Single-machine dual-pump fracturing fluid mixing device and method

Abstract

This invention provides a single-unit, dual-pump fracturing fluid mixing device and method. The device includes a power system, a power distribution system, a hydraulic system, multiple mixing units connected in parallel, a powder storage and conveying system, and a pneumatic system. The power system, power distribution system, and hydraulic system are connected sequentially. The hydraulic system drives the mixing units and the powder storage and conveying system. The power system provides power to the pneumatic system. The mixing unit includes a mixing device, a supply centrifugal pump, a discharge pump, an intake manifold, and a discharge manifold. The mixing device is connected to the powder storage and conveying system, the supply centrifugal pump, and the discharge pump. The supply centrifugal pump is connected to the intake manifold, and the discharge pump is connected to the discharge manifold. The discharge manifold includes a first discharge port and a second discharge port. In the mixing device, the fracturing fluid goes through the first discharge port to an external sand mixing vehicle and through the second discharge port to an external fracturing fluid manifold. The method can be implemented using the above device. This invention is suitable for mixing small-volume and large-volume fracturing fluids.

Description

Technical Field

[0001] This invention relates to the field of fracturing technology, specifically to a single-unit dual-pump fracturing fluid mixing device and method. Background Technology

[0002] During the testing and production of oil and gas wells, if the original permeability of the formation is low or the formation is contaminated during drilling, cementing, well washing, or well killing, the production of oil and gas wells will be low. This problem can be solved by fracturing technology.

[0003] Fracturing technology refers to the process of pumping fracturing fluid with a certain viscosity into the formation using a high-pressure pump before testing the production process of an oil and gas well. By applying high pressure exceeding the formation closure pressure, the oil and gas reservoir is broken up to form fractures. The viscosity of the fracturing fluid is then used to transport proppant such as ceramic particles and quartz sand into the formation to support the fractures, creating fractures of a certain geometric size and high conductivity, thereby increasing the production of oil and gas wells.

[0004] In existing technologies, fracturing fluid mixing devices generally include a feed inlet, a liquid inlet, a drain outlet, and a hydration tank (also known as a buffer tank, etc.). The thickener powder and the base liquid enter the mixing device, where they are mixed and synthesized. Then, the mixture undergoes hydration in the water tank to gradually and slowly form a viscous liquid, which is then discharged from the drain outlet.

[0005] With the development of fracturing technology, especially horizontal well and coalbed methane well fracturing technology, the discharge capacity of fracturing projects has increased rapidly, and the supporting fracturing fluid mixing equipment has begun to face problems. First, due to road transportation conditions and the overall area limitations of the well site, it is not possible to simply increase the number of fracturing fluid mixing equipment to increase the overall fluid mixing speed. Second, if the mixing discharge capacity is increased by increasing the power output of the mixing equipment, the specifications and grades of the engines, gearboxes, valves, and other components need to be significantly upgraded, resulting in excessively high equipment costs and increased maintenance difficulty. At the same time, when such ultra-high power mixing devices are used in low-discharge bridge-jetting operations in horizontal wells or in conventional fracturing operations with small discharge capacities, it will lead to a large amount of power redundancy and unnecessary additional emissions. Therefore, providing a single-unit dual-pump fracturing fluid mixing device and method is of great significance.

[0006] Chinese Patent Application No. CN201920403087.5, entitled "A Multifunctional Liquid Supply Skid," discloses a multifunctional liquid supply skid comprising a skid frame and a working device disposed within the skid frame. The working device includes a power unit, a traveling device, a hydraulic system, a pneumatic system, and a lifting system. The hydraulic system includes an intake manifold and an exhaust manifold, with a centrifugal pump connected between the intake and exhaust manifolds and connected to the power unit. This multifunctional liquid supply skid integrates a traveling system, a boom system, a lifting system, and a pneumatic system, eliminating the need for a crane on-site, reducing on-site operating costs, and making it more convenient to use. However, the structure of this multifunctional liquid supply skid differs from that of this application. Summary of the Invention

[0007] The purpose of this invention is to address at least one of the aforementioned shortcomings of the prior art. For example, one objective of this invention is to provide a single-unit dual-pump fracturing fluid mixing device with a reasonable structure that is suitable for both small-displacement and large-displacement fracturing fluid mixing operations. Another objective of this invention is to provide a single-unit dual-pump fracturing fluid mixing method.

