Patent Application
20180223831
This application relates generally to a monitoring system and, more particularly, to a system and method of monitoring the performance of a hydraulic pump and generating a notification upon a failure of the pump.
Hydraulic fracturing or fracking operations are often used during well development in the oil and gas industry. For example, in formations in which oil or gas cannot be readily or economically extracted from the earth, a hydraulic fracturing operation may be performed. Such a hydraulic fracturing operation typically includes pumping large amounts of fracking fluid at high pressure to induce cracks in the earth, thereby creating pathways via which the oil and gas may flow. Hydraulic fracturing or fracking pumps are typically relatively large positive displacement pumps. Fracking fluid often contains water, proppants and other additives and is pumped downhole by the fracking pump at a sufficient pressure to cause fractures and fissures to form within the well.
As a result of the abrasive and sometimes corrosive nature of the fracking fluid and the high pressures to which the fracking pumps are subjected, fracking pumps may be at a relatively high risk of failure. Systems have been proposed for monitoring pump failures. For example, U.S. Patent Publication No. 2016/0168976 discloses a system for detecting leakage in a fracking by monitoring the suction pressure, the discharge pressure, and a pump cylinder pressure. Each pressure may be measured by a different pressure sensor. A simplified system for monitoring a fracking pump would be desirable.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein, nor to limit or expand the prior art discussed. Thus, the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate that any element is essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.
In one aspect, a pump monitoring and notification system for a hydraulic pump includes a transmission speed sensor and a controller. The transmission speed sensor is associated with a transmission operatively connected to the hydraulic pump and generates transmission speed data indicative of an output speed of the transmission. The controller is configured to access a transmission threshold, with the transmission threshold being based upon variations in a rotational speed of the transmission, access a time threshold, and determine a rotational speed of the transmission based upon the transmission speed data from the transmission speed sensor. The controller is further configured to determine a variation in rotational speed of the transmission based upon the rotational speed, compare the variation in rotational speed of the transmission to the transmission threshold, and generate an alert signal when the variation in rotational speed of the transmission exceeds the transmission threshold for a time period exceeding the time threshold.
In another aspect, a method of monitoring a hydraulic pump that is operatively connected to a transmission includes accessing a transmission threshold, with the transmission threshold being based upon variations in a rotational speed of the transmission, accessing a time threshold, and determining a rotational speed of the transmission based upon the transmission speed data from the transmission speed sensor associated with the transmission. The method further includes determining a variation in rotational speed of the transmission based upon the rotational speed, comparing the variation in rotational speed of the transmission to the transmission threshold, and generating an alert signal when the variation in rotational speed of the transmission exceeds the transmission threshold for a time period exceeding the time threshold.
In still another aspect, a pump system includes a prime mover, a transmission operatively connected to and driven by the prime mover, and a hydraulic pump operatively connected to and driven by the transmission. The pump system further includes a state sensor for generating data indicative of whether the prime mover is operating at a steady-state, a transmission speed sensor associated with the transmission for generating transmission speed data indicative of an output speed of the transmission, and a controller. The controller is configured to access a transmission threshold, with the transmission threshold being based upon variations in a rotational speed of the transmission, access a time threshold, and determine a rotational speed of the transmission based upon the transmission speed data from the transmission speed sensor. The controller is further configured to determine a variation in rotational speed of the transmission based upon the rotational speed, compare the variation in rotational speed of the transmission to the transmission threshold, and generate an alert signal when the variation in rotational speed of the transmission exceeds the transmission threshold for a time period exceeding the time threshold.
Referring to
The transmission 13 may be configured with a plurality of gears operative between the engine 12 and the output shaft (not shown) of the transmission to alter the rotational speed of the output from the engine. In some instances, a fixed gear mechanism or coupling depicted generally at 17 may be provided between the output shaft of the transmission 13 and the drive shaft 21 of the hydraulic pump 14 to further change or reduce the rotational speed between the engine 12 and the pump.
