Methods, Systems, and Computer Readable Media for Sectional-Based Speed Control of a Linear Pump

- Lufkin Industries, Inc.

Described are methods, systems, and computer readable media for adjusting the speed control of a pump assembly. The method can include the steps of setting the speed of a first stroke of the pump assembly to a first value and setting the speed of a second stroke of the pump assembly to a second value, modifying the speed of the first stroke while the pump is engaged in an upstroke, and modifying the speed of the second stroke while the pump is engaged in a downstroke through manual or automatic configuration processes. The computer readable medium can include an application that can be adapted to execute instructions that can configure the upstrokes and downstroke of the pump. Through these automatic or manual configuration parameters, a linear pump can execute fully configurable multiple speed settings within a stroke on the pump assembly, thus increasing the pump's efficiency irrespective of pump fillage. The methods and systems described herein are applicable to a variety of pump assemblies, including linear rod pumps, hydraulic rod pumps, artificial lift systems, and the like.

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Description
CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 61/704,913, filed Sep. 24, 2012, the entire disclosure of which is incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

REFERENCE TO APPENDIX

Not applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The inventions disclosed and taught herein relate generally to methods, systems, and computer readable media for adjusting the speed control of a linear pump. In one aspect, the invention relates to a method that includes the steps of setting the speed of a first stroke of the linear pump to a first value and setting the speed of a second stroke of the pump to a second value. The method can further include the steps of modifying the speed of the first stroke while the pump is engaged in an upstroke, and modifying the speed of the second stroke while the pump is engaged in a downstroke through manual or automatic configuration processes. In another aspect, the invention relates to a computer readable medium configured to store an application adapted to execute instructions for adjusting the speed control of a linear pump. The application can execute the steps of controlling the speed of a first stroke and a second stroke of a linear pump. Further, the application can execute the steps of modifying the speed of the first stroke a plurality of times while the pump is engaged in an upstroke and modifying the speed of the second stroke a plurality of times while the pump is engaged in a downstroke.

2. Description of the Related Art

Well operators have utilized pump well monitors employing controllers, such as rod pump controllers, for years to adjust the speed of a linear pump. For example, these rod pump controllers can adjust the speed of the pump by setting the speed of the pump's upstroke and downstroke to different values. Adjusting the speed of the pump is arguably the most critical when the pump approaches its “corners”—i.e., when the pump transitions from an upstroke to a downstroke and vise-a-versa. This is because at these corners, the pump is susceptible to an increased risk of damage to the artificial lift during the pumping process.

In particular, the pump's corners are located at the top of the pump's upstroke and at the bottom of the pump's downstroke. Approaching and passing through these transition points is commonly referred to in the art as “cornering.” Because a particular pump's artificial lift can be exposed to an increase risk of damage or failure at the corners of the pumps strokes, the speed of the pump as it approaches its corners can be of critical importance. In other words, pumps are susceptible to an increased risk of damage or even failure without the means to adjust the pump's speed throughout the entire pumping process. The problem, however, is that prior art solutions specifically lack the control over the degree of variability to a pump's speed throughout the pumping process required to simultaneously decrease the risk of damage to the pump while maximizing the pump's efficiency.

What is required, therefore, is a solution that can configure a linear pump through multiple, sectional-based speed settings. A sectional-based variable speed solution could decrease the risk of damage to the artificial lift during the pumping process by employing a fully configurable process for adjusting the speed of the pump at multiple points throughout its cycle.

Accordingly, the inventions disclosed and taught herein are directed to methods, systems, and computer readable media for adjusting the speed control of a linear pump that overcomes the problems as set forth above.

BRIEF SUMMARY OF THE INVENTION

The inventions disclosed and taught herein are directed to methods, systems, and computer readable media for adjusting the speed control of a linear pump. The objects described below and other advantages and features of the invention are incorporated in the application as set forth herein, and the associated appendices and drawings, related to the sectional-based speed control of a linear pump.

Described are methods, systems, and computer readable media for adjusting the speed control of a linear pump. The method can include the steps of setting the speed of a first stroke of the linear pump to a first value and setting the speed of a second stroke of the pump to a second value, modifying the speed of the first stroke while the pump is engaged in an upstroke, and modifying the speed of the second stroke while the pump is engaged in a downstroke through manual or automatic configuration processes. The computer readable medium can include an application that can be adapted to execute instructions that can configure the upstrokes and downstrokes of the pump. Through these automatic or manual configuration parameters, a linear pump can execute fully configurable multiple speed settings within a stroke on the linear pump thus increasing the pump's efficiency irrespective of pump fillage.

The disclosure also provides a method for adjusting the speed control of a linear pump that can include the steps of setting the speed of a first stroke of the linear pump to a first value and setting the speed of a second stroke of the linear pump to a second value. The method can further include the steps of modifying the speed of the first stroke while the pump is engaged in an upstroke and modifying the speed of the second stroke while the pump is engaged in a downstroke. Furthermore, the first and second values are adapted to be configurable throughout the upstroke and downstroke, respectively.