[0008] To achieve the above objectives, the present invention provides a single-unit dual-pump fracturing fluid mixing device. The device may include a power system, a power distribution system, a hydraulic system, multiple mixing units arranged in parallel, a powder storage and conveying system, and a pneumatic system. The power system, power distribution system, and hydraulic system are connected sequentially. The hydraulic system is configured to drive the mixing units and the powder storage and conveying system. The power system provides a power source to the pneumatic system. The mixing unit includes a mixing device, a supply centrifugal pump, a discharge pump, a suction manifold, and a discharge manifold. The mixing device is connected to the powder storage and conveying system. The supply centrifugal pump is connected to an external water source via the suction manifold, and its outlet is connected to the suction port of the mixing device. The suction port of the discharge pump is connected to the discharge port of the mixing device, and its outlet is connected to the discharge manifold. The discharge manifold includes a first discharge port and a second discharge port, the diameter of which is smaller than that of the second discharge port. The fracturing fluid in the mixing device flows through the first discharge port to an external sand mixing vehicle, and through the second discharge port to an external fracturing fluid manifold.

[0009] According to one or more exemplary embodiments of one aspect of the present invention, the apparatus may further include a control room, wherein the control room is provided with a control system, the control system controlling the output power of the hydraulic system to adjust the flow rates of the supply centrifugal pump and the discharge pump and the powder supply speed of the powder storage and conveying system.

[0010] According to one or more exemplary embodiments of one aspect of the present invention, the device may further include a support unit, wherein the power system, power distribution system, hydraulic system, multiple sets of mixing units arranged in parallel, powder storage and conveying system and pneumatic system are all located on the support unit.

[0011] According to one or more exemplary embodiments of one aspect of the present invention, the carrying unit may include a chassis, a trailer chassis, or a skid.

[0012] According to one or more exemplary embodiments of one aspect of the present invention, the power system may include an engine and / or an electric motor; the engine may include electric start and / or pneumatic start.

[0013] According to one or more exemplary embodiments of one aspect of the present invention, the power distribution system may include a one-in-three-out type and / or a one-in-four-out type.

[0014] According to one or more exemplary embodiments of one aspect of the present invention, the discharge pump may include a rotary pump or a vane pump.

[0015] According to one or more exemplary embodiments of one aspect of the present invention, the powder storage and conveying system may be provided with a multi-stage feeding auger shaft.

[0016] According to one or more exemplary embodiments of one aspect of the present invention, a tachometer may be provided on the feeding auger shaft.

[0017] Another aspect of the present invention provides a single-unit dual-pump fracturing fluid mixing method, which can be implemented by the single-unit dual-pump fracturing fluid mixing device described above. The method includes: selectively activating one or more mixing units during low / high displacement fracturing or pumping operations, activating the corresponding suction manifold to draw in clean water, and activating the corresponding discharge pump to ensure normal fluid output; adjusting the supply centrifugal pump and discharge pump to the required fluid output for the construction parameters; activating the powder storage and conveying system to operate at the powder supply speed corresponding to the fluid output; clean water and powder entering the mixing equipment, forming fracturing fluid, and then being discharged through the discharge pump and discharge manifold; sampling and testing the fluid output at the first discharge interface; if the viscosity does not meet the construction requirements, adjusting the powder supply speed and the fluid output, and retesting the viscosity until the construction requirements are met; after completing the mixing work, stopping the powder supply, while the supply centrifugal pump and discharge pump continue to operate, and the drawn-in clean water cleans the residual fracturing fluid and powder in the device, after which the supply centrifugal pump and discharge pump are stopped.

[0018] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0019] (1) The single-unit dual-pump fracturing fluid mixing device proposed in this invention can meet the fluid mixing process requirements of fracturing operations in oil and gas fields. Depending on the different discharge requirements, one or two mixing units can be activated. The mixing unit mixes the fracturing thickener powder with the liquid such as water sucked in by the liquid supply centrifugal pump to form fracturing fluid, which is then transported to external sand mixing trucks, external fracturing fluid supply manifolds, etc., for use in fracturing operations.

