordinate axis;

[0034] A difference change rate determination unit for determining the change rate of the difference between the area of the rectangle corresponding to each downstroke data point and the area of the corresponding graph;

[0035] An effective stroke determination unit for determining that if the difference change rate is less than or equal to the predetermined value, the displacement value of the downstroke data point corresponding to the difference change rate is the effective stroke.

[0036] The present invention has at least the following beneficial effects:

[0037] The present invention proposes an effective stroke determination method and device based on the equivalent area of the indicator diagram. By determining that the area of the rectangle between the downstroke data point and the zero point of the coordinate axis is equal to or close to the area of the graph of the downstroke data point curve and the zero point of the coordinate axis to determine the effective stroke, the calculation process of this method is simple, less affected by the fluctuation of the indicator diagram curve, and can adapt to the calculation of the effective stroke under various working conditions, providing a strong technical support for improving the accuracy of production calculation and liquid level conversion by the indicator diagram method. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The drawings herein are incorporated into and form a part of this specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.

[0039] Figure 1 Showing the well working diagram curve according to an embodiment of the present invention;

[0040] Figure 2 Showing schematic diagrams of the curvature method, slope method and projection interception method in the common effective stroke calculation method according to an embodiment of the present invention;

[0041] Figure 3 Showing the flowchart of the effective stroke determination method based on the equivalent area of the working diagram according to an embodiment of the present invention;

[0042] Figure 4 Showing the schematic diagram of the effective stroke calculation principle according to an embodiment of the present invention;

[0043] Figure 5 Showing the schematic diagrams of the rectangular area and the graphic area according to an embodiment of the present invention;

[0044] Figure 6 Showing the well working diagram curve of Well Bei 2-324-P45 according to an embodiment of the present invention;

[0045] Figure 7 Showing the well working diagram curve of Well Bei 2-324-P49 according to an embodiment of the present invention;

[0046] Figure 8 Showing the well working diagram curve of Well Bei 2-Ding 1-437 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0047] Various exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are shown in the drawings, the drawings do not have to be drawn to scale unless otherwise specified.

[0048] The special term "exemplary" herein means "serving as an example, embodiment or illustration". Any embodiment described as "exemplary" here does not have to be construed as superior to or better than other embodiments.

[0049] As used herein, the term "and / or" is merely a description of the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent three cases: A exists alone, both A and B exist simultaneously, and B exists alone. Additionally, the term "at least one" as used herein means any one of multiple items or any combination of at least two of multiple items. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set composed of A, B, and C.

[0050] In addition, for a better illustration of the present invention, numerous specific details are given in the following detailed embodiments. Those skilled in the art should understand that the present invention can still be implemented without some of these specific details. In some instances, methods, means, elements, and circuits well-known to those skilled in the art are not described in detail so as to highlight the gist of the present invention.

[0051] Figure 1 Showing the well performance graph curve according to an embodiment of the present invention; Figure 2 Showing the schematic diagrams of the curvature method, slope method, and projection intercept method in the common effective stroke calculation method according to an embodiment of the present invention; Figure 3 Showing the flowchart of the effective stroke determination method based on the equivalent area of the performance graph according to an embodiment of the present invention; Figure 4 Showing the schematic diagram of the effective stroke calculation principle according to an embodiment of the present invention; Figure 5 Showing the schematic diagrams of the rectangular area and the graphic area according to an embodiment of the present invention; Figure 6 Showing the well performance graph curve of Well Bei 2-324-P45 according to an embodiment of the present invention; Figure 7 Showing the well performance graph curve of Well Bei 2-324-P49 according to an embodiment of the present invention; Figure 8 Showing the well performance graph curve of Well Bei 2-Ding 1-437 according to an embodiment of the present invention. As Figures 1 - 8 As shown, a method for determining the effective stroke based on the equivalent area of the performance graph includes: Step S01: Obtain the performance graph for which the effective stroke is to be determined, and determine the downstroke data points on the performance graph; Step S02: Respectively determine the area of the rectangle formed between each downstroke data point and the zero point of the performance graph coordinate axis, and respectively determine the area of the graph formed between the curve composed of each downstroke data point and the subsequent downstroke data points and the zero point of the performance graph coordinate axis; Step S03: Determine the difference change rate between the area of the rectangle corresponding to each downstroke data point and the area of the corresponding graph; Step S04: Judge that if the difference change rate is less than or equal to a predetermined value, then the displacement value of the downstroke data point corresponding to the difference change rate is the effective stroke.