The step of modifying the speed of the first stroke can further include decreasing the speed of the pump to equate to a third value subsequent to the pump completing approximately 80% of its upstroke and the step of setting the speed of the second stroke can further include the step of setting the speed to a value greater than the third value. Furthermore, the step of modifying the speed of the second stroke can further include decreasing the speed of the pump to equate to a fourth value subsequent to the pump completing approximately 80% of its downstroke. Finally, the step of setting the speed of the first stroke can further include setting the speed to a value greater than the fourth value.

The disclosure also provides a computer readable medium configured to store an application for adjusting the speed control of a linear pump. The application can be adapted to execute instructions that can include the steps of controlling the speed of a first stroke and a second stroke of a linear pump, modifying the speed of the first stroke a plurality of times while the pump is engaged in an upstroke, and modifying the speed of the second stroke a plurality of times while the pump is engaged in a downstroke. Furthermore the step of controlling the speed of the first and second stokes can include configuring the speeds of the upstroke and downstroke, respectively.

The disclosure also provides a system for adjusting the speed control of a pump system. The system can include a linear pump that can be adapted to perform an upstroke and a downstroke at a first and second speed, respectively, and a control unit that can be adapted to execute instructions including modifying the speed of the upstroke while the linear pump is engaged in an upstroke, and modifying the speed of the downstroke while the linear pump is engaged in a downstroke. The step of modifying the speed of the first and second stokes can further include configuring the speeds of the upstroke and downstroke, respectively.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The following figures form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these figures in combination with the detailed description of specific embodiments presented herein.

FIG. 1 illustrates an exemplary linear pumping system as an exemplary embodiment of a system for implementing the inventions described herein.

FIG. 2 illustrates an exemplary first embodiment of various pumping stages of a sectional-based speed controlled linear pump.

FIG. 3A illustrates an exemplary second embodiment of various pumping stages of a sectional-based speed controlled linear pump.

FIG. 3B illustrates a graphical representation of a linear pump's speed versus it position in accordance with the various pumping stages illustrated in FIG. 3A.

FIG. 4A illustrates select aspects of the geometry of a sectional-based speed controlled linear pump.

FIG. 4B illustrates additional select aspects of the geometry of sectional-based speed controlled linear pump as depicted in FIG. 4A.

FIG. 5 illustrates a flow diagram depicting an exemplary method for adjusting the speed control of a pump system.

FIG. 6 illustrates an exemplary system for adjusting the speed control of a pump.

While the inventions disclosed herein are susceptible to various modifications and alternative forms, only a few specific embodiments have been shown by way of example in the drawings and are described in detail below. The figures and detailed descriptions of these specific embodiments are not intended to limit the breadth or scope of the inventive concepts or the appended claims in any manner. Rather, the figures and detailed written descriptions are provided to illustrate the inventive concepts to a person of ordinary skill in the art and to enable such person to make and use the inventive concepts.

DETAILED DESCRIPTION OF THE INVENTION

Those skilled in the art will appreciate that not all features of a commercial embodiment of the inventions are described or shown for the sake of clarity and understanding. Persons of skill in this art will appreciate that the development of an actual commercial embodiment incorporating aspects of the present inventions will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business-related, government-related and other constraints, which may vary by specific implementation, location and from time to time. While a developer's efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of skill in this art having benefit of this disclosure.

It must be understood that the inventions disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. Lastly, the use of a singular term, such as, but not limited to, “a,” is not intended as limiting of the number of items. Also, the use of relational terms, such as, but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and the like are used in the written description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the appended claims.

Particular embodiments of the invention may be described below with reference to block diagrams and/or operational illustrations of methods. It will be understood that each block of the block diagrams and/or operational illustrations, and combinations of blocks in the block diagrams and/or operational illustrations, can be implemented by analog and/or digital hardware, and/or computer program instructions. Such computer program instructions may be provided to a processor of a general-purpose computer, special purpose computer, ASIC, and/or other programmable data processing system. The executed instructions may create structures and functions for implementing the actions specified in the block diagrams and/or operational illustrations.

The Figures described above and the written description of specific structures and functions below are not presented to limit the scope of what Applicant has invented or the scope of the appended claims. Rather, the Figures and written description are provided to teach any person skilled in the art to make and use the invention for which patent protection is sought. Those skilled in the art will appreciate that not all features of a commercial embodiment of the invention are described or shown for the sake of clarity and understanding. Persons of skill in this art will also appreciate that the development of an actual commercial embodiment incorporating aspects of the present invention will require numerous implementation-specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation-specific decisions may include, and likely are not limited to, compliance with system-related, business-related, government-related, and other constraints, which may vary by specific implementation, location and from time to time. While a developer's efforts might be complex and time-consuming in an absolute sense, such efforts would be, nevertheless, a routine undertaking for those of skill in this art having benefit of this disclosure.

The terms “couple,” “coupled,” “coupling,” “coupler,” and like terms are used broadly herein and can include any method or device for securing, binding, bonding, fastening, attaching, joining, inserting therein, forming thereon or therein, communicating, or otherwise associating, for example, mechanically, magnetically, electrically, chemically, operably, directly or indirectly with intermediate elements, one or more pieces of members together and can further include without limitation integrally forming one functional member with another in a unity fashion. The coupling can occur in any direction, including rotationally.