[0020] (2) The single-machine dual-pump fracturing fluid mixing device proposed in this invention can effectively increase the maximum mixing capacity of a single mixing device, which is equivalent to two fracturing mixing devices, thus doubling the output capacity range. In other words, the technical requirements for supplying high-capacity operations by a single mixing device can be solved by operating two mixing systems at the same time, and the energy consumption and cost of supplying medium and low-capacity operations by operating a single mixing system separately can be reduced.

[0021] (3) The single-machine dual-pump fracturing fluid mixing method proposed in this invention can be applied to both small-displacement and large-displacement fracturing fluid mixing operations. It has the characteristics of high power adaptability, wide displacement range adaptability, and low cost. Attached Figure Description

[0022] The above and other objects and features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0023] Figure 1 A schematic diagram of the structure of a single-unit dual-pump fracturing fluid mixing device of the present invention is shown in a front view.

[0024] Figure 2 This shows a schematic diagram of another main view of the single-unit dual-pump fracturing fluid mixing device of the present invention;

[0025] Figure 3 A schematic diagram of one side view of the single-unit dual-pump fracturing fluid mixing device of the present invention is shown;

[0026] Figure 4 A schematic diagram of the structure of the single-unit dual-pump fracturing fluid mixing device of the present invention is shown from another side view.

[0027] Explanation of key figure labels:

[0028] 1-Bearing unit, 2-Power system, 3-Hydraulic system, 4-Mixing equipment, 5-Liquid supply centrifugal pump, 6-Discharge pump, 7-Powder storage and conveying system, 8-Suction manifold, 9-Discharge manifold, 10-Power distribution system, 11-Control room, 12-Pneumatic system, 13-Control system. Detailed Implementation

[0029] In the following, a single-unit dual-pump fracturing fluid mixing device and method of the present invention will be described in detail with reference to the accompanying drawings and exemplary embodiments.

[0030] In the description of this application, it should be understood that the terms "middle," "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first," "second," etc., are used only for the convenience of description and distinction, and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality" or "several" means two or more. In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two elements. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] Exemplary Example 1

[0032] This exemplary embodiment provides a single-unit dual-pump fracturing fluid mixing device.

[0033] The single-unit dual-pump fracturing fluid mixing device mainly includes a power system, a power distribution system, a hydraulic system, multiple mixing units set in parallel, a powder storage and conveying system, and a gas circuit system.

[0034] The system comprises a power system, a power distribution system, and a hydraulic system connected sequentially. The hydraulic system is configured to drive the mixing unit and the powder storage and conveying system. The power system provides power to the pneumatic system. The mixing unit includes a mixing device, a liquid supply centrifugal pump, a discharge pump, a suction manifold, and a discharge manifold. The mixing device is connected to the powder storage and conveying system. The liquid supply centrifugal pump is connected to an external water source via the suction manifold, and its outlet is connected to the suction port of the mixing device. The suction port of the discharge pump is connected to the discharge port of the mixing device, and its outlet is connected to the discharge manifold. The discharge manifold includes a first discharge port and a second discharge port, with the diameter of the first discharge port being smaller than that of the second discharge port. The fracturing fluid in the mixing device is discharged through the first discharge port to an external sand mixing truck, and the fracturing fluid is discharged through the second discharge port to an external fracturing fluid manifold.

[0035] In this exemplary embodiment, the first discharge port may be a 2-inch discharge port. The second discharge port may be a 4-inch discharge port.

[0036] In this exemplary embodiment, the single-unit dual-pump fracturing fluid mixing device may further include a control room equipped with a control system (remote control system). The control system controls the output power of the hydraulic system to adjust the flow rates of the supply centrifugal pump and the discharge pump, as well as the powder supply speed of the powder storage and conveying system.

[0037] In this exemplary embodiment, the single-unit dual-pump fracturing fluid mixing device may further include a support unit. The power system, power distribution system, hydraulic system, multiple sets of mixing units arranged in parallel, powder storage and conveying system, and air circuit system are all located on the support unit.

