Device for exchanging pressure between at least two fluid flows and method for operating the same

Abstract

An apparatus for exchanging pressure between at least two fluid streams can include a valve apparatus comprising a valve actuator configured to move at a variable rate in order to selectively fill and empty at least one tank. An apparatus for exchanging a characteristic between at least two fluid streams can include a valve apparatus comprising staggered and superimposed openings positioned along a path of the valve actuator. The staggered and superimposed openings can be configured to selectively and gradually communicate an inlet with the at least one tank. Methods of operating an apparatus for exchanging pressure between at least two fluid streams are also provided.

Description

[0001] This application is a divisional application of Chinese invention patent application No. 201980073866.6, filed on November 8, 2019, entitled "Fluid Exchange Device and Related Systems and Methods".

[0002] Priority rights

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 758,359, filed November 9, 2018, entitled "Fluid Exchange Devices and Related Systems, and Methods", the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0004] This disclosure generally relates to exchange devices. More specifically, embodiments of this disclosure relate to fluid exchange devices, systems, and methods for exchanging one or more of the properties (e.g., pressure) between fluids. Background Technology

[0005] Industrial processes often involve hydraulic systems, which include pumps, valves, impellers, and more. Pumps, valves, and impellers are used to control the flow of fluids used in hydraulic processes. For example, some pumps are used to increase (e.g., boost) the pressure in a hydraulic system, while others are used to move fluid from one location to another. Some hydraulic systems include valves to control the direction of fluid flow. Valves can include control valves, ball valves, gate valves, globe valves, check valves, isolation valves, combinations thereof, etc.

[0006] Some industrial processes involve the use of corrosive, abrasive, and / or acidic fluids. These types of fluids can increase wear on components of hydraulic systems. Increased wear can lead to increased maintenance and repair costs or the need for premature equipment replacement. For example, abrasive, corrosive, or acidic fluids can increase wear on internal pump components such as impellers, shafts, blades, and nozzles. Some pumps are repairable, and operations may choose to repair the worn pump by replacing worn parts, which can result in prolonged downtime of the worn pump, leading to the need for redundant pumps or reduced productivity. Other operations may replace the worn pump, at a higher cost but with reduced downtime.

[0007] Well completion operations in the oil and gas industry often involve hydraulic fracturing (often referred to as fracturing or fracture-inducing) to increase the release of oil and gas from rock formations. Hydraulic fracturing involves pumping a fluid (such as fracturing fluid, fracture fluid, etc.) containing a combination of water, chemicals, and proppant (e.g., sand, ceramics) into the well under high pressure. The high pressure of the fluid increases the size and propagation of fractures within the rock formation, releasing more oil and gas, while the proppant prevents the fractures from closing after the fluid is depressurized. Fracturing operations use high-pressure pumps to increase the pressure of the fracturing fluid. However, the proppant in the fracturing fluid increases wear and maintenance on the high-pressure pump due to its abrasive properties, and essentially reduces the pump's service life. Summary of the Invention

[0008] Different implementations may include a device for exchanging pressure between at least two fluid flows. The device may include at least one high-pressure inlet, at least one low-pressure inlet, at least one high-pressure outlet, and at least one low-pressure outlet. At least one high-pressure inlet may be configured to receive fluid at a first higher pressure. At least one low-pressure inlet may be configured to receive downhole fluid (e.g., fracturing fluid, drilling fluid) at a first lower pressure. At least one high-pressure outlet may be configured to output downhole fluid at a second higher pressure, which is greater than the first lower pressure. At least one low-pressure outlet may be configured to output fluid at a second lower pressure, which is less than the first higher pressure. The device may include a valve device. The valve device may include a valve actuator configured to move at a variable rate to selectively fill and empty at least one tank communicating with at least one low-pressure outlet and at least one high-pressure inlet. The valve actuator may also be configured to: selectively communicate fluid at the first higher pressure with downhole fluid at the first lower pressure to pressurize the downhole fluid to the second higher pressure; and selectively output fluid at the second lower pressure from the pressure exchange device through at least one low-pressure outlet.

[0009] Another embodiment may include a device for exchanging pressure between at least two fluid flows. The device may include at least one high-pressure inlet, at least one low-pressure inlet, at least one high-pressure outlet, at least one low-pressure outlet, and at least one tank. The at least one high-pressure inlet may be configured to receive fluid at a first higher pressure. The at least one low-pressure inlet may be configured to receive downhole fluid at a first lower pressure. The at least one high-pressure outlet may be configured to output downhole fluid at a second higher pressure, which is greater than the first lower pressure. The at least one low-pressure outlet may be configured to output fluid at a second lower pressure, which is less than the first higher pressure. The at least one tank may be positioned between the at least one high-pressure inlet and the at least one high-pressure outlet. The device may also include a valve device comprising a valve actuator. The valve device may include staggered and overlapping openings positioned along the path of the actuator. The staggered and overlapping openings may be configured to selectively and progressively connect the at least one high-pressure inlet to the at least one tank.

[0010] Another embodiment may include a method of operating a device for exchanging pressure between at least two fluid flows. The method may include: receiving a fluid at a first higher pressure into a high-pressure inlet of the device; and receiving a downhole fluid at a lower pressure into a low-pressure inlet of the device. An actuator of the device may communicate the fluid at the first higher pressure with the downhole fluid at the first lower pressure to pressurize the downhole fluid to a second higher pressure greater than the first lower pressure. The actuator may move at a first speed as its valve member approaches the opening between the high-pressure inlet and the low-pressure inlet. The speed of the actuator may decrease from the first speed to a second speed as the valve member passes through the opening.

[0011] Another embodiment may include a method of operating a device for exchanging pressure between at least two fluid flows. The method may include: receiving fluid at a first higher pressure into a high-pressure inlet of the device; and receiving downhole fluid at a lower pressure into a low-pressure inlet of the device. An actuator of the device may be used to communicate the fluid at the first higher pressure with the downhole fluid at the first lower pressure, thereby pressurizing the downhole fluid to a second higher pressure greater than the first lower pressure. The method may further include moving the actuator of the device along an alternating opening between the high-pressure inlet and the low-pressure inlet, and intersecting only a small portion of the front end of the alternating opening each time the valve member of the actuator passes through the opening. Attached Figure Description

[0012] Although this specification is accompanied by claims that are specifically pointed out and expressly claimed as embodiments of this disclosure, the different features and advantages of embodiments of this disclosure can be more readily identified from the following description of embodiments of this disclosure when read in conjunction with the accompanying drawings:

[0013] Figure 1 This is a schematic diagram of a hydraulic fracturing system according to one embodiment of the present disclosure;

[0014] Figure 2 This is a cross-sectional view of a fluid exchange device according to one embodiment of the present disclosure;

[0015] Figure 3A This is a cross-sectional view of a control valve in a first position according to one embodiment of the present disclosure;

[0016] Figure 3B This is a cross-sectional view of a control valve in a second position according to one embodiment of the present disclosure;

[0017] Figure 4 This is a cross-sectional view of a control valve according to one embodiment of the present disclosure;

[0018] Figure 5 This is a view of a valve port according to one embodiment of the present disclosure; and

[0019] Figure 6 This is a view of a valve port according to one embodiment of the present disclosure. Detailed Implementation

[0020] The illustrations presented herein are not intended to be actual views of any particular fluid exchanger or its components, but are merely idealized representations used to describe exemplary embodiments. The figures are not necessarily drawn to scale. Elements common to all figures may retain the same reference numerals.