[0052] In the embodiment of the present invention, according to the definition of effective stroke, the effective stroke is obtained from the stroke curve of the power diagram. Theoretically, the effective stroke is the curve segment after the unloading point, and the curvature and slope change greatly, and the load of each data point in the effective stroke curve segment is small and stable, which is also the main basis for calculating the effective stroke by the curvature method, slope method and projection interception method. After analysis, in addition to the above-mentioned rules, the effective stroke also has the curve area of ​​the effective stroke curve segment relative to the horizontal coordinate that is equivalent to the rectangular area formed by the coordinates of the effective stroke starting point D and the zero point coordinates of the coordinate axis, that is, the effective stroke can be calculated by the power diagram equivalent area method. The actual power diagram is not regular, but the rules are consistent, and can be obtained by various calculation methods.

[0053] The work curve can be represented by a parallelogram, such as Figure 4 As shown, in Figure 4 In the diagram, line AB is the loading line, point A is the bottom dead center of the donkey head, and is also the starting point of the power diagram; line BC is the maximum load line, when it reaches point B, the loading is completed, the fixed valve is opened, and the floating valve is closed; line CD is the unloading line, point C is the bottom dead center of the donkey head, and is also the starting point of the downstroke; line DA is the minimum load line, when it reaches point D, the unloading is completed, the fixed valve is closed, and the floating valve is opened; line ABC is the upstroke line; line CDA is the downstroke line; S p is the effective piston travel, i.e. the effective stroke; S is the stroke of the polished rod; λ is the stroke loss, λ=SS p .

[0054] The specific principle of the method of the present invention is: in the stroke curve under the power diagram, if Figure 5 As shown, the displacement is calculated in descending order. When a data point (S i , P i ) and the zero point coordinate (0, 0) of the coordinate axis form the area of ​​the rectangle JXMJ i , infinitely close to or equal to the data point (S i , P i ) and the coordinates of the starting point of the power diagram curve (S 0 , P 0 The area of ​​the curve formed by the continuous curve between ) and the horizontal axis is QXMJ i At this time, S i is the effective stroke S p In order to ensure the calculation accuracy, a specific calculation quantification standard is designed, namely: when (JXMJ i -QXMJ i ) / JXMJ i <=0.02 (refer to the load sensor displacement error standard ±2%), at this time S i is the effective stroke S p .

[0055] The effective stroke determination method based on the equivalent area of the dynamometer card provided by the embodiments of the present invention specifically includes the following steps:

[0056] Step S01: Obtain the dynamometer card for which the effective stroke is to be determined, and determine the downstroke data points on the dynamometer card.

[0057] In the present invention, the method for determining the downstroke data points on the dynamometer card includes: screening all the data points on the dynamometer card, and finding the data point with the largest corresponding displacement value among them; taking the data point immediately following the data point with the largest displacement value as the starting point of the downstroke; among the two curves formed by the data points between the starting point of the downstroke and the starting point of the dynamometer card curve, the data points on the curve located below are the downstroke data points.

[0058] In the present invention, if there are multiple data points with the largest displacement value, then select the first-occurring data point among them as the data point with the largest displacement value; wherein, the first-occurring data point is: starting from the starting point of the dynamometer card curve, along the upper half of the dynamometer card curve towards the lower half, the first data point found with the largest displacement value.

[0059] In the embodiments of the present invention, it is assumed that the dynamometer card curve is composed of m + n data points in total. That is, the numbers of each data point passed from the first starting point (S 0 , P 0 ) of the curve along the upper half of the curve (upstroke data points) to the lower half of the curve (downstroke data points) and then back to the starting point are: 0, 1, 2,..., m + n - 1, where m is the starting point of the downstroke data points and n is the number of downstroke data points; thus forming a data point set GTQX corresponding to the displacement S and the load P, such as GTQX = {(S 0 , P 0 ), (S 1 , P 1 )(S 2 , P 2 ),..., (S m+n-1 , P m+n-1 )}.

[0060] To find the starting data points of the upstroke and downstroke of the dynamometer card, first, it is necessary to find the point S m-1 with the largest displacement value on the dynamometer card, that is, S m-1 = max(S 0 , S 1 , S 2 , …, S m+n-1 ).

[0061] On the dynamometer card curve, there may be multiple points with the largest displacement value. Then, starting from the first starting point (S 0 , P 0)Start along the upper half curve (upstroke data points) to the lower half curve (downstroke data points) direction, that is, from S 0 Start to S m+n-1 The data point corresponding to the maximum displacement value that first appears in S m-1 .

[0062] The coordinates of the data point with the largest displacement value are: (S m-1 , P m-1 ), take it as the demarcation point between the up and down strokes, then the starting point of the down stroke is: (S m , P m ), from (S m , P m ) start to the last data point (S m+n-1 , P m+n-1 ) are all downstroke data points.

