Patent Application
20110236225
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. The technical field generally relates to positive displacement pumps, and more specifically but not exclusively to high pressure positive displacement pumps. Operations with positive displacement pumps having several cylinders occasionally encounter high pressure situations, failures of one or more pumps within the pumping system, or otherwise perform pumping operations requiring a broad range of fluid rates and pressures within the same pumping operations. Changing a displacement of a pump in the present art includes utilizing a pump with a multi-speed transmission, performing operations on a pump requiring significant disassembly of the pump, and/or exposure of personnel to treating iron or other fluid conduits during high pressure pumping operations. In certain contexts, including oilfield pumping applications, shutting down pumping for extended periods during a pumping operation can be detrimental to the success of the pumping operation. Therefore, further technological developments are desirable in this area.
One embodiment is a unique method for rapidly changing specific pump displacement during a pumping operation. Other embodiments include unique methods, systems, and apparatus to rapidly connect or disconnect portions of a pump fluid end from the pump power end. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.
For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the invention as illustrated therein as would normally occur to one skilled in the art to which the invention relates are contemplated herein.
Referencing
The system 100 includes an actuator 112 that couples the power end to a selectable subset of the plungers 110. The selectable subset includes any number of plungers 110 from zero plungers 110 (i.e. the power end is disconnected from the fluid end) to all of the plungers 110. The exemplary fluid end 108 includes a first set of plungers 110a and a second set of plungers 110b, and the fluid end 108 operates as a triplex pump when operating either set of plungers 110a, 110b, and as a six-plex fluid end when operating both sets of plungers 110a, 110b. In the position illustrated in
In certain embodiments, the system 100 further includes a controller 116 that performs certain operations for rapid configuration of a pump displacement. In certain embodiments, the controller forms a portion of a processing subsystem including one or more computing devices having memory, processing, and communication hardware. The controller 116 may be a single device or a distributed device, and the functions of the controller may be performed by hardware or software. Certain operations of the controller 116 may be performed manually by an operator, or provided as operator inputs to the controller 116 through switches, levers, and other inputs. Certain operations of the controller 116 may be performed by a computer in response to instructions provided on a computer readable medium.
The controller 116 selects the subset of the plungers 110 according to a job pumping rate, a job pumping pressure, and/or a fluid end failure event indicator. For example, the job pumping rate and/or the job pumping pressure may be provided to the controller 116 by an operator in accordance with a job design, and the controller 116 selects a subset of the plungers 110 in response to the job pumping rate and pressure. The plungers 110 may be of different sizes, for example the first set of plungers 110a may be smaller plungers utilized in lower rate higher pressure applications, and the second set of plungers 110b may be larger plungers utilized in higher rate higher pressure applications. The controller 116 determines the job pumping rate and/or pressure by any method understood in the art, including at least detecting the rate and pressure according to sensors, software values stored on a computer readable medium, values provided by switches or electronic inputs, values provided on a datalink, and/or by values provided as inputs such as a pumping rate command or a maximum pressure limitation.
In the example provided, the controller 116 selects the first set of plungers 110a, the second set of plungers 110b, or both sets of plungers 110a, 110b. The utilization of sets of three plungers is desirable from a perspective of smooth delivery of the fluid out of the pump 104. However, the controller 116 may select any number of plungers 110. For example, where the job pressure and the available power of the power end 106 require it, a single plunger 110 is selected. The controller 116 may perform any cost or benefit analysis understood in the art before selecting the plungers 110, including determining whether a job failure will occur if the pump 104 is completely unavailable to deliver fluid, determining a degree of cavitation or pressure pulsing that occurs in response to off-nominal pumping conditions, determine the values of any user overrides (e.g. a user command instructing the controller 116 to deliver fluid under any circumstances, or to discontinue pumping if groups of three plungers 110 cannot be utilized). In certain embodiments, the controller 116 may de-select specific plungers in response to a detected failure condition of the specific plunger 110 or related valves (not shown) or other components of the fluid end 108 related to the specific plunger 110.
