A fracturing fluid mixing device for underground coal mines

Abstract

The present invention relates to an underground coal mine fracturing fluid mixing device, which belongs to the technical field of coal mine hydraulic fracturing fluid mixing, and comprises a feeding system, a mixing box and a booster device for providing high-pressure water; the feeding system comprises a feeding hopper, a feeding port is provided on the top of the feeding hopper, and a discharge port connected to the mixing box inlet is provided at the bottom of the feeding hopper; the inlet of the booster device is a water inlet channel, and the outlet of the booster device is connected to a clean water branch pipe and a clean water inlet pipe, the clean water branch pipe is connected to the discharge port of the feeding system, and the clean water inlet pipe is connected to the mixing box inlet, so as to achieve mixing of the high-pressure water sprayed out through the clean water inlet pipe; the clean water branch pipe has two outlet branches, and the two outlet branches are respectively connected to the discharge port punching port and the discharge port drainage port arranged in an upper and lower manner, thereby reducing the blockage of the feeding port; the mixing box comprises four mixing boxes distributed in a rectangular array, and a diagonal flow mode is formed, which not only has a good mixing effect, but also makes the device structure more compact.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine hydraulic fracturing fluid mixing, and relates to a coal mine underground fracturing fluid mixing device. Background Art

[0002] With the development of long-hole directional drilling and staged hydraulic fracturing in coal mines, which aims to increase permeability over a wide range and achieve high flow rates, the use of sand in hydraulic fracturing has gradually become recognized as a promising method for achieving better results. Unlike the use of sand as a proppant in the oil industry, sand particles cannot directly support the coal seam due to the insufficient strength of the coal matrix. Instead, they form a mosaic with the coal matrix, creating gaps between the sand particles that provide pathways for gas flow, thus increasing the permeability of the coal seam and improving extraction efficiency. Because the high-viscosity mixing equipment used in the oil industry is too bulky to be directly introduced into the confined spaces of underground coal mine tunnels or drilling sites, the current sand-added fracturing fluid used is still plain water. Compared to surface wells, long-hole directional drilling in coal mines often utilizes upward drilling. During the upward flow of the sand fluid, sand particles are easily deposited, leading to blockage of the fracturing string or high-pressure hose, sand addition failure, or poor results. Therefore, there is an urgent need to develop a high-viscosity mixing device suitable for sand-added fracturing in coal mines, which can provide better sand-carrying capacity and enhance fracturing effectiveness. Summary of the Invention

[0003] In view of this, the purpose of the present application is to provide a coal mine underground fracturing fluid mixing device to achieve the mixing of sand-added fracturing fluid.

[0004] In order to achieve the above object, the present invention provides the following technical solutions:

[0005] A coal mine underground fracturing fluid mixing device includes a feeding system, a mixing box and a booster device for providing high-pressure water; the feeding system includes a feeding hopper, the top of the feeding hopper is provided with a feeding port, and the bottom of the feeding hopper is provided with a discharge port connected to the mixing box inlet; the inlet of the booster device is a water inlet channel, and the outlet of the booster device is connected to a clean water branch pipe and a clean water inlet pipe, the clean water branch pipe is connected to the discharge port of the feeding system, and the clean water inlet pipe is connected to the mixing box inlet.

[0006] Optionally, the mixing box includes a first mixing box, a second mixing box, a third mixing box, and a fourth mixing box arranged along the direction of fluid flow. The first mixing box achieves mixing through a high-pressure water flow sprayed from a clean water inlet pipe. The second mixing box, the third mixing box, and the fourth mixing box are provided with a stirring rod with a stirring blade to achieve mixing through stirring of the stirring rod.

[0007] Optionally, the first mixing box, the second mixing box, the third mixing box and the fourth mixing box are distributed in a rectangular array and have a rectangular cross-section. The top of the first mixing box is provided with a first exchange port connected to the second mixing box, the bottom of the second mixing box is provided with a second exchange port connected to the third mixing box, the top of the third mixing box is provided with a third exchange port connected to the fourth mixing box, and the bottom of the fourth mixing box is provided with a mixing box outlet. The first exchange port and the second exchange port, the second exchange port and the third exchange port, and the third exchange port and the mixing box outlet are all arranged diagonally to form a diagonal flow pattern.

