A method for identifying intermittent fluid production of a pumping unit well by a dynamometer card

Abstract

The present application belongs to the technical field of pumping unit well production, and specifically provides a pumping unit well intermittent liquid production indicator diagram discrimination method, which uses real-time collected ground indicator diagrams, obtains ground indicator diagram maximum and minimum load mean values through geometric characteristic method and standard error method, then respectively obtains all sample ground indicator diagram maximum load mean standard deviation and minimum load mean standard deviation, identifies intermittent liquid production wells according to specific threshold values, realizes continuous automatic discrimination of pumping unit well intermittent liquid production, effectively improves oil well interval intelligent level, overcomes the problems of large workload, low efficiency, inability to meet the development needs of oil field intelligent interval pumping, high cost, high failure rate and inability to effectively apply in the method of determining oil well intermittent liquid production, and meets the development needs of oil field intelligent interval pumping, has high judgment accuracy, reduces workload, has high efficiency, is low in cost and effectively applied in actual production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pumping unit well production, and particularly relates to a pumping unit well intermittent liquid production indicator diagram discrimination method. BACKGROUND

[0002] For low-permeability, low-yield and low-pressure "three-low" oilfields, with the year-by-year decrease of oil well yield, the contradiction between formation liquid supply capacity and pumping unit well production parameters is increasingly prominent, and intermittent liquid wells begin to appear in large numbers. If this part of wells continues to be exploited all day long, energy will be wasted, and the service life of the downhole pumping unit will also be affected. Therefore, the oilfield usually adopts intermittent pumping for production. With the promotion of oilfield intelligentization and Internet of Things construction, as one of the most practical and potential technical means for oilfield yield control and reduction investment, oil well intermittent pumping also faces the transformation from manual to intelligentization, and one of the important bases for determining the intermittent pumping system of pumping unit wells is to understand the intermittent liquid production law of the oil well, which requires timely acquisition and analysis of the liquid production state of the oil well. However, with the gradual increase in the number of intermittent pumping oil wells in the oilfield, the workload of manual statistical analysis to determine the liquid production state of the oil well becomes huge and inefficient, which cannot meet the development needs of oilfield intelligent intermittent pumping.

[0003] After consulting relevant patents, there are two methods to obtain the liquid production of the oil well: one is to use a mechanical device to obtain the liquid production, and the patent "Intermittent oil well liquid production indication and check valve" (CN201120382347.9) is involved. The patent uses the turning of the wellhead mechanical device to determine the wellhead liquid production state. This method is relatively direct, but the cost is high, the failure rate is high, and it cannot meet the needs of the digital development of the oilfield. The other method mainly uses the analysis of the oil well indicator diagram to determine the intermittent liquid production of the oil well. This method is currently mainly used for oil well working condition diagnosis and yield calculation, but there is still a lack of effective application for intermittent liquid production judgment of the oil well, and there is still room for further exploration and utilization. SUMMARY

[0004] The pumping unit well intermittent liquid production indicator diagram discrimination method provided by the present application aims to overcome the problems of large workload, low efficiency, and inability to meet the development needs of oilfield intelligent intermittent pumping in the prior art for manual statistical analysis to determine the liquid production state of the oil well. The second purpose is to overcome the problems of high cost, high failure rate, and ineffective application in the prior art for determining the intermittent liquid production of the oil well.

[0005] Therefore, the present application provides a pumping unit well intermittent liquid production indicator diagram discrimination method, which comprises the following steps:

[0006] 1) Collect the ground indicator diagram of the pumping unit in the target time period;

[0007] 2) Convert all the ground indicator diagrams collected in step 1) into pump indicator diagrams;

[0008] 3) According to four geometric feature points obtained from each pump indicator diagram, solve the load line B_FMU and the pump indicator diagram load line B_FMD in each pump indicator diagram; the four geometric feature points are the leftmost point P L , the rightmost point P R , the uppermost point P U , and the lowermost point P D in the pump indicator diagram;

