System and Method for Monitoring Valve Wear in a Fluid Pump

- Caterpillar Inc.

A pump for pumping fluid includes a pressure sensor disposed in the discharge outlet that communicates with a plurality of pumping chambers. The pressure sensor monitors the discharge pressure and transmits the discharge pressure to a logic device. The logic device is configured to analyze the discharge pressure verses time, determine a peak-to-peak amplitude associated with the discharge pressure verses time, and to detect a pressure spike corresponding to the maximum or high peak-to-peak amplitude. The pressure spike may correspond to uncharacteristic operation of a discharge valve or a suction valve associated with the pump.

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Description
TECHNICAL FIELD

This patent disclosure relates generally to a system and method for detecting wear on valves included in a fluid pump and, more particularly, to monitoring valve wear in pumps that may be used in hydraulic fracturing or “fracking” operations.

BACKGROUND

Hydraulic fracturing, or “fracking,” is a technique used in the oil, gas industry to recover oil and gas by directing pressurized fracking fluid into a downhole wellbore for inducing cracks in deep rock formations underground to release oil and/or gas therein, and through which the oil and gas can readily flow when the pressurized fluid is removed. The pumps used in fracking operations to pressurize and direct the fracking fluids are typically large positive displacement pumps capable of generating tremendously high pressures. Because the fracking fluid is abrasive and because of the high pressures utilized in fracking operations, the internal components of the pump are subject to wear and possible failure. Accordingly, operation of the pumps is monitored in order to conduct preventative maintenance when necessary and avoid disrupting the fracking operation. By way of reference, U.S. Patent Publication No. 9,260,959 discloses a system for controlling and monitoring operation of a hydraulic fracking pump and related equipment.

SUMMARY

The disclosure describes, in one aspect, a pump for pumping fluid, for example, in a hydraulic fracking operation. The pump includes an intake manifold, a discharge outlet, and a plurality of pumping chambers in fluid communication with the intake manifold and the discharge outlet to receive and discharge fluid. To detect a discharge pressure from the plurality of pumping chambers, a pressure sensor may be disposed in the discharge outlet. The pump further may be associated with a logic device configured to receive discharge pressure data from the pressure sensor, to analyze the discharge pressure data verses time, and to determine the peak-to-peak amplitude of the discharge pressure verses time to detect a discharge pressure spike.

In another aspect, the disclosure describes a method of operating a pump. The method includes receiving electronic signals indicative of a discharge pressure associated with the discharge of fluid from the pump. A logic device, dedicated in part to the analysis of the discharge pressure, analyzes the discharge pressure verses time. The logic device further determines a high peak-to-peak amplitude of the discharge pressure to detect a discharge pressure spike in the discharge pressure. According to the method, the discharge pressure spike may be associated with uncharacteristic operation of a discharge valve or a suction valve associated with the pump.

In another aspect, the disclosure describes a system for monitoring operation of a pump discharging fluid. The system includes a pressure sensor disposed in the discharge outlet to measure a discharge pressure from a plurality of pumping chambers discharging fluid to the discharge outlet. The system also includes a logic device communicating with the sensor to receive discharge pressure data reflecting the discharge pressure. The logic device may be configured to determine a peak-to-peak amplitude associated with the discharge pressure and compare the peak-to-peak amplitude with a discharge pressure threshold. If high peak-to-peak amplitude exceeds the discharge pressure threshold, the logic device may issue an alarm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of mobile fracking machine including a plurality of components disposed on a trailer for pressurizing and directing fracking fluid to a wellbore during a fracking operation.

FIG. 2 is a perspective view of an embodiment of a fluid pump including a plurality of aligned pumping chambers that can pressurize and direct fracking fluid in accordance with the present disclosure.

FIG. 3 is a cross-sectional view of a pumping chamber illustrating the arrangement of the internal components of the pump including suction and discharge valves and a piston reciprocally disposed in the pumping chamber for charging the fracking fluid.

FIG. 4 is a block diagram of an embodiment of a computer system for monitoring and controlling operation of the fluid pump and including a logic device specifically for monitoring discharge pressure from the pump.

FIG. 5 is a plot graphing the discharge pressure of the pump verses time, including various high-pressure spikes and illustrating the peak-to-peak amplitude of those spikes.

FIG. 6 is a flowchart of a possible routine or process for analyzing the discharge pressure of the pump to detect discharge pressure spikes and assess wear or deterioration of the internal components.

