A powder-liquid mixer and method thereof

Abstract

The application discloses a powder-liquid mixing device and a method thereof, and relates to the field of powder-liquid mixing devices.The powder-liquid mixing device comprises a first mixing pipeline, a second mixing pipeline and a third mixing pipeline, and an internal material pipeline is arranged in the first mixing pipeline.After the base liquid enters the first mixing pipeline, the base liquid continues to flow into a first mixing chamber, and because the flow capacity of the first mixing chamber is smaller than the flow capacity of the first mixing pipeline close to a first feeding port, the base liquid is compressed and the flow rate is increased; after the guan gum powder enters the internal material pipeline from a second feeding port, the guan gum powder continues to enter the inside of an internal discharging pipeline, the guan gum powder is discharged into the first mixing chamber through a powder discharging hole on the internal discharging pipeline, and the guan gum powder in the first mixing chamber is mixed with the compressed base liquid, so that the guan gum powder and the base liquid are mixed more sufficiently, and the powder-liquid is configured on site for use, thereby avoiding the phenomenon that the viscosity of the fracturing fluid is reduced during storage and transportation.

Description

Technical Field

[0001] This invention relates to the field of powder-liquid mixers, and particularly to a powder-liquid mixer and its method. Background Technology

[0002] In the process of oil and gas field development, fracturing is the most common way to increase production. Every year, oil fields increase their oil production by about three percent of the total output using this method.

[0003] In this process, the quality of fracturing fluid preparation is a crucial factor in ensuring the success of fracturing operations. Fracturing fluid is mainly composed of a mixture of guar gum powder and base fluid in a certain proportion, and the viscosity and uniformity of the mixture are the main criteria for judging the quality of fracturing fluid.

[0004] Traditional fracturing fluid preparation typically involves adding guar gum powder and base fluid to a mixing tank. The powder-liquid mixer mainly consists of a base fluid delivery pipe, a powder extraction pipe, a powder-liquid mixing pipe, and a mixing chamber. The base fluid flows into the mixing chamber through the delivery pipe, while the guar gum powder is extracted into the mixing chamber through the extraction pipe. At this point, the guar gum powder and base fluid are thoroughly mixed, forming a powder-liquid mixture which is then discharged. The fracturing fluid is then allowed to fully swell and reach the required viscosity before fracturing operations are performed. However, this method of fracturing fluid preparation has the following problems:

[0005] 1. The fracturing fluid contains unevenly dispersed fracturing powder with a large number of powder clumps;

[0006] 2. The preparation time is relatively long, which affects the efficiency of fracturing operations;

[0007] 3. The viscosity of fracturing fluid decreases during storage and transportation.

[0008] To address the shortcomings of traditional fracturing fluid mixing processes, it is necessary to propose a powder-liquid mixer and its method to solve the aforementioned problems. Summary of the Invention

[0009] The purpose of this invention is to provide a powder-liquid mixer and method to solve the problems of uneven dispersion of adhesive powder in fracturing fluid, large amount of powder clumps, long preparation time, which affect the efficiency of fracturing operations and the decrease in viscosity of fracturing fluid during storage and transportation.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a powder-liquid mixer, comprising a first mixing pipe, a second mixing pipe, and a third mixing pipe, wherein the first mixing pipe, the second mixing pipe, and the third mixing pipe are sequentially connected, and flange fixing plates are fixedly welded to both ends of the first mixing pipe, the second mixing pipe, and the third mixing pipe, and adjacent flange fixing plates are fixed together by bolts. A first inlet is provided at the end of the first mixing pipe away from the second mixing pipe, for preparing base liquid and guar gum powder. The base liquid and guar gum powder can be stored in a tank. A material pump is used to transport the base liquid and guar gum powder to the first mixing pipe, and the material pump transports the base liquid from the first inlet to the first mixing pipe. In the material pipeline, the third mixing pipeline has an outlet at its end furthest from the second mixing pipeline. The upper end of the first mixing pipeline has a threaded hole into which an inlet pipe is installed. The upper end of the inlet pipe is a second inlet. A material pump delivers guar gum powder from the second inlet into the first mixing pipeline. An internal material pipeline is located inside the first mixing pipeline. The upper end of the internal material pipeline is connected to the lower end of the inlet pipe. End sealing caps and an internal outlet pipe are connected to both ends of the internal material pipeline along its length. The internal outlet pipe is rotatably mounted at the end of the internal material pipeline and is equipped with... The powder outlet holes are arranged to penetrate both the inner and outer rings of the internal discharge pipe. Multiple powder outlet holes are provided and evenly distributed. A conical material pipe is integrally formed at the end of the internal discharge pipe furthest from the internal material pipe, and a cylindrical material pipe is integrally formed at the end of the conical material pipe furthest from the internal discharge pipe. The conical material pipe has a conical shell structure, and the diameter of the end of the conical material pipe closest to the internal discharge pipe is larger than the diameter of the end of the conical material pipe closest to the cylindrical material pipe. After the base liquid enters the first mixing pipe, it continues to flow into the first mixing chamber. Because the flow rate in the first mixing chamber is less than that in the first mixing pipe... The flow rate near the first inlet is high, so the base liquid is compressed and the flow rate increases. After the guar gum powder enters the internal material pipeline from the second inlet, it continues to enter the internal discharge pipeline. After passing through the powder outlet on the internal discharge pipeline, the guar gum powder is discharged into the first mixing chamber. In the first mixing chamber, the guar gum powder and the compressed base liquid are mixed. The mixing during compression makes the guar gum powder and the base liquid more thoroughly mixed. After the guar gum powder is discharged from the powder outlet, a portion of guar gum powder remains in the internal discharge pipeline. The other portion of guar gum powder will be discharged sequentially through the conical material pipeline and the cylindrical material pipeline, and then mixed with the primary mixture in the second mixing pipeline for a second mixing.