[0009] 4) Determine the opening and closing points of the four valves in each pump indicator diagram; the opening and closing points of the four valves are the fixed valve opening point P SO , the fixed valve closing point P SC , the traveling valve opening point P TO , and the traveling valve closing point P TC ;

[0010] 5) Determine the opening and closing points of the four valves in each ground indicator diagram according to the opening and closing points of the four valves in each pump indicator diagram;

[0011] 6) Solve the maximum load mean standard deviation DM_FMU and the minimum load mean standard deviation DM_FMD of each ground indicator diagram;

[0012] 7) Determine whether each ground indicator diagram is flowing according to the maximum load mean standard deviation and the minimum load mean standard deviation of each ground indicator diagram;

[0013] 8) Determine the oil well flowing period and the non-flowing period in the target time period according to whether each ground indicator diagram is flowing.

[0014] Preferably, the pump indicator diagram load line B_FMU and the pump indicator diagram load line B_FMD in the step 3) are solved by an iterative method, B_BAND=(F D -F U ) / 8, B_BAND is a threshold value; the calculation method of the pump indicator diagram load line B_FMU is: walking through an upstroke, starting from the point P L and iteratively calculating to the point P R , the iteration condition is |F(i)-F U |<B_BAND; the calculation method of the pump indicator diagram load line B_FMD is: walking through a downstroke, starting from the point P R and iteratively calculating to the point P L , the iteration condition is |F(i)-F D |<B_BAND.

[0015] Preferably, the calculation formula of the pump indicator diagram load line B_FMU is:

[0016]

[0017] Where, Fi is the i sample load value, U i is the i sample position value.

[0018] Preferably, the calculation formula of the pump work diagram load line B_FMD is:

[0019]

[0020] Preferably, the method of determining the opening and closing points of the four valves in each pump work diagram is the same and is the method of solving the standard deviation of the average load change through the stationary point.

[0021] Preferably, the method of solving the standard deviation of the average load change through the stationary point to determine the opening point P SO of the fixed valve in each pump work diagram includes the following steps:

[0022] 4.1) Dividing the F1 region, the F2 region, the F3 region and the F4 region in the pump work diagram, wherein the opening point P SO of the fixed valve is in the F1 region, the closing point P SC of the fixed valve is in the F2 region, the opening point P TO of the traveling valve is in the F3 region, and the closing point P TC of the traveling valve is in the F4 region;

[0023] 4.2) In the F1 region, between the point P1 and the point K, assuming that a point is the opening point P SO of the fixed valve, then from P1 to P SO , the standard deviation of the load change is shown in formula (3)

[0024]

[0025] Wherein: F1, F2, …, F n : P1 to P SO all load change sample data;

[0026] P1 to PSO all load change average;

[0027] n: the number of load change between sample points;

[0028] From P SO to the point K, the standard deviation of the load change is shown in formula (4)

[0029]

[0030] Wherein: F n+1 , F n+2 , …, F n+m : P SOThe total load change amount sample data of K;

[0031] P SO The total load change amount average of K;

[0032] m: the number of load change amount between sample points;

[0033] The standard error of the total average load change amount between the above two sample inner adjacent points is shown in formula (5)

[0034] Z(P SO ) = σ1+ σ2 (5)

[0035] When Z = min{Z(P SO )}, P SO is the fixed valve opening point;

[0036] 4.3) The fixed valve closing point P SC , the sliding valve opening point P TO and the sliding valve closing point P TC are obtained by using the method of step 4.2).

[0037] Preferably, the calculation method of the standard deviation of the maximum load average DM_FMU of the ground dynamometer diagram in step 6) is shown in formula (6)

[0038]

[0039] Wherein: N≤144.

[0040] Preferably, the calculation method of the standard deviation of the minimum load average DM_FMD of the ground dynamometer diagram in step 6) is shown in formula (7)

[0041]

[0042] Preferably, the method for judging whether each ground dynamometer diagram is liquid or not in step 7) is:

[0043] When σ DM_FMU <1 and , it means that the ground dynamometer diagram does not produce liquid at this time;

[0044] When σ DM_FMU <1 and , it means that the ground dynamometer diagram produces liquid at this time.