Exemplary System for Implementing the Inventions Taught Herein

FIG. 1 illustrates an exemplary pumping system as used as an exemplary embodiment of a subsurface pump in which the inventions described herein may be applied to for implementing the described inventions. While such pumping system, alternatively referred to herein as a ‘pump assembly’, is illustrated as a linear rod pump (LRP), the systems and methods described within the present disclosure are not limited to LRPs, and may be applied to a variety of pump assemblies, including but not limited to hydraulic or pneumatic rod pumps and artificial lift pump assemblies.

In order to introduce the aspects of the present invention, reference may be first made to FIG. 1 which is an exemplary, diagrammatic view of a well provided with a linear drive pump and a drive assembly for that pump, as will be generally understood in accordance with the prior art. In FIG. 1, it may be seen that well 10 includes a casing 12 that extends from a down hole location upwardly to a surface location to form a wellhead 14. A water delivery tube 16 is located coaxially within casing 12, and a progressive cavity pump 18 is provided with a rotor and is located at the down hole location within the interior of water delivery tube 16. A sucker rod 20 is located axially within water delivery tube 16 such that rotation of the sucker rod 20 acts to rotate progressive cavity pump 18 thereby to pump fluid from the down hole location to the surface location.

With continued reference to FIG. 1, a drive assembly 22 is provided to rotate sucker rod 20. Here it may be seen that drive assembly 22 includes a frame 24 that is mounted on cross-member 26 that, as is known in the art, communicates with the interior 13 of casing 12 so as to separate, for example, oil and natural gas from well 10. A stuffing box 28 rotatably receives a polish rod 30 therethrough with polish rod 30 being connected to sucker rod 20 whereby rotation of polish rod 30 will act to rotate sucker rod 20 thereby to drive pump 18. A bearing box 32 is mounted at an upper portion of frame 24 and the friction block 34 is mounted on an upper exposed end portion of polish rod 30 so that the weight of the polish rod 30, sucker rod 20 and any fluid in delivery tube 16 is supported by bearing box 32. A pulley 36 is attached to the output shaft of the bearing box at a location between bearing block 32 and friction block 34. A drive motor 40 has an output shaft 42 that is connected to a pulley 44 with pulley 44 acting to drive pulley 36 by means of a belt 38.

When the rod string 36 is in an upstroke, the traveling valve 46 is closed and the fluid is lifted upward in the tubing 38. During the upstroke, fluid is drawn upward into the pump barrel 50 through the open standing valve 48. During the downstroke, as the plunger 42 is lowered, the traveling valve 46 is open thereby permitting fluid within the pump barrel 50 to pass through the valve to allow the plunger 42 to move downward. The fluid within the tubing 38 and the barrel 50 is held fixed in place by the closed standing valve 48. The rod string 36 does not carry any weight of fluid during the downstroke, but does lift the entire column of fluid during the upstroke.

The well manager unit 52 receives or derives surface rod and load information and other information with regard to the pump's position and speed. With specific reference to the inventions taught herein, certain modifications to the above-described prior art system can be implemented—e.g., through the addition and integration of the control unit 610 (as described in greater detail with reference to FIG. 6)—to improve the pumping characteristics of a linear pump in accordance the descriptions provided below.

Sectional-Based Speed Control of a Linear Pump

Referring to the Figures, FIG. 2 illustrates a first embodiment of various pumping stages of a sectional-based speed controlled linear pump. More specifically, FIG. 2 illustrates a graphical representation of a linear pump as it travels through various sections within an upstroke and a downstroke.

The first embodiment of the pumping stages 200 can include an upstroke section 210 and a downstroke section 220. The upstroke section 210 can further include a first section 230 and a third section 250. The downstroke section 250 can further include a second section 240 and a fourth section 260. The pumping stages 200 illustrated in FIG. 2 depict an embodiment where the speed of a particular linear pump can be adjusted up to four distinct speeds—one for each section.

As the pump begins its upstroke in upstroke section 210, the speed of the stroke can be set to a first value at the point it exits the fourth section 260 and enters the first section 230. For example, the speed of the linear pump can be increased to a speed greater than a value to which it was set in the fourth section 260. As the pump approaches its corner, the speed of the upstroke can be modified while engaged in the upstroke as the pump crosses from the first section 230 to the third section 250. In an exemplary and non-limiting illustrative embodiment, the third section 250 can begin once the stroke completes approximately 80% of its upstroke. In other examples, this third section 250 can begin as early or as late as an operator desires. For example, an operator may choose to adjust the third section 230 to begin at approximately 40% of the upstroke's completion, or as late as approximately 95% of the upstroke's completion. The manner in which these sections can be configured is described in greater detail below.

The term “approximately,” when used in reference to a particular location of the pump during its upstroke or downstroke, can include a particular position or range of positions near or approaching the specified position. For example, “approximately 40% of the upstroke's completion” can include not only the position that defines 40% of the upstroke's completion, but additional positions as well, including, but not limited to a +/−5% variation from the desired position. Although this +/−5% variation falls within the scope of the range covered by the term “approximately,” it is not limiting as an upper or lower bound and is merely provided as a particular illustrative example of what one of ordinary skill in the art would recognize the term “approximately” to include.