[0011] This invention is based on an internal material pipe 11 installed inside the first mixing pipe 1. From a structural perspective, it optimizes the uniform mixing of the powder-liquid mixer. In actual research and development, ICEM-CFD software was used to mesh the established flow channel model, and FLUENT software was used to numerically simulate the mixing process of the solid and liquid phases in the mixer. When the base liquid passes through the first mixing chamber, it draws out the adhesive powder, causing a sudden change in the flow field. To ensure the accuracy of parameters such as velocity and content of each phase, the Euler multiphase flow model is selected. Simultaneously, considering factors such as vortices, rotation, and viscosity, the standard k-ε model from the eddy viscosity model is adopted for the turbulence model.

[0012] For example, in the standard k-ε model, the continuity equation and momentum equation can be expressed as:

[0013] Continuity equation:

[0014]

[0015] Momentum equation:

[0016]

[0017]

[0018]

[0019]

[0020]

[0021] In the formula,

[0022] μ eff —Effective viscosity

[0023] μ eff =μ+μ t

[0024] μ—molecular viscosity;

[0025] μ t — Turbulent viscosity.

[0026] Applying the standard k-ε model to close the governing equations, the basic equations are:

[0027]

[0028]

[0029] In the formula, G k It is the term that generates turbulent kinetic energy k due to the average velocity gradient.

[0030]

[0031] In the above formula,

[0032] C 1ε =1.44,C 2ε =1.92,σ k =1.0,

[0033] ε k =1.3

[0034] To more accurately calculate parameters such as velocity and volume fraction of the solid and liquid phases, when selecting the more accurate Euler multiphase flow model, the flow control equations are solved using the finite difference method, with the discretization scheme being a second-order upwind difference scheme. The pressure field and velocity field are coupled using the SIMPLE algorithm in the FLUENT solver in combination with the multigrid method.

[0035] Preferably, the end of the end sealing cap is threadedly connected to the end of the internal material pipe, and the end of the end sealing cap away from the internal material pipe has an arc-shaped protrusion structure; the arc-shaped protrusion structure facilitates the entry of the base liquid into the first mixing chamber and is easy to disassemble and clean.

[0036] Preferably, the outer diameter of the internal discharge pipe is smaller than the inner diameter of the first mixing pipe, and a first mixing chamber is formed between the outer ring of the internal discharge pipe and the inner ring of the first mixing pipe.

[0037] Preferably, a fan blade is fixedly installed on the outer ring of the internal discharge pipe. Multiple fan blades are provided and are distributed at equal angles along the axis of the internal discharge pipe. When the base liquid passes through the outer ring of the internal discharge pipe, it will push the fan blades, thereby driving the internal discharge pipe to rotate. During the rotation of the internal discharge pipe, the fan blades will stir the guar gum powder and the base liquid, thereby increasing the degree of mixing between the guar gum powder and the base liquid.

[0038] Preferably, a base plate is fixedly installed on the inner ring of the inner discharge pipe near the inner material pipe, and a support shaft is rotatably installed in the middle of the base plate. Two limit nuts are connected to the support shaft by threaded engagement, and the two limit nuts are respectively movably attached to the two sides of the base plate. The end of the support shaft away from the inner discharge pipe is connected to the end sealing cover by threaded engagement.

[0039] Preferably, the substrate is provided with through holes that penetrate both sides of the substrate. Multiple through holes are provided and arranged in a circular array. When the guar gum powder enters the internal discharge pipe through the internal material pipe, it will pass through the through holes. Since the substrate is rotatably mounted on the support shaft and is fixed at the inner circle of the internal discharge pipe, the internal discharge pipe can rotate relative to the end of the internal material pipe.