[0045] Preferably, the target time period in step 1) is one day, and one ground dynamometer diagram is collected every 10 minutes.

[0046] The beneficial effects of the present application are:

[0047] The method for identifying intermittent fluid production dynamometer diagrams in pumping wells provided by this invention mainly utilizes real-time acquired surface dynamometer diagrams, and proceeds through the following eight steps: 1) Acquiring surface dynamometer diagrams of the pumping unit within a target time period; 2) Converting all surface dynamometer diagrams acquired in step 1) into pump dynamometer diagrams; 3) Based on four geometric feature points obtained from each pump dynamometer diagram, solving for the upper load line B_FMU and lower load line B_FMD of each pump dynamometer diagram; the four geometric feature points are the leftmost point P in the pump dynamometer diagram. L The rightmost point P R , the top point P U The lowest point P D 4) Determine the switching points of the four valves in each pump operation diagram; the switching points of the four valves are the fixed valve opening points P. SO Fixed valve closing point P SC , the opening point P of the traveling valve TO and the valve closing point P TC 5) Determine the switching points of the four valves in each surface dynamometer diagram based on the switching points of the four valves in each pump dynamometer diagram; 6) Solve for the standard deviation of the maximum load mean DM_FMU and the standard deviation of the minimum load mean DM_FMD in each surface dynamometer diagram; 7) Determine whether liquid is being produced in each surface dynamometer diagram based on the standard deviation of the maximum load mean and the standard deviation of the minimum load mean in each surface dynamometer diagram; 8) Determine the liquid production period and non-liquid production period of the oil well within the target time period based on whether liquid is being produced in each surface dynamometer diagram; This achieves continuous automatic identification of intermittent liquid production in pumping wells, effectively improving the level of intelligent intermittent pumping in oil wells, meeting the development needs of intelligent intermittent pumping in oil fields, with an accuracy rate of over 95%, reducing workload, increasing efficiency, reducing cost, and effectively applicable to actual production. Attached Figure Description

[0048] The present invention will now be described in further detail with reference to the accompanying drawings.

[0049] Figure 1 This is a flowchart illustrating the method for identifying intermittent fluid production indicator diagrams in pumping wells;

[0050] Figure 2 It is a composition diagram of the ground construction drawing;

[0051] Figure 3 This is a diagram illustrating the composition of a pump power diagram;

[0052] Figure 4 This is a diagram showing the switching points of the four valves in the pump operation diagram;

[0053] Figure 5 It is an intermittent discharge curve. Detailed Implementation

[0054] Example 1:

[0055] likeFigures 1-5 As shown in the figure, a pumping unit well intermittent fluid indicator diagram distinguishing method comprises the following steps:

[0056] 1) Collect the ground indicator diagram of the pumping unit in the target time period;

[0057] The ground indicator diagram is the relationship curve of the pumping unit suspension point load and its displacement, which is obtained by synchronously collecting the displacement sensor and the load sensor of the pumping unit well RTU. A ground indicator diagram contains 200 data points inside, and each data point contains load displacement information. As shown in the figure, the horizontal coordinate of the ground indicator diagram is the displacement value, and the vertical coordinate is the load value. Figure 2

[0058] The load line DM_FMU on the ground indicator diagram: from the fixed valve opening point to the fixed valve closing point, all the data points in the middle correspond to the average load, also known as the maximum average load of the ground indicator diagram.

[0059] The load line DM_FMD on the ground indicator diagram: from the traveling valve opening point to the traveling valve closing point, all the data points in the middle correspond to the average load, also known as the minimum average load of the ground indicator diagram.

[0060] The load difference DM_FL of the ground indicator diagram: the difference between the maximum average load of the ground indicator diagram and the minimum average load of the ground indicator diagram.

[0061] 2) Convert all the ground indicator diagrams collected in step 1) into pump indicator diagrams;

[0062] The relationship curve of the load and its displacement at the connection between the pumping rod and the pump plunger is obtained by converting the ground indicator diagram into the pump indicator diagram. The conversion method of the ground indicator diagram into the pump indicator diagram is the prior art, and its specific conversion method is not introduced in detail here.

