High-characteristic-value foam fracturing fluid forming device for shale oil and gas

Abstract

The invention belongs to the technical field of shale gas exploitation, and particularly relates to a high-characteristic-value foam fracturing fluid forming device for shale oil gas. Comprising a first mixing mechanism, a high-characteristic-value foam generating mechanism and a second mixing mechanism, the first mixing mechanism is used for mixing foam fracturing fluid with a propping agent, the high-characteristic-value foam generating mechanism is used for generating high-characteristic-value foam fracturing fluid, the outlet end of the high-characteristic-value foam generating mechanism is connected with a first conveying pipe, and the outlet end of the high-characteristic-value foam generating mechanism is connected with a second conveying pipe; the outlet end of the first mixing mechanism is connected with a second conveying pipe, the first conveying pipe and the second conveying pipe are both communicated with the inlet end of the second mixing mechanism, and the second mixing mechanism is used for mixing the high-characteristic-value foam fracturing fluid with the foam fracturing fluid mixed with the propping agent. The high-characteristic-value foam fracturing fluid mixed with the proppant can be generated, so that the water consumption can be reduced, the sand-carrying property can be remarkably improved, and meanwhile, the high-characteristic-value foam fracturing fluid has the characteristics of thorough reverse drainage, small damage to strata and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of shale gas exploitation, and in particular relates to a device for forming a high-characteristic-value foam fracturing fluid for shale oil and gas. Background Art

[0002] Unconventional oil and gas resources are currently hot energy sources for global development and utilization. Unconventional oil and gas reservoirs represented by shale oil and shale gas have problems such as dense reservoirs, high seepage resistance and stress sensitivity. Its congenital underdevelopment determines that the implementation of fracturing transformation is an important way to achieve industrialized exploitation. Hydraulic fracturing technology has been widely used worldwide, but conventional hydraulic fracturing has problems such as high water consumption, incomplete backflow, high filtration loss and damage to the formation. Foam fracturing fluid has been used in the development of shale oil and shale gas reservoirs because of its advantages such as strong sand carrying capacity, complete backflow and little damage to the formation. As a type of foam fracturing technology, high eigenvalue foam fracturing technology has more outstanding advantages in reducing or solving the problems existing in conventional fracturing. The high eigenvalue foam fracturing fluid system has the characteristics of low reservoir damage and high backflow. At the same time, due to the low liquid content, ultra-low water consumption fracturing can be achieved.

[0003] A key to high eigenvalue foam fracturing technology is to produce dense, uniform foam with a high eigenvalue (gas accounts for about 80% to 95% of the foam volume), that is, high gas content, thin liquid film, and dense and uniform foam. Traditional foam fracturing fluid generators are mainly aimed at foam fracturing fluid systems with conventional eigenvalues ​​(about 50% to 80%). Unlike the spherical bubbles in conventional foam fracturing fluid systems, high eigenvalue foams are composed of polyhedral bubbles, and the units that divide the polyhedrons are thin liquid films, and the formation of a large number of thin liquid films requires more sufficient mixing and stirring. However, current foam fracturing fluid generators are still mainly aimed at conventional foam systems, facing the problem of difficulty in producing uniform and stable high eigenvalue foams, which easily leads to low viscosity of the fracturing fluid and poor sand carrying capacity. Therefore, it is urgent to design a high eigenvalue foam fracturing fluid forming device for shale oil and gas. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, the present invention provides a device for forming a high characteristic value foam fracturing fluid for shale oil and gas, and specifically discloses the following technical solutions:

[0005] A high characteristic value foam fracturing fluid forming device for shale oil and gas, comprising a first mixing mechanism, a high characteristic value foam generating mechanism and a second mixing mechanism, the first mixing mechanism comprising a premixer and a remixer, the inlet end of the premixer is connected with a first feed pipe and a first air inlet pipe, the first feed pipe is used to inject foam fracturing fluid and proppant into the premixer, the first mixing mechanism is used to mix the foam fracturing fluid with the proppant, the outlet end of the premixer is connected with the inlet end of the remixer through a first discharge pipe, the high characteristic value foam generating mechanism comprises a first generating pipe, a second generating pipe and a third generating pipe connected in sequence through a pipeline, for generating a high characteristic value foam fracturing fluid, the first generating pipe The inlet end of the tube is connected to a second feed pipe and a second air inlet pipe, one end of the second air inlet pipe is connected to the gas distribution mechanism in the first generating tube, the outlet end of the third generating tube is connected to the first delivery pipe, the outlet end of the remixer is connected to the second delivery pipe, the first delivery pipe and the second delivery pipe are both connected to the inlet end of the second mixing mechanism, the second mixing mechanism is used to mix the high characteristic value foam fracturing fluid with the foam fracturing fluid mixed with the proppant, the outlet end of the second mixing mechanism is connected to the high characteristic value foam fracturing fluid discharge pipe, and valves are arranged on the first feed pipe, the first air inlet pipe, the second feed pipe, the second air inlet pipe and the first delivery pipe.

[0006] Furthermore, a first annular protrusion with a triangular cross-section is provided on the inner wall of the premixer, a cylindrical base is fixedly connected to the bottom of the premixer, a conical diverter is provided above the base, a cylindrical groove is opened at the bottom of the diverter, the top of the base is slidably installed in the cylindrical groove, a spring is provided in the base, the top of the spring is fixedly connected to the diverter, and the bottom end is fixedly connected to the bottom wall of the premixer, a partition plate is fixedly connected to the outer surface of the diverter, both sides of the partition plate are slidably connected to the inner wall of the premixer, an electromagnet is fixedly installed on the bottom wall of the premixer located at the center of the base, an iron block is fixedly installed at the position of the bottom of the diverter corresponding to the electromagnet, and the bottom of the premixer is located on both sides of the partition plate and is respectively connected to two first discharge pipes.

[0007] Furthermore, the remixer includes a mixing plate, a grid-shaped mixing channel is arranged inside the mixing plate, and the grid-shaped mixing channel is provided with two liquid inlet channels and one liquid outlet channel. The two liquid inlet channels are respectively connected to the two first discharge pipes at the bottom of the premixer, and the liquid outlet channel is connected to the second delivery pipe.

[0008] Furthermore, the air distribution mechanism includes an air distribution pipe with a sealed bottom end, the top end of the air distribution pipe is connected to the second air inlet pipe, a plurality of annular sealing sleeves are rotatably connected to the air distribution pipe from top to bottom, the annular sealing sleeves are sleeved on the air distribution pipe, an upper fixing plate and a lower fixing plate are provided at a position corresponding to each annular sealing sleeve on the air distribution pipe, an annular air cavity is provided in the middle of the annular sealing sleeve, the upper fixing plate and the lower fixing plate are both located in the annular air cavity, and the upper fixing plate is in close contact with the top wall of the annular air cavity, and the lower fixing plate is in close contact with the annular air cavity. The bottom wall of the cavity is tightly attached, and ventilation holes are provided on the side walls of the air distribution pipe corresponding to the positions of each annular sealing sleeve. The air distribution pipe is connected with the corresponding annular air cavity through the ventilation holes. A plurality of blades are fixedly connected to the periphery of the annular sealing sleeve along the circumferential direction, and a plurality of first through holes are provided on the end faces of the blades along the length direction of the blades. An air supply channel is provided inside the blades along the length direction of the blades, and the air supply channel is connected with the annular air cavity. A plurality of first air distribution holes connected with the corresponding air supply channels are provided on the side surfaces of the same side of the plurality of blades.

[0009] Furthermore, the first generating tube is an inverted truncated cone-shaped structure, and the length of the blades on the annular sealing sleeve on the air distribution tube gradually shortens from top to bottom.