[0021] As used herein, relational terms such as “first,” “second,” “top,” “bottom,” etc., are generally used for clarity and convenience in understanding the contents of this disclosure and the accompanying drawings, and do not imply or depend on any particular preference, orientation, or order, unless the context clearly indicates otherwise.

[0022] As used herein, the term “and / or” means and includes any and all combinations of one or more associated listed items.

[0023] As used herein, the terms “vertical” and “lateral” refer to the orientation described in the accompanying drawings.

[0024] As used herein, the terms “substantially” or “about” relating to a given parameter mean and include, to a certain extent, a degree of conformity to a given parameter, characteristic, or condition that would be understood by a person skilled in the art, such as within acceptable manufacturing tolerances. For example, a substantially conforming parameter could be at least 90%, at least 95%, at least 99%, or even 100%.

[0025] As used herein, the term "fluid" can mean and include fluids of any type and composition. Fluids can take the form of liquids, gases, or combinations thereof, and in some cases may include solid materials. In some embodiments, the fluid can be converted between liquid and gaseous forms during cooling or heating processes as described herein. In some embodiments, the term fluid includes gases, liquids, and / or pumpable mixtures of liquids and solids.

[0026] Embodiments of this disclosure may relate to exchange devices (e.g., pressure exchangers) capable of exchanging one or more properties between fluids. Such exchangers (e.g., pressure exchangers) are sometimes referred to as “flow work exchangers” or “isobaric devices” and are machines used to exchange pressure energy from a fluid system flowing at relatively high pressure to a fluid system flowing at relatively low pressure.

[0027] In some industrial processes, pressure needs to be increased in certain parts of the operation to achieve desired results, after which the pressurized fluid is depressurized. In other processes, some fluids used in the process are available at high pressure, while others are available at low pressure, and it is desirable to exchange pressure energy between these two fluids. Therefore, in some applications, the ability to efficiently transfer pressure between two fluids can result in significant economic improvements.

[0028] In some implementations, the exchanger disclosed herein may resemble and include different components and configurations of the pressure exchanger disclosed in U.S. Patent 5,797,429 to Shumway, issued August 25, 1998, the disclosure of which is incorporated herein by reference in its entirety.

[0029] Although some embodiments of this disclosure are described as being used and employed as pressure exchangers between two or more fluids, those skilled in the art will understand that embodiments of this disclosure can be used in other implementations, such as, for example, exchanging other properties (e.g., temperature, density, etc.) and / or components between one or more fluids and / or mixtures of two or more fluids.

[0030] In some implementations, pressure exchangers can be used to protect moving parts (e.g., pumps, valves, impellers, etc.) in processes where the fluid—which may damage moving parts (e.g., abrasive fluids, corrosive fluids, acidic fluids, etc.)—requires high pressure.

[0031] For example, the pressure exchange device according to embodiments of this disclosure can be implemented in hydrocarbon-related processes such as hydraulic fracturing or other drilling operations (e.g., underground downhole drilling operations).

[0032] As mentioned above, well completion operations in the oil and gas industry often involve hydraulic fracturing, drilling operations, or other downhole operations that use high-pressure pumps to increase the pressure of downhole fluids (e.g., fluids intended to be directed into the underground formation or wellbore, such as fracturing fluid, drilling fluid, drilling mud). The proppant, chemicals, additives, etc., that generate mud in these fluids often increase the wear and maintenance of high-pressure pumps.

[0033] In some embodiments, the hydraulic fracturing system may include a hydraulic energy transfer system that transfers pressure between a first fluid (e.g., a clean fluid, such as a partially (e.g., largely) or substantially proppant-free fluid or a pressure-exchange fluid) and a second fluid (e.g., a fracturing fluid, such as a proppant-containing fluid, an abrasive fluid, or a contaminated fluid). Such a system can at least partially (e.g., substantially, primarily, completely) isolate the high-pressure first fluid from the second contaminated fluid while still being able to pressurize the second contaminated fluid with the high-pressure first fluid, without having to pass the second contaminated fluid directly through a pump or other pressurization device.

[0034] While some of the embodiments discussed herein may be directed to fracturing operations, in other embodiments, the exchanger systems and devices disclosed herein can be used for other operations. For example, the devices, systems, and / or methods disclosed herein can be used for other downhole operations, such as, for example, downhole drilling operations.

[0035] Figure 1A system diagram illustrating one embodiment of a hydraulic fracturing system 100 is provided, which utilizes a pressure exchanger between a first fluid flow (e.g., a clean fluid flow) and a second fluid flow (e.g., a fracturing fluid flow). Although not explicitly described, it should be understood that each component of system 100 may be directly connected to or coupled via fluid conduits (e.g., pipes) to adjacent (e.g., upstream or downstream) components. The hydraulic fracturing system 100 may include one or more devices for pressurizing the first fluid flow, such as, for example, fracturing pumps 102 (e.g., reciprocating pumps, centrifugal pumps, vortex pumps, etc.). System 100 may include multiple fracturing pumps 102, such as at least two fracturing pumps 102, at least four fracturing pumps 102, at least ten fracturing pumps 102, at least sixteen fracturing pumps, or at least twenty fracturing pumps 102. In some embodiments, the fracturing pumps 102 may supply relatively clean fluid at high pressure to the pressure exchanger 104 from a fluid source 101. In some implementations, fluid may be supplied separately to each fracturing pump 102 (e.g., in a parallel configuration). After being pressurized in the fracturing pump 102, the high-pressure cleaning fluid 110 may be combined and transmitted to the pressure exchanger 104 (e.g., in a serial configuration).

[0036] As used herein, "clean" fluid can describe a fluid that is at least partially or substantially free of (e.g., substantially free of or completely free of) chemicals and / or proppant typically found in fracturing fluids, and "turbid" fluid can describe a fluid that is at least partially contained in chemicals and / or proppant typically found in fracturing fluids.

[0037] Pressure exchanger 104 can transfer pressure from high-pressure clean fluid 110 to low-pressure fracturing fluid (e.g., fracturing fluid 112) to provide high-pressure fracturing fluid 116. The clean fluid can be discharged from pressure exchanger 104 as low-pressure fluid 114 after transferring pressure to low-pressure fracturing fluid 112. In some embodiments, low-pressure fluid 114 can be a fluid that is at least partially or substantially clean, containing virtually no chemicals and / or proppant except for small amounts of chemicals and / or proppant that may be transferred from fracturing fluid 112 to low-pressure fluid 114 in pressure exchanger 104.

[0038] In some implementations, pressure exchanger 104 may include one or more pressure exchanger devices (e.g., operating in parallel). In such a configuration, high-pressure inputs can be separated and supplied to the input of each of the pressure exchanger devices. When the high-pressure fracturing fluid exits pressure exchanger 104, the outputs of each of the pressure exchanger devices can be combined. For example, and as referenced below. Figure 4The pressure exchanger 104 discussed may include two or more (e.g., three) pressure exchanger devices operating in parallel. As shown, the pressure exchanger 104 may be mounted on a mobile platform (e.g., a truck trailer) that can be relatively easily installed at and removed from the fracturing well site.

[0039] After exiting the pressure exchanger 104, the low-pressure clean fluid 114 can travel to and be collected in a mixing chamber 106 (e.g., agitator unit, mixing unit, etc.). In some embodiments, the low-pressure fluid 114 can be converted (e.g., modified, transformed, etc.) into low-pressure fracturing fluid 112 in the mixing chamber 106. For example, a proppant can be added to the low-pressure clean fluid 114 in the mixing chamber 106 to form low-pressure fracturing fluid 112. In some embodiments, the low-pressure clean fluid 114 can be discharged as waste.