The controller 116 further provides an actuator command in response to the selected subset of the plungers 110. In certain embodiments, the actuator command is a direct control of the actuator 112 (e.g. hydraulic, electric, pneumatic, or datalink command) that couples the selected plungers 110 from the power end 106 and de-couples the un-selected plungers 110 from the power end 106. The actuator command may be any actuator command understood in the art to effect the appropriate movement of the actuator 112, including at least a display value visible to an operator instructing the operator which plungers 110 should be coupled or de-coupled from the power end 106. In certain embodiments, the actuator command may be provided by a pre-determined value based on a pumping rate, for example a written table stored in the vicinity of the pump that instructs which plungers 110 are to be coupled and de-coupled according to the pumping rate that is to be provided by the pump 104. The written table and/or any data stored on a computer readable medium associated with the pump 104 may be updated according to the conditions of the pump 104—for example according to the size of the presently installed plungers 110 on the pump 104.
The controller 116 further selects the subset of the plungers according to a determined event. The determined events include any event known in the art that is affected by the specific displacement (i.e. the amount of fluid delivered from the pump for each rotation of the power end 106—e.g. a crankshaft 118 of the power end). Exemplary determined events include an overpressure event, a high pressure event, a low pressure event, a pump failure event, a plunger failure event, a service event, a pump startup event, a cavitation event, a blender failure event, and/or a low-pressure fluid delivery failure event. A high pressure event includes any pressure in the system 100 that is above a threshold value, for example a pressure that is high relative to the maximum force allowed at the power end 106, a high pressure relative to a maximum treatment pressure, a high pressure relative to the treating equipment (e.g. the treating iron, a casing segment at least partially exposed to treatment pressure, etc.). In one embodiment, the controller 116 disconnects the power end 106 from all of the plungers 110 in response to an overpressure event.
An embodiment of the exemplary system 100 includes a wellbore 120 fluidly coupled to a formation of interest 122, and a data gathering module 124 that determines pressure data from the wellbore 120. The data gathering module 124 may include a computer that determines data from various sensors distributed in the system 100, although any data gathering module 124 is contemplated herein. The controller 116 further selects a subset of the plungers 110 according to a treatment pressure value from a mini-frac operation performed on the formation of interest 122. For example, after the treating equipment is connected to the wellbore 120, a mini-frac treatment (a small, data gathering fracture treatment) is performed that determines at least one of a leakoff value for the formation 122, a fracture closure pressure, or other parameters, and the treatment pressure value is determined according to the data from the mini-frac operation. The treatment pressure value may be any treatment pressure that is determined from a mini-frac or other pumping diagnostic test, and can include at least any of an estimated maximum treating pressure, a pressure that will be required to break down or fracture a formation, and/or a not-to-exceed pressure such as a pressure to avoid fracturing a formation neighboring the formation of interest 122.
In certain embodiments, the controller 116 selects the subset of the plungers 110 to communicate a pressure pulse to a downhole device (not shown). Pressure pulses may be utilized to communicate with downhole tools, communicate with or respond to logging tools, or to perform any other pressure pulse operations understood in the art.
An exemplary apparatus includes the pump 104 having the power end 106 and the fluid end 108, the fluid end 108 having a number of plungers 110. The apparatus further includes the actuator 112 that couples the power end 106 with a selectable number of the plungers 110, and a controller 116 that selects a number of the plungers 110 according to a job pumping rate and/or a job pumping pressure. The controller 116 further provides an actuator command in response to the selected number of the plungers 110. The exemplary apparatus includes the pump having two groups of three plungers 110a, 110b, where the selectable number of the plungers includes the first group of three plungers 110a, the second group of three plungers 110b, and/or both of the groups of three plungers 110a, 110b. In certain embodiments, the controller 116 selects the number of the plungers according to an event including an overpressure event, a high pressure event, a low pressure event, a pump failure event, a plunger failure event, a service event, a pump startup event, a cavitation event, a blender failure event, and/or a low-pressure fluid delivery failure event. The actuator 112 may be operated manually in certain embodiments.
