Foam generator and nitrogen foam generating device for nitrogen foam fracturing

Abstract

The invention relates to the technical field of petrochemical engineering, in particular to a foam generator and a nitrogen foam generating device for nitrogen foam fracturing. Gas is injected into foam generating liquid in a rotating mode through the hollow rotating column to prepare foam, the gas can increase the nitrogen filling range in the circumferential direction of the hollow rotating column through centrifugal force and can also be distributed in the axial direction of the hollow rotating column, the uniformity of bubble distribution and the particle size is good, the nitrogen utilization rate is high, and waste of nitrogen resources is small; and the equipment is low in energy consumption and high in preparation efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical industry, in particular to a foam generator and a nitrogen foam generating device for nitrogen foam fracturing. Background Art

[0002] Nitrogen foam fracturing is an oil extraction technology. Nitrogen foam generator plays a key role in this technology. It can produce nitrogen foam to improve the fracturing effect. This device usually consists of nitrogen supply system, foam generator, control system, etc. The nitrogen supply system provides high-pressure nitrogen to the foam generator; the foam generator is a key device for generating foam, which forms foam by mixing nitrogen with a specific liquid; the control system can adjust the ratio of nitrogen and liquid to achieve the desired foam characteristics.

[0003] In the prior art, foam generators generally use a stirring impeller that rotates at high speed to stir the injected nitrogen, liquid medicine and water. The stirring efficiency is low, and there are problems such as coarse bubble particle size and low uniformity. The foam formation is not stable enough, which affects the quality and performance of the foam. The patent document with the prior art publication number CN206053919U proposes a new intelligent high-pressure and large-displacement nitrogen foam device. The solution sets a gas-liquid mixing chamber at the front end of the foam generator cavity, and arranges an unpowered stirring impeller at the rear end. In the gas-liquid mixing chamber, the gas is directly introduced into the distribution pipe through the gas inlet and dispersed into small bubbles. The liquid enters in a rotating manner to drive the gas mixing; then the preliminarily mixed foam liquid passes through the first spiral stirring impeller and the second spiral stirring impeller, and then changes direction several times and stirs with water to crush the gas and form microbubbles in the water. Although this solution prepares foam by graded method - first pre-treatment to achieve mixing of liquid and gas, and then stirring to crush the gas, the quality and performance of the produced foam are improved to a certain extent, but the foam preparation time is long, and the liquid enters the liquid in a rotating manner (the gas-liquid mixing chamber is filled with liquid), which consumes a lot of energy for the equipment. At the same time, because the gas drives the mixing by rotating through the liquid, the stirring efficiency is low, which can easily lead to waste of nitrogen resources. Summary of the invention

[0004] The purpose of the present invention is to provide a foam generator and a nitrogen foam generating device for nitrogen foam fracturing in view of the problems of high energy consumption and nitrogen waste in the prior art for preparing nitrogen foam.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: A foam generator, characterized in that it includes a reaction tank, the reaction tank is provided with a gas inlet, a liquid inlet and a foam outlet; a hollow rotating column is provided in the reaction tank, the hollow rotating column is rotatably connected to the reaction tank, the hollow rotating column is used for rotation, the hollow rotating column is a hollow structure, the hollow rotating column is connected to the gas inlet, and is used to introduce gas into the hollow rotating column at the gas inlet, a plurality of exhaust holes are axially provided on the side wall of the hollow rotating column; the foam outlet is located above the hollow rotating column.

[0006] When the foam generator is used to prepare nitrogen foam, the foam generating liquid is injected through the liquid inlet; nitrogen is injected through the gas inlet, and the nitrogen is dispersed into small bubbles through a plurality of exhaust holes arranged along the axial direction on the side wall of the hollow rotating column. While the small bubbles are discharged from the exhaust holes, the hollow rotating column is driven to rotate at a high speed, and the small bubbles are broken and diffused in the foam generating liquid by utilizing centrifugal force and cutting of the inner wall of the exhaust hole, so that the bubbles are fully in contact with the foam generating liquid to form foam, and after the foam escapes, it can be discharged through the foam outlet and put into use.

[0007] In this solution, gas is injected into the foam generating liquid in a rotating manner through a hollow rotating column. The gas can increase the nitrogen filling range along the circumference of the hollow rotating column through centrifugal force, and can also be distributed along the axial direction of the hollow rotating column, thereby facilitating the rapid generation of a large amount of foam. The bubble distribution and particle size have good uniformity. Compared with the method of directly introducing the gas, the nitrogen utilization rate is greatly improved and the waste of nitrogen resources is reduced. Moreover, compared with the prior art of using liquid for rotational injection, the resistance of the gas rotating into the liquid is smaller, which is conducive to reducing the energy consumption of the equipment.

