COMPUTER-IMPLEMENTED METHOD FOR DETERMINING AN OPERATIONAL PROPERTY OF A DRILL-ROD BOREHOLE PUMP, ANALYSIS DEVICE, AND PUMP SYSTEM FOR SAME

Abstract

A computer-implemented method for determining an operational property of a drill-rod borehole pump. A load-distance diagram with curve points for the pump is ascertained by an analysis device using a detection device and is provided as an operational load-distance diagram with operational curve points. Wherein in a training mode, a load-distance diagram model for the pump with model curve points is generated and trained on the basis of machine learning, at least two specified analysis regions are determined in the load-distance diagram model, and a reference point is ascertained from the model curve points of at least one region. In an operating mode for the operational load-distance diagram, a check is carried out to determine whether the at least one reference point is contained within the surface contained by the operational curve points, and if so, the operational property of the conveyor pump is determined therefrom.

Claims

1. A computer-implemented method for determining an operating property of a pumpjack, wherein the pumpjack has a pump head, which is connected to a kinematic converter via a rod system, and the kinematic converter is driven by a motor during operation and a load-travel graph containing curve points is determined for the pumpjack by an analysis device using a recording device and is provided as an operating load-travel graph containing operating curve points, the method comprising: in a training mode, producing and training by the analysis device at least one load-travel graph model for the pumpjack containing model curve points on the basis of machine learning, and determining at least two predefined analysis ranges comprising at least some of the model curve points in the at least one load-travel graph model, and using the model curve points in at least one range from the analysis ranges to ascertain a reference point, and, in an operating mode, checking the operating load-travel graph for whether the at least one reference point determined in the training mode is enclosed within an area enclosed by the operating curve points, and if so, determining the operating property of the pumpjack therefrom.

2. The method as claimed in claim 1, wherein the geometric center of an area that is defined by the model curve points in the respective range is used for determining the reference point.

3. The method as claimed in claim 1, wherein a reference point is determined for each range.

4. The method as claimed in claim 1, wherein at least one analysis range is defined by a polygon.

5. The method as claimed in claim 1, wherein at least four ranges are determined.

6. The method as claimed in claim 5, wherein the ranges overlap one another at least in part.

7. The method as claimed in claim 1, wherein at least one range is defined for which there is provision for no enclosed curve point to be taken into account for the subsequent check.

8. The method as claimed in claim 1, wherein derived curve data from the load-travel graph model and underlying operating curve points from the operating load-travel graph are normalized with respect to one another for the check in the operating mode.

9. The method as claimed in claim 1, wherein the motor is electrically operated and the recording device is designed to record electrical power consumption of the motor during the operation thereof, from which power consumption the operating properties of the pumpjack are determined.

10. The method as claimed in claim 1, wherein the operating curve points and the model curve points each have intervals between two adjacent points on the respective curves that are on average at least 50% of the greatest interval between two adjacent points on the respective curve.

11. A computer program stored on a non-transitory computer readable medium, comprising: instructions stored thereon that, when executed by a computer, cause said computer to carry out the method as claimed in claim 1.

12. A non-transitory electronically readable data carrier comprising: readable control information stored thereon, which control information comprises at least a computer program configured in such a way that it performs a method as claimed in claim 1 when the data carrier is used in a computing apparatus.

13. A non-transitory data carrier comprising: the computer program as claimed in claim 11.

14. An analysis device comprising: a memory for determining an operating property of a pumpjack, wherein the analysis device is designed to analyze a provided operating load-travel graph using the method as claimed in claim 1 and to ascertain the operating property therefrom.

15. A pump system for determining an operating property of a pumpjack, wherein the pumpjack comprises a pump head, which is connected to a kinematic converter via a rod system, and the kinematic converter is driven by a motor during operation, the pump system comprising: a recording device, designed to record and provide a load-travel graph relating to the pumpjack containing curve points, and the analysis device as claimed in claim 14 designed to ascertain the operating property from the provided operating load-travel graph.

16. The method as claimed in claim 5, wherein at least six ranges are determined.

17. The method as claimed in claim 5, wherein at least eight ranges are determined.

18. The method as claimed in claim 5, wherein the ranges are adjacent to one another.

19. The method as claimed in claim 10, wherein the operating curve points and the model curve points each have intervals between two adjacent points on the respective curves that are on average at least at least 80% of the greatest interval between two adjacent points on the respective curve.