[0063] 3) According to the four geometric feature points obtained from each pump indicator diagram, the load line B_FMU on the pump indicator diagram and the load line B_FMD on the pump indicator diagram are solved in each pump indicator diagram; the four geometric feature points are the leftmost point P L , the rightmost point P R , the uppermost point P U , and the lowermost point P D of the pump indicator diagram; (see Figure 3 )

[0064] 4) Determine the opening and closing points of the four valves in each pump indicator diagram; the opening and closing points of the four valves are the fixed valve opening point P SO , the fixed valve closing point P SC , the traveling valve opening point P TO , and the traveling valve closing point P TC ;

[0065] ​Standard error refers to the standard deviation of sample mean in repeated equal-precision measurement, reflecting the variation degree of sample mean to population mean. When sample changes, sample mean also changes, and the variation degree of sample mean to population mean also changes. By using the property of standard error method, the points most likely to be opened and closed by the traveling valve and the fixed valve in the pump diagram can be calculated.

[0066] 5) Determine the opening and closing points of the four valves in each ground dynamometer diagram according to the opening and closing points of the four valves in each pump diagram;

[0067] 6) Calculate the standard deviation of the maximum load average DM_FMU and the minimum load average DM_FMD of each ground dynamometer diagram;

[0068] 7) Determine whether each ground dynamometer diagram is liquid output according to the standard deviation of the maximum load average and the minimum load average of each ground dynamometer diagram;

[0069] 8) Determine the liquid output period and non-liquid output period in the target time period according to whether each ground dynamometer diagram is liquid output.

[0070] The intermittent liquid output dynamometer diagram discrimination method for pumping unit wells provided by the application mainly uses the real-time collected ground dynamometer diagram, realizes the continuous automatic discrimination of the intermittent liquid output of pumping unit wells through the above-mentioned eight steps, effectively improves the intelligent level among oil wells, meets the development needs of oil field intelligent pumping, and has a judgment accuracy of more than 95%, reduces the workload, is high in efficiency, low in cost, and can be effectively applied to actual production.

[0071] Preferably, the load line B_FMU and the pump diagram load line B_FMD in the step 3) are solved by an iterative method, B_BAND=(F D -F U ) / 8, B_BAND is a threshold value; the calculation method of the pump diagram load line B_FMU is: walking an upstroke, starting from P L point and iteratively calculating to P R point, the iteration condition is |F(i)-F U |<B_BAND; the calculation method of the pump diagram load line B_FMU is: walking an upstroke, starting from P R point and iteratively calculating to P L point, the iteration condition is |F(i)-F D |<B_BAND.

[0072] According to the actual operation on site, B_BAND=(F D -F U ) / 8, which is the best practicability and applicability, and has high calculation precision.

[0073] Preferably, the calculation formula of the load line B_FMU on the pump performance map is:

[0074]

[0075] wherein F i is the sample load value at i point, U i is the sample position value at i point.

[0076] Preferably, the calculation formula of the load line B_FMD on the pump performance map is:

[0077]

[0078] Preferably, the method for determining the opening point of each valve in the pump performance map in step 4) is the same and is the method of solving the standard deviation of the average load change by stationary point.

[0079] Preferably, the method for determining the opening point P SO of the fixed valve in each pump performance map by the method of solving the standard deviation of the average load change by stationary point comprises the following steps (see Figure 4 ):

[0080] 4.1) Dividing the F1 region, the F2 region, the F3 region and the F4 region in the pump performance map, wherein the opening point P SO of the fixed valve is in the F1 region, the closing point P SC of the fixed valve is in the F2 region, the opening point P TO of the traveling valve is in the F3 region, and the closing point P TC of the traveling valve is in the F4 region;

[0081] Taking the opening point P SO of the fixed valve as an example, from the point P1 to the opening point P SO of the fixed valve, the sucker rod is in a loading state, so the load change between the sample points in the region from the point P1 to the opening point P SO of the fixed valve in the pump performance map is large; similarly, from the opening point of the fixed valve to the point K, the load change is small. Herein, the load change between adjacent points in the region is set as a single sample point, and the average load change between all adjacent points in the region is set as the overall sample average load change. Therefore, the standard deviation of the average load change can be solved by stationary point to find the opening point P SO of the fixed valve.