[0008] Optionally, all stirring rods have independent drive devices, which are installed on the top of the mixing box.

[0009] Optionally, the discharge port is provided with a discharge port punching port and a discharge port drainage port arranged in an upper and lower manner, and the clean water branch pipe has two outlet branches, which are respectively connected to the discharge port punching port and the discharge port drainage port.

[0010] Optionally, the clean water inlet pipe and the clean water branch pipe are both provided with gate valves to adjust the flow rate.

[0011] Optionally, the boosting device is a centrifugal pump.

[0012] Optionally, a detachable hopper cover is provided on the top of the hopper.

[0013] Optionally, the hopper cover is connected to a water injection pipe to inject water into the hopper through the water injection pipe, and the water injection pipe is provided with a gate valve to control the on-off of the water injection pipe.

[0014] Optionally, the clean water branch pipe is divided into two outlet branches, a discharge port flushing pipe and a discharge port drainage pipe, near the discharge port of the feeding system. The discharge port flushing pipe and the discharge port drainage pipe are respectively connected to the discharge port flushing port and the discharge port drainage port.

[0015] Optionally, the discharge port punching port and the discharge port drainage port are respectively opened on the side wall and the bottom of the discharge port.

[0016] Optionally, the inlet of the mixing box is located at the top thereof, and is connected to the discharge port of the hopper through a liquid inlet pipe containing the feed liquid, and the outlet of the liquid inlet pipe containing the feed liquid and the outlet of the clean water inlet pipe are arranged up and down.

[0017] The beneficial effects of the present invention are:

[0018] 1. The clean water branch pipe of the present invention is a high-pressure pipeline and has two outlet branches, which are respectively connected to the discharge port punching port and the discharge port drainage port arranged in an upper and lower manner, which can reduce the blockage of the feeding port.

[0019] 2. The mixing box of the present invention adopts a multi-stage box structure. The four mixing boxes of the mixing box are distributed in a rectangular array, and a diagonal flow pattern is formed between them, which not only has a good mixing effect, but also makes the device structure more compact.

[0020] Other advantages, objects, and features of the present invention will be described in part in the following description and, in part, will be apparent to those skilled in the art upon examination of the following description or may be learned from practice of the present invention. The objects and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0022] Figure 1 This is a schematic diagram of the structure of a coal mine underground fracturing fluid mixing device of the present invention. Figure 1 ;

[0023] Figure 2 This is a schematic diagram of the structure of a coal mine underground fracturing fluid mixing device of the present invention. Figure 2 ;

[0024] Figure 3 This is a schematic diagram of the structure of a coal mine underground fracturing fluid mixing device of the present invention. Figure 3 .

[0025] Figure numerals: clean water inlet pipe gate valve 1, boosting device outlet 2, boosting device inlet 3, boosting device 4, ladder frame 5, motor 6, front end system frame 7, feeding hopper 8, feeding hopper cover 9, liquid inlet pipe 10, clean water inlet pipe 11, mixing box inlet 12, second mixing box motor 13, third mixing box motor 14, fourth mixing box motor 15, mixing box outlet 16, first mixing box 17, first exchange port 18, second mixing box stirring rod 19, second mixing box 20, second exchange port 21, third mixing box stirring rod 22, third mixing box 23, third exchange port 24, fourth mixing box stirring rod 25, fourth mixing box 26, clean water branch pipe gate valve 27, clean water branch pipe 28, discharge port flushing pipe 29, discharge port drainage pipe 30, discharge port 31. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention by means of specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present invention, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0027] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the dimensions of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0028] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0029] See Figures 1 to 3 A coal mine underground fracturing fluid mixing device, including a feeding system, a mixing box and a booster device 4 for providing high-pressure water; the booster device 4 is preferably a centrifugal pump; the feeding system includes a feeding hopper 8, the top of the feeding hopper 8 is provided with a feeding port, and the bottom of the feeding hopper 8 is provided with a discharge port 31 connected to the mixing box inlet 12; the inlet of the booster device is a water inlet channel, and the outlet 2 of the booster device is connected to a clean water branch pipe 28 and a clean water inlet pipe 11, the clean water branch pipe 28 is connected to the discharge port 31 of the feeding system, and the clean water inlet pipe 11 is connected to the mixing box inlet 12, so as to realize mixing with the high-pressure water sprayed through the clean water inlet pipe 11.