[0063] Step S02: Determine the area of the rectangle formed between each downstroke data point and the zero point of the indicator diagram coordinate axis respectively, and determine the area of the figure formed between the curve composed of each downstroke data point and the subsequent downstroke data points and the zero point of the indicator diagram coordinate axis respectively.

[0064] In the present invention, the method for determining the area of the rectangle formed between each downstroke data point and the zero point of the indicator diagram coordinate axis includes: using formula (1) to determine the area of the rectangle formed between each downstroke data point and the zero point of the indicator diagram coordinate axis;

[0065] JXMJ i =S i P i (1);

[0066] In the formula: S i is the displacement value corresponding to the downstroke data point i, P i is the load value corresponding to the downstroke data point i; (i = m, m + 1, m + 2, m + 3, ……, m + n - 1).

[0067] In the embodiment of the present invention, the rectangle formed between a certain downstroke data point and the zero point of the coordinate axis is: the rectangular area formed between the perpendiculars of this data point to the vertical axis and the horizontal axis of the indicator diagram and the partial axes of the vertical axis (load axis) and the horizontal axis (displacement axis) opposite to this perpendicular. The area JXMJ of this rectangular area is the displacement value corresponding to this data point multiplied by the load value corresponding to this data point, that is, formula (1).

[0068] Calculate the rectangular area JXMJ of each data point in the downstroke of the indicator diagram relative to the zero point coordinates of the coordinate axis in turn according to formula (1) i , and finally form a set of rectangular areas of each data point in the downstroke of the indicator diagram JXMJ = {JXMJ m 、JXMJm+1 , JXMJ m+2 , JXMJ m+3 , ……, JXMJ m+n-1}。

[0069] In the present invention, the method for respectively determining the area of the figure formed between the curve composed of each downward stroke data point and the subsequent downward stroke data points and the zero point of the dynamometer coordinate axis includes: using formula (2) to determine the area of the figure formed between the curve composed of each downward stroke data point and the subsequent downward stroke data points and the zero point of the dynamometer coordinate axis;

[0070]

[0071] where: m is the starting point of the downward stroke, n is the number of downward stroke data points, S i is the displacement value corresponding to the downward stroke data point i, and P i is the load value corresponding to the downward stroke data point i.

[0072] In an embodiment of the present invention, the curve composed of each downward stroke data point and the subsequent downward stroke data points is: the curve composed of all downward stroke data points between a certain downward stroke data point and the starting point of the curve. For example: if the downward stroke data point is (S m+1 , P m+1 ), then the data points (S m+1 , P m+1 ), (S m+2 , P m+2 ),

[0073] (S m+3 , P m+3 ), (S m+4 , P m+4 ) …… (S m+n-1 , P m+n-1 ), (S 0 , P 0 ) form a curve, which is the curve composed of the downward stroke data point (S m+1 , P m+1 ) and the subsequent downward stroke data points.

[0074] The figure formed between the curve qx composed of a certain downward stroke data point and the subsequent downward stroke data points and the coordinate axis zero point (0, 0) is: the figure area formed between the perpendicular line of this data point to the horizontal axis, the curve qx composed of this data point and the subsequent downward stroke data points, and the corresponding partial axes of the horizontal axis and the vertical axis.

[0075] Relative to the horizontal axis, the work diagram curve is divided into (m + n) trapezoidal units by each data point. Therefore, the area of the work diagram curve can be obtained by cumulative summation of the areas of the trapezoidal units. Therefore, according to the trapezoid area formula, the area of the graph between any section of the curve of the downstroke curve of the work diagram and the corresponding horizontal axis can be obtained, that is, formula (2).

[0076] Thus, through formula (2), the set of areas of the continuous curves between each data point and the starting point of the work diagram is calculated as QXMJ = {QXMJ m , QXMJ m+1 , QXMJ m+2 , QXMJ m+3 , ……, QXMJ m+n-1}.

[0077] Among them, since the curve area must be calculated starting from the starting point of the work diagram, therefore, in formula (3), (S m+n , P m+n ) appears, while the data point (S m+n , P m+n ) does not exist in the work diagram curve data point set. It is necessary to make S m+n = S 0 , P m+n = P 0 , that is, equate this data point to the starting point of the work diagram curve, so that the curve area and the rectangle area corresponding to each data point are comparable.

[0078] Step S03: Determine the difference change rate between the area of the rectangle corresponding to each of the downstroke data points and the area of the corresponding graph.

[0079] In the present invention, the method for determining the difference change rate between the area of the rectangle corresponding to each of the downstroke data points and the area of the corresponding graph includes: using formula (3) to determine the difference change rate between the area of the rectangle corresponding to each of the downstroke data points and the area of the corresponding graph;

[0080] MJCZL i = (JXMJ i - QXMJ i ) / JXMJ i (3);

[0081] In the formula: JXMJ i is the area of the rectangle corresponding to the downstroke data point i, and QXMJ i is the area of the graph corresponding to the downstroke data point i.