[0082] 4.2) In the F1 region, between the point P1 and the point K, assuming that a point is the opening point P SO of the fixed valve, then from P1 to P SO , the standard deviation of the load change is shown in formula (3)

[0083]

[0084] F1, F2, …, F n : P1 to P SO All load change sample data;

[0085] P1 to PSO All load change average;

[0086] n: the number of load changes between sample points;

[0087] From P SO to K points, the load change standard deviation is formula (4)

[0088]

[0089] F1, F2, …, F n+1 , …, F n+2 , …, F n+m : P SO to K All load change sample data;

[0090] P SO to K All load change average;

[0091] m: the number of load changes between sample points;

[0092] The standard error of the above two sample load changes between adjacent points to the overall average load change is formula (5)

[0093] Z(P SO ) = σ1+σ2 (5)

[0094] When Z = min{Z(P SO )}, P SO is the fixed valve opening point;

[0095] 4.3) Use the method of step 4.2), that is, the fixed valve closing point P SC , the movable valve opening point P TO and the movable valve closing point P TC are obtained.

[0096] Through the above method, the remaining three points (the fixed valve closing point P SC , the movable valve opening point P TO and the movable valve closing point P TC ) can be accurately determined. After determining the four valve switching points of the pump indicator diagram, the four valve switching points of the ground indicator diagram can be deduced.

[0097] Generally, the intermittent production law of oil well is difficult to grasp, the interval period of oil well production changes constantly, but the overall presents the following phenomena: the maximum load has no obvious change, the minimum load is obviously smaller when producing, and obviously larger when not producing, and the overall presents a sawtooth change trend.

[0098] In the actual judgment process, the ground dynamometer card collected in 1 day is taken as a sample, and the system generally collects a ground dynamometer card data every 10 minutes according to the requirements, that is, there are at most 144 ground dynamometer card data in a day. First, the four valve switching points of each ground dynamometer card are determined according to the above method, the ground dynamometer card maximum load average DM_FMU and the ground dynamometer card minimum load average DM_FMD can be obtained, and then the standard deviations of the maximum load average and the minimum load average of all samples are calculated, and the intermittent production well is identified according to the specific threshold value, and the specific algorithm process is as follows:

[0099] (1) Calculate the standard deviation of the ground dynamometer card maximum load average

[0100] Preferably, the calculation method of the ground dynamometer card maximum load average DM_FMU standard deviation in step 6) is shown in formula (6)

[0101]

[0102] Wherein: N≤144.

[0103] (2) Calculate the standard deviation of the ground dynamometer card minimum load average

[0104] Preferably, the calculation method of the ground dynamometer card minimum load average DM_FMD standard deviation in step 6) is shown in formula (7)

[0105]

[0106] (3) Intermittent production judgment criterion

[0107] Preferably, the method for judging whether each ground dynamometer card is producing or not in step 7) is:

[0108] When σ DM_FMU <1 and , it means that the ground dynamometer card (the i-th ground dynamometer card) does not produce at this time;

[0109] When σ DM_FMU <1 and , it means that the ground dynamometer card (the i-th ground dynamometer card) produces at this time.

[0110] Preferably, the target time period in step 1) is one day, and a ground dynamometer card is collected every 10 minutes.