[0030] The mixing box can be a single box or a multi-stage box, preferably a multi-stage box. When a multi-stage box is used, a four-stage box is preferably used, including a first mixing box 17, a second mixing box 20, a third mixing box 23, and a fourth mixing box 26 arranged along the direction of fluid flow. The first mixing box 17 is mixed by a high-pressure water flow sprayed from the clean water inlet pipe 11. The second mixing box 20, the third mixing box 23, and the fourth mixing box 26 are equipped with stirring rods with stirring blades to achieve mixing. The stirring rods preferably have independent drive devices, which can be installed on the top of the mixing box and directly connected to the stirring rods.

[0031] The first, second, third, and fourth mixing boxes 17, 20, 23, and 26 have rectangular cross-sections. The four mixing boxes can be arranged linearly or in a rectangular array. The top of the first mixing box 17 is provided with a first exchange port 18 that connects to the second mixing box 20. The bottom of the second mixing box 20 is provided with a second exchange port 21 that connects to the third mixing box 23. The top of the third mixing box 23 is provided with a third exchange port 24 that connects to the fourth mixing box 26. The bottom of the fourth mixing box 26 is provided with a mixing box outlet 16. When arranged in a rectangular array, the first exchange port 18 and the second exchange port 21, the second exchange port 21 and the third exchange port 24, and the third exchange port 24 and the mixing box outlet 16 are all arranged diagonally to form a diagonal flow pattern, which facilitates mixing and provides a more compact structure. The first exchange port 18, the second exchange port 21, the third exchange port 24, and the mixing box outlet 16 can be rectangular or circular.

[0032] The mixing box inlet 12 is located at the top of the mixing box, and is connected to the discharge port 31 of the hopper 8 through the liquid inlet pipe 10, and the liquid inlet pipe outlet and the water inlet pipe outlet are arranged up and down. This arrangement is conducive to mixing.

[0033] To reduce clogging of the discharge port, the discharge port 31 of the present invention is provided with a discharge port flushing port and a discharge port drainage port arranged in an upper and lower arrangement. The clean water branch pipe 28 has two outlet branches, which are respectively connected to the discharge port flushing port and the discharge port drainage port. This arrangement can effectively reduce clogging of the feeding port.

[0034] The clean water branch pipe 28 should be divided into two outlet branches, namely the discharge port flushing pipe 29 and the discharge port drainage pipe 30, near the discharge port 31 of the feeding system. The discharge port flushing pipe 29 and the discharge port drainage pipe 30 are respectively connected to the discharge port flushing port and the discharge port drainage port; the discharge port flushing port and the discharge port drainage port should be respectively opened on the side wall and bottom of the discharge port 31.

[0035] The clean water inlet pipe 11 and the clean water branch pipe 28 are respectively provided with a clean water inlet pipe gate valve 1 and a clean water branch pipe gate valve 27 to adjust the flow.

[0036] The top of the hopper 8 is also equipped with a removable hopper cover 9, which is connected to a water injection pipe for injecting water into the hopper 8. The water injection pipe is equipped with a gate valve to control the opening and closing of the water injection pipe. When the material at the feeding port is difficult to add, normal pressure water or high pressure water can be introduced through the water injection pipe to form a mixed fluid to improve fluidity.