[0008] In addition, this solution places the gas-liquid mixing and the hollow rotating column used for high-speed stirring in the same working space, and the operation sequence is synchronized. Compared with the prior art that arranges the gas-liquid mixing chamber and the unpowered stirring impeller at the front and back poles in the inner cavity of the foam generator, the foam generator provided by this solution has a more compact structure, higher space utilization, and higher preparation efficiency, which is conducive to reducing economic costs.

[0009] In this solution, both ends of the hollow rotating column can be rotatably connected to the reaction tank at the same time, or only one end can be rotatably connected to the reaction tank; the opposite end of the hollow rotating column away from the gas inlet can be closed to prevent the gas in the hollow rotating column from directly entering the reaction tank and wasting gas resources. The opposite end of the hollow rotating column away from the gas inlet can also be open. When the opening is set, the open end should be as close as possible to or directly contact the inner wall of the reaction tank; if necessary, the inner wall of the reaction tank can be provided with bearings or brackets to support the rotation of the end, while preventing the gas from directly entering the reaction tank, not limited to the above examples. The size of the hollow rotating column, the size of the drainage holes on its side wall, the rotation speed of the hollow rotating column and other parameters are determined according to the high precision requirements required for oil extraction fracturing.

[0010] As a preferred solution of the present invention, a plurality of stirring blades are provided on the side wall of the hollow rotating column along the axial direction. The stirring blades stir the foam generating liquid, which is beneficial to further improve the contact efficiency between the foam generating liquid and the nitrogen, accelerate the reaction, and further increase the uniformity of the mixing of the two.

[0011] As a preferred embodiment of the present invention, the reaction tank is of a cylindrical structure, and the reaction tank and the hollow rotating column are both arranged horizontally, that is, the reaction tank and the hollow rotating column are arranged in the same length direction, and are both laid flat along the length direction, the structural arrangement is reasonable, and the hollow rotating column occupies a large space in the reaction tank, which is conducive to the uniform distribution of bubbles; and the hollow rotating column is arranged horizontally, so that the bubbles generated are basically at the same height position, the buoyancy of the bubbles is basically the same, the distribution range in the reaction tank is large, and the uniformity of the size and distribution range of the bubbles generated is good.

[0012] As a further preferred embodiment of the present invention, the gas inlet and the foam outlet are respectively located at opposite ends of the reaction tank, and the liquid inlet is located on the side wall of the reaction tank, which is convenient for arranging pipelines. Specifically, an air outlet pipe is provided at the gas inlet, the outer wall of the air outlet pipe is rotatably connected to the hollow rotating column, the outer wall of the hollow rotating column is rotatably connected to the gas inlet, the air outlet pipe is bent upward at the gas inlet, which is conducive to avoiding the backflow of liquid in the reaction tank; a foam discharge pipe is provided at the foam outlet, the foam discharge pipe includes a first bend section and a second bend section, the first bend section is connected to the foam outlet, the first bend section is projected on the horizontal plane and is bent, which is convenient for discharging foam along the horizontal plane, the second bend section is connected to the first bend section, the second bend section is bent upward and the top of the second bend section is higher than the reaction tank, so that the water head of the second bend section is higher than the water head in the reaction tank, thereby forming a pressure difference, which has a certain blocking effect on the foam discharged laterally, avoiding the direct outflow of the foam, and also avoiding the loss of liquid in the foam in the reaction tank; a water pipe is provided at the liquid inlet for injecting liquid into the reaction tank. This scheme adopts a pipeline arrangement method to provide gas and liquid to the reaction tank, which is convenient for transmission and flexible in arrangement.

[0013] As other possible implementation modes, a connecting chamber may be sealed and arranged corresponding to the gas inlet / foam outlet / liquid inlet, and the injection of gas / liquid or the discharge of foam may be achieved by pressurizing or pumping the connecting chamber; the structure of the reaction tank is not limited to a circular cross-section, and a square cross-section, a gourd-shaped variable cross-section, a spherical structure, etc. may also be adopted; the gas inlet, foam outlet, and liquid inlet may also be flexibly arranged according to specific working conditions, and are not limited to the above examples.

[0014] As a preferred solution of the present invention, it also includes a first driving device, which is used to drive the hollow rotating column to rotate; the first driving device includes a driving wheel, a driven ring and a motor. When in use, the motor is connected to the driving wheel, and the driving wheel and the driven ring are connected by a belt, and the driven ring is set on the extended end of the hollow rotating column; wherein the extended end of the hollow rotating column can be the end close to the gas outlet or the end away from the gas outlet. The driving wheel is driven to rotate by the motor, and the hollow rotating column is driven to rotate by the belt and the driven ring, so as to prepare foam.