[0111] Example 2:

[0112] A method for identifying intermittent fluid production indicator diagrams in oil pumping wells includes the following steps:

[0113] Collect surface dynamometer diagrams of the pumping unit within the target time period; specifically, collect surface dynamometer diagram data of the pumping unit through the oilfield SCADA control system, and select all surface dynamometer diagram data of a day as a sample;

[0114] 2) Convert all ground dynamometer maps collected in step 1) into pump power maps; specifically, through the ground dynamometer map to pump power map conversion module, the collected ground dynamometer maps are converted into pump power maps using the corresponding mathematical model;

[0115] 3) Based on the four geometric feature points obtained from each pump dynamometer diagram, solve for the upper load line B_FMU and lower load line B_FMD of each pump dynamometer diagram; the four geometric feature points are the leftmost point P in the pump dynamometer diagram. L The rightmost point P R , the top point P U The lowest point P D ;

[0116] Specifically, the pump power is obtained through data analysis of the pump power diagram. Figure Four After identifying the geometric feature points, the upper and lower load lines of the pump power diagram are obtained by applying an iterative algorithm using the module for solving the upper and lower load lines of the pump power diagram.

[0117] 4) Determine the switching points of the four valves in each pump operation diagram; the switching points of the four valves are the fixed valve opening points P. SO Fixed valve closing point P SC , the opening point P of the traveling valve TO and the valve closing point P TC ;

[0118] Specifically, pump power Figure Four The valve switching point solution module uses the upper load line, lower load line, and standard error algorithm of the pump power diagram to obtain the opening and closing points of fixed valves and floating valves in the pump power diagram.

[0119] 5) Determine the switching points of the four valves in each ground dynamometer diagram based on the switching points of the four valves in each pump dynamometer diagram;

[0120] Specifically, ground-based power demonstration Figure Four The valve switching point solution module uses pump power Figure Four The four valve switching points on the ground dynamometer diagram can be derived from the valve switching points.

[0121] 6) Calculate the standard deviation of the maximum load mean DM_FMU and the standard deviation of the minimum load mean DM_FMD for each ground dynamometer chart;

[0122] 7) According to the maximum load mean standard deviation and the minimum load mean standard deviation of each ground dynamometer diagram, whether each ground dynamometer diagram is out of liquid is judged;

[0123] 8) According to whether each ground dynamometer diagram is out of liquid, the oil well out of liquid period and the oil well not out of liquid period in the target time period are determined;

[0124] 9) The corresponding curves are exported by the drawing module Figure 5 ), in which the purple line (the fourth line from top to bottom according to the left end) represents the green line (the first line from top to bottom according to the left end) represents the brown line (the second line from top to bottom according to the left end) represents the mean and the blue line (the third line from top to bottom according to the left end) represents the minimum load mean line of the ground dynamometer diagram.

[0125] According to the intermittent out of liquid diagnosis criterion, the part above the intersection of the blue line and the green line is the not out of liquid period, and the remaining part is the out of liquid period.

[0126] The present application is based on the ground dynamometer diagram data of the pumping well, the intermittent out of liquid of the pumping well is judged by using the geometric characteristic method and the standard error method, the ground dynamometer diagram data of the oilfield is collected by using the oilfield SCADA system, the maximum load mean of the ground dynamometer diagram and the minimum load mean of the ground dynamometer diagram are obtained by using the geometric characteristic method and the standard error method, then the maximum load mean standard deviation and the minimum load mean standard deviation of all sample ground dynamometer diagrams are obtained, the intermittent out of liquid well is identified according to the specific threshold, and finally the continuous automatic discrimination of the intermittent out of liquid of the pumping well is realized, and the judgment accuracy is more than 95%.

[0127] In the description of the present application, it should be understood that if the orientation or position relationship indicated by the terms such as "upper", "lower" and the like is based on the orientation or position relationship shown in the drawings, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the position relationship in the drawings are only used for exemplary description, and cannot be understood as a limitation on the present application.

[0128] The above examples are only illustrative of the present application, and do not constitute a limitation on the protection scope of the present application, and any design identical or similar to the present application belongs to the protection scope of the present application.