[0040] Preferably, a stirring plate is fixedly installed on the outer ring of the cylindrical material pipe. Multiple stirring plates are arranged at equal angles along the axis of the cylindrical material pipe. Each stirring plate has multiple mixing compression holes, which are evenly spaced. Each mixing compression hole includes an inlet / outlet hole and an internal hole. Two inlet / outlet holes are provided, connected to both ends of the internal hole. The diameter of the internal hole is smaller than the diameter of the inlet / outlet holes. The ends of the two inlet / outlet holes furthest from the internal hole penetrate both sides of the stirring plate. The secondary mixture enters the internal hole through the inlet / outlet holes and is discharged through the inlet / outlet holes at the other end of the internal hole, achieving compression followed by release. This facilitates thorough mixing of the base liquid and guar gum powder in the secondary mixture, reducing the likelihood of uneven dispersion of guar gum powder and the presence of large powder clumps.

[0041] Preferably, a third inlet is provided at the upper end of the second mixing pipe. A first connecting pipe is threadedly connected to the third inlet. A flexible hose is fixedly provided at the end of the first connecting pipe away from the third inlet. A pump body is provided at the end of the flexible hose away from the first connecting pipe. A second connecting pipe is provided on the pump body and connected to a tank storing guar gum powder. When the pump body is started, the guar gum powder is discharged sequentially through the flexible hose, the first connecting pipe, and the third inlet into the outer ring of the cylindrical material pipe. When the guar gum powder is discharged into the outer ring of the cylindrical material pipe, it mixes with the primary mixture to form a secondary mixture. When the guar gum powder and the base liquid are mixed for the second time, the mixture pushes the stirring plate to rotate, thereby using the stirring plate to fully stir the mixture. The second discharge of guar gum powder from the third inlet can increase the pressure in the pipe, allowing the mixture to pass through the second and third mixing pipes more quickly, reducing the preparation time, improving the fracturing operation efficiency, and avoiding the phenomenon that the mixture degree is reduced due to insufficient pressure after entering the second and third mixing pipes.

[0042] Furthermore, the powder-liquid mixture in this invention is prepared and used on-site, avoiding the phenomenon of viscosity reduction of fracturing fluid during storage and transportation.

[0043] Preferably, an expansion channel is provided at the inner ring of the third mixing pipe, with a small opening at the end of the expansion channel facing the second mixing pipe and a large opening at the end of the expansion channel away from the second mixing pipe.

[0044] The present invention also discloses a powder-liquid mixing method, including any of the powder-liquid mixers described above, and further including the following steps:

[0045] S1: First mixing: Prepare base liquid and guar gum powder. The base liquid is fed into the first mixing pipe from the first inlet. The base liquid inside the first mixing pipe is squeezed into the first mixing chamber. The guar gum powder is fed into the internal discharge pipe from the second inlet. The guar gum powder diffuses into the first mixing chamber through the powder outlet and mixes with the base liquid for the first time to obtain a first mixture.

[0046] S2: Second mixing. After the guar gum powder and base liquid in the first mixing chamber are mixed for the first time, they flow into the space between the outer ring of the cylindrical material pipe and the inner ring of the second mixing pipe for a second mixing. When the pump is started, the base liquid is injected into the interior of the second mixing pipe for the second time. After the base liquid is injected for the second time, the base liquid pushes the stirring plate to rotate, which causes the cylindrical material pipe, the conical material pipe and the internal discharge pipe to rotate. The guar gum powder and base liquid are fully mixed for the second time after being stirred by the stirring plate, forming a secondary mixture.

[0047] S3: After the secondary mixture is mixed between the outer ring of the cylindrical material pipe and the inner ring of the second mixing pipe, it is discharged into the interior of the third mixing pipe. After passing through the expansion channel, it is discharged from the outlet. As the opening of the expansion channel gradually increases from the end closest to the second mixing pipe to the end furthest from the second mixing pipe, the compressed secondary mixture is gradually released when passing through the expansion channel, thereby allowing the guar gum powder and base liquid in the secondary mixture to better interact and mix, forming a powder-liquid mixture.

[0048] The technical effects and advantages of this invention are as follows:

[0049] To address the issues of uneven dispersion of guar gum powder in fracturing fluid, resulting in large amounts of powder clumps, long preparation times, reduced fracturing efficiency, and decreased viscosity of fracturing fluid during storage and transportation, an internal material pipeline is installed inside the first mixing pipeline. After the base fluid enters the first mixing pipeline, it continues to flow into the first mixing chamber. Because the flow rate in the first mixing chamber is less than that at the end of the first mixing pipeline near the first inlet, the base fluid is compressed and its flow rate increases. Meanwhile, the guar gum powder, after entering the internal material pipeline from the second inlet, continues into the internal discharge pipeline. After passing through the powder outlet on the internal discharge pipeline, the guar gum powder is discharged into the first mixing chamber. The guar gum powder in the first mixing chamber mixes with the compressed base fluid. This mixing during compression ensures a more thorough mixing of the guar gum powder and the base fluid.