Referencing
Referencing
In the first engaged position (not shown), the pin 302 moves up and engages the pony rod 114, while the second pin 304 moves down and the clamp 308 is no longer fixed to the stationary portion of the fluid end 306. It can be seen from the illustration in
Referencing
The apparatus illustrated in
In certain embodiments, the pony rod 114 includes a pony rod lip 504 and the plunger 110 includes a plunger lip 506. A clamp 502 couples or de-couples the pony rod 114 and the plunger 110 by engaging or dis-engaging the lips 504, 506. The clamp 502 may be a rigid clamp encompassing both lips 504, 506, and may have a quick disconnect lever or other device. For example, a Style 78 Snap-Joint Coupling, sold by Victualic Company, 4901 Kesslersville Road, Easton, Pa., or a similar device, may be utilized in certain embodiments. A clamp 502 may be operated mechanically, electromagnetically, thermally, or by any other means understood in the art. Referencing
Another exemplary apparatus includes the actuator having a dog tooth clamp 602 that couples a pony rod protrusion 604 to a plunger protrusion 606. A rotation of the plunger 110 (or the pony rod 114, although generally the pony rod 114 is rotationally fixed) to an engaged position engages the dog tooth clamp 602 with an opposing protrusion. Referencing
The following descriptions provide illustrative embodiments of performing procedures for rapidly configuring a pump displacement. Operations illustrated are understood to be exemplary only, and operations may be combined or divided, and added or removed, as well as re-ordered in whole or part, unless stated explicitly to the contrary herein. Certain operations described may be implemented by a computer executing a computer program product on a computer readable medium, where the computer program product comprises instructions causing the computer to execute one or more of the operations, or to issue commands to other devices to execute one or more of the operations.
A procedure includes an operation to pump a first displacement amount of a fluid from a positive displacement pump having a first number of plungers with a rotation of a power end of the pump. The first displacement amount is related to the swept volume of the first number of plungers in response to the rotation of the power end of the pump (e.g. less any volumetric efficiency losses), and will be further related to the area of the face of the plungers. The procedure further includes an operation to change the first number of plungers to a second number of plungers, and to pump a second displacement amount of the fluid from the positive displacement pump, having the second number of plungers, with a rotation of the power end of the pump. In certain embodiments, the second displacement amount of the fluid is a distinct amount of fluid from the first displacement amount (i.e. the swept volume of the second amount of plungers is different from the swept volume of the first amount of plungers). In certain additional embodiments, the second amount of plungers may: include the first amount of plungers, be a different set of plungers from the first amount of plungers, or be a set of plungers that is a partial or complete subset of the first amount of plungers.
An exemplary operation of the procedure includes changing the plungers by switching from one set of three plungers to a second set of three plungers. An alternate operation of the procedure includes adding a set of plungers, subtracting a set of plungers, and/or de-coupling all of the plungers from the power end. The operation to change the plungers further includes, in certain embodiments, an operation to determine that a pumping pressure has increased past a threshold, and to perform the operation to change the plungers in response to the pumping pressure increasing past the threshold.
The exemplary procedure may be performed remotely or by an operator located at the pump. An exemplary procedure includes an operation to select the first set of plungers, the second set of plungers, or both sets of plungers, thereby operating a six-plex pump at a selectable one of three distinct specific displacement values. Another exemplary procedure includes starting the pump in an ongoing pumping operation (e.g. with other fluidly coupled pumps already pumping) with a first plunger or number of plungers, and increasing the number of plungers to the second number of plungers after the pump is started. The first number of plungers and/or the second number of plungers may include a single plunger, or zero plungers where a change in the plungers occurs in response to an overpressure event or other pump shutdown situation.
In certain embodiments, the changing from the first number of plungers to the second number of plungers occurs within a changing time value. The changing time value varies according to the specific system and the purpose of the change in the plungers. In certain embodiments, a rapid change is desirable (e.g. in a near-screenout situation due to fluid leakoff where a lengthy shutdown may risk pumping job failure) and available (e.g. a rapid actuator response is possible such as an automated sliding sleeve, displacement rod, etc.) and the changing time value is less than five seconds. In certain embodiments, dependent upon the actuator mechanism which will be understood by one of skill in the art having the benefit of the disclosures herein, the changing time value is less than ten seconds (e.g. manual quick-disconnect clamps in certain embodiments) or less than thirty seconds (e.g. where several operations to roll the pumps during changeover are required, dependent upon the pump controls and response). In certain embodiments, the changing time value may be less than sixty seconds, or a time greater than sixty seconds. The changing time values described herein are exemplary, and depend upon the specific requirements and implementation of the system. In certain embodiments, the changing is performed without stopping pumping operations of the pump.
