System and method for mixing materials at a well site

Abstract

A technique facilitates mixing fluids for well treatment operations. According to embodiments, dry powder materials, such as friction reducers, can be thoroughly mixed into one or more fluids associated with a well treatment operation. The powder materials are mixed with liquids, such as water, through a series of venturi mixers arranged to thoroughly mix the materials. In some applications, the venturi mixers are mounted on modular units that are easily moved to a desired well site. Additional modular units can be added to increase the amount of mixed product as needed for a given well treatment operation, such as a hydraulic fracturing operation.

Description

[0001] Cross-references to related applications

[0002] This document is based on and claims priority to U.S. Provisional Application Serial No. 63 / 057,365, filed on July 28, 2020, which is incorporated herein by reference in its entirety. Background Technology

[0003] In many oil well applications, treatment operations utilize various well treatment fluids that are pumped downhole to facilitate the production of well fluids, such as oil and gas, from a given well. Treatment operations can include hydraulic fracturing, in which well treatment fluids in the form of hydraulic fracturing fluids are pumped downhole along the wellbore and carried out into the surrounding formation. Some well treatment operations involve incorporating friction modifiers into the well treatment fluids to provide improved flow properties and enhanced distribution of fracturing fluids or other well treatment fluids. For example, various hydraulic fracturing fluids may be infused with friction modifiers, which are typically combined with the fluids via a metering tank, where various hydraulic fracturing fluid components are introduced for mixing.

[0004] However, current mixing systems often fail to adequately mix the components. In applications using hydraulic fracturing fluids, the presence of proppant in the fracturing fluid creates complex hydrodynamics, limiting the ability to thoroughly mix certain materials, such as dry friction-reducing powders. Without adequate mixing, friction-reducing powders exhibit a phenomenon known as "fisheyes" when dropped into the liquid. Wetted powder tends to form a skin around the small bag of dry powder, creating "fisheyes" of unmixed powder. Furthermore, current mixing systems tend to reject the proppant and stop mixing after reaching a certain concentration of friction-reducing powder. Summary of the Invention

[0005] Generally, a system and method are provided for facilitating the mixing of fluids used in well treatment operations. According to embodiments, dry powder materials, such as dry friction modifiers or high-viscosity dry friction modifiers (HVFRs), can be thoroughly mixed into one or more fluids associated with the well treatment operation. The dry powder material is combined with a liquid, such as water, via a series of Venturi mixers arranged to thoroughly mix the material. In some applications, the Venturi mixers are mounted on modular skids that can be easily moved to the desired well site. Additional modular skids can be added to increase the amount of mixed product, depending on the needs of a given well treatment operation, such as a hydraulic fracturing operation.

[0006] However, many modifications may be made without substantially departing from the teachings of this disclosure. Therefore, such modifications are intended to be included within the scope of this disclosure as defined in the claims. Attached Figure Description

[0007] Some embodiments of this disclosure will now be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. However, it should be understood that the drawings illustrate various implementations described herein and are not intended to limit the scope of the various techniques described herein, and:

[0008] Figure 1 This is a schematic diagram of an example of a Venturi mixer system according to an embodiment of the present disclosure, the Venturi mixer system being arranged to thoroughly mix dry powder materials used in well treatment operations such as hydraulic fracturing operations.

[0009] Figure 2 This is a schematic diagram of an example of a Venturi mixer system according to an embodiment of the present disclosure combined with other components to facilitate the mixing and conveying of dry powder materials;

[0010] Figure 3 This is a schematic diagram of an example of a well site layout utilizing a Venturi mixer system according to an embodiment of this disclosure;

[0011] Figure 4 This is a schematic diagram of an example of a sensor and control system used in conjunction with a Venturi mixer system according to an embodiment of this disclosure;

[0012] Figure 5 This is a schematic diagram illustrating an example well site layout utilizing a Venturi mixer system in an integrated hydraulic fracturing arrangement for delivering fracturing fluid to a wellbore, according to embodiments of this disclosure; and

[0013] Figure 6 This is a schematic diagram of another example of a well site layout utilizing a Venturi mixer system in an integrated hydraulic fracturing arrangement for delivering fracturing fluid to a wellbore, according to an embodiment of this disclosure. Detailed Implementation

[0014] In the following description, numerous details are set forth to provide an understanding of some embodiments of this disclosure. However, those skilled in the art will understand that the system and / or methods can be practiced without these details, and that various changes or modifications can be made to the described embodiments.