[0038] Furthermore, the carrier unit may include a chassis, a trailer chassis, or a skid.

[0039] In this exemplary embodiment, the power system may include an engine and / or an electric motor.

[0040] Furthermore, the engine may include electric start and / or pneumatic start.

[0041] In this exemplary embodiment, the power distribution system may include a one-in-three-out type and / or a one-in-four-out type.

[0042] In this exemplary embodiment, the discharge pump may include a rotary pump or a vane pump.

[0043] In this exemplary embodiment, the powder storage and conveying system may be equipped with a multi-stage feeding auger shaft.

[0044] Furthermore, a tachometer may be installed on the feeding auger shaft.

[0045] In this exemplary embodiment, the single-unit dual-pump fracturing fluid mixing device can mainly achieve the following two different process requirements: (1) single-pump fluid mixing: one mixing unit is activated for fracturing and bridge jet pumping operations with medium and low displacement; (2) multi-pump (dual-pump) medium and high displacement fluid mixing: multiple (two) mixing units are activated for fracturing operations with high displacement.

[0046] Exemplary Example 2

[0047] This exemplary embodiment provides a method for mixing fracturing fluid using a single-machine dual-pump system.

[0048] The single-unit dual-pump fracturing fluid mixing method can be implemented using the single-unit dual-pump fracturing fluid mixing device described in Exemplary Example 1 above; the method may include the following steps:

[0049] When performing low / medium / high displacement fracturing or pumping operations, selectively start one or more mixing units, start the corresponding suction manifold to draw in clean water, and start the corresponding discharge pump to ensure normal liquid output.

[0050] Adjust the liquid supply centrifugal pump and discharge pump to the required liquid discharge rate for construction parameters; start the powder storage and conveying system and operate at the powder supply speed corresponding to the liquid discharge rate; clean water and powder enter the mixing equipment, and after forming fracturing fluid, they are discharged through the discharge pump and discharge manifold.

[0051] Samples of the liquid discharged from the first discharge port are taken for testing. If the viscosity does not meet the construction requirements, the powder supply speed and liquid discharge rate are adjusted, and the viscosity is tested again until the construction requirements are met.

[0052] After the mixing process is completed, the powder supply is stopped, while the liquid supply centrifugal pump and the discharge pump continue to operate. The clean water drawn in cleans the residual fracturing fluid and powder in the unit. After cleaning, the liquid supply centrifugal pump and the discharge pump are stopped.

[0053] To better understand the exemplary embodiments of the present invention described above, further explanation is provided below with reference to specific examples.

[0054] Example 1

[0055] This example provides a single-unit dual-pump fracturing fluid mixing device.

[0056] like Figures 1-4 As shown, the device may include a support unit and a power system 2, two sets of mixing equipment 4, two liquid supply centrifugal pumps 5, two discharge pumps 6, a powder storage and conveying system 7, a manifold system (inhalation manifold 8 and discharge manifold 9), a power distribution system 10, a hydraulic system 3, a pneumatic system 12, a control room 11, and a control system 13.