[0082] In the embodiment of the present invention, the rectangular area JXMJ set corresponding to each data point in the downstroke of the indicator diagram and the curve area set QXMJ are compared in terms of the difference change rate in sequence. That is, the rectangular area JXMJ corresponding to each downstroke data point in the rectangular area JXMJ set and the curve area set QXMJ is respectively i and the area QXMJ of the graph i are substituted into formula (3), and the calculation results form a set of area difference change rates MJCZL = {MJCZL m , MJCZL m+1 , ……, MJCZL m+n-1}.

[0083] Step S04: Determine that if the difference change rate is less than or equal to a predetermined value, the displacement value of the downstroke data point corresponding to the difference change rate is the effective stroke.

[0084] In the present invention, the predetermined value is: 0.02.

[0085] In the embodiment of the present invention, the set of area difference change rates is screened in sequence, that is, starting from MJCZL m , and screening in sequence according to MJCZL m+1 , MJCZL m+2 …… MJCZL m+n-1 . When the first difference change rate MJCZL i element value in the set is less than or equal to 0.02, the subscript XH of the element value corresponding to the downstroke data point (S XH , P XH ) is the data point corresponding to the effective stroke; the displacement value of the downstroke data point is the effective stroke, that is, the effective stroke S P = S XH .

[0086] In the embodiment of the present invention, taking Well Bei 2-324-P45 as an example, the calculation process of the effective stroke of the indicator diagram is as follows:

[0087] The obtained indicator diagram curve of Well Bei 2-324-P45 is as Figure 6 shown. The serial numbers in the figure are sequentially numbered from the starting point of the indicator diagram to the upper half curve and then to the lower half curve direction, that is, a total of 200 data points from 0 to 199. See Table 1 below. An additional data point, that is, serial number 200 (0, 29.8), is added to Table 1. It is the same as the starting data point (0, 29.8) of the curve. Designing this data point is for closing the curve to calculate the area of the indicator diagram curve and has no impact on the actual indicator diagram curve.

[0088] Table 1: Displacement and load data table of each data point of the indicator diagram curve of Well Bei 2-324-P45

[0089]

[0090]

[0091] By screening 200 data points of the dynamometer card curve in Table 1 in sequence number order, the data point with the first maximum displacement value is the data point with sequence number 103 (4.15, 52.52). This data point indicates the end of the upstroke. Therefore, the downstroke data points start from the next data point, i.e., sequence number 104 (4.15, 52.52), that is, m = 104 and n = 96. That is, the set of downstroke data points is: XXC{(S m , P m ), (S m+1 , P m+1 ), (S m+2 , P m+2 ), ……,

[0092] (S m+n-1 , P m+n-1 )} = XXC{(S104, P104), (S105, P105), (S106, P106), ……,

[0093] (S199, P199)}.

[0094] Using formula (1), calculate the rectangular area JXMJ formed by each data point of the downstroke of the dynamometer card relative to the zero coordinate of the coordinate axis in sequence, so as to form a set of rectangular areas of each data point of the downstroke of the dynamometer card JXMJ{JXMJ i , JXMJ m , JXMJm + 2, JXMJ m+1 , ……, JXMJ m+3 , ……, JXMJ m+n-1} = JXMJ{JXMJ 104 , JXMJ 105 , JXMJ 106 , JXMJ 107 , ……, JXMJ 199}. The specific calculation results are shown in Table 2 below;

[0095] Table 2: Rectangular area JXMJ of each data point of the downstroke curve of the dynamometer card of Well Bei 2 - 324 - P45 i Calculation result

[0096] Data point order Rectangle area Data point order Rectangle area Data point order Rectangle area Data point order Rectangle area 104 217.96 129 151.10 154 54.80 179 14.94 105 217.92 130 146.20 155 52.29 180 13.55 106 217.71 131 140.58 156 49.56 181 12.40 107 214.10 132 134.03 157 47.61 182 11.27 108 209.58 133 126.84 158 46.05 183 10.16 109 207.99 134 118.67 159 44.69 184 9.03 110 206.05 135 110.53 160 43.62 185 8.18 111 203.73 136 102.34 161 42.24 186 7.03 112 203.08 137 94.48 162 40.63 187 6.15 113 202.25 138 85.82 163 38.36 188 5.30 114 202.12 139 76.45 164 36.52 189 4.42 115 201.12 140 70.07 165 34.67 190 3.83 116 199.73 141 69.64 166 33.06 191 2.95 117 196.80 142 72.03 167 31.60 192 2.36 118 193.18 143 74.28 168 30.50 193 1.78 119 189.24 144 75.87 169 29.05 194 1.19 120 186.74 145 74.35 170 27.46 195 0.90 121 184.83 146 70.31 171 26.09 196 0.60 122 182.27 147 65.90 172 24.40 197 0.30 123 179.72 148 62.09 173 22.94 198 0.00 124 176.06 149 60.00 174 21.49 199 0.00 125 170.57 150 59.54 175 19.95 126 165.67 151 59.10 176 18.57 127 160.49 152 58.29 177 17.34 128 155.35 153 56.98 178 16.31