Once the upstroke enters the third section 250, the speed of the upstroke can be modified to a different speed by setting it to a third value. For example, the speed can be decreased so as to accommodate the pump as it approaches the corner of the upstroke. As the upstroke completes, and the pump transitions to a downstroke, the speed of the downstroke can be set to a second value as it exits the third section 250 and enters the second section 240. For example, the second value can be a value greater than or less than the third value.

Once the pump exits the second section 240 and enters the fourth section 260 during its downstroke, the speed of the downstroke can be modified to a fourth value that can be greater than or less than the second value. In an exemplary and non-limiting illustrative embodiment, the fourth section 260 can begin once the stroke completes approximately 80% of its downstroke. In other examples, an operator may choose to adjust the fourth section 260 to begin at approximately 40% of the downstroke's completion, or as late as approximately 95% of the downstroke's completion. The manner in which these sections can be configured is described in greater detail below.

Finally, as the pump transitions through the fourth section 260, it will reach its downstroke corner and transition through to the upstroke section 210 once again. Adjustments to the speed of the pump during the upstroke can occur again by setting the speed of the upstroke to the first value again (e.g., setting the speed to a value greater than the fourth value) at the transition point from the fourth section 260 to the first section 230 and the process described above can be repeated. In the alternative, at this transition point, the speed can be adjusted to a value less than the fourth value, or the speed can remain the same irrespective of the pump crossing between these two sections.

Although only four pump sections (e.g., first, second, third, and fourth) are defined in the above example, additional sections are contemplated as well. For example, as described in greater detail below in conjunction with FIG. 3, six distinct sections can be defined to increase the versatility of the speed of the pump throughout its various strokes. Furthermore, the speeds within a particular section can be varied as well. In other words, the first, second, third, and fourth values are configurable throughout the upstrokes and downstrokes of the linear pump within a particular section. For example, referring again to FIG. 2, the speed within the third section 250 can be adjusted a plurality of times before it transitions from the third section 250 to the section 240. By increasing the number of sections within a particular upstroke and/or downstroke of the pump, and by increasing the variability of the speeds within a particular section, an operator can maximize production and preventive measures in order to minimize the potential for failure throughout the pump's operation.

The configurability of the speeds within a particular section and/or through the transition of one section to another can be further illustrated with reference to Table 1, below, detailing the six main parameters of sectional-based speed change.

TABLE 1 CONFIGURATION PARAMETER OPTIONS Stroke Location Upstroke, Downstroke, Top Corner or Bottom Corner Start Position Percent of Stroke Period Speed Change Option Not used, Fixed, Auto, Auto+ or Auto− % Scaled Speed Percent of scaled speed Working Speed Limit Enable or Disable Override Fixed Corner Speed Enable or Disable Override

Table 1 illustrates six main configuration parameters. The first parameter is the Stroke Location parameter. The Stroke Location parameter defines the location of the section during the cycle of the pump. This parameter can indicate that the pump is either in its Upstroke, Downstroke, Top Corner, or Bottom Corner. Furthermore, this parameter can include a setting that can be tailored to a finer degree of granularity, such as a location (i.e., percent) the pump has travelled through a particular location. For example, a parameter of “Upstroke 50%” can be used when the pump has halfway completed the upstroke section 210. With this finer degree of granularity, speed of the pump can be modified with greater precision at various positions within its cycle.

The second parameter is the Start Position parameter. The Start Position parameter represents the starting location of the section measured by various units of measurement. For example, it can be measured using position measurement devices such a device for measuring revolutions per minute (rpm) and crank, inclinometer, accelerometer, string potential, etc. This parameter dictates when the speed of the pump is to be changed so the measurement device used is typically one that is capable of measuring with a high degree of precision and accuracy.

The third parameter is the Speed Change Option parameter. This parameter defines the action characteristics of a particular section. For example, this parameter can include five distinct characteristics:

    • Not used: The particular section is not set to perform any specific action—no speed change within the section;
    • Fixed: Regardless of any conditions, the process will force the fixed run speed;
    • Auto: This feature will allows the control unit to run the speed dictated by other features of the control unit—e.g., a change in speed due to a pump fillage or rod float mitigation, etc.;
    • Auto+: Same as Auto, but it allows the operator to increase the speed by an amount defined in the Percent of Scaled Speed parameter discussed in greater detail below;
    • Auto−: Same as Auto, but it allow the operator to decrease the speed by an amount defined in the Percent of Scaled Speed parameter discussed in greater detail below

Both the Auto+ and the Auto− features allow an operator to override the speed suggested by the control unit 610 (as shown in FIG. 6, below). For example, if the linear pump is known to run at a lower speed than the beam pump (e.g., during the initial pump installation, startup, when the well is running full, etc.), an operator may want to increase the speed of the pump by selecting the Auto+ feature in order to obtain fluid at an increased rate. Conversely, on wells that are maintenance prone, an operator may desire a speed slower than the speed dictated by the control unit. Accordingly, the operator may manually slow the speed of the pump by utilizing the Auto− feature.