[0015] The disclosure herein generally relates to systems and methods for facilitating the mixing of fluids used in well treatment operations. According to embodiments, dry powder materials, such as dry friction modifiers or high-viscosity dry friction modifiers (HVFRs), can be thoroughly mixed with one or more fluids associated with the well treatment operation. The dry powder material is combined with a liquid, such as water, via a series of Venturi mixers arranged to thoroughly mix the material. In some applications, the Venturi mixers are mounted on modular skids that can be easily moved to the desired well site and combined with other well site equipment. Additional modular skids can be added to increase the amount of mixed product, depending on the needs of a given well treatment operation, such as a hydraulic fracturing operation.

[0016] For example, a Venturi mixer system may include two Venturi mixers fluidly coupled in series to provide different, selectable flow rates (e.g., two flow rates) and enhanced mixing. Valves may be used to control the flow rate through one or more Venturi mixers and also to control the flow rate to a downstream pump (e.g., a downstream positive displacement pump). Each Venturi mixer may be configured to draw in a desired component, such as a dry powder material, and mix it with a liquid to form a desired fluid mixture. Sometimes, a Venturi mixer configured to draw in a dry component may be referred to as an ejector, while a Venturi mixer configured to draw in a liquid (e.g., a liquid / powder fluid mixture) may be referred to as an ejector pump.

[0017] Using multiple Venturi mixers (e.g., two Venturi mixers) in combination with a positive displacement pump or other suitable pump allows the mixing system to eliminate the need for a conventional metering tank. In some applications, the flow of the drive fluid to one Venturi mixer can be shut off via a valve to reduce the overall flow rate through the Venturi mixer system, for example, providing two flow rates. Additionally, various sensors, such as pressure sensors, can be used between the Venturi mixer and the downstream pump to better control the downstream pump speed based on sensor feedback. By eliminating the metering tank, product concentration can be adjusted more quickly, thus allowing for rapid increases or decreases in the amount of HVFR or other dry powder materials based on the stage or operating characteristics of a given well treatment operation.

[0018] Each Venturi mixer utilizes the Venturi principle, which involves generating suction via a driving fluid guided through a Venturi tube. As the jet of driving fluid is guided through the Venturi tube, the suction can be used to draw in liquid or dry materials for mixing with the driving fluid. When using Venturi mixers in series, the mixers are appropriately sized so that the outlet flow rate of the first Venturi mixer can accommodate the full flow rate through the inlet of the second Venturi mixer. Each of the Venturi mixers can be driven by a suitable liquid (e.g., water) guided through a jet / Venturi tube.

[0019] This Venturi-based system offers several advantages, such as lower horsepower required for mixing. In fact, replacing a single large Venturi mixer with multiple Venturi mixers arranged in series does not increase the required horsepower. The series arrangement of Venturi mixers also significantly enhances mixing, such as that of powders. When powder falls into a fluid, a phenomenon known as "fisheye" often occurs. "Fisheye" forms when wetted powder forms a skin around a small bag of dry powder. The jet nozzles of the Venturi tubes forming each Venturi mixer generate highly turbulent flow that disperses the powder throughout the fluid. By placing two Venturi mixers in series, the dry powder undergoes very thorough hydration, thus eliminating all or almost all of the "fisheye." The arrangement of the mixers increases the system's mixing energy by increasing the amount of time the particles are under high shear, thus promoting more thorough mixing. In some applications, this more thorough mixing also increases the desired viscosity yield of the chemicals. It should be noted that the system can be used to thoroughly mix various powders (or liquids) into a liquid to form a desired fluid mixture. For example, the system can be used to facilitate the complete mixing of dry powder materials, such as high-viscosity friction reducer (HVFR) powder, into a liquid, such as water. An example of dry HVFR is polyacrylamide powder.