[0097] Using formula (2), calculate the area of the figure formed by the continuous curve between each data point of the downstroke of the dynamometer card and the starting point of the dynamometer card curve to the zero point of the coordinate axis in sequence, and obtain the set of areas of the continuous curves between each downstroke data point and the starting point of the dynamometer card (area of the figure) QXMJ{QXMJm , QXMJ m+1 , QXMJ m+2 , QXMJ m+3 , ……, QXMJ m+n-1} = QXMJ{QXMJ 104 , QXMJ 105 , QXMJ 106 , QXMJ 107 , ……, QXMJ 199}, and the specific calculation results are shown in Table 3 below;

[0098] Table 3: Graphic area QXMJ of each data point of the downstroke curve of the well pattern of Well Bei 2-324-P45 i Calculation result

[0099] Data point order Curve area Data point order Curve area Data point order Curve area Data point order Curve area 104 132.84 129 104.37 154 57.05 179 16.63 105 132.84 130 102.20 155 55.09 180 15.20 106 132.84 131 99.63 156 53.42 181 13.76 107 132.84 132 97.53 157 51.51 182 12.61 108 132.84 133 95.07 158 49.89 183 11.45 109 132.84 134 92.70 159 48.28 184 10.30 110 132.34 135 90.43 160 46.38 185 9.13 111 131.84 136 88.27 161 44.73 186 8.26 112 131.34 137 86.22 162 43.07 187 7.09 113 130.85 138 84.62 163 41.40 188 6.21 114 129.86 139 82.82 164 39.46 189 5.33 115 129.36 140 81.17 165 37.81 190 4.44 116 127.87 141 79.65 166 36.17 191 3.86 117 126.88 142 78.17 167 34.53 192 2.97 118 125.40 143 76.64 168 32.89 193 2.38 119 123.93 144 74.74 169 31.51 194 1.79 120 122.48 145 73.03 170 29.84 195 1.19 121 121.05 146 70.99 171 28.16 196 0.90 122 119.13 147 69.26 172 26.76 197 0.60 123 117.23 148 67.60 173 25.07 198 0.30 124 115.33 149 65.72 174 23.67 199 0.00 125 113.44 150 64.14 175 22.28 126 111.11 151 62.28 176 20.60 127 108.83 152 60.66 177 19.19 128 106.58 153 58.73 178 17.78

[0100] According to the set JXMJ of the rectangular areas of each downstroke data point calculated, and the set QXMJ of the curve areas of each downstroke data point calculated, corresponding one by one in ascending order of the serial numbers of each data point, according to formula (3), the calculation of the difference change rate is carried out, and the set MJCZL{MJCZL of the area difference change rates of each downstroke data point of the well pattern is calculated m , MJCZL m+1 , MJCZL m+2 , MJCZL m+3 , ……, MJCZL m+n-1} = MJCZL{MJCZL 104 , MJCZL 105 , MJCZL 106 , MJCZL 107 , ……, MJCZL 199}, and the specific calculation results are shown in Table 4 below;

[0101] Table 4: Area difference change rate MJCZL of each data point of the downstroke of the well pattern of Well Bei 2-324-P45 i Calculation result

[0102]

[0103]

[0104] Screen the set MJCZL of the difference change rates in Table 4 in the order of the serial numbers. The data point with the value of the first difference change rate element less than or equal to 0.02 is the data point with the serial number 138 (2.98, 28.8). The area difference change rate of this data point is 0.014. Therefore, the effective stroke of the well pattern of Well Bei 2-324-P45 is 2.98 m. The specific position of this data point is as Figure 6As shown in the figure; from the effect diagram, it conforms to the actual manual judgment result.

[0105] In the embodiment of the present invention, taking Well Bei 2-324-P49 as an example, the calculation process of the effective stroke of its dynamometer card is as follows:

[0106] The dynamometer card curve of Well Bei 2-324-P49 obtained is as Figure 7 shown. The serial numbers in the figure are sequentially numbered from the starting point of the dynamometer card to the upper half curve and then to the lower half curve direction, as shown in Table 5 below.