DETAILED DESCRIPTION

This disclosure relates a pump that may be used, for example, for performing a hydraulic fracking operation to recover oil and/or natural gas from below the surface of the earth by directing high-pressure fracking fluid into a downhole wellbore to induce cracks in the rock formations below. Referring to FIG. 1, wherein like reference numbers refer to like elements, there is illustrated an embodiment of a mobile fracking machine 100, which may be referred to as a fracking rig, used to pressurize hydraulic fracking fluid. In a fracking operation, one or more fracking machines 100 can be cooperatively arranged at a fracking site to pump the fracking fluid to a wellhead entrance to a subterranean wellbore leading to the rock formations to be fractured. The fracking fluid, which may be prepared onsite, may include water mixed with sand, ceramic particles, or other propellants, the purpose of which is to hold the fracture cracks open after the hydraulic pressure is removed. Oil and/or gas retrained in the underground rock layers is thereby released and can be recovered at the surface through the fracture cracks and wellbore.

The fracking machine 100 can include as a power source or prime mover such as an internal combustion engine 102 like a diesel-burning compression ignition engine the combusts diesel fuel stored in one or more tanks 104 to generate mechanical or motive power. However, other examples of prime movers include gasoline-burning spark ignition engines, gas-burning turbines, and the like. To pressurize the fracking fluid, the internal combustion engine 102 is operatively coupled via drivetrain components 105 such as a crankshaft, transmission, and driveshaft to a positive displacement hydraulic pump 106, which may connected to hoses, pipes, and the like to receive low pressure fluid from storage tanks and discharge high pressure fluid to the wellhead. To cool the internal combustion engine 102, the fracking machine 100 can include a radiator 108 that circulates coolant to and from the engine thereby transferring the generated heat to the environment. The components of the fracking machine 100 may be disposed on a mobile trailer 110 supported on wheels 112 to move the fracking machine to different locations; however, in other embodiments, the fracking machine 100 can be stationary.

Referring to FIG. 2, the pump 106 can be a large scale, positive displacement pump cable of generating pressures of 15 kilopounds per square inch or more and flow rates in the hundreds of liters per second. The pump 106 can include a connecting rod housing 120 that receives the rotating mechanical power from the internal combustion engine through the drivetrain components and/or transmission, and converts the rotary motion to linear reciprocal motion via an internal crankshaft coupled to a plurality of connecting rods 122. The connecting rod housing 120 may also include journals, lubricant circuits, packings, gearing and the like to facilitate the rotational to reciprocal power conversion. A flywheel may be operatively coupled to the internal crankshaft to assist operation of the pump 106. The connecting rods 122 may protrude from the side of the connecting rod housing 120 and can reciprocate back and forth with respect to a pumping unit 124 offset to the side of the connecting rod housing 120 that pressurizes the fracking fluid. The pumping unit 124 is composed of a plurality of pumping chambers 126 arranged in an inline configuration and aligned horizontally with respect to the connecting rod housing 120. In the illustrated embodiment, the pumping unit 124 includes three aligned pumping chambers 126, but in other embodiments may include a lesser or larger number of pumping chambers 126.

To receive the low-pressure fracking fluid, the pumping unit 124 can communicate with an inlet manifold 130 disposed generally underneath the pumping unit 124. To distribute fluid to the individual pumping chambers 126, the inlet manifold 130 can include a fluid rail 132 having a common inlet port 134 that can be attached to a hose or other piping and a plurality of inlet lines 136 that lead to the pumping chambers 126. To discharge the fracking fluid pressurized in the pumping chambers 126, the pumping unit 124 can include a common discharge outlet 138 disposed on the top of the pumping unit and that communicates with each of the pumping chambers 126. The discharge outlet 138 can connect to high-pressure lines or the like that direct pressurized fluid to the wellhead. It should be appreciated that, in other embodiments, different configurations for receiving and discharging fracking fluid to and from the pumping unit 124, including different number or locations of discharge outlets 138, are contemplated.