[0010] Furthermore, a plurality of orifice plates are arranged at equal intervals inside the second generating tube along the length direction of the second generating tube, a plurality of holes are opened on the orifice plates, and the internal structure of the holes is a Venturi tube-like structure.

[0011] Furthermore, the third generating tube is an annular inverted tooth tube, the inner wall of the annular inverted tooth tube forms a plurality of annular triangular protrusions, a wire mesh is arranged on the upper part of the annular triangular protrusions, and the wire mesh is a steel wire mesh with a mesh number of 100-130.

[0012] Furthermore, the second mixing mechanism includes a mixing tube, a plurality of continuous second annular protrusions are arranged on the inner wall of the mixing tube, the axial cross-sections of the plurality of continuous second annular protrusions are wavy, a stirring shaft is arranged at the center of the mixing tube, a plurality of triangular stirring blades are arranged on the stirring shaft, the stirring blades are arranged at positions corresponding to the grooves between the two second annular protrusions, a plurality of second through holes are opened on the stirring blades, one end of the stirring shaft passes through one end side wall of the mixing tube and is fixedly connected to the output shaft of the driving motor, and the high characteristic value foam fracturing fluid discharge pipe is connected to the other end side wall of the mixing tube.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] In the present invention, by providing a first mixing mechanism, a high characteristic value foam generating mechanism and a second mixing mechanism, a uniform and stable high characteristic value foam fracturing fluid mixed with a proppant can be generated, thereby not only reducing water consumption but also significantly improving sand carrying capacity, and having the characteristics of thorough back discharge and little damage to the formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0016] Figure 2 for Figure 1 A partial enlarged view of point A in the middle.

[0017] Figure 3 It is a top view of the diverter head and the partition plate in the present invention.

[0018] Figure 4 for Figure 1 A partial enlarged view of point B in the middle.

[0019] Figure 5 It is a bottom view of the annular sealing sleeve and the blades thereon in the present invention.

[0020] Figure 6 for Figure 5 Cross-sectional view along CC direction.

[0021] Figure 7 It is a schematic diagram of the structure of the second generating tube in the present invention.

[0022] Figure 8 It is a left view of the orifice plate of the present invention.

[0023] Fig. 9 It is a schematic structural diagram of the second mixing mechanism in the present invention.

[0024] 1-premixer, 2-remixer, 3-first feed pipe, 4-first air inlet pipe, 5-first discharge pipe, 6-first generator pipe, 7-second generator pipe, 8-third generator pipe, 9-second feed pipe, 10-second air inlet pipe, 11-first delivery pipe, 12-second delivery pipe, 13-high characteristic value foam fracturing fluid discharge pipe, 14-valve, 15-first annular protrusion, 16-base, 17-diverter, 18-spring, 19-partition plate, 20-electromagnet, 21-iron block, 2 2-mixing plate, 23-grid-shaped mixing channel, 24-air distribution pipe, 25-annular sealing sleeve, 26-upper fixed plate, 27-lower fixed plate, 28-annular air cavity, 29-air vent, 30-blade, 31-first through hole, 32-air supply channel, 33-first air distribution hole, 34-air distribution disk, 35-orifice plate, 36-eyelet, 37-wire mesh, 38-mixing tube, 39-second annular protrusion, 40-stirring shaft, 41-stirring blade, 42-second through hole, 43-drive motor. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] Reference Figure 1-9 A high characteristic value foam fracturing fluid forming device for shale oil and gas comprises a first mixing mechanism, a high characteristic value foam generating mechanism and a second mixing mechanism, the first mixing mechanism comprises a premixer 1 and a remixer 2, the inlet end of the premixer 1 is connected with a first feed pipe 3 and a first air inlet pipe 4, the first feed pipe 3 is used to inject foam fracturing fluid and proppant into the premixer 1, the first mixing mechanism is used to mix the foam fracturing fluid with the proppant, the outlet end of the premixer 1 is connected with the inlet end of the remixer 2 through a first discharge pipe 5, the high characteristic value foam generating mechanism comprises a first generating pipe 6, a second generating pipe 7 and a third generating pipe 8 which are connected in sequence through pipelines, and is used to generate high characteristic value foam fracturing fluid, the inlet end of the first generating pipe 6 is connected with the second feed pipe 4, and ... and the proppant, the outlet end of the premixer 1 is connected with the inlet end of the remixer 2 through a first discharge pipe 5, the high characteristic value foam generating mechanism comprises a first generating pipe 6, a second generating pipe 7 and a third generating pipe 8 which are connected in sequence through pipelines, and is used to generate Pipe 9 and a second air inlet pipe 10, the second feed pipe 9 is used to inject foam fracturing fluid into the first generating pipe 6, one end of the second air inlet pipe 10 is connected to the gas distribution mechanism in the first generating pipe 6, the outlet end of the third generating pipe 8 is connected to the first delivery pipe 11, the outlet end of the remixer 2 is connected to the second delivery pipe 12, the first delivery pipe 11 and the second delivery pipe 12 are both connected to the inlet end of the second mixing mechanism, the second mixing mechanism is used to mix the high characteristic value foam fracturing fluid with the foam fracturing fluid mixed with the proppant, the outlet end of the second mixing mechanism is connected to the high characteristic value foam fracturing fluid discharge pipe 13, the first feed pipe 3, the first air inlet pipe 4, the second feed pipe 9, the second air inlet pipe 10 and the first delivery pipe 11 are all provided with valves 14.