[0107] Table 5: Displacement and load data table of each data point of the dynamometer card curve of Well Bei 2-324-P49

[0108]

[0109]

[0110]

[0111] By screening the 200 data points of the dynamometer card curve in Table 5 in sequence number order, the data point with the first maximum displacement value is the serial number 103 (4.27, 57.91). This data point indicates the end of the upstroke. Therefore, the data points of the downstroke start from the next data point, that is, the serial number 104 (4.27, 57.36), that is, m = 104, n = 96. That is, the set of downstroke data points is: XXC{(S m , P m )、(S m+1 , P m+1 )、(S m+2 , P m+2 )、……、

[0112] (S m+n-1 , P m+n-1 )} = XXC{(S104, P104)、(S105, P105)、(S106, P106)、……、

[0113] (S199, P199)}.

[0114] Using formula (1), calculate the rectangular area JXMJ formed by each data point of the downstroke of the dynamometer card relative to the zero coordinate of the coordinate axis in turn i , thus forming a set of rectangular areas of each data point of the downstroke of the dynamometer card JXMJ{JXMJ m 、JXMJ m+1 、JXMJ m+2 、JXMJ m+3 、……、JXMJ m+n-1} = JXMJ{JXMJ 104 、JXMJ 105, JXMJ 106 , JXMJ 107 , ……, JXMJ 199} The specific calculation results are shown in Table 6 below.

[0115] Using formula (2), calculate the area of the figure formed by the continuous curve between each data point in the downstroke of the indicator diagram and the starting point of the indicator diagram curve to the zero point of the coordinate axis in sequence, and obtain the set QXMJ of the areas of the continuous curves between each downstroke data point and the starting point of the indicator diagram (the area of the figure) {QXMJ m , QXMJ m+1 , QXMJ m+2 , QXMJ m+3 , ……, QXMJ m+n-1} = QXMJ{QXMJ 104 , QXMJ 105 , QXMJ 106 , QXMJ 107 , ……, QXMJ 199} The specific calculation results are shown in Table 6 below.

[0116] According to the set JXMJ of the rectangular areas of each downstroke data point calculated, and the set QXMJ of the curve areas of each downstroke data point calculated, corresponding one by one in ascending order of the serial numbers of each data point, according to the formula

[0117] (3), calculate the difference change rate, and calculate the set MJCZL of the difference change rates of the areas of each downstroke data point of the indicator diagram {MJCZL m , MJCZL m+1 , MJCZL m+2 , MJCZL m+3 , ……, MJCZL m+n-1} = MJCZL{MJCZL 104 , MJCZL 105 , MJCZL 106 , MJCZL 107 , ……, MJCZL 199} The specific calculation results are shown in Table 6 below;

[0118] Table 6: Difference change rate MJCZL of the areas of each data point of the downstroke curve of the indicator diagram of Well Bei 2-324-P49 i Calculation results

[0119]

[0120] Screen the set MJCZL of the difference change rates in Table 6 in sequential order. The first data point whose difference change rate element value is less than or equal to 0.02 is the data point with serial number 132 (3.29, 26.27). The area difference change rate of this data point is -0.017. Therefore, the effective stroke of the dynamometer card of Well Bei 2-324-P49 is 3.29 m. The specific position of this data point is as shown in Figure 7 ; Judging from the effect diagram, it conforms to the actual manual judgment result.

[0121] In the embodiment of the present invention, taking Well Bei 2-Ding 1-437 as an example, the calculation process of its effective stroke of the dynamometer card is as follows:

[0122] The obtained dynamometer card curve of Well Bei 2-Ding 1-437 is as shown in Figure 8 ; In the figure, the serial numbers are sequentially numbered from the starting point of the dynamometer card along the upper half curve to the lower half curve direction, as shown in Table 7 below.

[0123] Table 7: Displacement and load data table of each data point of the dynamometer card curve of Well Bei 2-Ding 1-437

[0124]

[0125]

[0126] By screening the 200 data points of the dynamometer card curve in Table 7 in sequential order, the first data point with the maximum displacement value is the data point with serial number 102 (3.63, 52.05). This data point indicates the end of the upstroke. Therefore, the data points of the downstroke start from the next data point, that is, the data point with serial number 103 (3.63, 52.01), that is, m = 103, n = 97. That is, the set of downstroke data points is: XXC{(S m , P m )、(S m+1 , P m+1 )、(S m+2 , P m+2 )、……、(S m+n-1 , P m+n-1 )} = XXC{(S 103 , P 103 )、(S 104 , P 104 )、(S 105 , P 105 )、……、(S 199 , P 199 )}.