To monitor the fluid pressure and/or flow rate of fracking fluid into and out of the pumping unit 124, one or more pressure sensors can be operatively associated with the pump 106. For example, a first pressure sensor 140 can be disposed in or proximate to the discharge outlet 138 to measure the fluid pressure being discharged from the pumping unit 124. Because it is arranged in the discharge outlet 138, the first pressure sensor 140 may measure the combined discharge pressure from each of the plurality of pumping chambers 126. In other embodiments, a plurality of first pressure sensors 140 can be associated with each of the individual pumping chambers 126 and the output of each sensor combined to determine a common discharge pressure. The first pressure senor 140 can operate on electrical principles, mechanical principles, electromechanical principles, piezoelectrics, magnetic, or utilize any other suitable technologies or combinations thereof to measure the fluid force being commonly discharged from the combination of pumping chambers 126. The first pressure sensor 140 can read the high-pressure fracking fluid being discharged from the pump 106 in any suitable units such as, for example, kilopascals, pounds per square inch (PSI), bars, or the like. The first pressure sensor 140 can transmit in real time data regarding the discharge pressure as electrical or electronic signals in either analog or digital format. Additionally, to measure the pressure of the low-pressure fracking fluid being received into the pumping unit 124, a second pressure sensor 142 can be disposed in the inlet manifold 130.

Referring to FIG. 3, there is illustrated the internal components of the pumping chamber 126, which may include a solid chamber block 150 into which is disposed a hollow, interior cavity including a suction chamber 152 communicating with the inlet manifold, a cylinder bore 154, and a discharge chamber 156 communicating with the common discharge port. The suction chamber 152, cylinder bore 154, and discharge chamber 156 are interconnected and communicate with each other to provide a flow path for fracking fluid within the pumping chamber 126. To create a pumping action, a plunger or piston 160 is slidably disposed in the cylinder bore 154 and can be connected to the connecting rods to responsively reciprocate within the cylinder bore 154. To selectively isolate the cylinder bore 154, the pumping chamber 126 can include a suction valve 162 disposed in the suction chamber 152 and a discharge valve 164 disposed in the discharge chamber 156. In an embodiment, the suction valve 162 and discharge valves 164 can be configured as plug valves having a tapered surface that can seat against a corresponding valve seat 166 formed in chamber block 150 at suitable locations of the suction and discharge chambers 152, 156. Springs may be utilized to bias the suction and discharge valves 162, 164 against their respective valve seats 166. In other embodiments, other styles of suction and discharge valves such as poppet valves may be used.

During the pumping cycle, the piston 160 is retracted in the cylinder bore 154 creating an internal vacuum in the pumping chamber 126. The vacuum causes the suction valve 162 to lift into the suction chamber 152 thereby opening the suction chamber 152 to receive fracking fluid. Because of its orientation, however, the vacuum draws the discharge valve 164 against its respective valve seat 166 thereby keeping the discharge chamber 156 closed. When the piston 160 reciprocally changes direction and extends into the cylinder bore 154, the fracking fluid drawn therein becomes highly pressurized causing the opposite reaction of the suction and discharge valves 162, 164. Specifically, the suction valve 162 is forced against its respective valve seat 166 closing the suction chamber 152 while the discharge valve 164 is lifted from its valve seat 166 thereby opening the discharge chamber 156 allowing the pressurized fracking fluid to exit the pumping chamber 126. The pumping cycle can be repeated many times to continuously move fracking fluid through the pumping chamber 126.

To monitor, coordinate, and regulate operation of the various components the mobile fracking machine 100 including the pump 106, the mobile machine may be operatively associated with a computer control system adapted to process and execute various software instructions, programs, algorithms, functions, steps, routines, tasks, and processes. Referring to FIG. 4, there is illustrated a possible embodiment of the computer system 200 that may be implemented using general purpose, commercially available hardware, special purpose hardware devices disposed on the various components of the fracking machine, or combinations thereof. The computer system 200 can include at least one microprocessor or central processing unit (CPU) 202 for receiving digital or binary data, processing the date, and outputting the results. The CPU 202 can be embodied as an integrated circuit having appropriate circuitry including multiple integrated transistors for carrying out its processes. The CPU 202 can be a general purpose or special purpose device.

To communicate with the other components of the computer system 200, the CPU 202 may be connected to a communications system 204, such as one or more communications busses, data links, communications networks, etc., designed to carry electronic signals between the components of the computer system 200. The communications system 204 can carry digital bits and/or bytes or analog signals and can operate in serial or parallel operating modes. The electronic signals may be multiplexed or combined to increase bandwidth along the communications system 204. The various components of the computer system 200 can be communicatively connected to the communications system 204 by ports, adapters, or the like.