[0020] General Reference Figure 1 An example of the mixing system 20 is shown having a plurality of Venturi mixers 22. In the specific example shown, the plurality of Venturi mixers 22 includes a first Venturi mixer 24, which is arranged in series with a second Venturi mixer 26. A driving fluid 28, such as water, can be supplied to the plurality of Venturi mixers 22 under pressure via a pump 30, such as a centrifugal pump.

[0021] For example, the drive fluid 28 can be divided into a first drive fluid flow 32 for driving the first Venturi mixer 24 and a second drive fluid flow 34 for driving the second Venturi mixer 26. The control valve 36 can be positioned along the second drive fluid flow 34 and can be adjusted to control the amount of drive fluid delivered to the second Venturi mixer 26.

[0022] During operation, a first drive fluid flow 32 is directed into a jet 38 and through a corresponding Venturi tube 40 of a first Venturi mixer 24. The fluid flow through the Venturi tube 40 generates suction at the suction inlet / inlet 42, which draws in the desired additive 44. In the example shown, the additive 44 may be in the form of a dry powder material 46, such as dry HVFR powder or other suitable powder, which can be supplied from container 48 and mixed with a liquid, such as water, at a rinsing basin 50 or other suitable mixing device.

[0023] Dry powder material 46 is mixed with a first drive fluid flow 32 within a first Venturi mixer 24, and the resulting mixture 52 is discharged through the Venturi mixer outlet 54. The fluid mixture 52 discharged from outlet 54 is directed to the suction / inlet 56 of a second Venturi mixer 26. The second drive fluid flow 34 is directed into a jet 58 and through a corresponding Venturi tube 60 of the second Venturi mixer 26 to generate suction at the suction / inlet 56. Thus, the discharged fluid mixture 52 is drawn in through inlet 56 and mixed with the second drive fluid flow 34 to produce an output mixture 62, which is discharged through the Venturi mixer outlet 64 of the second Venturi mixer 26. The output mixture 62 can be directed to a downstream pump 66, such as a positive displacement pump, which pumps the mixture 62 to the desired downstream components of the well treatment system, such as a hydraulic fracturing system, as described in more detail below. Control valve 36 can be opened or closed to establish different flow rates of the output mixture 62, for example, two different flow rates.

[0024] Fluid movement through jets 38 and 58 generates significant turbulence, allowing for rigorous mixing of components drawn in through the corresponding inlets 42 and 56. By using cascaded Venturi mixers 24 and 26 and maintaining desired end flow and suction pressure, mixing performance is significantly improved without requiring more additional power than a single Venturi mixer. In the example shown, components (or at least some components) of the mixing system 20 are mounted on a modular unit 68, which can be easily transported to the desired well site and then moved to the desired location at each well site for coupling with the corresponding equipment. For example, the modular unit 68 may be in the form of a skid or trailer sized for road transport between well sites.

[0025] General Reference Figure 2 Another example of a mixing system 20 is shown, in which multiple Venturi mixers 22 have been combined with various sensors and other components to provide enhanced control over the operation of the mixing system 20. In this example, the drive fluid 28 may be in the form of water pumped to the Venturi mixers 24, 26 via pump 30. Pressure sensor 70 or other suitable sensor may be positioned between pump 30 and Venturi mixers 24, 26 to provide feedback on the supply pressure.