[0040] In many hydraulic fracturing operations, a separate process can be used to heat the fracturing fluid 112 before it is discharged downhole (e.g., to ensure proper proppant mixing in the fracturing fluid). In some embodiments, using low-pressure clean fluid 114 to produce fracturing fluid 112 can eliminate the need for heating the fracturing fluid. For example, the low-pressure clean fluid 114 may already be at an elevated temperature due to the pressure applied to the high-pressure clean fluid 110 by the fracturing pump 102. After the pressure in the high-pressure clean fluid 110, which has already been heated by the fracturing pump 102, is transferred, the now-low-pressure clean fluid 114 retains at least some of its thermal energy as it travels from the pressure exchanger 104 to the mixing chamber 106. In some embodiments, using the already elevated low-pressure clean fluid 114 to produce fracturing fluid can eliminate the need for heating the fracturing fluid. In other embodiments, the elevated temperature of the low-pressure clean fluid 114 may result in a reduction in the amount of heating required for the fracturing fluid.

[0041] After proppant is added to low-pressure fluid 114, the fracturing fluid 112 can be discharged from mixing chamber 106. The low-pressure fracturing fluid 112 can then enter pressure exchanger 104 at the fracturing fluid end via fluid conduit 108 connected (e.g., coupled) between mixing chamber 106 and pressure exchanger 104. Upon entering pressure exchanger 104, the low-pressure fracturing fluid 112 can be pressurized by the pressure transmitted from high-pressure clean fluid 110 through pressure exchanger 104. The high-pressure fracturing fluid 116 can then exit pressure exchanger 104 and be delivered downhole.

[0042] Hydraulic fracturing systems typically require high operating pressures for the high-pressure fracturing fluid 116. In some embodiments, the desired pressure of the high-pressure fracturing fluid 116 can be between about 8,000 PSI (55,158 kPa) and about 12,000 PSI (82,737 kPa), such as between about 9,000 PSI (62,052 kPa) and about 11,000 PSI (75,842 kPa), or about 10,000 PSI (68,947 kPa).

[0043] In some embodiments, the high-pressure cleaning fluid 110 may be pressurized to a pressure at least substantially the same as or slightly greater than the desired pressure of the high-pressure fracturing fluid 116. For example, the high-pressure cleaning fluid 110 may be pressurized to between about 0 PSI (0 kPa) and about 1000 PSI (6,894 kPa) higher than the desired pressure of the high-pressure fracturing fluid 116, such as between about 200 PSI (1,379 kPa) and about 700 PSI (4,826 kPa) higher than the desired pressure, or between about 400 PSI (2,758 kPa) and about 600 PSI (4,137 kPa) higher than the desired pressure, to account for pressure and any pressure loss during the exchange process.

[0044] Figure 2 An embodiment of a pressure exchanger 200 is illustrated. The pressure exchanger 200 may be a linear pressure exchanger, meaning that it operates by moving or translating an actuating component substantially along a linear path. For example, the actuating component may move linearly to selectively connect low-pressure and high-pressure fluids at least partially (e.g., indirectly connect them, where the pressure of the high-pressure fluid can be transferred to the low-pressure fluid), as discussed in detail below.

[0045] The linear pressure exchanger 200 may include one or more (e.g., two) chambers 202a, 202b (e.g., tanks, collectors, cylinders, pipes, conduits, etc.). The chambers 202a, 202b (e.g., parallel chambers 202a, 202b) may include pistons 204a, 204b configured to substantially maintain separation of high-pressure clean fluid 210 and low-pressure clean fluid 214 (e.g., the clean side) from high-pressure contaminated fluid 216 and low-pressure contaminated fluid 212 (e.g., the contaminated side), while allowing pressure transfer between the respective fluids 210, 212, 214, and 216. The size of pistons 204a and 204b (e.g., the outer diameter of pistons 204a and 204b relative to the inner diameter of chambers 202a and 202b) can be configured to allow pistons 204a and 204b to travel through chambers 202a and 202b while minimizing fluid flow around pistons 204a and 204b.

[0046] The linear pressure exchanger 200 may include a cleaning control valve 206 configured to control the flow of high-pressure cleaning fluid 210 and low-pressure cleaning fluid 214. Each of the chambers 202a and 202b may include one or more fouling control valves 207a, 207b, 208a, and 208b configured to control the flow of low-pressure fouling fluid 212 and high-pressure fouling fluid 216.

[0047] although Figure 2 The implementation envisions a linear pressure exchanger 200, but other implementations may include other types of pressure exchangers involving other mechanisms for selectively communicating low-pressure and high-pressure fluids at least partially (e.g., rotary actuators, such as those disclosed in U.S. Patent 9,435,354, issued September 6, 2016, the disclosure of which is incorporated herein by reference in its entirety, etc.).

[0048] In some embodiments, the cleaning control valve 206 selectively allows (e.g., input, placement, etc.) high-pressure cleaning fluid 210 supplied from the high-pressure inlet port 302 into a first chamber 202a on the clean side 220a of the piston 204a. This cleaning control valve includes an actuating rod 203 that moves one or more stops 308 along (e.g., linearly) the body 205 of the valve 206. The high-pressure cleaning fluid 210 can act on the piston 204a, causing it to move toward the contaminated side 221a of the piston 204a and compressing the contaminated fluid in the first chamber 202a to produce high-pressure contaminated fluid 216. The high-pressure contaminated fluid 216 can exit the first chamber 202a through a contaminated discharge control valve 208a (e.g., an outlet valve, high-pressure outlet). Essentially simultaneously, low-pressure contaminated fluid 212 can enter a second chamber 202b through a contaminated fill control valve 207b (e.g., an inlet valve, low-pressure inlet). Low-pressure contaminated fluid 212 can act on the contaminated side 221b of piston 204b, causing piston 204b to move in the second chamber 202b toward the clean side 220b of piston 204b. When piston 204b moves toward the clean side 220b of piston 204b, low-pressure cleaning fluid 214 can be discharged through cleaning control valve 206 (e.g., evacuation, discharge, etc.), thereby reducing the space on the clean side 220b of piston 204b in the second chamber 202b. After each piston 204a, 204b has moved the basic length (e.g., most of the length) of the corresponding chamber 202a, 202b, one cycle of the pressure exchanger is completed. (This "cycle" can be half a cycle in which pistons 204a, 204b move along the length of chambers 202a, 202b in one direction, while a complete cycle includes pistons 204a, 204b moving along the length of chambers 202a, 202b in one direction and then in another direction to return to substantially the original position.) In some embodiments, only a portion of the length can be utilized (e.g., in cases of reduced capacity). After one cycle is completed, the actuation rod 203 of the cleaning control valve 206 can be repositioned to allow high-pressure cleaning fluid 210 to enter the second chamber 202b, thereby turning the second chamber 202b into a high-pressure chamber and the first chamber 202a into a low-pressure chamber, and the process is repeated.

[0049] In some embodiments, each chamber 202a, 202b may have a higher pressure on one side of the pistons 204a, 204b, causing the pistons to move away from the higher pressure. For example, the high-pressure chambers may experience pressures between approximately 8,000 PSI (55,158 kPa) and approximately 13,000 PSI (89,632 kPa), with the highest pressure in the high-pressure clean fluid 210, causing the pistons 204a, 204b to move away from the high-pressure clean fluid 210, compressing and discharging the contaminated fluid, thereby producing high-pressure contaminated fluid 216. In contrast, the low-pressure chambers 202a, 202b may experience much lower pressures, where the relatively higher pressure in the low-pressure contaminated fluid 212 in the current low-pressure chambers 202a, 202b is still sufficient to cause the pistons 204a, 204b to move away from the low-pressure contaminated fluid 212, thereby discharging low-pressure contaminated fluid 214. In some embodiments, the pressure of the low-pressure turbid fluid 212 may be between about 100 PSI (689 kPa) and about 700 PSI (4,826 kPa), for example between about 200 PSI (1,379 kPa) and about 500 PSI (3,447 kPa), or between about 300 PSI (2,068 kPa) and about 400 PSI (2,758 kPa).