For example, to rapidly send and store data to and from the CPU 202, the computer system can include a main memory 210 such as random access memory communicatively connected to the communications system 204 in close proximity to the CPU 202. The main memory 210 can be composed of multiple individual memory cells arranged in an addressable format that data can be written and read to. However, main memory 210 is typical volatile in nature and loses any stored data when power is cut. To store data more permanently, the computer system 200 can include non-volatile memory or secondary storage 212. Examples of secondary storage include hard drives, magnetic disks, optical disks, tapes, erasable programmable memory (EPROM), programmable read only memory (PROM) and other storage mediums. Accordingly, the secondary storage 212 may be permanently connected to the communications system 204 or removable from it.

To interface with an operator, the computer system 200 can include a monitor or operator display 220 such as a liquid crystal display (LCD) or technology connected to the communications system 204 through an appropriate driver 222. The communications system 204 can also connect with other input/output devices 224 to exchange information, including for example, keypads, touch screens, printers, etc. To interface with external devices, the communications system 204 can include communication ports 226, such as serial ports, parallel ports, USB ports, jacks, and the like which connect to remote devices via data cables, fiber optics and the like. In further embodiments, the communications system 204 may include transmitters/receivers 228 configured for wireless communications to send and receive data and information wirelessly. By way of example, the first and second pressure sensors 140, 142 may interface with the computer system through these communication ports 226 or transmitters/receivers 228.

Referring back to FIG. 1, the components of the computer system 200 can be configured to form an electronic control module (ECM), electronic control unit (ECU), or electronic controller responsible for monitoring and regulating operation of the fracking machine 100 including the internal combustion engine 102, the pump 106, and any drivetrain components 105 operatively disposed between the engine and the pump. For example, the computer system 200 can adjust the speed and/or pressure of the pump 106 by regulating operation of the internal combustion engine 102 and/or the transmission if included. In various embodiments, the components of the computer system 200 shown in FIG. 4 can be included in a single hardware package or module, though in other embodiments, they may be distributed in different locations on the fracking machine 100.

The capacity of the computer system 200 to monitor and regulate discharge pressure from the pump may be restricted by the task management requirements of the CPU 202 arising from allocating CPU capacity among multiple operations and/or by the congestion of data traffic over the communications system 204. Therefore, in an embodiment, the computer system 200 can include a dedicated logic device 230 for monitoring and regulating pump pressure. The logic device 230 may be an integrated or discrete circuit or a plurality of integrated or discrete circuits including circuitry configured for conducting specific logical functions associated with the discharge pressure of the pump. Examples of suitable logic devices 230 include programmable logic devices such as field programmable gate arrays (FPGA), dedicated or customized logic devices such as application specific integrated circuits (ASIC) and gate arrays, or any other suitable type of circuitry or microchip. The logic device 230 can be configured to process digital or analog signals or can be configured as a mixed signal device. To receive data regarding pressures associated with the pump, the logic device 230 can be directly connected to the first and second pressure sensors 140, 142, although in other embodiments, the logic device 230 may also be communicatively connected to the communications system 204. In various embodiments, the logic device 230 can be a separate device from the other components of the computer system 200 or may be physically integrated with the other components of the computer system 200. The logic device may perform other operations or processes associated with the pump.

In an aspect of the disclosure, the logic device 230 can be configured to monitor the pressure data received from the first and/or second pressure sensors 140, 142 to assess the operating condition of the suction and discharge valves associated with the pump. Referring to FIG. 5, for example, there is illustrated an exemplary plot 300 of the discharge pressure along the Y-axis 302 verses time along the X-axis 304 as measured by the first pressure sensor 140 associated with the pump 106. The discharge pressures along the Y-axis 302 and time along the X-axis 304 shown in FIG. 5 are exemplary only but may correlate with pressures and timing typically associated with a fracking operation. The plot 300 graphs a discharge pressure curve 306 over time along the X-axis 304 as illustrated.