[0026] As shown, a portion of the driving fluid / water 28 can be directed along streamline 72 to the rinsing basin 50 to mix with the dry powder material 46. By mixing the water with the dry powder material 46, the fluid can be introduced into the suction port 42. However, some systems can be designed to draw in the dry powder directly through the suction port 42. In the illustrated embodiment, a controllable valve 74 is positioned along streamline 72 to control the amount of water delivered to the rinsing basin 50. Similarly, a controllable valve 76 can be positioned between the rinsing basin 50 and the suction port 42 to control the amount of fluid available at the suction port 42, for example, to cut off the flow to the suction port 42. In some embodiments, a sensor 77 can be used to monitor the flow rate from the rinsing basin 50.

[0027] The output mixture 62 can be monitored via sensor 78. For example, sensor 78 may be a pressure sensor located between outlet 64 and pump 66 to monitor the pump inlet pressure (suction pressure) of the fluid supply pump 66. In some embodiments, an additional sensor 80, such as a pressure sensor and / or a pump rate sensor, may be positioned downstream of pump 66 to monitor desired parameters of the output mixture 62 discharged from the positive displacement pump 66 (or other suitable pump) used to supply fluid to other components of the well system.

[0028] In the illustrated embodiment, the output mixture 62 is divided into two discharge streams flowing along a first discharge stream 82 and a second discharge stream 84. For example, the first stream 82 is used to direct the output mixture 62 (e.g., a concentrated mixture of water and HVFR) to a desired downstream system component, such as an agitator or manifold. The second stream 84 can be used to direct the output mixture 62 to another desired downstream system component, such as an agitator or other component. The fluid flow along each of the streams 82 and 84 can be controlled via corresponding valves, such as a controllable valve 86, a check valve 88, and / or a manual valve 90. A flow control device 92, for example, with a flow control orifice, can be positioned along one or both of the streams 82 and 84 to deliver a constant flow rate independent of pressure. Furthermore, a flow rate sensor can be incorporated into the device 92 or positioned in another suitable location or along one or both of the streams 82 and 84.

[0029] Depending on the application, a single flow line, such as a first discharge flow line 82, may be used, or additional flow lines may be added to allow the output mixture 62 to be directed to additional well site components. In some applications, an optional recirculation line 94 may be provided to allow at least a portion of the output mixture 62 discharged from pump 66 to be directed to a desired location upstream of venturi mixers 24, 26. The flow rate along the recirculation line 94 may be controlled by one or more suitable valves, such as check valve 96 and controllable valve 98.

[0030] Refer again Figure 2Various systems can be used to deliver, for example, dry HVFR powder material 46 to the rinsing basin 50 and / or the first Venturi mixer 24. In the example shown, the dry HVFR powder material 46 is housed in a container 48, which is in the form of multiple hoppers 100. Each hopper 100 can be configured to supply the dry powder material 46 downward by gravity via a valve 102, a controllable valve 104, and a sensor 106, for example, a level sensor, which monitors the dry powder material 46 supplied by the corresponding hopper 100. A single hopper 100 can be used. However, using multiple hoppers 100 can enhance functionality, such as providing backup, redundancy, and / or delivering multiple different ingredients / chemicals into the mixture.

[0031] In the example shown, dry powder material 46 from each hopper 100 flows into manifold 108 and can be moved along manifold 108 toward discharge port 112 via a corresponding transport mechanism 110, such as a motorized auger. Flow sensor 114 (or other suitable sensor) can be used to monitor the flow of powder along manifold 108 from each hopper 100. When the dry powder material 46 reaches discharge port 112, it can be gravity-fed through controllable valve 116 and enter flush basin 50. Valve 116 allows the system to be sealed against moisture. The dry powder material 46 may be sensitive to moisture, such as humid air, and valve 116 can be closed between well site operation phases or when the system is not otherwise used to protect the dry powder material 46 from moisture exposure. In some embodiments, overflow valve 118 can be used to clear blockages and also helps clean transport mechanism 110. As the dry powder material 46 moves into flush basin 50, it combines with the flow of water directed into flush basin 50 via flow line 72.