[0050] Refer again Figure 1 In some embodiments, system 100 may include optional devices (e.g., pumps) to pressurize the low-pressure contaminated fluid 212 when it is supplied to chambers 202a, 202b (e.g., pressurize it to a pressure level suitable for moving pistons 204a, 204b toward the clean side).

[0051] Refer again Figure 2 If any fluid is squeezed past pistons 204a and 204b (e.g., leaking, seeping, etc.), it will generally tend to flow from the higher-pressure fluid to the lower-pressure fluid. The high-pressure clean fluid 210 can be maintained at the highest pressure in the system, so that it is generally substantially uncontaminated. The low-pressure clean fluid 214 can be maintained at the lowest pressure in the system. Therefore, the low-pressure clean fluid 214 may be contaminated by the low-pressure contaminated fluid 212. In some embodiments, the low-pressure clean fluid 214 can be used to produce the low-pressure contaminated fluid 212, substantially offsetting any damage caused by contamination. Similarly, any contamination of the high-pressure contaminated fluid 216 by the high-pressure clean fluid 210 will have minimal impact on the high-pressure contaminated fluid 216.

[0052] In some embodiments, the contamination control valves 207a, 207b, 208a, and 208b may be check valves (e.g., flap valves, non-return valves, reflux valves, holding valves, or one-way valves). For example, one or more contamination control valves 207a, 207b, 208a, and 208b may be ball check valves, diaphragm check valves, swing check valves, tilting disc check valves, flap valves, shut-off check valves, lift check valves, in-line check valves, duckbill valves, etc. In other embodiments, one or more contamination control valves 207a, 207b, 208a, and 208b may be actuated valves (e.g., solenoid valves, pneumatic valves, hydraulic valves, electronic valves, etc.) configured to receive a signal from a controller and open or close in response to that signal.

[0053] The fouling control valves 207a, 207b, 208a, and 208b can be arranged in a relative configuration such that when chambers 202a and 202b are in a high-pressure configuration, the high-pressure fouling fluid opens the fouling discharge control valves 208a and 208b, while the pressure in chambers 202a and 202b keeps the fouling filling control valves 207a and 207b closed. For example, the fouling discharge control valves 208a and 208b include check valves that open in a first direction away from chambers 202a and 202b, while the fouling filling control valves 207a and 207b include check valves that open in a second, opposite direction into chambers 202a and 202b.

[0054] Sludge discharge control valves 208a and 208b can be connected to downstream components (e.g., fluid conduits, individual or shared manifolds) such that high pressure in the downstream components keeps sludge discharge valves 208a and 208b closed in chambers 202a and 202b in a low-pressure configuration. This configuration allows low-pressure sludge fluid to open sludge filling control valves 207a and 207b and enter chambers 202a and 202b.

[0055] Figure 3A and Figure 3B Cross-sectional views of one embodiment of the cleaning control valve 300 at two different locations are illustrated. In some embodiments, the cleaning control valve 300 may be similar to the control valve 206 discussed above. The cleaning control valve 300 may be a multi-port valve (e.g., a 4-way valve, a 5-way valve, etc.). (Valve, etc.). The cleaning control valve 300 may have one or more high-pressure inlet ports (e.g., one port 302), one or more low-pressure outlet ports (e.g., two ports 304a, 304b), and one or more chamber connection ports (e.g., two ports 306a, 306b). The cleaning control valve 300 may include at least two stops 308 (e.g., plugs, pistons, discs, valve members, etc.). In some embodiments, the cleaning control valve 300 may be a linearly actuated valve. For example, the stops 308 may be linearly actuated such that the stops 308 are along a substantially straight line (e.g., along the longitudinal axis L of the cleaning control valve 300). 300 )move.

[0056] The cleaning control valve 300 may include an actuator 303 configured to actuate the cleaning control valve 300 (e.g., an actuator coupled to the valve stem 301 of the cleaning control valve 300). In some embodiments, the actuator 303 may be electronic (e.g., solenoid coil, rack and pinion, ball screw, segmented spindle, movable coil, etc.), pneumatic (e.g., lever cylinder, diaphragm actuator, etc.), or hydraulic. In some embodiments, the actuator 303 may enable the cleaning control valve 300 to move the valve stem 301 and the stop 308 at a variable rate (e.g., variable speed, adjustable speed, etc.).

[0057] Figure 3A A cleaning control valve 300 in a first position is illustrated. In the first position, the stop 308 can be positioned to allow high-pressure cleaning fluid to enter the cleaning control valve 300 through the high-pressure inlet port 302 and exit through the chamber connection port 306a to enter the first chamber. In the first position, low-pressure cleaning fluid can travel through the cleaning control valve 300 between the chamber connection port 306b and the low-pressure outlet port 304b (e.g., it can exit through the low-pressure outlet port 304b).

[0058] Figure 3B The cleaning control valve 300 in a second position is illustrated. In this second position, the stop 308 can be positioned to allow high-pressure cleaning fluid to enter the cleaning control valve 300 through the high-pressure inlet port 302 and exit through the chamber connection port 306b to enter the second chamber. Low-pressure cleaning fluid can travel through the cleaning control valve 300 between the chamber connection port 306a and the low-pressure outlet port 304a (e.g., it can exit through the low-pressure outlet port 304a).

[0059] Now for reference Figure 2 , Figure 3A and Figure 3BThe cleaning control valve 206 is illustrated in a first position, wherein the high-pressure inlet port 302 is connected to the chamber connection port 306a to supply high-pressure cleaning fluid to the first chamber 202a. After circulation is complete, the cleaning control valve 206 can move the stop 308 to a second position, thereby connecting the high-pressure inlet port 302 to the second chamber 202b via the chamber connection port 306b.

[0060] In some embodiments, the cleaning control valve 206 may pass through a substantially fully closed position at the midpoint of its stroke between the first and second positions. For example, in the first position, the stop 308 may maintain fluid passage between the high-pressure inlet port 302 and the chamber connection port 306a, and between the chamber connection port 306b and the low-pressure outlet port 304b. In the second position, the stop 308 may maintain fluid passage between the high-pressure inlet port 302 and the chamber connection port 306b, and between the chamber connection port 306a and the low-pressure outlet port 304a. The transition between the first and second positions may involve at least substantially closing both fluid passages to change the connection of the chamber connection port 306a from the high-pressure inlet port 302 to the low-pressure outlet port 304a, and to change the connection of the chamber connection port 306b from the low-pressure outlet port 304b to the high-pressure inlet port 302. The fluid passages may be substantially closed at least at the midpoint of the stroke to achieve the change of connection.

[0061] When fluids are operated under high pressure, opening and closing valves can cause pressure pulsations (e.g., water hammer), which can damage components in the system when high pressure is suddenly introduced into or removed from the system. Therefore, pressure pulsations can occur in the middle of the stroke when fluid passages are closed and opened respectively.