Referring to FIGS. 2, 3, 4, and 5, the pump 106 may discharge a steady state discharge pressure 308 of approximately 45,000 kPa under normal operating conditions. The steady state discharge pressure 308 may result from the combined discharge pressures of the plurality of the pumping chambers 126 included in the pumping unit 124. Furthermore, the timing associated with the plurality of the pumping chambers 126 can be configured to maintain steady state, balanced operation of the pumping unit 124. For example, the timing can be set such that the piston 160 disposed in a first pumping chamber 126 may be conducting a discharge stroke while the piston 160 in an adjacent pumping chamber 126 is conducting an opposing suction stroke. Hence, the plurality of pumping chambers 126 discharge to the discharge outlet 138 and draw from the inlet manifold 130 at different respective times. Where a number of different pumping chambers 126 are arranged inline, the stroke timing for the individual pumping chambers 126 can be varied with respect to each other to reduce pulsations in the pump 106. The difference in stroke timing can be accomplished by connecting the connecting rods 122 to the crankshaft disposed in the connecting rod housing 120 at different relative angular positions. Accordingly, the pumping unit 124 maintains a relatively consistent steady state discharge pressure 308 of, for example, 45,000 kPa.

If, however, the suction and/or discharge valves 162, 164 associated with one of the plurality of pumping chambers 126 were to operate uncharacteristically, for example, due to wear or deterioration of the suction and/or discharge valves 162, 164 or the associated valve seat 166, the irregular operation may be reflected in the discharge pressure curve 306. For example, uncharacteristic operation of the suction and/or discharge valves 162, 164 may be manifested as discharge pressure spikes 310 appearing in the discharge pressure from the pump 106. The discharge pressure spikes 310 can be significant, for example, increasing the discharge pressure curve 306 to approximately 60,000 kPa or decreasing it to approximately 30,000 kPa.

The discharge pressure spikes 310 may result from wear or deterioration affecting the timing of valve operation. For example, if the opening of the discharge valve 164 is delayed while the piston 160 extends into the cylinder bore 154 on a discharge stroke, the pressure of the fracking fluid in the cylinder bore 154 would be raised significantly over the steady state discharge pressure 308. Likewise, opening the discharge valve 164 too early could also cause significant discharge pressure spikes 310. Further, if the suction valve 162 operates incorrectly, insufficient fracking fluid may be drawn into the pumping chamber 126 or may be discharged back out of the pumping chamber 126 resulting in pressure spikes. The size or proportion of the discharge pressure spikes 310 may reflect the degree of wear or deterioration of the suction and/or discharge valves 162, 164. The frequency of the discharge pressure spikes 310 may indicate the number of suction and/or discharge valves 162, 164 that are deteriorating. For example, plot 300 may reflect the number of discharge pressure spikes 310 that occur if a single discharge and/or suction valve 162, 164 operates uncharacteristically. However, if multiple valves begin to operate uncharacteristically, the frequency of the discharge pressure spikes 310 will increase.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable to monitoring operation of a pump 106 used, for example, during a fracking operation by, in part, monitoring the discharge pressure associated with the high-pressure fracking fluid discharged from the pump 106. Referring to FIG. 6, there is illustrated an embodiment of a process 400 or routine that may be performed or executed by the computer control system 200 in conjunction with the logic device 230 of FIG. 4. The process 400 can be embodied as software including instructions and commands written in computer-executable programming code. It should be appreciated the precise and detailed processes described herein are exemplary for the purposes of the disclosure, and aspects of the processes may be used in various operating modes or in various combinations.

Referring collectively to FIGS. 2-6, in an initial receiving data step 402, the process 400 can receive information and data regarding the discharge pressure from the first pressure sensor 140 associated with the discharge outlet 138 of the pumping unit 124. The discharge pressure data can be in the form of electronic signals that can be communicated directly or indirectly to the logic device 230 operatively associated with the computer system 200. In a further embodiment, in the receiving data step 402 the process 400 can also receive pressure data from the second pressure sensor 142 disposed in the inlet manifold 130. In a subsequent data analysis step 404, the process 400 can analyze the discharge pressure data received during the receiving data step 402 with respect to a fixed or discrete period or over a continuous time. For example, the data analysis step 404 can perform this analysis by graphing the discharge pressure along the Y-axis 302 verses time along the X-axis 304 as indicated in or provide by the plot 300 in FIG. 4. The plot 300 enables a temporal analysis of the operation of the pump 106.

In a specific embodiment, the process 400 can determine the peak-to-peak amplitude associated with the discharge pressure curve 306. The process 400 can make this determination in a peak-to-peak determination step 406. Referring to plot 300, the peak-to-peak amplitude corresponds to the change from the highest value or peak to the lowest value or trough of the discharge pressure curve. Accordingly, a stable peak-to-peak amplitude 320 may correspond to the steady state discharge pressure 308 and is relatively small or nominal in value indicating normal or characteristic operation of the pump 106. However, if the maximum or high peak-to-peak amplitudes 322 assessed by the peak-to-peak determination step 406 and corresponding to the discharge pressure spikes 310 are relatively large, it may indicate uncharacteristic operation of the pump 106 and particularly of the suction and/or discharge valves 162, 164. The peak-to-peak amplitude of the discharge pressure curve 306 may be measured in real time based on the discharge pressure data as it is received or it can be assessed by another suitable conversion process such as, for example, averaging the individual pressure fluctuations in the discharge pressure curve 306.