[0037] Example

[0038] A coal mine underground fracturing fluid mixing device, such as Figures 1 to 3 As shown, it includes a base plate, one end of the base plate is provided with a feeding system and a boosting device 4, and the other end is provided with a mixing box. The boosting device 4 is a centrifugal pump, which is located on the upper side of one end of the base plate, and includes a centrifugal pump body installed on the base plate and a motor 6 coaxially installed therewith to drive the centrifugal pump body to rotate. The feeding hopper 8 of the feeding system is located above the motor 6 and is installed on the base plate through a front end frame 7. A ladder 5 leading to the feeding hopper 8 is provided on the side of the feeding hopper 8 close to the centrifugal pump body. Clean water enters the boosting device 4 from the boosting device inlet 3 for pressurization and comes out from the boosting device outlet 2, and is divided into two tributaries. One tributary enters the mixing box inlet 12 through the mixing box clean water inlet pipe 11 and enters the mixing box. The other tributary enters the clean water branch pipe 28 and goes to the feeding system. The clean water branch pipe 28 is divided into a discharge outlet drainage pipe 30 and a discharge outlet flushing pipe 29 near the discharge port 31. The amount of water and water pressure entering the clean water branch pipe 28 are controlled by adjusting the opening and closing size of the clean water inlet pipe gate valve 1 of the mixing box and the clean water branch pipe gate valve 27, and then the material carrying and guiding capacity of the discharge outlet flushing pipe 29 and the discharge outlet drainage pipe 30 is controlled to achieve the adjustment of the amount of mixed material required to be added.

[0039] The feeding hopper 8 is used to store powdered or liquid materials. It has a feeding port at the top and a discharge port 31 at the bottom. The sides and bottom of the discharge port 31 are connected to the discharge port flushing pipe 29 and the discharge port drainage pipe 30, respectively. The discharge port flushing pipe 29 is responsible for flushing the material, and the discharge port drainage pipe 30 has the function of ejection and drainage. If the material in the feeding port is difficult to add, tap water is introduced from the water injection pipe installed on the feeding hopper cover 9 to form a mixed fluid, allowing it to flow more easily. The mixed liquid enters the mixing box inlet 12 through the mixing box liquid inlet pipe 10 and enters the mixing box together with the clean water.

[0040] The mixing box is in the shape of a rectangular parallelepiped and is divided into four mixing boxes, namely the first mixing box 17, the second mixing box 20, the third mixing box 23, and the fourth mixing box 26. Among them, the function of the first mixing box 17 is to achieve mixing through water pressure flow, and then enter the second mixing box 20, the third mixing box 23, and the fourth mixing box 26 in turn for step-by-step mixing, and is provided with a stirring rod (the stirring rod is provided with multiple stirring blades), and the stirring rod is driven by the respective mixing box motors on the top. Specifically, the second mixing box 20 is provided with a second mixing box stirring rod 19, and the second mixing box stirring rod 19 is driven to rotate by the second mixing box motor 13 located at the top thereof; the third mixing box 23 is provided with a third mixing box stirring rod 22, and the third mixing box stirring rod 22 is driven to rotate by the third mixing box motor 14 located at the top thereof; the fourth mixing box 26 is provided with a fourth mixing box stirring rod 25, and the fourth mixing box stirring rod 25 is driven to rotate by the fourth mixing box motor 15 located at the top thereof. The end cover located at the top of the mixing box is a sealing structure, Figure 2 Shown for cross-section only.

[0041] The mixed liquid in the first mixing box 17 flows into the second mixing box 20 through the first exchange port 18 at the top. The mixed liquid in the second mixing box 20 enters the third mixing box 23 through the second exchange port 21 at the bottom. The mixed liquid in the third mixing box 23 then flows into the fourth mixing box 26 through the third exchange port 24 at the top. The mixed liquid in the fourth mixing box 26 finally flows out through the bottom mixing box outlet 16. This diagonal flow pattern has a greater chance of passing through the stirring rod, resulting in a better stirring and mixing effect.

[0042] The invention adopts a closed continuous multi-stage rapid mixing system, which is simple to operate, small in size, and highly adaptable to underground coal mines, and is suitable for mixing mixed materials represented by guar gum powder with water.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should all be included in the scope of the claims of the present invention.