[0050] The base liquid pushes the fan blades at the outer ring of the internal discharge pipe, thereby driving the internal discharge pipe to rotate. During the rotation of the internal discharge pipe, the fan blades will stir the guar gum powder and the base liquid, thereby increasing the degree of mixing between the guar gum powder and the base liquid.

[0051] When the pump is started, guar gum powder is sequentially discharged into the outer ring of the cylindrical material pipe through the hose, the first connecting pipe, and the third inlet. When the guar gum powder is discharged into the outer ring of the cylindrical material pipe, it mixes with the primary mixture to form a secondary mixture. When the guar gum powder and the base liquid are mixed for the second time, the mixture pushes the stirring plate to rotate, thereby making the mixture fully stirred by the stirring plate. The second discharge of guar gum powder from the third inlet can increase the pressure in the pipeline, so that the mixture passes through the second and third mixing pipes faster, reducing the preparation time, improving the fracturing operation efficiency, and avoiding the phenomenon that the mixing degree is reduced due to insufficient pressure after the mixture enters the second and third mixing pipes.

[0052] In this invention, the powder-liquid mixture is prepared on-site for use, thus avoiding the phenomenon of viscosity reduction of fracturing fluid during storage and transportation;

[0053] The secondary mixture enters the interior of the internal hole through the inlet and outlet holes and then exits through the inlet and outlet holes at the other end of the internal hole. This compression and release operation is beneficial to the full mixing of the base liquid and guar gum powder in the secondary mixture, and it is less likely to cause uneven dispersion of guar gum powder or large powder clumps.

[0054] After being mixed between the outer ring of the cylindrical material pipe and the inner ring of the second mixing pipe, the secondary mixture is discharged into the interior of the third mixing pipe. After passing through the expansion channel, it is discharged from the outlet. As the opening of the expansion channel gradually increases from the end closest to the second mixing pipe to the end furthest from the second mixing pipe, the compressed secondary mixture is gradually released as it passes through the expansion channel, thereby allowing the guar gum powder and base liquid in the secondary mixture to better interact and mix, forming a powder-liquid mixture. Attached Figure Description

[0055] Figure 1 This is a schematic diagram of the powder-liquid mixer of the present invention from one perspective.

[0056] Figure 2 This is a schematic diagram of the powder-liquid mixer of the present invention from another perspective.

[0057] Figure 3 This is a cross-sectional view of the powder-liquid mixer of the present invention.

[0058] Figure 4 This is a schematic diagram of the connection between the first mixing pipe and the second mixing pipe of the present invention.

[0059] Figure 5 This is a schematic diagram of the mixing and compression hole structure of the present invention.

[0060] Figure 6 For the present invention Figure 4 Enlarged schematic diagram of the structure at point A in the middle.

[0061] In the diagram: 1. First mixing pipe; 2. Second mixing pipe; 3. Third mixing pipe; 4. First inlet; 5. Outlet; 6. Second inlet; 7. Flange fixing plate; 8. Third inlet; 9. Threaded hole; 10. Feed pipe; 11. Internal material pipe; 12. Internal outlet pipe; 13. End sealing cap; 14. Conical material pipe; 15. Cylindrical material pipe; 16. Mixing plate; 17. Powder outlet; 18. Expansion channel; 19. First connecting pipe; 20. Hose; 21. Pump body; 22. Second connecting pipe; 23. Mixing compression hole; 24. Inlet / outlet hole; 25. Internal hole; 26. Fan blade; 27. Support shaft; 28. Through hole; 29. ​​Base plate; 30. Limiting nut. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] This invention provides, for example Figures 1-6 The powder-liquid mixer shown includes a first mixing pipe 1, a second mixing pipe 2, and a third mixing pipe 3, which are connected sequentially. Flange fixing plates 7 are fixedly welded to both ends of the first mixing pipe 1, the second mixing pipe 2, and the third mixing pipe 3. Adjacent flange fixing plates 7 are fixed together by bolts. The first mixing pipe 1, the second mixing pipe 2, and the third mixing pipe 3 are easy to disassemble and maintain.