As depicted in
Referring to
Referring to
A discharge or outlet conduit (not shown) may be fluidly connected to an outlet manifold 36 positioned at the outlet end 35. The outlet manifold may include a plurality of outlet lines 37 with each outlet line being fluidly connected to one of the cylinders 40, such as at a location opposite the inlet lines 33. The outlet end 35 may include a discharge or outlet valve 43 (
During a pumping process, operation of the engine 12 may drive rotation of the transmission 13 and ultimately rotation of the drive shaft 21 of the hydraulic pump 14. Rotation of the drive shaft 21 causes reciprocating movement of the pistons 41 within cylinders 40. The reciprocating movement of the pistons 41 may cause fracking fluid to be drawn through the inlet manifold 32 from the inlet conduit (not shown) and into the cylinders 40 through the inlet lines 33 and past the inlet valves 42. Fracking fluid is driven by the pistons 41 past the outlet valves 43 through the outlet lines 37 and into outlet manifold 36.
The pumping system 10 may be controlled by the control system 60 as shown generally by an arrow in
The controller 61 may be an electronic controller that operates in a logical fashion to perform operations, execute control algorithms, store, retrieve, and access data and other desired operations. The controller 61 may include or access memory, secondary storage devices, processors, and any other components for running an application. The memory and secondary storage devices may be in the form of read-only memory (ROM) or random access memory (RAM) or integrated circuitry that is accessible by the controller. Various other circuits may be associated with the controller 61 such as power supply circuitry, signal conditioning circuitry, driver circuitry, and other types of circuitry.
The controller 61 may be a single controller or may include more than one controller disposed to control various functions and/or features of the pumping system 10. The term “controller” is meant to be used in its broadest sense to include one or more controllers and/or microprocessors that may be associated with the pumping system 10 and that may cooperate in controlling various functions and operations of the pumping system. The functionality of the controller 61 may be implemented in hardware and/or software without regard to the functionality. The controller 61 may rely on one or more data maps relating to the operating conditions and the operating environment of the pumping system 10 and the work site at which the pumping system is operating that may be stored in the memory of or associated with the controller. Each of these data maps may include a collection of data in the form of tables, graphs, and/or equations.
The control system 60 and controller 61 may be located on the trailer 15 or may be distributed with components also located remotely from or off-board the trailer.
Pumping system 10 may be equipped with a plurality of sensors that provide data indicative (directly or indirectly) of various operating parameters of elements of the system and/or the operating environment in which the system is operating. The term “sensor” is meant to be used in its broadest sense to include one or more sensors and related components that may be associated with the pumping system 10 and that may cooperate to sense various functions, operations, and operating characteristics of the element of the system and/or aspects of the environment in which the system is operating.
An engine speed sensor 62 (
In some instances, the hydraulic pump 14 may not include a significant number of sensors. In one example, the trailer 15 may not include electrical connections adjacent the hydraulic pump 14 and therefore the pump may not include sensors that require electrical input. In addition, the nature of and operating environment associated with the operation of the engine 12, the transmission 13, and the hydraulic pump 14 may result in fewer sensors being associated with the pump. For example, the hydraulic or fracking fluid may be abrasive and/or corrosive and thus the fluid section 30 of the hydraulic pump 14 may require maintenance substantially more frequently than the engine 12 or the transmission 13. Accordingly, it may be desirable to reduce the number of sensors associated with the hydraulic pump 14, when possible.
The abrasive and/or corrosive nature of the fracking fluid being pumped may cause substantial wear on the components of the hydraulic pump 14 and, in particular, the fluid section 30. Leaks are often more likely to occur at locations in which components of the hydraulic pump 14 move. More specifically, leaks may be likely to occur along the inlet wall or at the inlet valve 42 as indicated by the arrow 65 in
In addition to avoiding leaks in the hydraulic pump 14, it is desirable to avoid cavitation within the pump. Cavitation may be caused by various conditions including leaks as described above as well as low pressure or low flow at the inlet end 31. In addition to reduced performance of the hydraulic pump 14, cavitation may also cause significant damage to the pump.