[0062] In some embodiments, actuator 303 may be configured to move stop 308 at a variable speed along the stroke of cleaning control valve 206. When stop 308 moves from a first position to a second position, stop 308 may move at a high speed during the first portion of the stroke, which does not involve introducing new flow from high-pressure inlet port 302 into chamber connection ports 306a, 306b. When stop 308 approaches the closed position in the middle of the stroke (e.g., when stop 308 blocks chamber connection ports 306a, 306b during the transition between high-pressure inlet port 302 connection and low-pressure outlet ports 304a, 304b connection), stop 308 may decelerate to a low speed. Stop 308 may remain at a lower speed while high-pressure inlet port 302 is in communication with one of chamber connection ports 306a, 306b. After passing through chamber connection ports 306a and 306b, as the stop 308 approaches the second position, the stop 308 can accelerate to another high rate. The low rate in the middle of the stroke can reduce the opening and closing speed of the cleaning control valve 206, enabling the cleaning control valve to gradually introduce high pressure into and / or gradually remove high pressure from the chambers 202a and 202b.

[0063] In some embodiments, the movement of pistons 204a, 204b can be controlled by adjusting the rate of fluid flow (e.g., the rate of inflow of fluid) and / or the pressure difference between the clean sides 220a, 220b and the dirty sides 221a, 221b of pistons 204a, 204b, caused at least partially by the movement of the cleaning control valve 206. In some embodiments, it may be desirable to manipulate the pressure difference in each of the low-pressure chambers 202a, 202b and the high-pressure chambers 202a, 202b and / or to control the flow rate of fluid into and out of chambers 202a, 202b, so that pistons 204a, 204b in the low-pressure chambers and pistons 204a, 204b in the high-pressure chambers move at substantially the same speed. However, pistons 204a and 204b in the low-pressure chambers 202a and 202b may tend to move at a greater speed than pistons 204a and 204b in the high-pressure chambers 202a and 202b.

[0064] In some embodiments, the rate and / or pressure difference of the fluid flow can be varied to control the acceleration and deceleration of pistons 204a, 204b (e.g., by manipulating and / or changing the stroke of cleaning control valve 206, and / or by manipulating the pressure in the fluid flow using one or more pumps). For example, increasing the flow rate and / or pressure of the high-pressure cleaning fluid 210 can increase the rate and / or pressure difference of the fluid flow in chambers 202a, 202b when pistons 204a, 204b are near the clean end 224 of chambers 202a, 202b at the beginning of the high-pressure stroke can increase the rate and / or pressure difference of the fluid flow in chambers 202a, 202b. Increasing the rate and / or pressure difference of the fluid flow can cause pistons 204a, 204b to accelerate to a faster rate or move at a faster rate. In another example, the flow rate and / or pressure of the high-pressure cleaning fluid 210 can be reduced when pistons 204a, 204b are near the dirty end 226 of chambers 202a, 202b at the end of the high-pressure stroke. Reducing the fluid flow rate and / or pressure difference can slow down and / or stop the pistons 204a and 204b before they reach the contaminated ends of the respective chambers 202a and 202b.

[0065] Similar control over the stroke of the cleaning control valve 206 can be used to prevent pistons 204a and 204b from traveling to the furthest extent of the cleaning ends of chambers 202a and 202b. For example, the cleaning control valve 206 can close one of the chamber connection ports 306a and 306b before pistons 204a and 204b contact the furthest extent of the cleaning ends of chambers 202a and 202b, thereby preventing any further fluid flow and slowing and / or stopping pistons 204a and 204b. In some embodiments, the cleaning control valve 206 can open one of the chamber connection ports 306a and 306b to communicate with the high-pressure inlet port 302 before pistons 204a and 204b contact the furthest extent of the cleaning ends of chambers 202a and 202b, thereby slowing, stopping, and / or reversing the movement of pistons 204a and 204b.

[0066] If pistons 204a, 204b reach the clean end 224 or the contaminated end 226 of the respective chambers 202a, 202b, high-pressure fluid can bypass pistons 204a, 204b and mix with low-pressure fluid. In some embodiments, fluid mixing may be desirable. For example, if pistons 204a, 204b reach the contaminated end 226 of the respective chambers 202a, 202b during the high-pressure stroke, high-pressure cleaning fluid 210 can bypass pistons 204a, 204b (e.g., by traveling around pistons 204a, 204b or through valves in pistons 204a, 204b) to flush away any residual contaminants from the surfaces of pistons 204a, 204b. In some embodiments, fluid mixing may be undesirable. For example, if pistons 204a and 204b reach the clean end 224 of the corresponding chambers 202a and 202b during the low-pressure stroke, the low-pressure contaminated fluid 212 can bypass pistons 204a and 204b and mix with the low-pressure clean fluid, causing the clean area in the clean control valve 206 to be contaminated by the contaminated fluid.

[0067] In some embodiments, the hydraulic fracturing system 100 can prevent pistons 204a, 204b from reaching the clean ends 224 of the respective chambers 202a, 202b. For example, the clean control valve 206 may include control devices (e.g., sensors, safety devices, switches, etc.) to trigger a position change of the clean control valve 206 when pistons 204a, 204b are detected approaching the clean ends 224 of the respective chambers 202a, 202b, so that the system 100 can use the clean control valve 206 to change the flow path position before pistons 204a, 204b reach the clean ends 224 of the chambers 202a, 202b.

[0068] In some embodiments, pressure peaks may occur in the fluid. For example, pressure peaks may occur in the high-pressure cleaning fluid 210 when the cleaning control valve 206 is closed or open. In some embodiments, when pressure is transferred from the high-pressure cleaning fluid 210 to the contaminated fluid 212, chambers 202a, 202b and pistons 204a, 204b may suppress (e.g., reduce, balance, etc.) any pressure peaks in the high-pressure cleaning fluid 210 to produce high-pressure contaminated fluid 216 while minimizing pressure peaks.

[0069] In some implementations, the duration of each cycle can be correlated with the production of system 100. For example, in each cycle, pressure exchanger 200 can move a specific amount of sludge fluid, defined by the combined capacity of chambers 202a, 202b. In some implementations, pressure exchanger 200 can move between about 40 gallons (75.7 liters) and about 90 gallons (340.7 liters), such as between about 60 gallons (227.1 liters) and about 80 gallons (302.8 liters), or between about 65 gallons (246.1 liters) and about 75 gallons (283.9 liters). For example, in a system having one or more tanks (e.g., two tanks), each tank in pressure exchanger 200 can move between about 40 gallons (75.7 liters) and about 90 gallons (340.7 liters) (e.g., two tanks of about 60 gallons (227.1 liters) each cycle, moving about 120 gallons (454.2 liters)).

[0070] In some embodiments, the duration of circulation can be controlled by using a cleaning control valve 206 to change the fluid flow rate and / or the pressure difference across pistons 204a, 204b. For example, the flow rate and / or pressure of the high-pressure cleaning fluid 210 can be controlled so that the circulation corresponds to the desired flow rate of the contaminated fluid 212. In some embodiments, the duration of circulation can be controlled by controlling the fracturing pump 102 ( Figure 1 The flow rate and / or pressure can be controlled by means of the speed of the flow (e.g., by a variable frequency drive (VFD), a throttling control device, etc.), by means of a mechanical pressure control device (e.g., a variable blade, a pressure relief system, a venting valve, etc.), or by means of changing the position of the cleaning control valve 206 to limit the flow into or out of the chambers 202a, 202b.

[0071] In some embodiments, maximum production may be the desired condition, which can be achieved using the shortest possible cycle duration. In some embodiments, the shortest cycle duration may be defined by the speed of the actuator 303 on the cleaning control valves 206, 300. In some embodiments, the shortest cycle duration may be defined by the maximum pressure of the high-pressure cleaning fluid 210. In some embodiments, the shortest duration may be defined by the response time of the cleaning control valves 206, 300.