In an embodiment, the data analysis step 404 and the peak-to-peak determination step 406 can be conducted in the logic device 230 included with the computer system 200. A possible advantage of utilizing a separate logic device 230 dedicated to pressure analysis is the logic device 230 can be customized to the high operating frequencies associated with the pump 106 and the plurality of individual pumping chambers 126. Further, by analyzing the high peak-to-peak amplitude 322 that corresponds to the discharge pressure spikes 310, rather than the frequencies of the peaks, the logic device 230 may be functional over a range of variable operating conditions associated with the pump 106. In an embodiment, the logic device 230 may isolate the discharge pressure spikes 310 from the steady state discharge pressure 308 by filtering or deducting the stable peak-to-peak amplitude 320 from the high peak-to-peak amplitude 322.

In a pressure spike detection step 408, the process 400 can detect if the discharge pressure spikes 310 are present in the discharge pressure curve 306. The process 400 can conduct the pressure spike detection step 408 as part of the peak-to-peak determination step 406 and can execute it in the logic device 230. The pressure spike detection step 408 detects the discharge pressure spikes 310 as emphasized or highlighted with respect to the steady state discharge pressure 308 associated with normal pump operation, which may correspond to comparing the high peak-to-peak amplitude 322 with the stable peak-to-peak amplitude 320. Hence, pressure spike detection step 408 can determine if the suction and/or discharge valves 162, 164 are operating uncharacteristically, indicating they may be worn or deteriorating.

In an embodiment, to compare or assess the wear or deterioration, the process 400 can, in a receive discharge pressure threshold step 410, receive a discharge pressure threshold and can compare, in a threshold comparison step 412, the discharge pressure threshold to the discharge pressure spikes 310 or the high peak-to-peak amplitude 322 as determined. If the discharge pressure threshold is exceeded, the process 400, in an alarm step 414, can issue an appropriate alarm, such as an audio or visual alarm, to indicate that preventative maintenance and service of the suction and/or discharge valves 162, 164 may be required. The computer system 200 can communicate the alarm to an operator or other person associated with the fracking operation. An advantage of utilizing the discharge pressure threshold is that it can be set to prevent activation of the alarm if wear or deterioration of the suction and/or discharge valves 162, 164 remains in acceptable limits. In other words, the discharge pressure threshold can be set above the stable peak-to-peak amplitude 320. The discharge pressure threshold may be empirically determined.

In another possible embodiment, the logic device 230 can be synchronized to the pump speed and/or crankshaft configuration so the logic device 230 may be capable of determining which pumping chamber 126 may be associated with the problematic suction and/or discharge valves 162, 164. For example, by understanding which pumping chamber 126 is conducting a discharge stroke and concurrently assessing the discharge pressure curve 306, the process 400 can advantageously identify the pumping chamber 126 associated with the discharge pressure spikes 310. In those embodiments utilizing the dedicated logic device 230 for pressure analysis, a further possible advantage is that the logic device 230 can be programmable such as a programmable logic device (PLD). Hence, the programmable logic device 230 can be configured in the field for the specific factors and variables regarding the fracking operation, for example, specific discharge pressure ranges and/or pumping speeds. This may be particularly advantageous where a plurality of fracking machines are employed in cooperation together during a fracking operation. As a further possible advantage, inclusion of the logic device 230 may release the other components of the computer system 200 to monitor and regulate the other operations of the fracking machine.

It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.

Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.

The use of the terms “a” and “an” and “the” and “at least one” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The use of the term “at least one” followed by a list of one or more items (for example, “at least one of A and B”) is to be construed to mean one item selected from the listed items (A or B) or any combination of two or more of the listed items (A and B), unless otherwise indicated herein or clearly contradicted by context.

Accordingly, this disclosure includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.