The control system 60 may include a pump monitoring and notification system 68 as shown generally by an arrow in
Referring to
As leakage or cavitation begins to occur within the hydraulic pump 14, vibrations will begin to occur within the pump. Such vibrations may result in and be evident as an increase in the variations in the rotational speed of the hydraulic pump 14. In addition, the vibrations within the hydraulic pump 14 may be transferred to the transmission 13 through the coupling 17 between the pump and transmission and result in an increase in the variations in the rotational speed of the transmission. As depicted in
In one embodiment, the pump monitoring and notification system 68 may be configured to monitor the variations in the speed of rotation of the transmission 13 and generate an alert signal once the variations are equal to or greater than a predetermined transmission speed variation threshold. When monitoring the variations in the speed of the transmission 13, the speed of the transmission is measured relatively frequently, such as every millisecond. In order to determine the variation or difference between the maximum rotational speed of the transmission 13 and the minimum rotational speed of the transmission, the speeds may be measured over a predetermined period of time while operating the transmission at a steady state. As used herein, “steady state” refers to maintaining a constant or generally constant average speed. Accordingly, the transmission speed variation threshold may be defined as a difference between the maximum rotational speed of the transmission 13 and a minimum rotational speed of the transmission over a predetermined period of time while operating the transmission at a steady state. In some instances, the transmission 13 may only be operating at steady state if the rotational input to the transmission from the engine 12 is operating at a steady state.
In one example, the transmission speed variation threshold may be approximately 25 RPM. In other examples, the pump monitoring and notification system 68 may utilize other variation in rotational speed thresholds. For example, the pump monitoring and notification system 68 may be configured to use a smaller transmission speed variation threshold such as approximately 10, 15 or 20 RPM or a larger transmission speed variation threshold such as approximately 40 or 50 RPM. In another example, the transmission speed variation threshold may be between 10-60 RPM. In still another example, the transmission speed variation threshold may be between 20-50 RPM. In a further example, the transmission speed variation threshold may be at least 10 RPM or at least 15 RPM. Still other transmission speed variation thresholds are contemplated.
In another embodiment, the pump monitoring and notification system 68 may be configured to monitor the variations in the speed of rotation of the transmission 13 and generate an alert signal if the ratio between the current variation in the operational speed of the transmission 13 and the variation in rotational speed of the transmission during steady state operation exceeds a predetermined variation ratio threshold. The variation ratio threshold may be defined as a difference between a maximum rotational speed of the transmission and a minimum rotational speed of the transmission over a predetermined period of time while operating at a steady state divided by a variation in the rotational speed of the transmission while operating the transmission at a steady state and without a hydraulic pump failure.
In the example depicted in
The pump monitoring and notification system 68 may monitor the variations in the rotational speed of the transmission 13 by measuring the rotational speed at predetermined intervals. For example, the rotational speed of the transmission 13 may be measured once every millisecond. Other measurements intervals are contemplated. In order to reduce the likelihood of false warnings or alerts, the pump monitoring and notification system 68 may be configured to require the transmission speed variation threshold or variation ratio threshold to be met or exceeded for a predetermined length of time. In one example, the pump monitoring and notification system 68 may require the transmission speed variation threshold or variation ratio threshold to be met or exceeded for 60 seconds before generating an alert signal.
In other examples, the pump monitoring and notification system 68 may require the threshold to be met or exceed for longer or shorter periods of time. For example, the time threshold may be 30 seconds, 120 seconds, or any other desired time period.
If desired, the pump monitoring and notification system 68 may include, in addition or in the alternative, an accumulator function to account for the extent or degree to which the relevant transmission threshold (e.g., transmission speed variation threshold or variation ratio threshold) is exceeded. The accumulator function may integrate the extent to which the threshold is exceeded and establish an additional or accumulator threshold for the accumulator function. The accumulator function may sum the amount by which the threshold is exceeded and the sum or accumulated result compared to the accumulator threshold. Upon exceeding the accumulator threshold, the alert signal may be generated.