Claims

1. A coal mine underground fracturing fluid mixing device, characterized by: The invention comprises a feeding system, a mixing box and a booster device (4) for providing high-pressure water; the feeding system comprises a feeding hopper (8), the top of the feeding hopper (8) is provided with a feeding port, and the bottom of the feeding hopper (8) is provided with a discharge port (31) connected to the mixing box inlet (12); the inlet (3) of the booster device is a water inlet channel, and the outlet (2) of the booster device is connected to a clean water branch pipe (28) and a clean water inlet pipe (11); the clean water branch pipe (28) is connected to the discharge port (31) of the feeding system, and the clean water inlet pipe (11) is connected to the mixing box inlet (12).

2. A coal mine underground fracturing fluid mixing device according to claim 1, characterized in that: The mixing box comprises a first mixing box (17), a second mixing box (20), a third mixing box (23), and a fourth mixing box (26) arranged along the flow direction of the fluid. The first mixing box (17) achieves mixing through a high-pressure water flow ejected from a clean water inlet pipe (11). The second mixing box (20), the third mixing box (23), and the fourth mixing box (26) are provided with stirring rods with stirring blades to achieve mixing through stirring of the stirring rods.

3. A coal mine underground fracturing fluid mixing device according to claim 2, characterized in that: The first mixing box (17), the second mixing box (20), the third mixing box (23), and the fourth mixing box (26) are arranged in a rectangular array and have a rectangular cross section. The top of the first mixing box (17) is provided with a first exchange port (18) connected to the second mixing box (20), the bottom of the second mixing box (20) is provided with a second exchange port (21) connected to the third mixing box (23), the top of the third mixing box (23) is provided with a third exchange port (24) connected to the fourth mixing box (26), and the bottom of the fourth mixing box (26) is provided with a mixing box outlet (16). The first exchange port (18) and the second exchange port (21), the second exchange port (21) and the third exchange port (24), and the third exchange port (24) and the mixing box outlet (16) are all arranged diagonally to form a diagonal flow pattern.

4. The coal mine underground fracturing fluid mixing device according to claim 2, characterized in that: All stirring rods have independent drive devices, which are installed on the top of the mixing box.

5. The coal mine underground fracturing fluid mixing device according to claim 1, characterized in that: The discharge port (31) is provided with a discharge port punching port and a discharge port drainage port arranged in an upper and lower manner. The clean water branch pipe (28) has two outlet branches, and the two outlet branches are respectively connected to the discharge port punching port and the discharge port drainage port.

6. The coal mine underground fracturing fluid mixing device according to claim 1, characterized in that: The clean water inlet pipe (11) and the clean water branch pipe (28) are both provided with gate valves to adjust the flow rate, and the booster device (4) is a centrifugal pump.

7. The coal mine underground fracturing fluid mixing device according to claim 1, characterized in that: A detachable hopper cover (9) is provided on the top of the hopper (8). The hopper cover (9) is connected to a water injection pipe for injecting water into the hopper through the water injection pipe. The water injection pipe is provided with a gate valve to control the on and off of the water injection pipe.

8. The coal mine underground fracturing fluid mixing device according to claim 5, characterized in that: The clean water branch pipe (28) is divided into two outlet branches, namely, a discharge outlet flushing pipe (29) and a discharge outlet drainage pipe (30), near the discharge outlet (31) of the feeding system. The discharge outlet flushing pipe (29) and the discharge outlet drainage pipe (30) are respectively connected to the discharge outlet flushing port and the discharge outlet drainage port.

9. The coal mine underground fracturing fluid mixing device according to claim 5, characterized in that: The discharge port punching port and the discharge port drainage port are respectively provided on the side wall and the bottom of the discharge port (31).

10. The coal mine underground fracturing fluid mixing device according to claim 1, characterized in that: The mixing box inlet (12) is located at the top thereof and is connected to the discharge port (31) of the feeding hopper (8) through the liquid feed pipe (10), and the liquid feed pipe outlet and the clean water feed pipe outlet are arranged up and down.

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