Claims

1. A pump for pumping fluid, the pump comprising:

an intake manifold;
a discharge outlet;
a plurality of pumping chambers in fluid communication with the intake manifold and the discharge outlet;
a pressure sensor disposed in the discharge outlet; and
a logic device configured to receive discharge pressure data from the pressure sensor, to analyze the discharge pressure data verses time; and to determine a high peak-to-peak amplitude of the discharge pressure data verses time to detect a discharge pressure spike.

2. The pump of claim 1, further comprising a discharge valve operatively disposed between one of the plurality of pumping chambers and the discharge outlet, wherein the discharge pressure spike is indicative of uncharacteristic operation of the discharge valve.

3. The pump of claim 2, further comprising a piston disposed in each of the plurality of pumping chambers.

4. The pump of claim 3, wherein the piston in each of the plurality of pumping chambers is configured to discharge fluid from the respective pumping chamber at different respective times.

5. The pump of claim 4, wherein discharge of fluid from the plurality of pumping chambers is associated with a steady state discharge pressure.

6. The pump of claim 1, wherein the logic device is further configured to receive a discharge pressure threshold value and to compare the discharge pressure threshold with the high peak-to-peak amplitude.

7. The pump of claim 6, wherein the logic device is further configured to issue an alarm if the high peak-to-peak amplitude associated with the discharge pressure spike exceeds the discharge pressure threshold.

8. The pump of claim 1, wherein the pump is a component of a fracking machine including a prime mover for operating the pump.

9. The pump of claim 8, wherein the logic device is a dedicated component of a computer system operatively associated with the fracking machine.

10. The pump of claim 9, wherein the logic device is a programmable logic device.

11. A method of operating a pump, the method comprising:

receiving electronic signals indicative of a discharge pressure associated with discharge of fluid from the pump;
analyzing discharge pressure verses time with a logic device dedicated at least in part to analysis of the discharge pressure;
determining a high peak-to-peak amplitude of the discharge pressure to detect a discharge pressure spike in the discharge pressure, the discharge pressure spike associated with uncharacteristic operation of a discharge valve or a suction valve associated with the pump.

12. The method of claim 11, further comprising comparing the high peak-to-peak amplitude to a discharge pressure threshold and activating an alarm if the high peak-to-peak amplitude exceeds the discharge pressure threshold.

13. The method of claim 12, wherein the pump includes a plurality of pumping chambers configured to discharge fluid at different respective times.

14. The method of claim 13, wherein discharge of fluid from the plurality of pumping chambers is associated with a steady state discharge pressure.

15. The method of claim 14, wherein the steady state discharge pressure is associated with a stable peak-to-peak amplitude.

16. The method of claim 15, wherein the electronic signals indicative of the discharge pressure are transmitted from a pressure sensor disposed in a discharge outlet communicating with each of the plurality of pumping chambers.

17. The method of claim 11, wherein the logic device is a programmable logic device.

18. A system for monitoring operation of a pump discharging fluid, the system comprising:

a pressure sensor disposed in a discharge outlet of the pump to measure a discharge pressure from a plurality of pumping chambers discharging fluid to the discharge outlet;
a logic device communicating with the pressure sensor to receive discharge pressure data reflecting the discharge pressure, the logic device configured to determine a high peak-to-peak amplitude associated with the discharge pressure, compare the high peak-to-peak amplitude with a discharge pressure threshold; and to issue an alarm if the high peak-to-peak amplitude exceeds the discharge pressure threshold.

19. The system of claim 18, wherein the discharge of fluid from the plurality of pumping chambers provides a stable peak-to-peak amplitude, and the high peak-to-peak amplitude corresponds to a discharge pressure spike in the discharge pressure.

20. The system of claim 19, wherein the discharge pressure spike indicates uncharacteristic operation of at least one of a suction valve or a discharge valve operatively associated with at least one of the plurality of pumping chambers.

Patent History
Publication number: 20180202423
Type: Application
Filed: Jan 19, 2017
Publication Date: Jul 19, 2018
Applicant: Caterpillar Inc. (Peoria, IL)
Inventors: Yanchai Zhang (Dunlap, IL), Zhijun Cai (Dunlap, IL), Zhaoxu Dong (Dunlap, IL)
Application Number: 15/410,467
Classifications
International Classification: F04B 19/22 (20060101); F04B 51/00 (20060101); F04B 49/10 (20060101); F04B 53/14 (20060101); F04B 53/16 (20060101); F04B 17/05 (20060101); F04B 53/10 (20060101); E21B 43/26 (20060101);