As an example, the pump monitoring and notification system 68 may be configured to permit the hydraulic pump 14 to operate for a relatively long period of time before generating an alert signal if the transmission speed variation threshold or variation threshold ratio is exceeded by a relatively small amount (e.g., 10%). However, the pump monitoring and notification system 68 may generate an alert signal relatively quickly if the transmission speed variation threshold or variation threshold ratio is exceeded by a relatively large amount (e.g., 75%).
Alert signals generated by the pump monitoring and notification system 68 may take any desired form. In one example, an alert signal may provide a notice or warning to personnel or systems at the work site and/or remote from the work site. In another example, an alert signal may, in addition or in the alternative, include a command to shutdown or reduce the operation of the pumping system 10 in order to reduce the likelihood of further damage to the hydraulic pump 14.
The pump monitoring and notification system 68 may be configured so that the controller 61 receives information from various sensors and systems of the pumping system 10 and processes the information to determine when pump leakage or cavitation is occurring without directly using or requiring the operating characteristics of the hydraulic pump 14 (e.g., input pressure, output pressure, rotational speed of the pump). As such, the pump monitoring and notification system 68 may determine that pump leakage or cavitation is occurring without sensors directly monitoring the operating characteristics of the hydraulic pump 14.
As depicted in
The industrial applicability of the system described herein will be readily appreciated from the foregoing discussion. The pump monitoring and notification system 68 may be used with pumping systems 10 that include a prime mover, such as an engine 12, operatively connected to drive transmission 13, and with the transmission operatively connected to drive the hydraulic pump 14. The pump monitoring and notification system 68 may determine whether the hydraulic pump 14 is experiencing leakage or cavitation based upon variations in the rotational speed of the transmission 13 without monitoring additional aspects or operating characteristics of the pump.
The pumping system 10 may be operated at block 81. Data from the engine speed sensor 62 and the transmission speed sensor 63 may be received at block 82. At block 83, the controller 61 may determine the engine speed based upon the engine speed data received from the engine speed sensor 62. The controller 61 may determine at decision block 84 whether the engine 12 is operating at a steady state so that the pump monitoring and notification system 68 may be operated in an accurate manner.
If the engine 12 is not operating in a steady state manner, analysis of the variations in the transmission speed may not provide reliable data. Accordingly, when the engine 12 is not operating in a steady state manner, the pumping system 10 may continue to be operated and blocks 81-84 repeated.
If the engine 12 is operating in a steady state manner, the controller 61 may determine at block 85 the speed of the transmission 13 based upon the transmission speed data received from the transmission speed sensor 63. Based upon the transmission speed, the controller 61 may determine at block 86 the magnitude of the variation in the transmission speed.
The controller 61 may access the transmission speed variation threshold and compare the magnitude of the variation in transmission speed to the transmission speed variation threshold. If the variation in transmission speed does not exceed the transmission speed variation threshold at decision block 87, the pumping system 10 may continue to be operated and blocks 81-87 repeated. If the variation in transmission speed does exceed the transmission speed variation threshold, the controller 61 may access the time threshold and determine at decision block 88 whether the time during which the variation in transmission speed exceeds the transmission speed variation threshold also exceeds the time threshold. If the time threshold has not been reached, the pumping system 10 may continue to be operated and blocks 81-88 repeated. If the time threshold has been reached, an alert signal may be generated by controller 61 at block 89. In some instances, the pumping system 10 may continue to be operated and blocks 81-89 repeated. In other instances, the alert signal may also include a command to shut down or reduce the operation of the pumping system 10.
Other configurations of the operation of the pump monitoring and notification system 68 are contemplated. For example, rather than setting or storing a transmission speed variation threshold at block 80, a variation ratio threshold may be set or stored that defines a threshold ratio between the magnitude of steady state operation of the transmission and the magnitude of the variation in transmission speed during a pump failure. An example using the variation ratio threshold may operate generally in accordance with the example depicted in
In another aspect of the second example that is different from the example depicted in
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.
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.