[0027] In this embodiment, a first annular protrusion 15 with a triangular cross-section is provided on the inner wall of the premixer 1, a cylindrical base 16 is fixedly connected to the bottom of the premixer 1, a conical diverter 17 is provided above the base 16, the diverter 17 is located below the first annular protrusion 15, a cylindrical groove is provided at the bottom of the diverter 17, the top of the base 16 is slidably installed in the cylindrical groove, a spring 18 is provided in the base 16, the top of the spring 18 is fixedly connected to the diverter 17, and the bottom is fixedly connected to the bottom wall of the premixer 1, a partition plate 19 is fixedly connected to the outer surface of the diverter 17, both sides of the partition plate 19 are slidably connected to the inner wall of the premixer 1, an electromagnet 20 is fixedly installed on the bottom wall of the premixer 1 located at the center of the base 16, an iron block 21 is fixedly installed at the bottom of the diverter 17 corresponding to the position of the electromagnet 20, and the bottom of the premixer 1 is located on both sides of the partition plate 19 and is connected to two first discharge pipes 5 respectively. The setting of the premixer 1 can make the proppant and the foam fracturing fluid preliminarily mixed. After the electromagnet 20 is energized, it can generate suction to the iron block 21 at the bottom of the diverter head 17, so that the diverter head 17 moves downward. After the electromagnet 20 is powered off, the diverter head 17 is released upward under the action of the spring 18, so that the diverter head 17 vibrates up and down, thereby avoiding blockage of the premixer 1.

[0028] In this embodiment, the remixer 2 includes a mixing plate 22, and a grid-shaped mixing channel 23 is provided inside the mixing plate 22. The grid-shaped mixing channel 23 is provided with two liquid inlet channels and one liquid outlet channel. The two liquid inlet channels are respectively connected to the two first discharge pipes 5 at the bottom of the premixer 1, and the liquid outlet channel is connected to the second delivery pipe 12. Since the grid-shaped mixing channel 23 includes a plurality of channel intersections, the foam fracturing fluid mixed with the proppant can be mixed once when passing through the channel intersections, thereby improving the mixing effect.