20. The method as claimed in claim 10, wherein the operating curve points and the model curve points each have intervals between two adjacent points on the respective curves that are on average at least 95% of the greatest interval between two adjacent points on the respective curve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The invention is explained in more detail below on the basis of an exemplary embodiment that is shown in the accompanying drawings, in which:

[0070] FIG. 1 shows an exemplary embodiment of a system according to the invention with a pumpjack,

[0071] FIG. 2 shows an exemplary embodiment of a pump head of a pumpjack,

[0072] FIG. 3 shows an exemplary embodiment of a flowchart for a method for determining a load-travel graph from the power consumption of an electrically operated pump motor,

[0073] FIG. 4 shows a first exemplary embodiment of a load-travel graph,

[0074] FIG. 5 shows load-travel graphs for a pump for different powers,

[0075] FIG. 6 shows load-travel graphs for a pump for different loads and operating modes,

[0076] FIG. 7 shows a temporal representation of a current characteristic of an electric drive motor for a pumpjack,

[0077] FIG. 8-12 show examples of operating load-travel graphs containing curve points.

DETAILED DESCRIPTION OF INVENTION

[0078] FIG. 1 shows an exemplary embodiment of a pump system 100 according to the invention with a pumpjack 1 of sucker rod pump type.

[0079] The pump system 100 comprises a pump head 110, which is connected to a kinematic converter 120 via a rod system 5, 10.

[0080] The rod system 5, 10 forms a so-called “rod string” and runs through a wellhead 6, to which a flowline 7 for drawing off a conveyed medium 14 is connected.

[0081] The wellhead 6 is adjoined by a casing 8, in which a tubing 9 that guides the rod system 5 or 10 runs.

[0082] Attached to the lower end of the rod system 10 is the pump head 110, which contains a plunger 11 in a barrel 12. A movement by the plunger 11 results in the conveyed medium 14 being pumped away.

[0083] The casing 8 is formed in a well 13.

[0084] The kinematic converter 120 is driven for example by a prime mover in the form of an electric motor 3 via a gear reducer 4. The kinematic converter 120 can additionally comprise a hydraulic force amplifier.

[0085] The mechanical link for the kinematic converter 120 is provided in this example by way of a walking beam 2, but can vary depending on the pump type used.

[0086] A person skilled in the art is familiar with such kinematic converters, as with the description thereof, in the form of “properties of a kinematic converter”, by the transformation function of mechanical movements and forces.

[0087] The kinematic converter 120 converts a rotational movement of the motor 3 into a linear movement of the rod system 5, 10.

[0088] The properties of the kinematic converter 120 can be described for example by way of lever actions and translations, and also by way of the electrical drive power and moving masses. It should be remembered that the position of a flywheel mass along a rotational movement and the corresponding force effect on the rod system 10 have a temporal relationship, referred to as the reference phase angle. A reference phase angle can be determined for a respective pump arrangement by applying the kinematic principles of mechanics, as is known to a person skilled in the art.

[0089] Furthermore, there is provision for a recording means 130, which is designed to record the current draw and the operating voltage of the individual phases of the motor 3 during the operation thereof. This can be achieved by way of an ammeter or voltmeter, for example, which records discrete measurement points containing current or voltage values in particular with high temporal resolution.

[0090] The recorded current and operating voltage values can be used to determine the effective power consumption and the apparent power consumption.

[0091] Furthermore, there is provision for an analysis or computing device 140 having a memory 150, designed to carry out the method according to the invention using the recording means 130.

[0092] A person skilled in the art knows how a reference phase angle can be ascertained for the kinematic converter 120 by using the properties of the kinematic converter 120 and the power consumption 72 of the motor 3, which reference phase angle describes the relationship between the maximum 83 of the power consumption 72 and the maximum of the force acting on the rod system of the subsurface pump 1.

[0093] A person skilled in the art also knows how a torque characteristic can be ascertained from the power consumption 72 of the motor 3 by using the properties of the kinematic converter 120.

[0094] The recording means 130 is designed to record an operating load-travel graph for the pump 1 containing curve points and to provide it to the computing or analysis device 140 having the memory 150.

[0095] The analysis device 140 is designed to analyze the provided operating load-travel graph using the method according to the invention and to ascertain the operating property therefrom.

[0096] The method according to the invention can be implemented as a computer program comprising instructions that, when executed by a computer 140, cause said computer to carry out the method according to the invention.

[0097] Furthermore, the method according to the invention can be available as an electronically readable data carrier having readable control information stored thereon, which control information comprises at least the computer program according to the invention and is configured in such a way that it performs the method according to the invention when the data carrier is used in a computing apparatus 140.