Claims

1. A method for identifying intermittent fluid production of a pumping unit well by using a dynamometer card, characterized in that: The method comprises the following steps: 1) collecting surface dynamometer cards of pumping units in a target time period; 2) converting all the surface dynamometer cards collected in step 1) into pump dynamometer cards; 3) solving the load line B_FMU and the pump diagram load line B_FMD in each pump diagram according to four geometric feature points obtained from each pump diagram; the four geometric feature points are the leftmost point P L , the rightmost point P R , the uppermost point P U , and the lowermost point P D in the pump diagram; the pump diagram load line B_FMU and the pump diagram load line B_FMD in step 3) are solved by an iterative method, B_BAND=(F D -F U ) / 8, B_BAND is a threshold value; the calculation method of the pump diagram load line B_FMU is: walking through an upstroke, starting from the point P L and iteratively calculating to the point P R , and the iteration condition is ; The calculation method of the pump work diagram load line B_FMD is as follows: walking a down stroke, starting from P R point and iteratively calculating to P L point, the iteration condition is ; 4) determining the opening and closing points of the four valves in each pump work diagram; the opening and closing points of the four valves are the fixed valve opening point P SO , the fixed valve closing point P SC , the traveling valve opening point P TO and the traveling valve closing point P TC ; the method of step 4) determining the opening and closing points of the four valves in each pump work diagram is the same and is the method of solving the standard deviation of the average load change by using the stationary point. 5) determining the opening and closing points of the four valves in each surface dynamometer card according to the opening and closing points of the four valves in each pump dynamometer card; 6) solving the maximum load average standard deviation DM_FMU and the minimum load average standard deviation DM_FMD of each surface dynamometer card; 7) judging whether each surface dynamometer card is flowing or not according to the maximum load average standard deviation and the minimum load average standard deviation of each surface dynamometer card; the method for judging whether each surface dynamometer card is flowing or not in step 7) is as follows: When and , it means that the ground dynamometer diagram at this time does not produce liquid; When and , indicates that the ground indicator diagram at this time is liquid; 8) determining the flowing time period and the non-flowing time period of the oil well in the target time period according to whether each surface dynamometer card is flowing or not.

2. The method of claim 1, wherein: The calculation formula of the load line B_FMU on the pump dynamometer card is as follows: Formula (1) wherein, F i is i point sample load values, U i is i point sample position values.

3. The method of claim 1, wherein: The calculation formula of the load line B_FMD on the pump dynamometer card is as follows: Equation (2).

4. The method of claim 1, wherein: The method for determining the fixed valve opening point P in each pump work diagram by solving the standard deviation of the load average change amount through the stationary point SO The method comprises the following steps: 4.1) Dividing F1 region, F2 region, F3 region and F4 region in the pump work diagram, where the fixed valve opening point P SO is in the F1 region, the fixed valve closing point P SC is in the F2 region, the traveling valve opening point P TO is in the F3 region, the traveling valve closing point P TC is in the F4 region; 4.2) In the F1 region, between the points P1 to K, assume a point as a fixed valve opening point P SO , then from P1 to P SO , the load variation standard deviation is seen in equation (3) （3） wherein: F1, F2,..., F n : P1 to P SO All load production variation sample data; : P1 to PSO all load change amount mean; n: the number of load change amounts between sample points; From P SO To K point, load variation standard deviation is seen in equation (4) （4） Where: F n+1 , F n+2 ,..., F n+m : P SO to K all load change volume sample data; : P SO Mean change from baseline in total load of K m: the number of load change amounts between sample points; The standard error of the load change amount between the above two sample points to the overall average load change amount is as shown in formula (5) （5） When Z = min{ Z(P SO )}, P SO is the fixed valve opening point. 4.3) The method of step 4.2) is used, i.e. the fixed valve closing point P SC , the valve opening point P TO and the valve closing point P TC are determined.

5. The method of claim 1, wherein: The calculation method of the maximum load average standard deviation DM_FMU of the surface dynamometer card in step 6) is as shown in formula (6) , Equation (6) Wherein, N≤144.

6. The method of claim 1, wherein: The calculation method of the minimum load average standard deviation DM_FMD of the surface dynamometer card in step 6) is as shown in formula (7) , formula (7).

7. The method of claim 1, wherein: The target time period in step 1) is one day, and one surface dynamometer card is collected every 10 minutes.

Images