The fourth parameter is the Percent of Scaled Speed parameter. This parameter defines the exact speed to run the pump or the amount of speed to add to and/or subtract from during the Fixed, Auto+, or Auto− settings as defined in the Speed Change Option parameter described above. For example, this parameter can be adjusted by integer value increments defining the percent of speed scaling of the pump. Notably, this speed scaling value is not the same as the actual minimum and/or maximum speed of the pump. If desired, this parameter can be adjusted to a finer degree of granularity than just integer value increments of the percent of speed scaling, such as tenths, or even hundredths of a percent of speed scaling.

The fifth parameter is the Working Speed Limit Overdrive parameter. This parameter can override the minima and maxima working speeds. Further, this parameter allows the sectional-based speed change to go beyond the working speed threshold as needed by a particular application. This parameter is limited, however, by the minimum and maximum Variable Frequency Drive (VFD) scaling speeds.

The sixth parameter is the Fixed Corner Speed Override parameter. This parameter is a function of a standard defined for a particular linear pump. For example, often pump manufactures define maxima values to run the pump (e.g., 50 Hz) to prevent the potential for causing damage to the equipment. Although the control unit can be programmed to not exceed the maximum value set by the manufacturer of a particular pump, this parameter can be employed to override the maximum value recommended by the equipment manufacturer.

FIG. 3A illustrates a second embodiment of various pumping stages of a sectional-based speed controlled linear pump. FIG. 3B illustrates a graphical representation of a linear pump's speed versus its position in accordance with the various pumping stages illustrated in FIG. 3A. These Figures will be described in conjunction with one another.

As similarly illustrated in FIG. 2, the speed of the pump can be divided into a varying number of sections. FIGS. 3A and 3B illustrate an embodiment where the pump is able to engage in at least six distinct speeds across six unique sections. The pumping stages 300 can include first 310A, second 320A, third 330A, fourth 340A, fifth 350A, and sixth 360A sections throughout a complete upstroke-downstroke cycle. By doing so, the speed of the upstroke and the downstroke can be controlled and modified a plurality of times while engaged in an upstroke and/or a downstroke. For example, after the pump corners at the conclusion of the downstroke, the pump exits the sixth section 360A and enters the first section 310A. This is illustrated in FIG. 3A as occurring at 5% completion of the upstroke. Referring specifically to FIG. 3B, the bar graph 305 illustrates the change of speed in the upstroke at this transition point (here, shown as a decrease from 50% to 10%).

As the pump continues in its upstroke, it approaches the second section 320A at 45% percent of completion during the upstroke and the speed is increased from 10% (FIG. 3B, 310B) to 20% (FIG. 3B, 320B). This process continues as the pump begins its upper cornering after completing approximately 90% of its upstroke (transitioning from the second section 320A to the third section 330A) coinciding with another modification in the speed of the pump (as shown transitioning from 20% in 320B to 50% in 330B). Similar transitions are illustrated at the conclusion of the upper cornering as the pump begins its downstroke and the cycle continues.

Although these Figures depict a pump being divided into six particular regions, greater or fewer sections are contemplated as well. Furthermore, the particular speed within a section can be varied as well (one or more times within each section). For example, the speed of the pump at the fifth section 350A is illustrated as 75%. The speed of the pump can be set to other speeds as well, including a slower speed than that which is defined for the fourth section 340A. These speed settings can be varied either automatically though the programming of the control unit 610 (as shown in FIG. 6 below) or manually through the intervention of an operator through the parameters defined in Table 1 above, for example.

Lastly, the positions of the transition points can be varied as well and are only depicted in the Figures for illustrative purposes. For example, although the transition between the third section 330A and the fourth section 340A is illustrated as occurring upon 5% completion of the downstroke's movement (illustrated as 95% from the bottom of the upstroke in FIG. 3A), this position is fully configurable. It can, therefore, be modified either automatically though the programming of the control unit 610 (as shown in FIG. 6 below) or manually through the intervention of an operator through the parameters defined in Table 1 above. This configurability can be defined by examining the geometry of the pump with respect to its position along the upstroke and downstroke as illustrated in FIGS. 4A and 4B below.

FIG. 4A illustrates select aspects of the geometry of sectional-based speed controlled linear pump. FIG. 4B illustrates additional select aspects of the geometry of sectional speed controlled linear pump as depicted in FIG. 4A.

Referring specifically to FIG. 4A, positions throughout a particular pump's upstroke and downstroke can be defined as a function of the stroke length (SL) (defined as the length from the bottom of a downstroke to the top of an upstroke. As the pump approaches a corner of the upstroke and/or downstroke, the pump travels along a partial circular path along the sprocket, defined by the Radius (R). The Linear Length (L) is defined as the distance between the center of each of the sprockets as measured linearly from the lower end of the upstroke to the upper end of the downstroke between the two sprockets. Accordingly, the Stroke Length (SL) can be defined as the sum of the Linear Length and the Radius for each of the two sprockets: SL=L+2*R. With such a configuration, it is desirable to control the speed of the pump at a constant rate as the pump corners during the upstroke (i.e., the distance less than or equal to R) and corners during the downstroke (i.e., the distance that is greater than or equal to L+R).