[0098] The method according to the invention can also be available as a data carrier signal that transmits the computer program according to the invention.

[0099] FIG. 2 shows a further, more detailed example of a pump head 111 according to the prior art.

[0100] The rod string, or the rod system 10, is driven in accordance with FIG. 1 and set in an up-and-down linear motion.

[0101] In the variant of the pump head 111 that is shown, the well 13 contains a cover tube 15 with vertical grooves that, inside the cover tube 15, guides a rotating tube 18 with spiral grooves by way of a retaining device 16 and a self-aligning bearing 17.

[0102] A recording tube 19 is connected by way of a winged nut 20 to a plunger assembly 21 located in a pump liner 22.

[0103] A calibrated rod 23 is connected by way of a stylus 24 and a retaining device 25 to the rod system 10, which drives the plunger assembly by way of the linear movement.

[0104] FIG. 3 shows an exemplary embodiment of a flowchart for a method for determining a load-travel graph from the power consumption of an electrically operated pump motor, having the following steps: [0105] a) recording the current draw and the operating voltage of the motor 3 at a sampling frequency over at least one pump cycle, which can be assigned to in each case four operating phases of the subsurface pump 1, in the form of discrete measurement points containing current values, and determining the power consumption 72 of the motor 3 therefrom using power values, [0106] b) determining a period duration 85 and a maximum 82 of the power consumption 72, corresponding to the torque maximum of the subsurface pump 1, for a pump cycle, c) determining a reference phase angle for the kinematic converter 120 by using the properties of the kinematic converter 120 and the power consumption of the motor 3, which reference phase angle describes the relationship between the maximum 82 of the power consumption and the maximum of the force acting on the rod system of the subsurface pump 1, [0107] d) ascertaining a torque characteristic from the power consumption of the motor 3 by using the properties of the kinematic converter 120, [0108] e) determining the operating properties of the delivery pump 1 from the torque characteristic ascertained in step d) by using the period duration determined in step b) and the reference phase angle determined in step c).

[0109] The power values can be determined by way of the product of the discrete current values and the operating voltage.

[0110] The period duration 85 can be ascertained by way of the power values of the measurement points, for example using an approximated polynomial 80.

[0111] However, the period duration 85 can also be ascertained for example using a polynomial 80 that takes statistical mean values of the power values of the respective measurement points over at least five, preferably at least ten, particularly preferably at least fifty, pump cycles into account for interpolation points of the polynomial.

[0112] A reference value 81 at which there is a maximum for the change in the respective power value between two directly successive measurement points can be ascertained for the measurement points, and the period duration 85 is ascertained using the reference value 81.

[0113] The operating properties of the delivery pump 1 can be determined using a load-travel graph 30, 50, 54, 57, 60-65, which is ascertained from the torque characteristic ascertained in step d) by using the period duration determined in step b) and the reference phase angle determined in step c).

[0114] The reference phase angle can be determined in relation to the absolute maximum of the power values of the measurement points within a pump cycle.

[0115] FIG. 4 to FIG. 6 show examples of load-travel graphs, which are frequently used to determine the operating properties of pumpjacks.

[0116] FIG. 4 shows a load-travel graph 30.

[0117] The x-axis plots the position 31 of the polished rod, and the y-axis plots the load 32 on the polished rod.

[0118] A lowest point of the pump stroke 33 and a highest point of the pump stroke 34 can be seen.

[0119] Furthermore, a peak of the polished rod 35 (PPRI) is shown.

[0120] A dashed line is used to show a card 36 of the polished rod for pump speed equal to zero.

[0121] Furthermore, a card 37 of the polished rod for pump speed greater than zero is shown.

[0122] A minimum load on the polished rod 38 (MPRL) is shown.

[0123] A gross plunger load 39 can also be read off.

[0124] Additionally, a weight of the rods in the fluid 40 can be determined, and also forces 41 and 42, and a pump stroke or pump travel 43.

[0125] FIG. 5 shows load-travel graphs 50 showing rod load for specified value as a function of the load 32 on the polished rod over the respective position 31 of the polished rod.

[0126] A load-travel graph 51 shows operation of full pump power.

[0127] A load-travel graph 52 shows operation when the conveyed medium has been pumped dry.

[0128] A respective specified value 53 can be seen.

[0129] Furthermore, load-travel graphs 54 showing rod load for a change of operation as a function of the load 32 on the polished rod over the respective position 31 of the polished rod are shown, with respective angles 55, 56 being able to be read off.

[0130] Furthermore, load-travel graphs 57 showing rod load with the respective mechanical work of the rods are shown.