[0064] Prepare the base liquid and guar gum powder. The base liquid and guar gum powder can be stored in a tank. Use a material pump to transport the base liquid and guar gum powder to the first mixing pipe 1. The first mixing pipe 1 is provided with a first inlet 4 at the end away from the second mixing pipe 2. The material pump transports the base liquid from the first inlet 4 into the first mixing pipe 1. The third mixing pipe 3 is provided with an outlet 5 at the end away from the second mixing pipe 2. The upper end of the first mixing pipe 1 is provided with a threaded hole 9. A feed pipe 10 is installed in the threaded hole 9. The upper end of the feed pipe 10 is the second inlet 6. The material pump transports the guar gum powder from the second inlet 6 into the interior of the first mixing pipe 1.

[0065] To address the issues of uneven dispersion of the fracturing fluid's binder powder, resulting in large powder clumps, prolonged preparation time, reduced fracturing efficiency, and decreased viscosity of the fracturing fluid during storage and transportation, an internal material pipe 11 is installed inside the first mixing pipe 1. The upper end of the internal material pipe 11 is connected to the lower end of the feed pipe 10. End sealing caps 13 and internal discharge pipes 12 are connected to both ends of the internal material pipe 11 along its length. The internal discharge pipe 12 is rotatably mounted at the end of the internal material pipe 11, and its outer diameter is smaller than the inner diameter of the first mixing pipe 1. A first mixing chamber is formed between the outer ring of the material pipe 12 and the inner ring of the first mixing pipe 1. The internal discharge pipe 12 is provided with powder outlet holes 17, which penetrate both the inner and outer rings of the internal discharge pipe 12. Multiple powder outlet holes 17 are provided and are evenly distributed. A conical material pipe 14 is integrally provided at the end of the internal discharge pipe 12 away from the internal material pipe 11. A cylindrical material pipe 15 is integrally provided at the end of the conical material pipe 14 away from the internal discharge pipe 12. Multiple stirring plates 16 are fixedly provided at the outer ring of the cylindrical material pipe 15. Multiple mixing plates 16 are distributed at equal angles along the axis of the cylindrical material pipe 15. The conical material pipe 14 has a conical shell structure. The diameter of the end of the conical material pipe 14 near the internal discharge pipe 12 is larger than the diameter of the end of the conical material pipe 14 near the cylindrical material pipe 15. After the base liquid enters the first mixing pipe 1, it continues to flow into the first mixing chamber. Since the flow rate of the first mixing chamber is less than the flow rate of the end of the first mixing pipe 1 near the first inlet 4, the base liquid is compressed and the flow rate increases. Meanwhile, the guar gum powder enters the internal material pipe 11 from the second inlet 6 and... Continuing into the internal discharge pipe 12, the guar gum powder is discharged into the first mixing chamber after passing through the powder outlet 17 on the internal discharge pipe 12. The guar gum powder in the first mixing chamber mixes with the compressed base liquid. This mixing during compression ensures a more thorough mixing of the guar gum powder and base liquid. This invention is based on an internal material pipe 11 located inside the first mixing pipe 1, optimizing the uniform mixing of the powder-liquid mixer from a structural perspective. In actual research and development, ICEM-CFD software was used to mesh the established flow channel model, and FLUENT software was used to numerically simulate the mixing process of the solid and liquid phases in the mixer. When the base liquid passes through the first mixing chamber, it draws out the guar gum powder, causing a sudden change in the flow field. To ensure the accuracy of parameters such as velocity and content of each phase, the Euler multiphase flow model is selected. Simultaneously, considering factors such as vortices, rotation, and viscosity, the standard k-ε model from the eddy viscosity model is adopted for the turbulence model.

[0066] For example, in the standard k-ε model, the continuity equation and momentum equation can be expressed as:

[0067] Continuity equation:

[0068]

[0069] Momentum equation:

[0070]

[0071]

[0072]

[0073]

[0074]

[0075] In the formula,

[0076] μ eff —Effective viscosity

[0077] μ eff =μ+μ t

[0078] μ—molecular viscosity;

[0079] μ t — Turbulent viscosity.

[0080] Applying the standard k-ε model to close the governing equations, the basic equations are:

[0081]

[0082]

[0083] In the formula, G k It is the term that generates turbulent kinetic energy k due to the average velocity gradient.

[0084]

[0085] In the above formula,

[0086] C 1ε =1.44,C 2ε =1.92,σ k =1.0,

[0087] ε k =1.3

[0088] To more accurately calculate parameters such as velocity and volume fraction of the solid and liquid phases, when selecting the more accurate Euler multiphase flow model, the flow control equations are solved using the finite difference method, with the discretization scheme being a second-order upwind difference scheme. The pressure field and velocity field are coupled using the SIMPLE algorithm in the FLUENT solver in combination with the multigrid method.