Referring specifically to FIG. 4B, additional aspects of the pump's geometry are defined to further illustrate possible transition points between various sections of the pump as a function of the pump's Stroke Length (SL), sprocket radii (R), and Linear Length (L). Specifically, four additional zones or sections are defined:

    • LUScorner, defined as the distance in which the modification to the speed of the upstroke should begin as the pump approaches its upper corner. For example, LUScorner can include the distance (in terms of inches) where the speed of the pump should decelerate to account for the approaching upper corner. In other examples, the speed can be increased or not adjusted at all at this transition point.
    • LDStransition, defined as the distance in which the speed of the downstroke is adjusted at the completion of its cornering and transition to a downstroke. For example, LDStransition can include the distance (in terms of inches) where the speed of the pump should accelerate to return to the pump's speed before it reached the LUScorner transition point. In other examples, the speed can be increased to a value other than the pump's speed before reaching the LUScorner transition point, decreased, or not adjusted at all at this transition point.
    • LUScorner, defined as the distance in which the modification to the speed of the downstroke should begin as the pump approaches its lower corner. For example, LUScorner can include the distance (in terms of inches) where the speed of the pump should decelerate to account for the approaching lower corner. In other examples, the speed can be increased or not adjusted at all at this transition point.
    • LUStransition, defined as the distance in which the speed of the upstroke is adjusted at the completion of its corning and transition to an upstroke. For example, LUStransition can include the distance (in terms of inches) where the speed of the pump should accelerate to return to the pump's speed before it reached the LDScorner transition point. In other examples, the speed can be increased to a value other than the pump's speed before reaching the LDScorner transition point, decreased, or not adjusted at all at this transition point.

Because each of these lengths can be defined as a function of the Linear Length (L) of the pump and the length of the sprockets' radii (R), simple formulas can be derived to define the position of each of these transition points:

    • Position of LUScorner=R+L−LUScorner;
    • Position of LDStransition=R+L+LDStransition;
    • Position of LDScorner=R+LDScorner;
    • Position of LDStransition=R−LDStransition

The system described herein is fully configurable and thus, the control unit 610 (as illustrated in FIG. 6) can be programmed to account for various desired speeds and transition points as a function of the Linear Length (L) of the pump and the sprockets' radii (R) of a given pump. Accordingly, the control unit can be programmed with the desired speeds and transition points to function as a fully configurable sectional-based controller for a linear pump. Additional parameters are illustrated below in Table 2 defining possible configurations to be implemented by the control unit 610 (as shown in FIG. 6). These are not exhaustive.

TABLE 2 Parameter Description Units RawPosn Current position Inches L Linear distance Feet RawPosn Sprocket radius Feet PLScorner Percent change in speed as approaching corner % of L PLStransition Percent change in speed after corner transition % of R CnrHz Cornering Speed Hz LScorner Distance for change in speed as approaching Inches corner LStransition Distance for change in speed after corner transition Inches Posn Scaled current position Inches CoHz Output speed (defined by the speed algorithm) Hz

In accordance with the description above, an operator can further manually implement additional changes in the position of speed transition points, the number of transition points, and the speed for each transition point. By doing so, the system is fully customizable to account for various wells, operating conditions, or equipment limitations.

FIG. 5 illustrates a flow diagram depicting an exemplary method for adjusting the speed control of a pump system. The method 500 can include the step 510 of setting the speed of a first stroke of the linear pump to a first value and the step 520 setting the speed of a second stroke of the linear pump to a second value. The method 500 can further include the step 530 of modifying the speed of the first stroke while the pump is engaged in an upstroke and the step 540 of modifying the speed of the second stroke while the pump is engaged in a downstroke. Furthermore, the first and second values are adapted to be configurable throughout the upstroke and downstroke, respectively.

The step 530 of modifying the speed of the first stroke can further include decreasing the speed of the pump to equate to a third value subsequent to the pump completing approximately 80% of its upstroke and the step 520 of setting the speed of the second stroke can further include the step of setting the speed to a value greater than the third value. Furthermore, the step 540 of modifying the speed of the second stroke can further include decreasing the speed of the pump to equate to a fourth value subsequent to the pump completing approximately 80% of its downstroke. Finally, the step 510 of setting the speed of the first stroke can further include setting the speed to a value greater than the fourth value.

FIG. 6 illustrates a system for adjusting the speed control of a pump. The system 600 can include a control unit 610, a pump 620, and a display unit 630. For example, the control unit 610 can include any controller, processor, central processing unit (CPU), or any other logic (such as hardware, software, firmware, or a combination thereof) capable of carrying out the variable speed operations of the pump. For example, the control unit 610 can include a controller comprising both hardware and software adapted to adjust the speed of the pump through a Variable Speed Drive (VSD) mechanism through a communication interface (not shown) such as an analog or digital interface. The communication between the control unit 610 and the pump 620 can occur, wirelessly, such as through GPS signals, radio frequency signals, infrared signals, or the like, or in the alternative, through a wired coupling. The pump 620 can include hydraulic pumps, and other pumps including artificial lifts, such as sucker rod lifts (e.g., beam pumps, linear pumps, etc.).