[0127] Using formula (1), sequentially calculate the rectangular area JXMJ formed by each data point of the downstroke of the dynamometer card relative to the zero coordinate of the coordinate axis i , thereby forming a set JXMJ of rectangular areas of each data point of the downstroke of the dynamometer card JXMJ{JXMJm , JXMJ m+1 , JXMJ m+2 , JXMJ m+3 , ..., JXMJ m+n-1 =JXMJ{JXMJ 103 、JXMJ 104 、JXMJ 105 、JXMJ 106 、……、JXMJ 199}, the specific calculation results are shown in Table 8 below.

[0128] Using formula (2), the area of ​​the figure formed between the continuous curve between each data point of the downstroke of the power diagram and the starting point of the power diagram curve to the zero point of the coordinate axis is calculated in sequence, and the continuous curve area (the area of ​​the figure) set QXMJ{QXMJ m ,QXMJ m+1 ,QXMJ m+2 ,QXMJ m+3 、……、QXMJ m+n-1 =QXMJ 103 、QXMJ 104 、QXMJ 105 、QXMJ 106 、……、QXMJ 199}, the specific calculation results are shown in Table 8 below.

[0129] According to the calculated rectangular area set JXMJ of each downstroke data point and the calculated curve area set QXMJ of each downstroke data point, the difference change rate is calculated according to formula (3) according to the one-to-one correspondence of the data point numbers from small to large, and the difference change rate set MJCZL{MJCZL m ,MJCZL m+1 ,MJCZL m+2 ,MJCZL m+3 , ..., MJCZL m+n-1 =MJCZL{MJCZL 103 、MJCZL 104 、MJCZL 105 、MJCZL 106 、……、MJCZL 199}, the specific calculation results are shown in Table 8 below;

[0130] Table 8: Area difference change rate of each data point on the travel curve of the Bei2-D1-437 well performance chart MJCZL i Calculation results

[0131]

[0132]

[0133] Screen the set MJCZL of difference change rates in Table 8 in sequential order. The first data point whose difference change rate element value is less than or equal to 0.02 is the data point of serial number 152 (1.76, 18.41). The area difference change rate of this data point is -0.106. Therefore, the effective stroke of the dynamometer card of Well Bei 2-Ding 1-437 is 1.76 m. The specific position of this data point is as Figure 8 shown; from the effect diagram, it conforms to the actual manual judgment result.

[0134] It can be understood that the above-mentioned various method embodiments mentioned in the present invention can be combined with each other to form a combined embodiment without violating the principle logic. Due to space limitations, the present invention will not elaborate further.

[0135] The execution subject of the effective stroke determination method based on the equivalent area of the dynamometer card can be an effective stroke determination device based on the equivalent area of the dynamometer card. For example, the effective stroke determination method based on the equivalent area of the dynamometer card can be executed by a terminal device, a server, or other processing devices. Among them, the terminal device can be a user equipment (UE), a mobile device, a user terminal, a terminal, a cellular phone, a cordless phone, a personal digital assistant (PDA), a handheld device, a computing device, a vehicle-mounted device, a wearable device, etc. In some possible implementation manners, the effective stroke determination method based on the equivalent area of the dynamometer card can be implemented by a processor calling computer-readable instructions stored in a memory.

[0136] Those skilled in the art can understand that in the above method of the specific implementation manner, the writing order of each step does not mean a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined according to its function and possible internal logic.

[0137] The present invention also provides an effective stroke determination device based on the equivalent area of the dynamometer card, including: an acquisition unit, configured to acquire a dynamometer card for which an effective stroke is to be determined and determine the downstroke data points on the dynamometer card; an area determination unit, configured to respectively determine the area of the rectangle formed between each downstroke data point and the zero point of the dynamometer card coordinate axis and the area of the graph formed between the curve formed by each downstroke data point and the subsequent downstroke data points and the zero point of the dynamometer card coordinate axis; a difference change rate determination unit, configured to determine the difference change rate between the area of the rectangle corresponding to each downstroke data point and the area of the corresponding graph; an effective stroke determination unit, configured to determine that if the difference change rate is less than or equal to a predetermined value, the displacement value of the downstroke data point corresponding to the difference change rate is the effective stroke.

[0138] In some embodiments, the functions of the device provided by the embodiments of the present invention or the modules and units included therein can be used to execute the methods described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0139] The present invention determines the corresponding displacement as the effective stroke by gradually rectifying the area of the downward curve of the dynamometer card that moves down with the plunger until the rectangular area is equal to the remaining actual downward curve area. The calculation method of the present invention is simple and easy to operate. The unique dynamometer card equivalent area method adopted not only innovates the original calculation method but also retains the theoretical basis of the original effective stroke calculation. The method is not affected by problems such as the fluctuation of the dynamometer card curve, pump bumping, and resistance encountered during downward movement, eliminates calculation errors, can adapt to the calculation of the effective stroke under various working conditions, improves the calculation accuracy and stability of the effective stroke, and successfully realizes the accurate calculation of the effective stroke of the dynamometer card of the pumping well, providing an effective and fast new technical means and strong technical support for meeting the requirements of digital dynamometer card production calculation, liquid level conversion accuracy, and working condition diagnosis.