[0032] In some implementations, dry powder material 46 can be supplied from a single tank 100. This allows a second tank 100 to be used as a backup tank 100 for redundancy. For example, when the primary tank 100 is empty or the flow of dry powder material 46 from the primary tank 100 is interrupted, a valve can be controlled to allow the dry powder material 46 to flow from the backup tank 100. However, tanks 100 can be used simultaneously or for different chemicals. In some applications, controllable valve 104 can be automatically controlled based on data obtained from various sensors, such as a level sensor 106 and / or additional sensors, such as a weight monitoring sensor.

[0033] Regardless of the specific configuration of the mixing system 20 and its cooperating components, system 20 can be used to facilitate certain control advantages by achieving multiple flow rates. In hydraulic fracturing operations, for example, the output mixture flow 62 from modular unit 68 can be modulated to combine with fluid flows from, for example, agitator 120, such as... Figure 3 As shown.

[0034] For example, the modular unit 68 shown, such as a skid or trailer, may include venturi mixers 24, 26 connected in series with a downstream pump 66, which may be in the form of a positive displacement pump with a constant flow rate outlet. The agitator 120 may include various agitators configured to mix water, proppant, additives, and / or other desired components of a given hydraulic fracturing fluid. The mixing system 20 on the modular unit 68 can be used to supply, for example, a mixture of water and dry HVFR powder constituting the output stream 62. Thus, the modular unit 68 (via the downstream pump 66) and the agitator 120 can supply corresponding fluid streams 62, 122 to the hydraulic fracturing manifold 124 (see...). Figure 3 ).

[0035] It should be noted that changing the auger speed of the auger 110 will change the amount of dry powder material 46 added. Additionally, the output flow 62 can be staged by activating different Venturi mixers 24, 26 to provide different outflow rates, for example, two mixers for a higher rate and one mixer for a lower rate. Depending on the operation, the desired mass rate of the dry powder material can vary from the beginning to the middle to the end of the fracturing phase. Using a specific example, for each modular unit 68, the desired mass rate of dry HVFR powder can range from 1 lb per minute to 50 lb per minute. At the beginning of the fracturing phase, a low concentration of friction modifier mixed with water (often referred to as "slickwater") may be primarily used, while at the end of the fracturing phase, a high concentration of high-viscosity friction modifier mixed with water may be necessary to produce a high fluid viscosity, which helps carry the proppant into the wellbore and out to the formation.

[0036] The use of dual Venturi mixers 24 and 26 enables the generation of multiple flow rate states. For a constant inlet pressure, for example, dual Venturi mixers 24 and 26 can be used to establish two different flow rates. For illustrative purposes, Figure 3 The example illustrates a modular unit 68 and its corresponding mixer system 20, which can be adjusted to provide two different flow rates: 6 barrels per minute at 80 psi or 8 barrels per minute at 80 psi. This dual-rate flow would allow operations to begin, for example, at a total downhole rate of 15 barrels per minute, with agitator 120 contributing 9 barrels per minute and the corresponding modular unit 68 contributing 6 barrels per minute. As the total downhole flow rate increases to, for example, 100 barrels per minute, the output of agitator 120 can be increased to 92 barrels per minute, while the output of the corresponding modular unit 68 can be increased to contribute 8 barrels per minute.

[0037] It should be noted that flow can be established by the proppant agitator 120 before flow is established at modular unit 68 to avoid certain undesirable flow results, such as backflow to the agitator 120 before proper discharge and application of back pressure. In this particular example, agitator 120 includes a centrifugal pump or vortex pump that can respond quickly to flow rate changes from a high-pressure positive displacement pump. Pump 66 associated with modular unit 68 can also be a positive displacement pump, controlled to capture all flow from venturi mixers 24, 26 and respond to varying back pressures applied by agitator 120. Pump 66 helps maintain a stable flow rate to avoid back pressure that could overflow flush basin 50 or cause other problems in the system.