[0015] As another possible implementation, the first driving device may also drive the hollow rotating column to rotate by means of gear transmission. For example, the first driving device includes a motor and a driving gear connected to the motor, and a driven gear is provided on the protruding end of the hollow rotating column, and the driving gear and the driven gear are meshed, which is not limited to the above example.

[0016] The present invention also provides a nitrogen foam generating device for nitrogen foam fracturing, comprising any one of the above-mentioned foam generators, and further comprising: A nitrogen storage tank, the nitrogen storage tank is used to store nitrogen, the nitrogen storage tank is connected to a gas inlet via an air pump, and the air pump is used to extract gas from the nitrogen storage tank; A foam generating liquid storage water tank is used to store the foam generating liquid. The foam generating liquid storage water tank is connected to the liquid inlet through a water pump. The water pump is used to extract the foam generating liquid from the foam generating liquid storage water tank.

[0017] In this scheme, the foam generating liquid configured in advance is stored in the foam generating liquid storage water tank, and the foam generating liquid in the foam generating liquid storage water tank is extracted by a water pump and transported to the inside of the reaction tank. At the same time, the nitrogen in the nitrogen storage tank is extracted by an air pump and enters the reaction tank. The efficient operation of the water pump and the air pump ensures the continuous supply and flow of the foam generating liquid and gas, which is conducive to ensuring the smooth progress of the reaction and the stability and uniformity of the generated foam. At the same time, it is also convenient to control the foam preparation process through the air pump and the water pump, thereby improving the preparation efficiency and nitrogen utilization rate.

[0018] As a preferred embodiment of the present invention, the present invention further comprises a movable frame, and the foam generating liquid storage water tank and the nitrogen storage tank are both fixedly mounted on the frame, so as to facilitate movement and improve flexibility of use.

[0019] As a preferred solution of the present invention, the foam generating liquid storage water tank is installed in the middle of the frame, and the water pump is located at the head of the frame; the nitrogen storage tank is installed at the tail of the frame, and the air pump is installed on the top of the foam generating liquid storage water tank; the reaction tank is installed at the head of the frame, and the reaction tank is installed above the water pump. The overall structure is compact, the space utilization rate is high, and the pipeline layout is convenient.

[0020] As a preferred embodiment of the present invention, the present invention also includes a storage assembly for storing a traction rope, wherein the storage assembly is installed at either end of the frame; the storage assembly includes a storage box and a braking device; an opening is provided on the storage box, and a storage tray is provided inside the storage box, wherein the storage tray is used for winding the traction rope, and rotating shafts are provided at both ends of the storage tray, wherein the rotating shafts are rotatably connected to the storage box, and a crank is provided at one end of the rotating shaft, wherein the crank is located outside the storage box for easy manual operation; the braking device includes a worm gear 1, a worm screw 1, a brake pad and a rotating handle, wherein the brake pad is used to contact the rotating shaft, wherein the brake pad is fixedly connected to the end face of the worm gear 1, wherein the worm gear 1 is meshed with the worm screw 1, wherein the worm screw 1 is connected to the rotating handle, and wherein the rotating handle is located outside the storage box.

[0021] This solution sets a storage assembly at the head of the frame for connecting a carrier, and the device is dragged by the carrier to achieve movement. In the storage assembly, the opening on the storage box is used for the traction rope to pass through, and the storage tray is driven to rotate by the crank to retract and release the traction rope; the worm is controlled by the rotating handle to rotate, thereby driving the worm wheel to rotate, and the brake pad is driven by the worm wheel to rotate, so as to achieve approach and distance from the rotating column, thereby controlling the extension length of the traction rope and the stability of placement. The traction rope is dragged to solve the problem of the inconvenience of moving the device and improve its flexibility of use.