[0057] The system comprises a power system 2, a power distribution system 10, and a hydraulic system 3 connected sequentially. Each of these systems is independently connected to two parallel mixing units (mixing equipment 4), two liquid supply centrifugal pumps 5, and two discharge pumps 6. The hydraulic system 3 drives the mixing equipment 4, the liquid supply centrifugal pumps 5, the discharge pumps 6, and the material distribution, storage, and conveying system 7, respectively. The power system 2 is connected to the hydraulic system 3 via the power distribution system 10. A control system 13 is installed in the control room 11. The power system 2 provides power to the pneumatic system 12 via its own compressor. The control system regulates the powder supply speed of the powder storage and conveying system by controlling the output power of the hydraulic system. One or two sets of mixing equipment and their corresponding liquid supply centrifugal pumps and discharge pumps can be selectively activated for individual or parallel mixing. The supply centrifugal pump 5 is connected to an external water tank or water supply system via a suction manifold 8. Base fluids such as water can enter the suction ports of the two supply centrifugal pumps 5 through the suction manifold 8 and two independent pipelines. After passing through the supply centrifugal pumps 5, the fluid is independently discharged to the two connected mixing units 4. The discharge port of the supply centrifugal pump 5 is connected to the suction port of the mixing unit 4, used to transport the prepared liquid such as clean water into the mixing unit 4. The suction port of the discharge pump 6 is connected to the discharge port of the mixing unit 4, drawing in the mixed fracturing fluid and discharging it to the discharge manifold 9. The discharge port of the discharge pump 6 is connected to the discharge manifold 9, used to transport the mixed fracturing fluid to the external sand mixing truck and fracturing fluid manifold. Each of the two mixing units is connected to a powder storage and conveying system 7 via a top loading port, from which the powder storage and conveying system 7 supplies the powder used for mixing the fracturing fluid to the mixing unit 4. The mixing unit 4 is used to mix the water sucked in by the centrifugal pump 5 and the powder input from the powder storage and conveying system 7 to form fracturing fluid, which is then discharged through the discharge pump 6. The manifold system includes an intake manifold 8 and an exhaust manifold 9. The exhaust manifold 9 has 2-inch and 4-inch exhaust ports for discharging the mixed fracturing fluid to the mixing truck and the fracturing fluid manifold. A portion of the fracturing fluid can be discharged through the 2-inch port on the exhaust manifold 9 to the external mixing tank of the fracturing mixing truck. Simultaneously, a portion of the fracturing fluid can be discharged through the 4-inch port on the exhaust manifold to the external fracturing manifold, entering the suction port of the external high-pressure pump truck. The gas system and control system are connected to all necessary valves and sensors in the entire unit.

[0058] In this example, the load-bearing unit is one of the following: a chassis, a trailer chassis, or a skid.

[0059] In this example, the power system is either an engine or an electric motor; the engine is either an electric starter or a pneumatic starter.

[0060] In this example, the power distribution system is one of the following: a one-in-three-out or a one-in-four-out type.

[0061] In this example, the liquid supply centrifugal pump is a centrifugal pump driven by a hydraulic motor or an electric motor.

[0062] In this example, the discharge pump is a rotary pump or vane pump, driven by a hydraulic motor or electric motor. The maximum rated operating pressure of the discharge pump is 0.6 MPa.

[0063] In this example, the powder storage and conveying system may include multi-stage feeding augers with a maximum powder supply speed of 30 kg / min. The actual powder supply speed can be measured using a tachometer mounted on the feeding auger shaft, a storage tank support, or other means.

[0064] In this example, the hydraulic system is one or both of an open and closed system. A hydraulic system typically includes a hydraulic oil tank, filter, thermostat, hydraulic oil heat exchanger, flow control valve, etc. The hydraulic system drives a hydraulic pump via a transfer case, which in turn drives the supply centrifugal pump, discharge pump, and material distribution / storage / conveyor system. The flow control valve is controlled by an electrical signal from the control system to control the speed and magnitude of the hydraulic system's output units (centrifugal pump, discharge pump, storage / conveyor system).

[0065] In this example, the air circuit system includes an air compressor (a standard component of the power unit), an air tank, a check valve, pipelines, and valves, with the valves opened via a built-in switch in the control system.

[0066] In this example, the control system includes an electrical control system and a mixing control system. The electrical control system includes an electrical control cabinet, control modules, sensors, instruments, etc., used for regulating the hydraulic system, controlling the pneumatic system, and monitoring power system data in the control device. The mixing control system is installed in the control cabinet and is used for monitoring data, automatic control, and parameter adjustment.

[0067] Example 2

[0068] This example provides a method for mixing fracturing fluid using a single-unit dual-pump system.

[0069] Taking a single-unit dual-pump fracturing fluid mixing device with two sets of parallel mixing units as an example, when performing medium-to-low displacement fracturing operations or pumping operations, the single-unit dual-pump fracturing fluid mixing method may include:

[0070] (1) For fracturing or pumping operations with low to medium displacement, start the liquid supply centrifugal pump on either side and draw in clean water through the suction manifold.