[0029] In this embodiment, the air distribution mechanism includes an air distribution pipe 24 with a sealed bottom end, the top of the air distribution pipe 24 is connected to the second air inlet pipe 10, and a plurality of annular sealing sleeves 25 are rotatably connected to the air distribution pipe 24 from top to bottom. The annular sealing sleeves 25 are sleeved on the air distribution pipe 24, and an upper fixing plate 26 and a lower fixing plate 27 are provided at the position corresponding to each annular sealing sleeve 25 on the air distribution pipe 24. The upper fixing plate 26 and the lower fixing plate 27 are both annular, and an annular air cavity 28 is provided in the middle of the annular sealing sleeve 25. The upper fixing plate 26 and the lower fixing plate 27 are both located in the annular air cavity 28, and the upper fixing plate 26 is in close contact with the top wall of the annular air cavity 28, and the lower fixing plate 27 is in close contact with the bottom wall of the annular air cavity 28. A sealing gasket is arranged between the side wall of the air distribution pipe 24 and the side wall of the air distribution pipe 24 to ensure the sealing performance. A vent hole 29 is opened on the side wall of the air distribution pipe 24 at the position corresponding to each annular sealing sleeve 25. The air distribution pipe 24 is connected with the corresponding annular air cavity 28 through the vent hole 29. A plurality of blades 30 are fixedly connected to the periphery of the annular sealing sleeve 25 along the circumferential direction. A plurality of first through holes 31 are arranged on the end surface of the blade 30 along the length direction of the blade 30. An air supply channel 32 is arranged inside the blade 30 along the length direction of the blade 30. The air supply channel 32 is connected with the annular air cavity 28. A plurality of first air distribution holes 33 connected with the corresponding air supply channels 32 are opened on the side surfaces of the same side of the plurality of blades 30. The gas in the air distribution pipe 24 enters each annular air cavity 28 through the air vent 29, and then enters the air supply channel 32 in the blade 30, and is finally evenly discharged into the first generating tube 6 through the first air distribution hole 33, thereby generating foam. While the first air distribution hole 33 is exhausting, a reverse thrust is generated to cause the annular sealing sleeve 25 and the blade 30 thereon to start rotating. During the rotation of the blade 30, the first through hole 31 on the blade 30 further promotes the generation of foam, thereby generating high characteristic value foam.

[0030] In this embodiment, one end of the first air inlet pipe 4 extends into the premixer 1 and is connected to the air distribution plate 34. The outer periphery of the air distribution plate 34 is provided with a plurality of second air distribution holes for uniformly distributing air and promoting the generation of foam.

[0031] In this embodiment, the first generating tube 6 is an inverted truncated cone structure, and the length of the blades 30 on the annular sealing sleeve 25 on the air distribution tube 24 decreases from top to bottom.

[0032] In this embodiment, a plurality of orifice plates 35 are arranged at equal intervals inside the second generating tube 7 along the length direction of the second generating tube 7, and a plurality of holes 36 are opened on the orifice plates 35. The internal structure of the holes 36 is a venturi tube structure. When the high characteristic value foam fracturing fluid passes through the holes 36, the high characteristic value foam fracturing fluid can be mixed with the gas again, thereby further promoting the generation of high characteristic value foam.

[0033] In this embodiment, the third generating tube 8 is an annular inverted tooth tube, and the inner wall of the annular inverted tooth tube forms a plurality of annular triangular protrusions. A wire mesh 37 is arranged on the upper part of the annular triangular protrusions. The wire mesh 37 is made of a steel wire mesh with a mesh number of 100-130, which can play a role in evenly dispersing high characteristic value foam.