[0038] The ability to stagger the flow rates of the output stream 62 helps ensure that the modular unit 68 is not the primary flow enabler even at low flow rates. In many applications, it is beneficial for the proppant agitator 120 to consistently deliver the primary fluid to the downstream high-pressure pump.

[0039] Regarding the change in the amount of output flow 62, control valve 36 can be adjusted as described above to control the amount of drive fluid flow 34 moving through the second Venturi mixer 26 and thus control the total amount of output flow 62 supplied to the positive displacement pump 66. For example, if valve 36 is closed, the total amount of output flow 62 that can be supplied to pump 66 must pass through the first Venturi mixer 24 and then through the second Venturi mixer 26 via inlet 56. Therefore, the output flow 62 is reduced compared to the open valve position in which both drive fluid flow 32 and drive fluid flow 34 pass through Venturi mixers 24 and 26, respectively. This change results in a difference between two flow levels (e.g., 6 barrels per minute versus 8 barrels per minute).

[0040] General Reference Figure 4 A schematic diagram is provided to illustrate the ability of mixer system 20 to provide a rapid response to changes in the mass rate of dry powder material or the concentration of the fluid mixture based on, for example, changes in outlet flow rate and discharge pressure. This can be achieved via, for example, a computer / processor-based control system 126 that receives feedback from various sensors, such as sensors 70, 77, 78, and 80, to achieve an appropriate system response.

[0041] For example, control system 126 can be programmed to utilize control loops that are decoupled from each other. In some embodiments, control system 126 may be in the form of a proportional-integral-derivative (PID) controller that utilizes feedback from some sensors, such as sensors 70, 77, 78, 80, and compares the sensor feedback with the corresponding setpoint (SP) of each control loop. Figure 4In the example, three decoupled control loops 128, 130, and 132 are illustrated. Control loop 128 establishes a setpoint for the pump discharge pressure of centrifugal pump 30 while simultaneously monitoring the actual pump discharge pressure via sensor 70. External responses can also be monitored. Based on deviations from the setpoint, appropriate system adjustments / responses can be made.

[0042] Similarly, control loop 130 establishes a setpoint, but this setpoint is established relative to the flow rate from flush basin 50, while monitoring the actual flow rate from flush basin 50 via sensor 77. Likewise, system adjustments / responses can be performed based on the deviation from the setpoint. In this example, control system 126 can also be programmed to establish a setpoint regarding the suction at downstream discharge pump 66, while monitoring the actual pressure at this location via sensor 78 (see control loop 132). System adjustments / responses can be appropriately performed based on the deviation from the setpoint.

[0043] It should be noted that the driving fluid pressure of the Venturi mixers 24, 26 typically determines the flow rate of the output flow 62. Rapid system regulation can be achieved by monitoring the pressure / flow rate associated with the output flow 62. For example, if a large disturbance regarding the change in suction pressure is detected via sensor 78, certain operating parameters, such as the flow rate through the flush basin streamline 72 or the flow rate of the discharge pump 66, can be rapidly adjusted in response. This rapid regulation better protects system components from unwanted pressure pulses, system chemical contamination, and / or other unwanted events.

[0044] General Reference Figure 5 An example well site layout for hydraulic fracturing operations is shown. In this example, one to three modular units 68 (e.g., one to three skids and / or trailers) can be used to provide the required amount of dry powder material to be mixed with the fluid. For example, each modular unit 68 may include its own mixing system 20 in combination with an upstream pump 30 and a downstream pump 66. As shown, the drive fluid 28 may be in the form of water supplied via one or more tanks 134. The output streams 62 from one or more modular units 68 can be split, such that a portion of the output stream 62 is provided to a proppant agitator 136, while the remainder of the output stream 62 is provided to a manifold 138, which can also be used as a pipeline mixer to improve mixing. For example, a relatively small amount of the output stream 62 (e.g., one barrel per minute) may be supplied to the proppant agitator 136, while a larger remainder of the output stream (e.g., eight barrels per minute) may be supplied to the manifold 138. In some applications, the portion of the output stream 62 directed to the proppant agitator 136 may be optional.