[0131] FIG. 6 shows load-travel graphs 60-65 for different operating states.

[0132] Graph 60 shows load-travel graphs for normal operation.

[0133] Graph 61 shows load-travel graphs for a fluid deposit.

[0134] Graph 62 shows load-travel graphs for the influence of gas in the underground deposit.

[0135] Graph 63 shows a load-travel graph for a stuck plunger.

[0136] Graph 64 shows a load-travel graph for a leak through a standing valve.

[0137] A graph 65 shows a load-travel graph for a leak through a moving valve.

[0138] FIG. 7 shows an example of a temporal representation of a power characteristic of an electric drive motor for a pumpjack, which has been ascertained from the current draw and operating voltage of the motor 3.

[0139] The representation has a time axis 70 and an axis 71 for the amplitude of the current draw or power consumption.

[0140] A power consumption 72 is shown, for which it is possible to determine a zero point, or zero axis 80, and a polynomial for averaged power consumption 81.

[0141] A maximum value of the averaged power consumption 82 and zero crossings in the averaged power consumption 83, 84 can be ascertained for the polynomial 80.

[0142] Furthermore, a period duration 85 of the averaged power consumption can be determined for the polynomial 80.

[0143] This can be used to ascertain a phase angle 86 of the averaged power consumption, describing the relationship between the rotational movement of the motor 3 and the rod system 10 of the pump 1.

[0144] The ascertained values can be used to ascertain a corresponding load-travel graph in order to easily derive the operating properties of the pumpjack 1 therefrom. It can be seen that the absolute value of the period duration 85 does not need to be taken into account in a further calculation of the load-travel graph.

[0145] In other words, determining the power consumption does not require the drive frequency of the pump motor to be taken into account.

[0146] The desired operating properties of the pumpjack 1 can be defined by one or more appropriate load-travel graphs in terms of “specified values”, which are produced and trained as a machine-learning-based model in a training mode. It is also possible to use load-travel graphs relating to other pumps in this regard.

[0147] By way of example, a question about the gas content in an oil-water-gas mixture from a mining site can be answered by creating and training a training model for a known mixture.

[0148] Different training models can be produced for different questions regarding the state of the pump and the components thereof, and also the composition of the conveyed mixture.

[0149] This training model is used as a reference to an operating load-travel graph.

[0150] Differences in the operating load-travel graph from the training model can be identified as an undesirable operating property.

[0151] In a training mode, a load-travel graph model containing model curve points is produced and trained by the analysis device 140 on the basis of machine learning.

[0152] At least two predefined analysis ranges comprising at least some of the model curve points are then determined in the load-travel graph model.

[0153] The model curve points are then used to ascertain a reference point for at least one range from the analysis ranges, which reference point corresponds for example to the geometric center of the curve points in the respective range, or area formed by the curve points and the range limits, for example the graph axes.

[0154] In an operating mode, the analysis device 140 checks for the operating load-travel graph whether the at least one reference point determined in the training mode is enclosed within the area enclosed by the operating curve points.

[0155] If this is so, the operating property of the delivery pump 1 is determined from the reference point identified as “enclosed”.

[0156] FIG. 8 shows an example of an operating load-travel graph DC1 containing curve points.

[0157] Four ranges Q1-Q2 in the form of quadrants are shown, separated by a value 2 for the travel 31 and a value 0.5 for the load 32.

[0158] The ranges can be directly adjacent to one another, for example, with the result that no ranges containing enclosed curve points arise without an association with reference points.

[0159] If desired, ranges can also be excluded, however, for example in order to prevent ranges that contain often error-prone curve points from being deliberately excluded in order to achieve an improvement in robustness for the determination of the operating property of the pump.

[0160] Range limits can also overlap, for example, and so a curve point can be assigned to multiple ranges.

[0161] The measurement curve points and the model curve points between two adjacent points on the respective curves can each have intervals that are on average at least 50%, preferably at least 80% and particularly preferably at least 95% of the greatest interval between two adjacent points on the respective curve.

[0162] This can result in approximately identical intervals between measurement curve points.

[0163] FIG. 9 shows an example of an operating load-travel graph DC2 containing curve points.

[0164] Analogously to the preceding figure, a centroid point C21-C24 is shown for each of four ranges, which centroid point corresponds to the geometric center of the curve points in the respective range, or area formed by the curve points and the range limits, for example the graph axes.

[0165] It can be advantageous if the ranges overlap one another at least in part in order to better define a reference point for the range, for example if a range contains too few curve points.