[0072] In some implementations, the pressure difference between the high-pressure cleaning fluid 210 and the low-pressure cleaning fluid 214 may require small incremental movements when the cleaning control valve 206 opens and closes. For example, if the pressure difference between the high-pressure cleaning fluid 210 and the low-pressure cleaning fluid 214 is high, even a small opening can allow large pressure pulses and / or rapid pressure increases on the low-pressure side of the cleaning control valve 206. To accurately control the pressure across the valve, the valve may utilize flow restriction to maintain the pressure difference across the valve. Systems with high pressure differences may struggle to generate sufficient flow restriction to use the cleaning control valve 206 to control the pressure in chambers 202a, 202b.

[0073] Figure 4 A cross-sectional view illustrating one embodiment of a cleaning control valve 400 is shown. In some embodiments, the cleaning control valve 400 may be similar to the control valves 206 and 300 discussed above. The cleaning control valve 400 may have one or more inlet ports (e.g., high-pressure inlet port 402), one or more outlet ports (e.g., low-pressure outlet ports 404a, 404b), and one or more outlet and / or inlet ports (e.g., chamber connection ports 406a, 406b). The cleaning control valve 400 may include one or more stops 408 on the valve stem 401. In some embodiments, the cleaning control valve 400 may be a linearly actuated valve. For example, the stops 408 may be linearly actuated such that the stops 408 are along a substantially straight line (e.g., along the longitudinal axis L of the cleaning control valve 400 together with the valve stem 401). 400 The cleaning control valve 400 can be cylindrical (e.g., having a substantially circular cross-section, an annular cross-section, etc.) or can be another cross-sectional shape (e.g., polygonal shape, rectangular shape, etc.).

[0074] In some embodiments, at least one of the low-pressure outlet ports 404a, 404b, the high-pressure inlet port 402, and the chamber connection ports 406a, 406b may include one or more openings 410. For example, chamber connection ports 406a, 406b may include at least three or at least four openings 410, and / or low-pressure outlet ports 404a, 404b may include at least three or at least four openings 410. In some embodiments, the opening 410 may be defined by a valve body bushing 412 (e.g., a housing, sleeve, which may be replaceable). In some embodiments, the body bushing 412 may include a metallic material (e.g., stainless steel, polymeric material, or a combination thereof). The valve body bushing 412 may include an opening wall 414 that may define the opening 410. In some embodiments, the opening 410 may be defined such that the larger (e.g., primary) dimension of the opening 410 is perpendicular to the longitudinal axis L of the cleaning control valve 400. 400The path of the blocking element 408. For example, the main dimension of the opening 410 extends along the lateral dimension of the control valve 400 (e.g., along the circumference). In another embodiment, the main dimension of the opening 410 is along the longitudinal axis L of the cleaning control valve 400. 400 extend.

[0075] In some embodiments, the opening 410 may be defined as a substantially uniform shape, such as a square or rectangular opening. However, a substantially uniform shape may cause the open area to increase or decrease abruptly as the stop 408 initially opens or closes the port. In some embodiments, the opening 410 may be defined as a shape with a gradually increasing or decreasing area (e.g., a triangular shape, an elliptical shape, an egg-shaped shape, a circular shape, a parabolic shape, a polygonal shape, etc.) such that as the stop 408 moves across the opening 410, the area of ​​the opening 410 that allows fluid flow may gradually decrease or increase compared to a substantially uniform opening.

[0076] In some embodiments, the openings 410 may be arranged such that each opening 410 is individually opened and / or closed at different times (e.g., respectively) as the stop 408 moves in a substantially linear manner. For example, when the stop 408 moves from a first position to a second position, the stop 408 may close (e.g., block, obstruct, etc.) the first opening 410 in each of the chamber connection ports 406a, 406b. The stop 408 may then close the second opening 410 in each of the chamber connection ports 406a, 406b. The stop 408 may then continue to close the additional openings 410 in each of the chamber connection ports 406a, 406b until all openings 410 in each of the chamber connection ports 406a, 406b are closed. The stop 408 may continue to move in a substantially linear manner, opening the first opening 410 in each of the chamber connection ports 406a, 406b. Then, the blocking member 408 can open the second opening 410 in each of the chamber connection ports 406a and 406b. Then, the blocking member 408 can continue to open any additional opening 410 in each of the chamber connection ports in turn, until all openings 410 in each of the chamber connection ports are open.

[0077] Figure 5 Examples of valve devices (e.g., cleaning control valves 206, 300) are shown. Figure 2 , Figure 3A and Figure 3B One embodiment of port 500 has a plurality of openings 510. (See also...) Figure 4 and Figure 5The opening 510 may have a long dimension 502 and a short dimension 504 (e.g., based on the total number of openings 510 and / or the desired opening / pressure / flow characteristics). For example, an opening 510 (e.g., a high-pressure opening) may be 4.25 inches (10.795 cm) long and 0.50 inches (1.27 cm) wide, and another set of openings 510 (e.g., a low-pressure opening) may be 3.00 inches (7.62 cm) long and 0.50 inches (1.27 cm) wide. The openings 510 may be arranged such that the long dimension 502 is substantially perpendicular to the path of the stop 408. Figure 4 This allows opening 510 and port 500 to be positioned similarly to those described above. Figure 4 It operates in the manner illustrated by the low-pressure outlet ports 404a, 404b and / or chamber connection ports 406a, 406b.

[0078] In some embodiments, the openings 510 may be arranged such that the elongation 502 is substantially parallel to the path of the stop 408, and the ends 506 of each opening 510 may be substantially aligned (e.g., axially aligned). For example, the stop 408 may begin to expose an area (e.g., the rounded end) of each opening 510 (e.g., intersecting with each opening) substantially simultaneously as the stop 408 begins to move across the openings. As the stop 408 moves across the openings 510, the exposed area of ​​the openings 510 may gradually increase.

[0079] In some implementations, the velocity of the stop 408 can be varied to provide a controlled increase in the flow through the opening 510. For example, when a large pressure differential exists across the opening, the pressure may rise rapidly on the low-pressure side of the opening 510 as the opening 510 begins to open to expose a small area (e.g., cross-section) of the opening 510. The actuator 303 ( Figure 3A and Figure 3B The speed at which the stop 408 moves is adjusted to control the rate of pressure increase on the low-pressure side of the stop 408. For example, the stop 408 may move slowly as the opening 510 is initially exposed, thereby limiting the fluid flow through the opening 510 and reducing the rate of pressure increase. As more of the opening 510 is exposed, the stop 408 may move at a faster speed. The faster speed may be used to make the pressure on both sides of the opening 510 equal, or it may be implemented after the pressure on both sides of the opening 510 has already been equalized.

[0080] The speed of the blocking member 408 can vary as it closes the opening 510. For example, when the blocking member 408 begins to reduce the exposed area of ​​the opening 510, it can move at a higher speed. When the exposed area of ​​the opening 510 is reduced to a small exposed area, the blocking member 408 can reduce its speed to avoid abruptly interrupting the fluid flow through the opening 510.

[0081] Figure 6 Examples of valve devices (e.g., cleaning control valves 206, 300) are shown. Figure 2 , Figure 3A and Figure 3B One embodiment of port 600 has a plurality of openings 610, which can be configured as described herein. Figure 4 and Figure 5 The openings 410 and 510 discussed are similar or identical in manner and are utilized in a similar way.