[0045] As further shown, proppant is supplied from proppant supplier 140 to proppant mixer 136. Additionally, water can be supplied from water tank 134 to proppant mixer 136 to mix with the sand. In some embodiments, various liquid additives can be supplied to proppant mixer 136 via liquid additive supplier 142. Output stream 62 is mixed with proppant, water, and liquid additives to produce a desired proppant slurry, which is mixed with the larger remaining portion of output stream 62 in manifold 138. The resulting fracturing fluid mixture is delivered at low pressure to multiple high-pressure pumps 144, which then pump the resulting fracturing fluid mixture back to manifold 138 at high pressure. This high-pressure well treatment fluid (e.g., fracturing fluid mixture) is then directed through wellhead 146 and downhole for distribution into the surrounding formation.

[0046] The number of modular units 68 employed can be selected to achieve the desired concentration of dry powder material (e.g., dry HVFR powder) in the fracturing fluid mixture to facilitate proppant movement through the wellbore and outwards into the surrounding formation. The mixing system 20 on each modular unit 68 ensures tight mixing of the dry powder material into the fluid to improve the efficiency of establishing the desired properties of the fracturing fluid mixture (e.g., higher viscosity). This higher viscosity facilitates the carryover of proppant particles into the surrounding formation during fracturing operations.

[0047] General Reference Figure 6 This illustrates another example of a well site layout used for hydraulic fracturing operations. In this example, many components are... Figure 5 The components described herein are the same or similar and are marked with common reference numerals.

[0048] As shown in the figure, one or more modular units 68 can be used to provide the desired amount of dry powder material, as referenced above. Figure 5 As stated above. However, in Figure 6 In this fracturing system layout, a separate flow of water from tank 134 is directed to centrifugal pump 148. Centrifugal pump 148 is used to supply water directly to manifold 138, which in turn supplies low-pressure water to a portion of high-pressure pump 144. In this arrangement, high-pressure pump 144 is divided into two groups, comprising pump 150 for water only and pump 152 for proppant slurry only.

[0049] Pump 150, used only for water, receives low-pressure water supplied from centrifugal pump 148 and pumps it back to manifold 138 under high pressure. Similarly, pump 152, used only for proppant slurry, receives low-pressure proppant slurry mixed with a dry powder material, such as dry HVFR powder, and then pumps the resulting proppant slurry mixture back to manifold 138 under high pressure. The high-pressure water and high-pressure proppant slurry are then combined into a well treatment / fracking fluid and directed under high pressure to wellhead 146 for distribution along the wellbore and carry-out into the surrounding formation.

[0050] In this type of operation (sometimes referred to as split-flow operation), such as a water-only flow and a proppant-only flow, the number of modular units 68 employed can be similarly selected to achieve the desired concentration of dry powder material, such as dry HVFR powder, for mixing into the proppant slurry flow. The mixing system 20 on each modular unit 68 again ensures that the dry powder material is tightly mixed to improve the efficiency of establishing the desired properties of the fracturing fluid mixture.

[0051] Depending on the parameters of a given operation, the mixing system 20 can be combined with various hydraulic fracturing well site layouts and other well treatment layouts. Each mixing system 20 or combination of mixing systems 20 can be mounted on a transportable skid, trailer, or other modular unit 68 along with various other desired components (e.g., pumps, flushing basins, sensor systems, containers, and / or other desired components). However, some operations may use mixing systems 20 that are not mounted on modular unit 68 and can be combined with or integrated into various other equipment. Furthermore, the sensors used to monitor various pressures, flow rates, and / or other parameters associated with each mixing system 20 can vary. Similarly, the treatment system 126 can take many forms and can be used to provide automated control of the flow rate through each mixing system 20 and / or to provide output to the operator. The number, type, and arrangement of the tandem Venturi mixers can also be adjusted according to the type of fluid being mixed and the overall parameters of a given well treatment operation.