Yet another exemplary procedure includes an operation to fluidly couple a pump having a number of plungers to a fluid line, an operation to couple a first subset of the plungers to a power end of the pump, and an operation to pump a fluid through the fluid line with the first subset of the plungers. The procedure further includes an operation to pump the fluid through the fluid line with the first subset of the plungers, an operation to couple a second subset of the plungers to the power end of the pump, and an operation to pump the fluid through the fluid line with the second subset of the plungers. The exemplary procedure further includes an operation to determine a treatment pressure value, and to perform the operation to couple the second subset of the plungers in response to the treatment pressure value.
Determining the treatment pressure value includes determining any treatment pressure value understood in the art that either indicates a different pump specific displacement (e.g. plunger head size) is desirable, or that a specific plunger or set of plungers has experienced a failure or requires maintenance. Exemplary operations to determine the treatment pressure value include determining the treatment pressure value from a mini-frac operation, determining a maximum treatment pressure observed during the pumping (which may be updated during the pumping), and/or predicting a maximum treatment pressure in response to pressures observed during the pumping with the first subset of the plungers. For example, the determination of the treatment pressure value may include an estimation that a maximum pressure allowable for the first set of plungers will be exceeded at a later point during a pumping operation, and a switch is made to the second set of plungers before the maximum pressure allowable is achieved. In certain embodiments, the procedure includes an operation to detect a fluid end failure event corresponding to the first subset of the plungers, and the operation to couple the second subset of the plungers in response to the fluid end failure event.
The exemplary procedure further includes an operation to provide a pressure pulse to a downhole device. Pressure pulses may be utilized to communicate with downhole tools, communicate with or respond to logging tools, or to perform any other pressure pulse operations understood in the art. In certain further embodiments, the procedure includes an operation to hold the first plurality of plungers at a most withdrawn position from the power end after the changing. Thereby, the dis-engaged plungers do not collide with the pony rods of the power end during operations.
As is evident from the figures and text presented above, a variety of embodiments according to the present invention are contemplated.
An exemplary method includes pumping a first displacement amount of a fluid from a positive displacement pump having a first number of plungers with a rotation of a power end of the pump, changing the first number of plungers to a second number of plungers, and pumping a second displacement amount of the fluid from the positive displacement pump having the second number of plungers with a rotation of the power end of the pump. The exemplary method further includes changing the plungers by switching from one set of three plungers to a second set of three plungers. The changing may include adding a set of plungers, or subtracting a set of plungers, including de-coupling all of the plungers from the power end. In certain embodiments, the method further includes determining that a pumping pressure has increased past a threshold, and performing the changing in response to the pumping pressure increasing past the threshold.
The exemplary method may be performed remotely. In certain embodiments, the first set of plungers has a first specific displacement and a second set of plungers having a second specific displacement, where the specific displacement is proportional to an amount of fluid pumped for each rotation of the power end. The exemplary method further includes selecting one of the first set of plungers, the second set of plungers, and both sets of plungers, thereby allowing a six-plex pump to operate at three distinct specific displacement values. The method further includes starting the pump in an ongoing pumping operation (e.g. with other fluidly coupled pumps already pumping) with the first plurality of plungers, and increasing the number of plungers to the second plurality of plungers after the pump is started. In certain embodiments, the first number of plungers and/or the second number of plungers may be a single plunger. In certain embodiments, the changing occurs within a changing time value that is less five seconds, ten seconds, thirty seconds, and/or sixty seconds. In certain embodiments, the changing is performed without stopping pumping operations of the pump. The exemplary method further includes providing a pressure pulse to a downhole device, and/or holding the first plurality of plungers at a most withdrawn position from the power end after the changing.
Another exemplary embodiment is an apparatus including a pump having a power end and a fluid end, the fluid end having a number of plungers. The apparatus further includes an actuator that couples the power end with a selectable number of the plungers, and a controller that selects a number of the plungers according to a job pumping rate and/or a job pumping pressure. The controller further provides an actuator command in response to the selected number of the plungers. The exemplary apparatus includes the pump having two groups of three plungers, where the selectable number of the plungers includes a first group of three plungers, a second group of three plungers, and/or both of the groups of three plungers. In certain embodiments, the controller selects the number of the plungers according to an event including an overpressure event, a high pressure event, a low pressure event, a pump failure event, a plunger failure event, a service event, a pump startup event, a cavitation event, a blender failure event, and/or a low-pressure fluid delivery failure event.