[0034] In this embodiment, the second mixing mechanism includes a mixing tube 38, on the inner wall of which are provided a plurality of continuous second annular protrusions 39, the axial cross-sections of the plurality of continuous second annular protrusions 39 are wavy, a stirring shaft 40 is provided at the center of the mixing tube 38, on which are provided a plurality of triangular stirring blades 41, the stirring blades 41 are provided corresponding to the groove positions between the two second annular protrusions, a plurality of second through holes 42 are provided on the stirring blades 41, one end of the stirring shaft 40 passes through the side wall of one end of the mixing tube 38 and is fixedly connected to the output shaft of the driving motor 43, and the high characteristic value foam fracturing fluid discharge pipe 13 is connected to the side wall of the other end of the mixing tube 38. When the high characteristic value foam fracturing fluid and the ordinary foam fracturing fluid mixed with proppant pass through the mixing tube 38, under the flow resistance and oscillation action of the continuous second annular protrusions 39 and the stirring action of the stirring blades 41, the ordinary foam fracturing fluid mixed with proppant can be fully mixed with the high characteristic value foam fracturing fluid, and the proppant can be dispersed on the liquid film of the high characteristic value foam, thereby generating a high characteristic value foam fracturing fluid that evenly carries the proppant for use in fracturing work.

[0035] In the present invention, by providing a first mixing mechanism, a high characteristic value foam generating mechanism and a second mixing mechanism, a uniform and stable high characteristic value foam fracturing fluid mixed with a proppant can be generated, thereby not only reducing water consumption but also significantly improving sand carrying capacity, and having the characteristics of thorough back discharge and little damage to the formation.

[0036] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A device for forming high characteristic value foam fracturing fluid for shale oil and gas, characterized in that: The invention comprises a first mixing mechanism, a high characteristic value foam generating mechanism and a second mixing mechanism, wherein the first mixing mechanism comprises a premixer and a remixer, wherein the inlet end of the premixer is connected with a first feed pipe and a first air inlet pipe, wherein the first feed pipe is used to inject foam fracturing fluid and proppant into the premixer, and the first mixing mechanism is used to mix the foam fracturing fluid with the proppant, wherein the outlet end of the premixer is connected with the inlet end of the remixer through a first discharge pipe, and the high characteristic value foam generating mechanism comprises a first generating pipe, a second generating pipe and a third generating pipe which are connected in sequence through pipelines, and are used to generate high characteristic value foam fracturing fluid, wherein the inlet end of the first generating pipe is connected with a second generating pipe, and the inlet end of the second generating pipe is connected with a first generating pipe, wherein the first generating pipe is connected with a second ... first generating pipe, wherein the first generating pipe is connected with a second generating pipe, wherein the first generating pipe is connected with a second generating pipe, wherein the first generating pipe is connected with a first generating pipe, wherein the first generating pipe is connected with a second generating pipe, wherein the first generating pipe is connected with a second generating pipe, wherein the first generating pipe is connected with a first generating pipe, wherein the first generating pipe is connected with a A feed pipe and a second air inlet pipe, one end of the second air inlet pipe is connected to the air distribution mechanism in the first generating pipe, the outlet end of the third generating pipe is connected to the first delivery pipe, the outlet end of the remixer is connected to the second delivery pipe, the first delivery pipe and the second delivery pipe are both connected to the inlet end of the second mixing mechanism, the second mixing mechanism is used to mix the high characteristic value foam fracturing fluid with the foam fracturing fluid mixed with proppant, the outlet end of the second mixing mechanism is connected to the high characteristic value foam fracturing fluid discharge pipe, and valves are arranged on the first feed pipe, the first air inlet pipe, the second feed pipe, the second air inlet pipe and the first delivery pipe.

2. A device for forming high characteristic value foam fracturing fluid for shale oil and gas according to claim 1, characterized in that: A first annular protrusion with a triangular cross-section is provided on the inner wall of the premixer, a cylindrical base is fixedly connected to the bottom of the premixer, a conical diverter is provided above the base, a cylindrical groove is provided at the bottom of the diverter, the top of the base is slidably installed in the cylindrical groove, a spring is provided in the base, the top of the spring is fixedly connected to the diverter, and the bottom end is fixedly connected to the bottom wall of the premixer, a partition plate is fixedly connected to the outer surface of the diverter, both sides of the partition plate are slidably connected to the inner wall of the premixer, an electromagnet is fixedly installed on the bottom wall of the premixer located at the center of the base, an iron block is fixedly installed at the position of the bottom of the diverter corresponding to the electromagnet, and the bottom of the premixer is located on both sides of the partition plate, which are respectively connected to two first discharge pipes.