Although the control unit 610 can be programmed to automatically vary the speed of the pump throughout its various sections within the pumping cycle, the control unit 610 further can be adapted to receive operator-based inputs, as described for example in Table 1 above, and control the VSD based on the particular input. In other words, the control unit 610 can be adapted to be programmed with automatic settings (e.g., settings prescribed by the manufacturer and/or those settings initially set forth by an operator) that can further be overridden manually by an operator before, during, or after, the pumping process completes. The settings of the control unit 610 can further be tailored based on the data analysis of historical data taken from one or more wells, pumps, etc. In this regard, adjustments can refined upon analyzing the pump's performance over previous operations to optimize the pump's production while still minimizing the potential for damage or failure to the equipment.

Furthermore, the control unit 610 can be adapted to monitor the electrical and mechanical conditions of the pump and the drive of its motors, and therefore, the control unit 610 can be adapted to override sectional-based speed changes automatically if desired, and/or manually by any of the parameters set forth, for example, in Table 1, above.

In the alternative, the control unit 610 can be replaced with a computer readable medium (not shown) configured store an application for adjusting the speed control of a linear pump. In this example, the computer readable medium can be employed to control the speed of the pump based on the logic and algorithms defined within its applications and based on the operator's manual inputs and overrides. In an exemplary and non-limiting illustrative embodiment, the computer readable medium can include instructions, such as an application, software, firmware, or other computer readable instructions for executing and/or performing one or more of adjusting the speed control of a linear pump 620.

The computer readable medium can refer to any storage medium that may be used to in conjunction with computer readable instructions. In an exemplary and non-limiting illustrative embodiment, the computer readable medium can include a computer readable storage medium. The computer readable storage medium can take many forms, including, but not limited to, non-volatile media and volatile media, floppy disks, flexible disks, hard disks, magnetic tape, other magnetic media, CD-ROMs, DVDs, or any other optical storage medium, punch cards, paper tape, or any other physical medium with patterns of holes. Computer readable storage media can further include RAM, PROM, EPROM, EEPROM, FLASH, combinations thereof (e.g., PROM EPROM), or any other memory chip or cartridge.

The computer readable medium can further include computer readable transmission media. Such transmission media can include coaxial cables, copper wire and fiber optics. Transmission media may also take the form of acoustic or light waves, such as those generated during radio frequency, infrared, wireless, or other media comprising electric, magnetic, or electromagnetic waves. Furthermore, the computer readable medium can, in one particular example, generate a report of the inferred daily production rate of the pump as described in greater detail above.

The display unit 630 can include a CRT, LCD, LED, plasma, or any other display format or configuration adapted to be used to display data or information on an electronic device. For example, the display unit 630 can include a computer monitor for outputting the configuration parameters of the pump. In particular, the output can include a display illustrating the various sections of the pump, the location of the pump, the current speed of the pump at that particular section, any override parameters, etc. Therefore, the display unit 630 can output the status of one or more of the parameters set forth in Table 1 and/or Table 2 above. Furthermore, a user interface (not shown) can be coupled to the display unit 630 and/or the control unit 610 so that the operator can manually manipulate the parameters displayed on the display unit 630. In an exemplary and non-limiting illustrative embodiment, the system 600 can include a computer system (not shown), such as a desktop computer, laptop computer, tablet, or the like. The operator can utilize the computer to allow an operator to monitor the various parameters and configurations of the pump, and manipulate the settings to adjust and/or configure the parameters and settings of the pump to the operator's desired configuration.

The order of steps can occur in a variety of sequences unless otherwise specifically limited. The various steps described herein can be combined with other steps, interlineated with the stated steps, and/or split into multiple steps. Similarly, elements have been described functionally and can be embodied as separate components or can be combined into components having multiple functions. Discussion of singular elements can include plural elements and vice-versa.

In some alternate implementations, the functions/actions/structures noted in the figures may occur out of the order noted in the block diagrams and/or operational illustrations. For example, two operations shown as occurring in succession, in fact, may be executed substantially concurrently or the operations may be executed in the reverse order, depending upon the functionality/acts/structure involved. For example, FIG. 5 illustrates one possible embodiment of a method of adjusting the speed control of a linear pump. More specifically, as presently disclosed in FIG. 5, the step 540 of modifying the speed of the second stroke occurs after the step 530 of modifying the speed of the first stroke. Other embodiments can include performing step 540 before step 530. In other embodiments, some steps can be omitted altogether. Therefore, though not explicitly illustrated in the Figures, any and all combinations or sub-combinations of the steps illustrated in FIG. 5, or additional steps described in the Figures or the detailed description provided herein, can be performed in any order, with or without regard for performing the other recited steps.

The inventions have been described in the context of preferred and other embodiments and not every embodiment of the invention has been described. Obvious modifications and alterations to the described embodiments are available to those of ordinary skill in the art. The disclosed and undisclosed embodiments are not intended to limit or restrict the scope or applicability of the invention conceived of by the Applicants, but rather, in conformity with the patent laws, Applicants intend to fully protect all such modifications and improvements that come within the scope or range of equivalent of the following claims.