[0052] Although several embodiments of this disclosure have been described in detail above, those skilled in the art will readily understand that many modifications can be made without substantially departing from the teachings of this disclosure. Therefore, such modifications are intended to be included within the scope of this disclosure as defined in the claims.

Claims

1. A system for well processing operations, comprising: Manifolds are configured to combine fluid flows into well treatment fluids for delivery into the wellbore. A stirring system, which is in fluid communication with the manifold to deliver a first fluid flow comprising water and proppant; as well as A mixer system, which is in fluid communication with the manifold to deliver a second fluid flow comprising water mixed with the dry powder material, the mixer system comprising: A first Venturi mixer is powered by a first drive fluid flow pumped through a first Venturi tube to generate suction at a first inlet, the first inlet being positioned to draw in a flow containing the dry powder material to discharge a mixture of the drive fluid and the dry powder material through a first outlet. as well as A second Venturi mixer, powered by a second driving fluid flow pumped through a second Venturi tube, generates suction at a second inlet connected in fluid communication with the first outlet. This second driving fluid flow combines with the mixture exiting from the first outlet to generate a second fluid flow, which exits from the second Venturi mixer through a second outlet to allow the second fluid flow to continue moving into the manifold. The mixer system further includes a control valve configured to control the second drive fluid flow to the second venturi mixer.

2. The system of claim 1, wherein the mixer system is mounted on a modular unit in the form of at least one skid or trailer.

3. The system of claim 2, wherein the mixer system comprises a plurality of mixer systems, each mixer system being mounted on a corresponding modular unit.

4. The system of claim 1, wherein the dry powder material is initially a dry friction modifier.

5. The system of claim 1, wherein the dry powder material was originally a dry high-viscosity friction reducer.

6. The system of claim 1, wherein the dry powder material is conveyed to the mixer system from multiple redundant or different hoppers providing the dry powder material.

7. The system of claim 1, wherein the first driving fluid flow and the second driving fluid flow comprise water flow.

8. The system of claim 1, further comprising a centrifugal pump configured to deliver the first drive fluid flow and the second drive fluid flow to the mixer system.

9. The system of claim 1, further comprising a sensor system for monitoring pressure to optimize fluid flow to the manifold.

10. A method for well treatment operations, comprising: The dry powder material is mixed with water via a mixing system; The flow rate through the hybrid system is monitored using a sensor system; Data from the sensor system is provided to a processing system for processing, thereby determining control inputs for controlling the flow through the hybrid system; The fluid flow of water and proppant is directed to the manifold to combine with the mixture of the dry powder material and water to produce a well treatment fluid; as well as The well treatment fluid is pumped from downhole into the wellbore. The hybrid system includes: A first Venturi mixer, powered by a first drive fluid flow pumped through a first Venturi tube to generate suction at a first inlet, the first inlet being positioned to draw in a flow containing the dry powder material, and to discharge a mixture of the drive fluid and the dry powder material through a first outlet; and A second Venturi mixer, powered by a second driving fluid flow pumped through a second Venturi tube, generates suction at a second inlet connected in fluid communication with the first outlet. This second driving fluid flow combines with the mixture exiting from the first outlet to generate a second fluid flow, which exits from the second Venturi mixer through a second outlet to allow the second fluid flow to continue moving into the manifold. The mixing system further includes a control valve configured to control the second drive fluid flow to the second venturi mixer.

11. The method of claim 10, wherein utilizing the sensor system includes monitoring the discharge pressure of the pump supplying water to the mixing system to drive the Venturi mixer.

12. The method of claim 11, wherein utilizing the sensor system includes monitoring the flow rate of a downstream pump that receives an output mixture of dry powder material and water from the mixing system.

13. The method of claim 11, wherein the sensor system includes monitoring the suction pressure of a positive displacement pump that receives the output mixture of dry powder material and water from the mixing system.

14. The method of claim 10, further comprising mounting the hybrid system on a modular unit of a size suitable for transport between well sites.

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