[0166] Furthermore, at least one range can be defined, for example, for which there is provision for no enclosed curve point to be taken into account for the subsequent check.

[0167] In other words, a range can be excluded from closer inspection.

[0168] This can be advantageous if for example a range is known to be particularly susceptible to interference and/or is not or only slightly relevant for specific statements about the operating properties.

[0169] When the method according to the invention is applied, there can also be provision for example for multiple, mutually independent, checks on operating properties to be performed sequentially or in parallel.

[0170] Of course, there may also be provision for an iterative check by applying the method according to the invention in order to progressively confirm particular suspicions regarding a supposed operating property by adjusting the criteria for the training model.

[0171] The accuracy requirements can be increased gradually, for example, by increasing reference points in the respective subsequent training model, or alternative reference points can even be examined, for example in order to use a combination of two different training models to draw further conclusions about the operating property that is to be examined.

[0172] FIG. 10 shows an example of an operating load-travel graph DC3 containing curve points.

[0173] Analogously to the preceding figure, a centroid point C31-C34 is shown for each of four ranges, which centroid point corresponds to the geometric center of the curve points in the respective range.

[0174] FIG. 11 shows an example of an operating load-travel graph DC4 containing curve points.

[0175] In this example, eight ranges are shown, separated by a value 2 for the travel 31 and a value greater than or less than 0.5 for the load 32, there being provision for two further ranges for the value 0.5 on the load axis 32.

[0176] A centroid point C41-C48 is shown for each of the eight ranges, which centroid point corresponds to the geometric center of the curve points in the respective range.

[0177] FIG. 12 shows an example of an operating load-travel graph DC5 containing curve points.

[0178] Analogously to the preceding figure, a centroid point C51-058 is shown for each of eight ranges, which centroid point corresponds to the geometric center of the curve points in the respective range.

REFERENCE SIGNS

[0179] 1 pumpjack [0180] 2 walking beam [0181] 3 prime mover, motor [0182] 4 gear reducer [0183] 5 polished rod [0184] 6 wellhead [0185] 7 flowline [0186] 8 casing [0187] 9 tubing [0188] 10 rod string [0189] 11 plunger [0190] 12 barrel [0191] 13 well [0192] 14 conveyed medium [0193] 15 cover tube with vertical grooves [0194] 16, 25 retaining device [0195] 17 self-aligning bearing [0196] 18 rotating tube with spiral grooves [0197] 19 recording tube [0198] 20 winged nut [0199] 21 plunger assembly [0200] 22 pump liner [0201] 23 calibrated rod [0202] 24 stylus [0203] 30 load-travel graph [0204] 31 position of the polished rod [0205] 32 load on the polished rod [0206] 33 lowest point of the pump stroke [0207] 34 highest point of the pump stroke [0208] 35 peak of the polished rod, PPRI [0209] 36 card of the polished rod for pump speed equal to zero [0210] 37 card of the polished rod for pump speed greater than zero [0211] 38 minimum load on the polished rod, MPRL [0212] 39 gross plunger load [0213] 40 weight of the rods in the fluid [0214] 41, 42 force [0215] 43 travel [0216] 50 load-travel graph showing rod load for specified value [0217] 51 pump, full power [0218] 52 pumped dry [0219] 53 specified value [0220] 54 load-travel graph showing rod load for change of operation [0221] 55, 56 angle [0222] 57 load-travel graph showing mechanical work of the rods [0223] 60 load-travel graph during normal operation [0224] 61 load-travel graph for a fluid deposit [0225] 62 load-travel graph for influence of gas [0226] 63 load-travel graph for stuck plunger [0227] 64 load-travel graph for a leak through a standing valve [0228] 65 load-travel graph for a leak through a moving valve [0229] 70 time axis [0230] 71 axis for amplitude of the current draw or power consumption [0231] 72 power consumption [0232] 80 selected zero point, or zero axis [0233] 81 polynomial for averaged power consumption [0234] 82 maximum value of the averaged power consumption [0235] 83, 84 zero crossing in the averaged power consumption [0236] 85 period duration of the averaged power consumption [0237] 86 ascertained phase angle of the averaged power consumption [0238] 100 pump system [0239] 110, 111 pump head [0240] 120 kinematic converter [0241] 130 recording means, recording device [0242] 140 computing device, analysis device [0243] 150 memory [0244] Q1-Q4 range, quadrant [0245] C21-C24, C31-C36, C41-C48 [0246] C51-C58 geometric center, centroid [0247] DC1-DC5 load-travel graph, Dynacard