Claims

1. A method for adjusting the speed control of a pump assembly, the method comprising the steps of:

setting the initial speed of the pump assembly to a first, initial value; and
modifying the speed of the pump assembly throughout the upstroke and downstroke of the pump assembly during operation;
wherein the upstroke and the downstroke speeds are configurable throughout the range of the upstroke and downstroke cycles.

2. A method for adjusting the speed control of a pump assembly, the method comprising the steps of:

setting the speed of a first stroke of the pump assembly to a first value;
setting the speed of a second stroke of the pump assembly to a second value;
modifying the speed of the first stroke while the pump is engaged in an upstroke; and
modifying the speed of the second stroke while the pump is engaged in a downstroke;
wherein the first and second values are configurable throughout the upstroke and downstroke, respectively.

3. The method for adjusting the speed control of a pump assembly according to claim 1 or claim 2, wherein the step of modifying the speed of the first stroke further includes decreasing the speed of the pump to equate to a third value subsequent to the pump completing approximately 80% of its upstroke.

4. The method for adjusting the speed control of a pump assembly according to claim 1 or claim 2, wherein the step of modifying the speed of the upstroke at a position includes determining a stroke position that is equivalent to a range from a first position near the start of the upstroke to a second position near the end of the upstroke.

5. The method for adjusting the speed control of a pump assembly according to claim 3, wherein the step of setting the speed of the second stroke further includes setting the speed to a value greater than the third value.

6. The method for adjusting the speed control of a pump assembly according to claim 1 or claim 2, wherein the step of modifying the speed of the second stroke further includes decreasing the speed of the pump to equate to a fourth value subsequent to the pump completing approximately 80% of its downstroke.

7. The method for adjusting the speed control of a pump assembly according to claim 6, wherein the step of setting the speed of the first stroke further includes setting the speed to a value greater than the fourth value.

8. The method for adjusting the speed control of a pump assembly according to claim 1 or claim 2, wherein the upstroke speed near the beginning of the upstroke or downstroke position is modified to a setting equal to, less than, or greater than the last recorded run speed value.

9. The method for adjusting the speed control of a pump assembly of claim 1 or claim 2, wherein the pump assembly is a linear rod pump, a hydraulic rod pump, or an artificial lift pump assembly.

10. The method for adjusting the speed control of a pump assembly according to claim 1 or claim 2, wherein the speed change position or location is a value based on a manual value entered by an operator, and/or a calculated value based on system data, system analysis, system diagnostic information, or a combination thereof.

11. The method for adjusting the speed control of a pump assembly according to claim 1 or claim 2, wherein the speed change value is a predefined valued based on a manual value entered by a user, and/or a calculated value based on system data, system analysis, system diagnostic information, or a combination thereof.

12. The method for adjusting the speed control of a pump assembly according to claim 1 or claim 2, wherein the speed change and the corresponding location position are adjusted a plurality of times through the stroke.

13. A computer readable medium configured to store an application for adjusting the speed control of a pump assembly, the application being adapted to execute instruction, comprising:

controlling the speed of the pump assembly throughout the stroke cycle; and
modifying the speed a plurality of times throughout the stroke cycle.

14. The computer readable medium of claim 13, wherein the pump assembly is selected from the group consisting of linear rod pumps, hydraulic rod pumps, and artificial lift pump assemblies.

15. A computer readable medium configured to store an application for adjusting the speed control of a pump assembly, wherein the application is adapted to execute instructions, comprising:

controlling the speed of a first stroke and a second stroke of a linear pump;
modifying the speed of the first stroke a plurality of times while the pump is engaged in an upstroke; and
modifying the speed of the second stroke a plurality of times while the pump is engaged in a downstroke;
wherein the step of controlling the speed of the first and second stokes comprises configuring the speeds of the upstroke and downstroke, respectively.

16. A system for adjusting the speed control of a pump, the system comprising:

a pump assembly, wherein the pump assembly is adapted to perform an upstroke and a downstroke at a first and second speed, respectively; and
a control unit, wherein the control unit is adapted to execute instructions, comprising: modifying the speed of the upstroke while the pump assembly is engaged in an upstroke; and modifying the speed of the downstroke while the pump assembly is engaged in a downstroke;
wherein the step of modifying the speed of the first and second stokes comprises configuring the speeds of the upstroke and downstroke, respectively.

17. A system for adjusting the speed control of a pump assembly, the system comprising:

a pump adapted to perform a plurality of speed change operations within a stroke;
a control unit, wherein the application is adapted to execute instructions, comprising:
controlling the speed of the pump;
modifying the speed of the pump on a plurality of times throughout the stroke, and
HMI and/or a communication infrastructure wherein speed change and the corresponding position/location values are set.
Patent History
Publication number: 20140188292
Type: Application
Filed: Sep 24, 2013
Publication Date: Jul 3, 2014
Applicant: Lufkin Industries, Inc. (Lufkin, TX)
Inventors: Doneil Dorado (Missouri City, TX), Tom Mills (Missouri City, TX)
Application Number: 14/035,046
Classifications
Current U.S. Class: Flow Control (e.g., Valve Or Pump Control) (700/282); Processes (417/53)
International Classification: F04B 49/06 (20060101); F04B 49/20 (20060101);