[0089] It should be noted that when the base liquid flows through the first mixing chamber, it will generate a certain suction force due to compression and acceleration, thereby better drawing the guar gum powder from the powder outlet 17 into the first mixing chamber. Since there are multiple powder outlets 17 and they are arranged in a ring array, the guar gum powder is sprayed out in a ring, which mixes more thoroughly with the base liquid.

[0090] Furthermore, a fan blade 26 is fixedly installed on the outer ring of the internal discharge pipe 12. Multiple fan blades 26 are provided and are distributed at equal angles along the axis of the internal discharge pipe 12. When the base liquid passes through the outer ring of the internal discharge pipe 12, it will push the fan blades 26, thereby driving the internal discharge pipe 12 to rotate. During the rotation of the internal discharge pipe 12, the fan blades 26 will be used to stir the guar gum powder and the base liquid, thereby increasing the degree of mixing of the guar gum powder and the base liquid.

[0091] After the guar gum powder is discharged from the powder outlet 17, a portion of the guar gum powder remains in the internal discharge pipe 12. The other portion of the guar gum powder will be discharged sequentially through the conical material pipe 14 and the cylindrical material pipe 15, and then mixed with the primary mixing liquid inside the second mixing pipe 2 before undergoing a second mixing.

[0092] The upper end of the second mixing pipe 2 is provided with a third inlet 8. A first connecting pipe 19 is connected to the third inlet 8 by a threaded connection. A hose 20 is fixedly installed at the end of the first connecting pipe 19 away from the third inlet 8. A pump body 21 is installed at the end of the hose 20 away from the first connecting pipe 19. A second connecting pipe 22 is installed on the pump body 21. The second connecting pipe 22 is connected to the tank storing guar gum powder. When the pump body 21 is started, the guar gum powder will be discharged sequentially through the hose 20, the first connecting pipe 19 and the third inlet 8 into the outer ring of the cylindrical material pipe 15. When the guar gum powder is discharged... When the guar gum powder enters the outer ring of the cylindrical material pipe 15, it is mixed with the primary mixture to form a secondary mixture. During the second mixing of the guar gum powder and the base liquid, the mixture pushes the stirring plate 16 to rotate, thereby making the mixture fully stirred by the stirring plate 16. The second discharge of guar gum powder from the third feed port 8 can increase the pressure in the pipeline, so that the mixture passes through the second mixing pipe 2 and the third mixing pipe 3 at a faster speed, reducing the preparation time, improving the fracturing operation efficiency, and avoiding the phenomenon that the mixture degree is reduced due to insufficient pressure after entering the second mixing pipe 2 and the third mixing pipe 3.

[0093] Furthermore, the powder-liquid mixture in this invention is prepared and used on-site, avoiding the phenomenon of viscosity reduction of fracturing fluid during storage and transportation.

[0094] Furthermore, the mixing plate 16 is provided with multiple mixing compression holes 23, which are evenly distributed. Each mixing compression hole 23 includes an inlet / outlet hole 24 and an internal hole 25. There are two inlet / outlet holes 24, which are connected to the two ends of the internal hole 25. The diameter of the internal hole 25 is smaller than the diameter of the inlet / outlet hole 24. The ends of the two inlet / outlet holes 24 that are away from the internal hole 25 penetrate through the two sides of the mixing plate 16. The secondary mixture will enter the interior of the internal hole 25 through the inlet / outlet hole 24 and then be discharged through the inlet / outlet hole 24 at the other end of the internal hole 25. This operation of compression and release is beneficial to the full mixing of the base liquid and guar gum powder in the secondary mixture, and it is less likely to cause uneven dispersion of guar gum powder or large powder clumps.

[0095] The end of the end sealing cap 13 is connected to the end of the internal material pipe 11 by a threaded connection. The end of the end sealing cap 13 away from the internal material pipe 11 has an arc-shaped protrusion structure. The arc-shaped protrusion structure facilitates the entry of the base liquid into the first mixing chamber and is easy to disassemble and clean.

[0096] A base plate 29 is fixedly installed on the inner ring of one end of the internal discharge pipe 12 near the internal material pipe 11. The base plate 29 is provided with through holes 28, which pass through both sides of the base plate 29. Multiple through holes 28 are provided and are arranged in a circular array. A support shaft 27 is rotatably installed in the middle of the base plate 29. Two limit nuts 30 are connected to the support shaft 27 by threaded engagement. The two limit nuts 30 are respectively movably attached to the two sides of the base plate 29. The end of the support shaft 27 away from the internal discharge pipe 12 is connected to the end sealing cap 13 by threaded engagement. When the guar gum powder enters the internal discharge pipe 12 through the internal material pipe 11, it will pass through the through holes 28. Since the base plate 29 is rotatably installed on the support shaft 27 and the base plate 29 is fixed in the inner ring of the internal discharge pipe 12, the internal discharge pipe 12 can rotate relative to the end of the internal material pipe 11.