[0140] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the embodiments disclosed herein.

Claims

1. An effective stroke determination method based on the equivalent area of a dynamometer card, characterized in that, it includes: Obtain the dynamometer card for which the effective stroke is to be determined, and determine the downstroke data points on the dynamometer card; Respectively determine the area of the rectangle formed between each downstroke data point and the zero point of the dynamometer card coordinate axis, and respectively determine the area of the figure formed between the curve composed of each downstroke data point and the subsequent downstroke data points and the zero point of the dynamometer card coordinate axis; Determine the difference change rate between the area of the rectangle corresponding to each downstroke data point and the area of the figure corresponding thereto; Judge that if the difference change rate is less than or equal to a predetermined value, then the displacement value of the downstroke data point corresponding to the difference change rate is the effective stroke.

2. The effective stroke determination method based on the equivalent area of a dynamometer card according to claim 1, characterized in that, The method for determining the downstroke data points on the dynamometer card includes: Screen all the data points on the dynamometer card and find the data point with the largest corresponding displacement value; Take the data point after the data point with the largest displacement value as the starting point of the downstroke; Among the two curves formed by the data points between the starting point of the downstroke and the starting point of the dynamometer card curve, the data points on the curve below are the downstroke data points.

3. The effective stroke determination method based on the equivalent area of a dynamometer card according to claim 2, characterized in that: If there are multiple data points with the largest displacement value, then select the first data point that appears as the data point with the largest displacement value; Among them, the first data point that appears is: starting from the starting point of the dynamometer card curve and searching along the upper half of the dynamometer card curve towards the lower half, the first data point with the largest displacement value found.

4. The effective stroke determination method based on the equivalent area of a dynamometer card according to claim 1, characterized in that, The method for determining the area of the rectangle formed between each downstroke data point and the zero point of the dynamometer card coordinate axis includes: Use formula (1) to determine the area of the rectangle formed between each downstroke data point and the zero point of the dynamometer card coordinate axis; JXMJ i = S i P i (1); Where: S i is the displacement value corresponding to the downstroke data point i, and P i is the load value corresponding to the downstroke data point i.

5. The effective stroke determination method based on the equivalent area of a dynamometer card according to any one of claims 1-4, characterized in that, The method for respectively determining the area of the figure formed between the curve composed of each downstroke data point and the subsequent downstroke data points and the zero point of the dynamometer card coordinate axis includes: Use formula (2) to determine the area of the figure formed between the curve composed of each downstroke data point and the subsequent downstroke data points and the zero point of the dynamometer card coordinate axis; Where: m is the starting point of the downward stroke, n is the number of data points in the downward stroke, S i is the displacement value corresponding to the data point i in the downward stroke, P i is the load value corresponding to the data point i in the downward stroke.

6. The effective stroke determination method based on the equivalent area of a dynamometer card according to claim 1, characterized in that, The method for determining the difference change rate between the area of the rectangle corresponding to each downstroke data point and the area of the figure corresponding thereto includes: Use formula (3) to determine the difference change rate between the area of the rectangle corresponding to each downstroke data point and the area of the figure corresponding thereto; MJCZL i = (JXMJ i - QXMJ i ) / JXMJ i (3); In the formula: JXMJ i is the area of the rectangle corresponding to the downstroke data point i, and QXMJ i is the area of the figure corresponding to the downstroke data point i.

7. The effective stroke determination method based on the equivalent area of a dynamometer card according to claim 1, characterized in that: The predetermined value is: 0.

02.

8. An effective stroke determination device based on the equivalent area of the dynamometer card, characterized in that, it includes: an acquisition unit, configured to acquire the dynamometer card of the effective stroke to be determined and determine the downstroke data points on the dynamometer card; an area determination unit, configured to respectively determine the area of the rectangle formed between each downstroke data point and the zero point of the dynamometer card coordinate axis, and respectively determine the area of the figure formed between the curve composed of each downstroke data point and the subsequent downstroke data points and the zero point of the dynamometer card coordinate axis; a difference change rate determination unit, configured to determine the difference change rate between the area of the rectangle corresponding to each downstroke data point and the area of the corresponding figure; an effective stroke determination unit, configured to determine that if the difference change rate is less than or equal to a predetermined value, the displacement value of the downstroke data point corresponding to the difference change rate is the effective stroke.

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