[0082] Reference Figure 4 and Figure 6 The opening 610 may have a long dimension 602 and a short dimension 604. The openings 610 may be arranged such that the long dimension 602 is substantially parallel to the path of the stop 408, and the end 606 (e.g., the front end) of each of the openings 610 is substantially not aligned with the ends 606 of the other openings 610 (e.g., along the transverse axis L). 400 ( Figure 4 (The direction of alignment). For example, the second opening 610b can be arranged adjacent to the first opening 610a (e.g., in a direction perpendicular to the long dimension 602 of the opening 610). As shown, the second opening 610b can be offset in the path direction of the stop 408 (e.g., in the direction of alignment with the cleaning control valve 400). Figure 4 The longitudinal axis L 400 (or axially offset) such that when the stop 408 begins to move across the opening from a substantially closed position, the stop 408 can begin to expose the area of ​​the first opening 610a while the area of ​​the second opening 610b remains closed (e.g., blocked by the stop 408).

[0083] In some embodiments, the offset between the first opening 610a and the second opening 610b may be less than about 50% of the length dimension 602 of the opening, such as between about 5% or 10% of the length dimension and about 40% of the length dimension, or about the short dimension 604.

[0084] As also shown, the third opening 610c may be offset relative to the second opening 610b (e.g., in addition to being offset relative to the first opening 610a). For example, the offset of the third opening 610c relative to the second opening 610b may be substantially the same amount as the offset of the second opening 610b relative to the first opening 610a. In some embodiments, the offset between the third opening 610c and the second opening 610b may be a different offset than the offset between the first opening 610a and the second opening 610b (e.g., a smaller offset or a larger offset).

[0085] In some implementations, the gradual or staggered offset of each opening 610 can allow for greater flow restriction when the port 600 is initially opened, where the stop 408 begins to move and initially exposes only a small portion of the area of ​​the first opening 610a. As the stop 408 continues to move, the exposed area of ​​the first opening 610a can continue to increase until the stop 408 reaches the end 606 (e.g., the front end) of the second opening 610b (e.g., intersecting with the end 606 of the second opening 610b). As the stop 408 continues to move, an area of ​​the second opening 610b may begin to be exposed as the exposed area of ​​the first opening 610a continues to expand. The exposed areas of both the first and second openings 610a and 610b may continue to expand until the stop 408 reaches the end 606 of the second opening 610b. As the stop 408 continues to move, an area of ​​the third opening 610c may begin to be exposed as the exposed areas of the first and second openings 610a and 610b continue to expand. The exposed areas of the first, second, and third openings 610a, 610b, and 610c can continue to expand until the blocking member 408 reaches the opposite end 607 of the first opening 610a (e.g., intersecting with the opposite end 607 of the first opening 610a). The entire area of ​​the first opening 610a can be exposed, and the blocking member 408 can continue to move, while the exposed areas of the second and third openings 610b and 610c continue to grow until the blocking member 408 reaches the opposite end 607 of the second opening 610b. The entire areas of the first and second openings 610a and 610b can be exposed, and the blocking member 408 can continue to move, while the exposed area of ​​the third opening 610c continues to grow until the blocking member 408 reaches the opposite end 607 of the third opening 610c. After the areas of all openings 610 are exposed, the port 600 can be fully opened.

[0086] When the blocking element 408 moves in the opposite direction, the port 600 can operate in a similarly reverse manner, starting with the port 600 fully open, then exposing the area of ​​all openings 610, and ending with the port 600 substantially closed and each of the openings 610 substantially closed (e.g., blocked or obstructed by the blocking element 408). Figure 4 )).

[0087] In some embodiments, the staggered arrangement of the openings 610 allows the stop 408 to pass through the openings at a greater speed, because the staggered openings 610 open one at a time, thereby reducing the amount of high-pressure fluid that can pass through the openings 610. Moving the stop 408 at a greater speed allows for faster valve circulation. In some embodiments, the greater speed can reduce the amount of fluid jetting and / or cavitation that occurs when the exposed area of ​​the opening 610 is relatively small, because the time period with such a small exposed area is reduced as the stop 408 moves faster.

[0088] In some embodiments, the openings 610 may be staggered along the outer circumference, wherein two or more openings 610 may have aligned front ends while still offset with respect to the front ends of the remaining openings 610.

[0089] In some implementations, the baffle 408 can be controlled at different speeds to regulate the flow through the opening 610. For example, the baffle 408 may move at a slower rate when interacting with only one opening 610, at a faster rate when interacting with two openings 610, and at an even faster rate when interacting with three openings 610, and so on. As the baffle 408 interacts with more openings, the pressure differential across the port 600 may decrease, and the flow coefficient (e.g., flow capacity (Cv)) may increase with the increase in the exposed area of ​​the opening 410.

[0090] In some embodiments, the stop 408 can be controlled at different speeds, so that the increase in the flow coefficient can be substantially constant (e.g., close to linear) with respect to time. For example, the stop 408 can initially move at a high speed, transition to a lower speed upon encountering one or more openings 610, and then increase back to a higher speed after the flow through the openings 610 has stabilized. In some embodiments, the stop 408 can initially move at a high speed only when passing through the first opening 610a. When the stop 408 begins to pass through the second opening 610b, the speed of the stop 408 may be reduced to compensate for the increase in the flow coefficient that may be caused by the increased area of ​​the second opening 610b. When the stop 408 begins to pass through the third opening 610c, the speed of the stop 408 can be further reduced to compensate for the increase in the flow coefficient that may be caused by the increased area of ​​the third opening 610c. The speed of the stop 408 can be kept constant when the stop 408 begins to pass through the third opening 610c. For example, the increase in the flow coefficient of the first opening 610a and / or the second opening 610b can begin to decrease, such that the change in the combined flow coefficient of port 600 can continue to increase at a substantially constant rate as the third opening 610c begins to open. As the stop 408 continues to pass through the opening 610, the increase in the flow coefficient can decrease until the flow coefficient is substantially constant when the opening 610 is near a position where it is almost fully open (e.g., substantially open, at least partially open, etc.). As the increase in the flow coefficient decreases, the velocity of the stop 408 can be increased to maintain the increase in the flow coefficient substantially constant with respect to time.

[0091] In some embodiments, the variable speed of the baffle 408 can provide greater control over the flow coefficient of port 500 by traveling at a reduced speed when the exposed area of ​​the opening 510 is relatively small. As the exposed area of ​​the opening 510 increases, the rate of change of the rated flow capacity (e.g., flow coefficient) can begin to decrease. As the exposed area of ​​the opening 510 approaches its maximum region (e.g., substantially fully open), the flow coefficient can remain substantially constant (e.g., smooth, reaching a steady state). The speed of the baffle 408 can increase as the rate of change of the flow coefficient decreases, thereby allowing the flow coefficient to change at a substantially constant rate (e.g., nearly linear with respect to time).

[0092] In some embodiments, in addition to or instead of the staggered arrangement of openings 410, 510, 610, one or more of the blocking members 408 may be shaped to gradually expose openings 410, 510, 610 to the fluid flow. For example, the ends of the plugs may include offset or rounded surfaces (e.g., inclined, arcuate, fan-shaped, circular, tortuous, zigzag, lateral surfaces) that would gradually expose openings 410, 510, 610.

[0093] As described above, in the case of high-pressure operating fluids, opening and closing the valve can cause pressure pulsations (e.g., water hammer), which can damage components in the system when high pressure is suddenly introduced into or removed from the system. Additionally, when the exposed area of ​​opening 510 is relatively small, a high pressure differential across valve port 500 can cause fluid jetting and / or cavitation (e.g., sudden vaporization). If the stop 408 moves at a reduced speed when the exposed area of ​​opening 510 is small (e.g., at the initial opening or final closing), prolonged fluid jetting and / or cavitation may occur, potentially damaging internal components of the system. However, according to embodiments of this disclosure, by varying the speed of the stop 408 and / or changing the geometry of opening 510 (e.g., spacing), fluid jetting, cavitation, and pressure pulsations can be reduced during the opening and / or closing of the valve assembly.