[0097] An expansion channel 18 is provided at the inner ring of the third mixing pipe 3. The end of the expansion channel 18 facing the second mixing pipe 2 has a small opening, and the end of the expansion channel 18 away from the second mixing pipe 2 has a large opening.

[0098] The present invention also discloses a powder-liquid mixing method, including any of the powder-liquid mixers described above, and further including the following steps:

[0099] S1: First mixing: Prepare base liquid and guar gum powder. The base liquid is fed into the first mixing pipe 1 from the first inlet 4. The base liquid inside the first mixing pipe 1 is squeezed into the first mixing chamber. The guar gum powder is fed into the internal discharge pipe 12 from the second inlet 6. The guar gum powder diffuses into the first mixing chamber through the powder outlet 17 and mixes with the base liquid for the first time to obtain a first mixture.

[0100] S2: Second mixing. After the guar gum powder and base liquid in the first mixing chamber are mixed for the first time, they flow into the space between the outer ring of the cylindrical material pipe 15 and the inner ring of the second mixing pipe 2 for a second mixing. When the pump body 21 is started, the base liquid is injected into the interior of the second mixing pipe 2 for the second time. After the base liquid is injected for the second time, the base liquid pushes the stirring plate 16 to rotate, so that the cylindrical material pipe 15, the conical material pipe 14 and the internal discharge pipe 12 rotate. The guar gum powder and base liquid are fully mixed for the second time after being stirred by the stirring plate 16, forming a secondary mixture.

[0101] S3: The secondary mixture is mixed between the outer ring of the cylindrical material pipe 15 and the inner ring of the second mixing pipe 2 and then discharged into the interior of the third mixing pipe 3. After passing through the expansion channel 18, it is discharged from the outlet 5. As the opening of the expansion channel 18 gradually increases from the end closest to the second mixing pipe 2 to the end furthest from the second mixing pipe 2, the compressed secondary mixture is gradually released when passing through the expansion channel 18, thereby allowing the guar gum powder and the base liquid in the secondary mixture to better interact and mix, forming a powder-liquid mixture.

[0102] It should be noted that when an element is referred to as "set on" or "provided with" another element, it can be directly on the other element or there may be an intermediate element. When an element is referred to as "connected to" or "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. "Fixed connection" means fixed connection. There are many ways of fixed connection, which are not within the scope of protection of this document. The terms "vertical", "horizontal", "left", "right" and similar expressions used in this document are only for illustrative purposes and do not represent the only implementation method.

[0103] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in the specification herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0104] This is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A powder-liquid mixer, characterized in that: The system includes a first mixing pipe (1), a second mixing pipe (2), and a third mixing pipe (3), characterized in that: the first mixing pipe (1), the second mixing pipe (2), and the third mixing pipe (3) are sequentially connected; both ends of the first mixing pipe (1), the second mixing pipe (2), and the third mixing pipe (3) are fixedly welded with flange fixing plates (7); adjacent flange fixing plates (7) are fixed together by bolts; a first inlet (4) is provided at the end of the first mixing pipe (1) away from the second mixing pipe (2); an outlet (5) is provided at the end of the third mixing pipe (3) away from the second mixing pipe (2); and a threaded hole (9) is provided at the upper end of the first mixing pipe (1). The threaded hole (9) is equipped with a feed pipe (10), the upper end of which is a second feed port (6). The first mixing pipe (1) is provided with an internal material pipe (11), the upper end of which is connected to the lower end of the feed pipe (10). The internal material pipe (11) is connected to an end sealing cap (13) and an internal discharge pipe (12) at both ends along the length of the first mixing pipe (1). The internal discharge pipe (12) is rotatably disposed at the end of the internal material pipe (11). The internal discharge pipe (12) is provided with a powder outlet (17), which simultaneously penetrates the internal discharge pipe (11). 2) The inner and outer rings are arranged, and multiple powder outlet holes (17) are arranged. The multiple powder outlet holes (17) are distributed at equal distances. A conical material pipe (14) is integrally arranged at the end of the inner discharge pipe (12) away from the inner material pipe (11). A cylindrical material pipe (15) is integrally arranged at the end of the conical material pipe (14) away from the inner discharge pipe (12). The conical material pipe (14) has a conical shell structure. The diameter of the end of the conical material pipe (14) near the inner discharge pipe (12) is larger than the diameter of the end of the conical material pipe (14) near the cylindrical material pipe (15). A stirring plate is fixedly arranged at the outer ring of the cylindrical material pipe (15). 16), the stirring plate (16) is provided in multiple ways, and the multiple stirring plates (16) are distributed at equal angles along the axis of the cylindrical material pipe (15). The stirring plate (16) is provided with mixing compression holes (23). The multiple mixing compression holes (23) are provided in multiple ways, and the multiple mixing compression holes (23) are distributed at equal distances. The mixing compression hole (23) includes an inlet and outlet hole (24) and an internal hole (25). There are two inlet and outlet holes (24). The two inlet and outlet holes (24) are connected to the two ends of the internal hole (25). The diameter of the internal hole (25) is smaller than the diameter of the inlet and outlet hole (24). The ends of the two inlet and outlet holes (24) away from the internal hole (25) respectively penetrate through the two sides of the stirring plate (16).The upper end of the second mixing pipe (2) is provided with a third inlet (8), and a first connecting pipe (19) is connected to the third inlet (8) by a threaded connection. A hose (20) is fixedly provided at the end of the first connecting pipe (19) away from the third inlet (8). A pump body (21) is provided at the end of the hose (20) away from the first connecting pipe (19). A second connecting pipe (22) is provided on the pump body (21). A fan blade (26) is fixedly provided at the outer ring of the internal discharge pipe (12). Multiple fan blades (26) are provided, and the multiple fan blades (26) are distributed at equal angles along the axis of the internal discharge pipe (12). An expansion channel (18) is provided at the inner ring of the third mixing pipe (3). The expansion channel (18) has a small opening at the end facing the second mixing pipe (2) and a large opening at the end away from the second mixing pipe (2).