The exemplary apparatus includes the actuator as a sliding sleeve that engages a ball in a groove and/or a shaped dog, and may further include a key or displacement rod that engages the sliding sleeve, the ball, and/or the shaped dog. In certain embodiments, the actuator includes a first pin that couples a clamp to a pony rod in a first engaged position and a second pin that fixes the clamp to a stationary portion of the fluid end in a second engaged position. The controller engages the first pin to couple the power end to a selected plunger, and engages the second pin to de-couple the power end from the selected plunger.
In certain embodiments, the actuator includes a first number of teeth on a pony rod that selectively engage a second number of teeth on a selected plunger shaft, and a pin that engages a helical gear that selectively locks the first plurality and second plurality of teeth into engagement. In an additional or alternate embodiment, the actuator includes a clamp that couples a pony rod lip to a plunger lip, where the clamp includes a flexible clamping member and a stabilizing pin. The stabilizing pin is biased into a stabilizing position that couples the pony rod lip to the plunger lip. The actuator further includes a displacement rod that moves the stabilizing pin into a release position that de-couples the pony rod lip from the plunger lip.
An exemplary apparatus includes the actuator having a dog tooth clamp that couples a pony rod protrusion to a plunger protrusion. The actuator further includes a stabilizing pin that prevents relative rotation of a selected plunger having the plunger protrusion and a pony rod having the pony rod protrusion. Rotation of the plunger and/or the pony rod may be utilized to engage and disengage the plunger and the pony rod.
Yet another exemplary embodiment is a system, including a blender providing low-pressure fluid to a pump, where the pump includes a power end and fluid end having a number of plungers. The system includes an actuator that couples the power end to a selectable subset of the plungers. The selectable subset includes any number of plungers from zero plungers (i.e. the power end is disconnected from the fluid end) to all of the plungers. The system further includes a controller that selects the subset of the plungers according to a job pumping rate, a job pumping pressure, and/or a fluid end failure event indicator, and that provides an actuator command in response to the selected subset of the plungers. The controller further selects the subset of the plungers according to an event including: an overpressure event, a high pressure event, a low pressure event, a pump failure event, a plunger failure event, a service event, a pump startup event, a cavitation event, a blender failure event, and/or a low-pressure fluid delivery failure event. The exemplary system includes the controller is further structured to select the subset of the plungers to communicate a pressure pulse to a downhole device. The controller further disconnects the power end from all of the plungers in response to an overpressure event. In certain embodiments, the selectable subsets of the plungers include a first set of three plungers having a first specific displacement, and a second set of three plungers having a second specific displacement.
An embodiment of the exemplary system includes a wellbore fluidly coupled to a formation of interest, and a data gathering module that determines pressure data from the wellbore. The controller further selects a subset of the plungers according to a treatment pressure value from a mini-frac operation performed on the formation of interest.
Yet another exemplary embodiment is a method including fluidly coupling a pump having a number of plungers to a fluid line, coupling a first subset of the plungers to a power end of the pump, pumping a fluid through the fluid line with the first subset of the plungers, and after the pumping the fluid through the fluid line with the first subset of the plungers, coupling a second subset of the plungers to the power end of the pump and pumping the fluid through the fluid line with the second subset of the plungers. The exemplary method further includes determining a treatment pressure value, and coupling the second subset of the plungers in response to the treatment pressure value. Determining the treatment pressure value includes performing a pressure determination operation such as: determining the treatment pressure value from a mini-frac operation, determining a maximum treatment pressure observed during the pumping, and/or predicting a maximum treatment pressure in response to pressures observed during the pumping with the first subset of the plungers. In certain embodiments, the method includes detecting a fluid end failure event corresponding to the first subset of the plungers, and coupling the second subset of the plungers in response to the fluid end failure event.
While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described and that all changes and modifications that come within the spirit of the inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.