[0071] (2) Start the discharge pump on the same side to ensure that the sucked clean water can pass through the 4-inch discharge port of the discharge manifold and be discharged to the externally connected fracturing manifold; open the 2-inch discharge port on the discharge manifold to ensure that the pipeline discharged to the external sand mixing truck is normal.

[0072] (3) Adjust the speed and discharge rate of the liquid supply centrifugal pump and the discharge pump through the control system to the liquid preparation working discharge rate required by the construction parameters.

[0073] (4) Start the powder storage and conveying system and operate at the powder supply speed corresponding to the liquid discharge rate. The powder enters the mixing equipment from the powder storage and conveying system at the set speed. After being fully mixed to form fracturing fluid, it is discharged through the discharge pump and discharge manifold.

[0074] (5) On the external sand mixing truck, the performance and quality of the mixed liquid are confirmed by sampling and testing the 2-inch discharge port. If the viscosity of the mixed fracturing fluid does not meet the construction requirements, the flow rate of the centrifugal pump and the discharge pump and the feeding speed of the powder are adjusted by the control system, and the viscosity of the mixed fracturing fluid is retested until the liquid performance indicators meet the construction requirements.

[0075] (6) After the construction is completed, the powder supply of the powder storage and conveying system shall be stopped first; the centrifugal pump and the discharge pump shall continue to work and use the sucked clean water to clean the residual fracturing fluid and powder in the entire device pipeline; after the cleaning is completed, the centrifugal pump and the discharge pump shall be stopped.

[0076] Example 3

[0077] This example provides a method for mixing fracturing fluid using a single-unit dual-pump system.

[0078] Taking a single-unit dual-pump fracturing fluid mixing device with two sets of parallel mixing units as an example, when performing high-flow-rate fracturing or pumping operations, the single-unit dual-pump fracturing fluid mixing method may include:

[0079] (1) For high-displacement fracturing operations, during the initial displacement increase stage of construction, one or two sets of liquid supply centrifugal pumps are started first according to the displacement requirements, and clean water is drawn in through the suction manifold.

[0080] (2) Start the discharge pumps on the same side or both sides to ensure that the sucked clean water can pass through the 4-inch discharge port of the discharge manifold and be discharged to the externally connected fracturing fluid manifold; open the 2-inch discharge valve on the discharge manifold to ensure that the pipeline discharged to the external sand mixing truck is normal.

[0081] (3) Adjust the speed and discharge rate of the supply centrifugal pump and the discharge pump through the control system to the required working discharge rate of the liquid preparation for the construction parameters.

[0082] (4) Start the powder storage and conveying system and operate at the powder supply speed corresponding to the liquid discharge rate. The powder enters the mixing equipment from the powder storage and conveying system at the set speed. After being fully mixed to form fracturing fluid, it is discharged through the discharge pump and discharge manifold.

[0083] (5) On the external sand mixing truck, the performance and quality of the mixed liquid are confirmed by sampling and testing the 2-inch discharge port. If the viscosity of the mixed fracturing fluid does not meet the construction requirements, the flow rate of the centrifugal pump and the discharge pump and the feeding speed of the powder are adjusted by the control system, and the viscosity of the mixed fracturing fluid is retested until the liquid performance indicators meet the construction requirements.

[0084] (6) After the construction is completed, the powder supply of the powder storage and conveying system shall be stopped first; the centrifugal pump and the discharge pump shall continue to work and use the sucked clean water to clean the residual fracturing fluid and powder in the entire device pipeline; after the cleaning is completed, the centrifugal pump and the discharge pump shall be stopped.

[0085] In summary, the beneficial effects include:

[0086] This invention provides a single-unit dual-pump fracturing fluid mixing device and method, mainly applied in the fracturing field. Utilizing a single power system, this invention employs a single-unit dual-pump structure to selectively drive one or more mixing systems. This effectively increases the maximum mixing capacity of a single mixing unit, equivalent to two fracturing mixing units, doubling the output capacity range. It solves the technical requirement of supplying high-capacity operations with a single mixing unit by operating two mixing systems simultaneously, while reducing energy consumption and cost when supplying medium-to-low-capacity operations by operating a separate mixing unit. It can be integrated into a skid, is easy to move, and requires minimal floor space.