[0094] Now for reference Figure 1 and Figure 2 In some embodiments, pressure exchanger 104 may be formed from multiple linear pressure exchangers 200 operating in parallel. For example, pressure exchanger 104 may be formed from two or more pressure exchangers (e.g., three, four, five or more pressure exchangers stacked in parallel configuration). In some embodiments, pressure exchanger 104 may be modular, allowing the number of linear pressure exchangers 200 to be varied based on flow requirements by adding or removing portions of the linear pressure exchangers. In some embodiments, operation may include multiple systems operating within a region, and the pressure exchanger 104 of each respective system may be adjusted as needed by adding or removing linear pressure exchangers from other systems within the same region.

[0095] Embodiments of this disclosure can provide systems including pressure exchangers that can be used to reduce the amount of wear experienced by high-pressure pumps, turbines, and valves in systems using abrasive, corrosive, or acidic fluids. Reduced wear can allow the system to operate for longer periods with less downtime and fewer costs associated with maintenance and / or replacement of system components, thereby increasing system profitability or productivity. In operations using abrasive fluids at high temperatures, such as fracturing operations, maintenance, replacement, and downtime of system components can result in millions of dollars in losses per operation. Embodiments of this disclosure can reduce the wear experienced by components in systems using abrasive, corrosive, or acidic fluids at high temperatures. Reduced wear will generally result in lower costs and increased profitability.

[0096] In some embodiments, adding flow restriction across the opening in a valve that handles relatively high-pressure fluids can enable relatively improved control of flow characteristics (e.g., pressure, flow rate, etc.). Embodiments of this disclosure allow valves to utilize flow restriction across the opening by varying the speed of the actuator within the valve and / or by using an opening configured to provide a gradual introduction of high-pressure fluid through the opening. This can reduce sudden pressurization and jet fluid velocities that cause cavitation and fluid jet erosion, thereby reducing wear on components.

[0097] Although this disclosure has described certain exemplary embodiments herein, those skilled in the art will recognize and understand that this disclosure is not limited thereto. Many additions, deletions, and modifications may be made to the exemplary embodiments without departing from the scope of the disclosure as claimed in the claims, including its legal equivalents. Furthermore, features from one embodiment may be combined with features from another embodiment while still being included within the scope of the disclosure contemplated by the inventors.

Claims

1. An apparatus for exchanging pressure between at least two fluid flows, the apparatus comprising: At least one high-pressure inlet, said at least one high-pressure inlet being used to receive a first fluid at a first higher pressure; At least one low-pressure inlet, said at least one low-pressure inlet being used to receive a second fluid at a lower pressure; At least one high-pressure outlet, the at least one high-pressure outlet being used to output a second fluid at a second higher pressure, the second higher pressure being greater than the lower pressure; At least one low-pressure outlet is provided for discharging the first fluid at a lower pressure, the lower pressure being less than the first higher pressure. At least one tank, said at least one tank being positioned between said at least one high-pressure inlet and said at least one high-pressure outlet; and A valve device including a valve actuator, the valve device including an offset opening positioned along a path of one or more valve members moving through the valve actuator, the offset opening being configured to selectively and progressively connect at least one high-pressure inlet to at least one tank as the valve actuator moves at a variable rate, so as to selectively fill and empty the at least one tank, the main length of the offset opening being substantially aligned with the path of the one or more valve members.

2. The device according to claim 1, wherein, The valve actuator is a linear valve actuator configured to move the one or more valve members along a linear path, wherein the offset openings are staggered along the linear path of the one or more valve members.

3. The device according to claim 1, wherein, The front end of each of the offset openings is positioned such that, as the one or more valve members travel along the path of the one or more valve members, the front side of the one or more valve members passes through only a portion of one of the front ends of the offset opening each time.

4. The device according to claim 1, wherein, The valve device is configured such that: When one or more valve components approach one of the offset openings between the at least one high-pressure inlet and the at least one low-pressure inlet, the valve actuator is moved at a first velocity; as well as When one or more valve components pass through the opening, the speed of the valve actuator is reduced from the first speed to a second lower speed.

5. The device according to claim 1, wherein, The front end of each of the offset openings is offset axially along the annular housing of the valve device, the path of the one or more valve components being defined by the annular housing.

6. The device according to claim 1, wherein, The front end of each of the offset openings is positioned such that, as the one or more valve members travel along the path of the one or more valve members, the front side of the one or more valve members passes through one or more of the front ends of the offset opening only on one lateral side of the valve device.

7. A method of operating a device for exchanging pressure between at least two fluid flows, the method comprising: The device receives fluid at a first relatively high pressure through its high-pressure inlet; The fluid, which is at a lower pressure, is received through a low-pressure inlet and enters into at least one tank. By using the actuator of the device to move the valve component, the fluid at the first higher pressure is connected to the downhole fluid at the lower pressure, so as to pressurize the downhole fluid to a second higher pressure greater than the lower pressure; When the valve member approaches the opening between the high-pressure inlet and the at least one tank, the actuator of the device moves at a first speed; as well as When the valve component passes through the opening, the speed of the actuator of the device is reduced from the first speed to a second lower speed.

8. The method of claim 7, further comprising increasing the speed of the actuator of the device from the second lower speed to approximately the first speed as the valve member passes through the opening.

9. The method according to claim 8, further comprising: After the valve member has moved through the opening, the direction of the valve member is reversed so that it can pass through the opening again; as well as When the valve member passes through the opening again, the speed of the actuator of the device is reduced to approximately the second lower speed.

10. The method of claim 7, further comprising: When the high-pressure inlet is configured to communicate with the at least one tank through the opening, the speed of the valve component is reduced.

11. The method of claim 7, further comprising: After passing through the opening, another opening is passed through, and the other opening and the opening define a group of staggered openings between the high-pressure inlet and the at least one tank.

12. The method of claim 7, further comprising: As the valve component passes through the opening, fluid at a first higher pressure is gradually removed from the device through the opening and enters the at least one tank.

13. The method of claim 7, further comprising: As the valve component passes through the additional opening, fluid at the first higher pressure is gradually introduced into the device through the additional opening.

14. The method of claim 13, further comprising: Fluid at the first higher pressure from the pump is supplied to the device through the additional opening.

15. A method of operating a device for exchanging pressure between at least two fluid flows, the method comprising: The fluid at a first relatively high pressure is received into the high-pressure inlet of the device; By moving the actuator of the device, the fluid at the first higher pressure is positioned in communication with another fluid at a lower pressure, so as to pressurize the other fluid to a second higher pressure greater than the lower pressure; and As the valve member approaches and passes through the opening of the device, the speed of the valve member is reduced from a first speed to a second lower speed using an actuator.

16. The method of claim 15, further comprising: As the valve component passes through the opening, fluid at the first higher pressure is gradually removed from the device into at least one tank through the opening.

17. The method of claim 16, further comprising: As the valve component passes through the additional opening, fluid at the first higher pressure is gradually introduced into the device through the additional opening.

18. The method of claim 15, further comprising: As the valve member moves through the opening, the actuator increases the speed of the valve member from the second lower speed back to approximately the first speed.

19. The method of claim 15, further comprising: After the valve member has moved through the opening, its direction is reversed so that it passes through the opening again.

20. The method of claim 19, further comprising: As the valve member passes through the opening again, the actuator reduces the speed of the valve member to approximately the second lower speed.

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