3. A device for forming high characteristic value foam fracturing fluid for shale oil and gas according to claim 2, characterized in that: The remixer includes a mixing plate, a grid-shaped mixing channel is arranged inside the mixing plate, and the grid-shaped mixing channel is provided with two liquid inlet channels and one liquid outlet channel. The two liquid inlet channels are respectively connected to the two first discharge pipes at the bottom of the premixer, and the liquid outlet channel is connected to the second conveying pipe.

4. The device for forming high characteristic value foam fracturing fluid for shale oil and gas according to claim 1, characterized in that: The air distribution mechanism comprises an air distribution pipe with a sealed bottom end, the top end of the air distribution pipe is connected to the second air inlet pipe, a plurality of annular sealing sleeves are rotatably connected to the air distribution pipe from top to bottom, the annular sealing sleeves are sleeved on the air distribution pipe, an upper fixing plate and a lower fixing plate are arranged at a position corresponding to each annular sealing sleeve on the air distribution pipe, an annular air cavity is arranged in the middle of the annular sealing sleeve, the upper fixing plate and the lower fixing plate are both located in the annular air cavity, and the upper fixing plate is in close contact with the top wall of the annular air cavity, and the lower fixing plate is in close contact with the top wall of the annular air cavity. The bottom wall is tightly attached, and ventilation holes are provided on the side walls of the air distribution pipe corresponding to the positions of each annular sealing sleeve. The air distribution pipe is connected with the corresponding annular air cavity through the ventilation holes. A plurality of blades are fixedly connected to the periphery of the annular sealing sleeve along the circumferential direction. A plurality of first through holes are provided on the end faces of the blades along the length direction of the blades. An air supply channel is provided inside the blades along the length direction of the blades. The air supply channel is connected with the annular air cavity, and a plurality of first air distribution holes connected with the corresponding air supply channels are provided on the side surfaces of the same side of the plurality of blades.

5. A device for forming high characteristic value foam fracturing fluid for shale oil and gas according to claim 4, characterized in that: The first generating tube is an inverted truncated cone structure, and the length of the blades on the annular sealing sleeve on the air distribution tube becomes shorter from top to bottom.

6. The device for forming high characteristic value foam fracturing fluid for shale oil and gas according to claim 1, characterized in that: A plurality of orifice plates are arranged at equal intervals inside the second generating tube along the length direction of the second generating tube, a plurality of holes are opened on the orifice plates, and the internal structure of the holes is a Venturi tube-like structure.

7. The device for forming high characteristic value foam fracturing fluid for shale oil and gas according to claim 1, characterized in that: The third generating tube is an annular inverted tooth tube, and the inner wall of the annular inverted tooth tube forms a plurality of annular triangular protrusions. A wire mesh is arranged on the upper part of the annular triangular protrusions, and the wire mesh is a steel wire mesh with a mesh number of 100-130.

8. The device for forming high characteristic value foam fracturing fluid for shale oil and gas according to claim 1, characterized in that: The second mixing mechanism includes a mixing tube, a plurality of continuous second annular protrusions are arranged on the inner wall of the mixing tube, and the axial cross-sections of the plurality of continuous second annular protrusions are wavy. A stirring shaft is arranged at the center of the mixing tube, and a plurality of triangular stirring blades are arranged on the stirring shaft. The stirring blades are arranged at positions corresponding to the grooves between the two second annular protrusions, and a plurality of second through holes are opened on the stirring blades. One end of the stirring shaft passes through the side wall of one end of the mixing tube and is fixedly connected to the output shaft of the driving motor, and the high characteristic value foam fracturing fluid discharge pipe is connected to the side wall of the other end of the mixing tube.

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