2. The powder-liquid mixer according to claim 1, characterized in that: The end of the end sealing cap (13) is connected to the end of the internal material pipe (11) by a threaded connection, and the end of the end sealing cap (13) away from the internal material pipe (11) has an arc-shaped protrusion structure.

3. The powder-liquid mixer according to claim 1, characterized in that: The outer diameter of the internal discharge pipe (12) is smaller than the inner diameter of the first mixing pipe (1), and a first mixing chamber is formed between the outer ring of the internal discharge pipe (12) and the inner ring of the first mixing pipe (1).

4. The powder-liquid mixer according to claim 1, characterized in that: A base plate (29) is fixedly installed at the inner ring of one end of the internal discharge pipe (12) near the internal material pipe (11). A support shaft (27) is rotatably installed in the middle of the base plate (29). Two limit nuts (30) are connected to the support shaft (27) by threaded engagement. The two limit nuts (30) are respectively movably attached to the two sides of the base plate (29). The end of the support shaft (27) away from the internal discharge pipe (12) is connected to the end sealing cover (13) by threaded engagement.

5. A powder-liquid mixer according to claim 4, characterized in that: The substrate (29) is provided with through holes (28), which simultaneously penetrate both sides of the substrate (29). Multiple through holes (28) are provided and are distributed in a circular array.

6. A method for mixing powder and liquid, characterized in that: The application of the powder-liquid mixer according to any one of claims 1-5 further includes the following steps: S1: First mixing, prepare base liquid and guar gum powder. The base liquid is transported from the first inlet (4) into the interior of the first mixing pipe (1). The outer ring of the inner outlet pipe (12) and the inner ring of the first mixing pipe (1) form the first mixing chamber. The base liquid inside the first mixing pipe (1) is squeezed into the first mixing chamber. The guar gum powder is transported from the second inlet (6) into the interior of the inner outlet pipe (12). The guar gum powder diffuses into the first mixing chamber through the powder outlet (17) and mixes with the base liquid for the first time to obtain a first mixed liquid. S2: Second mixing. After the first mixing of guar gum powder and base liquid in the first mixing chamber, they flow into the outer ring of the cylindrical material pipe (15) and the inner ring of the second mixing pipe (2) for a second mixing. When the pump body (21) is started, the base liquid is injected into the interior of the second mixing pipe (2) for a second time. After the base liquid is injected for the second time, the base liquid pushes the stirring plate (16) to rotate, so that the cylindrical material pipe (15), the conical material pipe (14) and the internal discharge pipe (12) rotate. The first mixture of guar gum powder and base liquid is fully mixed for the second time after being stirred by the stirring plate (16) to form a second mixture. S3: The secondary mixture is mixed between the outer ring of the cylindrical material pipe (15) and the inner ring of the second mixing pipe (2) and then discharged into the interior of the third mixing pipe (3). After passing through the expansion channel (18), it is discharged from the outlet (5). As the opening of the expansion channel (18) gradually increases from the end closest to the second mixing pipe (2) to the end furthest from the second mixing pipe (2), the compressed secondary mixture will be gradually released when passing through the expansion channel (18), thereby allowing the guar gum powder and the base liquid in the secondary mixture to better interact and mix to form a powder liquid.

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