[0087] Although the invention has been described above in conjunction with exemplary embodiments, those skilled in the art will understand that various modifications and changes can be made to the exemplary embodiments of the invention without departing from the spirit and scope defined by the claims.

Claims

1. A single-unit dual-pump fracturing fluid mixing device, characterized in that, The device includes a power system, a power distribution system, a hydraulic system, multiple sets of mixing units arranged in parallel, a powder storage and conveying system, and a pneumatic system. The power system, power distribution system, and hydraulic system are connected in sequence. The hydraulic system is configured to drive the mixing unit and the powder storage and conveying system. The power system provides power to the pneumatic system. The mixing unit includes mixing equipment, a liquid supply centrifugal pump, a discharge pump, a suction manifold, and a discharge manifold. The mixing equipment is connected to the powder storage and conveying system. The liquid supply centrifugal pump is connected to an external water source through the suction manifold, and the discharge port of the liquid supply centrifugal pump is connected to the suction port of the mixing equipment. The suction port of the discharge pump is connected to the discharge port of the mixing equipment, and the discharge port of the discharge pump is connected to the discharge manifold. The discharge manifold includes a first discharge port and a second discharge port, the diameter of which is smaller than that of the second discharge port. The fracturing fluid in the mixing equipment is discharged through the first discharge port to the external sand mixing truck, and the fracturing fluid is discharged through the second discharge port to the external fracturing fluid manifold.

2. The single-unit dual-pump fracturing fluid mixing device according to claim 1, characterized in that, The device also includes a control room, which is equipped with a control system. The control system controls the output power of the hydraulic system to adjust the flow rate of the liquid supply centrifugal pump and the discharge pump, as well as the powder supply speed of the powder storage and conveying system.

3. The single-unit dual-pump fracturing fluid mixing device according to claim 1, characterized in that, The device also includes a support unit, on which the power system, power distribution system, hydraulic system, multiple sets of parallel mixing units, powder storage and conveying system and air circuit system are all located.

4. The single-unit dual-pump fracturing fluid mixing device according to claim 3, characterized in that, The load-bearing unit includes a chassis, a trailer chassis, or a skid.

5. The single-unit dual-pump fracturing fluid mixing device according to claim 1, characterized in that, The power system includes an engine and / or an electric motor; the engine includes electric start and / or pneumatic start.

6. The single-unit dual-pump fracturing fluid mixing device according to claim 1, characterized in that, The power distribution system includes a one-in-three-out type and / or a one-in-four-out type.

7. The single-unit dual-pump fracturing fluid mixing device according to claim 1, characterized in that, The discharge pump includes a rotary pump or a vane pump.

8. The single-unit dual-pump fracturing fluid mixing device according to claim 1, characterized in that, The powder storage and conveying system is equipped with a multi-stage feeding auger shaft.

9. The single-unit dual-pump fracturing fluid mixing device according to claim 1, characterized in that, The feeding auger shaft is equipped with a tachometer.

10. A method for mixing fracturing fluid using a single-unit dual-pump system, characterized in that, The method is implemented using a single-unit dual-pump fracturing fluid mixing device as described in any one of claims 1 to 9, and the method includes: When carrying out medium-low / high displacement fracturing or pumping operations, selectively start one or more mixing units, start the corresponding suction manifold to draw in clean water, and start the corresponding discharge pump to ensure normal liquid output; Adjust the supply centrifugal pump and discharge pump to the required liquid dispensing rate for the construction parameters; start the powder storage and conveying system and operate at the powder supply rate corresponding to the liquid dispensing rate; clean water and powder enter the mixing equipment, and after forming fracturing fluid, it is discharged through the discharge pump and discharge manifold; Samples of the liquid discharged from the first discharge port are taken for testing. If the viscosity does not meet the construction requirements, the powder supply speed and liquid discharge rate are adjusted, and the viscosity is tested again until the construction requirements are met. After the mixing process is completed, the powder supply is stopped, while the liquid supply centrifugal pump and the discharge pump continue to operate. The clean water drawn in cleans the residual fracturing fluid and powder in the unit. After cleaning, the liquid supply centrifugal pump and the discharge pump are stopped.

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