[0022] As a preferred solution of the present invention, support columns are provided on both sides of the frame, threaded columns are provided inside the support columns, and limiting grooves are provided vertically on the threaded columns. Correspondingly, structures such as protrusions or rollers that cooperate with the limiting grooves are provided on the inner side walls of the support columns, wherein the protrusions can be continuous structures along the vertical direction, or multiple protrusions can be provided at intervals, so that the threaded columns can move relative to the support columns along the vertical direction, and circumferential limiting can be achieved through the limiting grooves; a support seat is provided at the bottom end of the threaded column, and the outer contour size of the support seat is larger than the outer contour size of the support column, which is used for limiting and supporting; a worm gear 2 is provided between the support seat and the support column, and the worm gear 2 is threadedly connected to the threaded column; a second driving device is provided at the bottom of the frame, and the second driving device includes a worm gear 2, and the worm gear 2 is meshed with the worm gear 2. By driving the worm gear 2 to rotate the worm gear 2, the threaded column is driven to move up and down along the support column; when the above-mentioned nitrogen foam generating device moves to the specified position, the driving support seat is supported on the ground, so as to solve the problem of unstable placement of the nitrogen foam generating device during use and improve the stability and safety of the device.

[0023] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The foam generator provided by the present invention prepares foam by injecting gas into the foam generating liquid in a rotating manner through a hollow rotating column. The gas can increase the nitrogen filling range along the circumference of the hollow rotating column through centrifugal force, and can also be distributed along the axial direction of the hollow rotating column. The bubble distribution and particle size uniformity are good, the nitrogen utilization rate is high, the nitrogen resource waste is small, the equipment energy consumption is small, and the preparation efficiency is high.

[0024] 2. The nitrogen foam generating device provided by the present invention stores the pre-configured foam generating liquid in the foam generating liquid storage water tank, and uses a water pump to draw the foam generating liquid in the foam generating liquid storage water tank and transport it to the inside of the reaction tank. At the same time, an air pump draws the nitrogen in the nitrogen storage tank into the reaction tank. The efficient operation of the water pump and the air pump ensures the continuous supply and flow of the foam generating liquid and gas, which is beneficial to ensure the smooth progress of the reaction, and the stability and uniformity of the generated foam are good. At the same time, it is also convenient to control the foam preparation process through the water pump and the air pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the cross-sectional structure of a foam generator provided by the present invention; Figure 2 The present invention provides a nitrogen foam fracturing nitrogen foam generating device. Figure 1 ; Figure 3 The present invention provides a nitrogen foam fracturing nitrogen foam generating device. Figure 2 ; Figure 4 It is a schematic diagram of the structure of the storage component; Figure 5 This is a schematic diagram of the internal structure of the storage component. Figure 1 ; Figure 6 This is a schematic diagram of the internal structure of the storage component. Figure 2 ; Figure 7 It is a structural diagram of the frame; Figure 8 It is a schematic diagram of the cross-sectional structure of the support column.

[0026] Icons: 1-frame; 2-support column; 3-tire; 4-storage box; 5-reaction tank; 6-foam discharge pipe; 7-water pump; 8-water pipe; 9-water extraction pipe; 10-air outlet pipe; 11-air pump; 12-foam generating liquid storage tank; 13-nitrogen storage tank; 14-fixed frame; 15-three-way air inlet pipe; 16-hollow rotating column; 17-exhaust hole; 18-driven ring; 19-belt; 20-driving wheel; 21-motor; 22-opening and closing plate; 23-fixing bolt ; 24-crank handle; 25-rotating handle; 26-worm one; 27-worm gear one; 28-storage tray; 29-traction rope; 30-traction hook; 31-rotating shaft; 32-brake pad; 33-support seat; 34-double-headed motor; 35-connecting shaft; 36-worm two; 37-worm gear two; 38-threaded column; 39-limiting groove; 40-stirring blade; 41-universal shaft one; 42-main shaft; 43-universal shaft two; 44-fixed shell; 45-filter screen; 46-scraper. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with specific embodiments. However, this should not be understood as the scope of the above subject matter of the present invention being limited to the following embodiments, and all technologies realized based on the content of the present invention belong to the scope of the present invention.

[0028] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or are the orientation or position relationship when the invented product / equipment / device is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0029] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0030] In addition, the expressions “first”, “second”, “third”, etc., which appear in the terms, are merely used to distinguish the description of the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0031] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0032] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0033] Example 1 like Figure 1 , Figure 2 As shown, this embodiment provides a foam generator, including a reaction tank 5 and a first driving device.

[0034] The reaction tank 5 is used to generate foam. The reaction tank 5 is provided with a gas inlet, a liquid inlet and a foam outlet. The gas inlet is used to inject gas, the liquid inlet is used to inject liquid, and the foam outlet is used to discharge excess nitrogen and foam. A hollow rotating column 16 is provided in the reaction tank 5. The hollow rotating column 16 is rotatably connected to the reaction tank 5. The hollow rotating column 16 is used to rotate. The hollow rotating column 16 is a hollow structure. The hollow rotating column 16 is connected to the gas inlet. A plurality of exhaust holes 17 are axially provided on the side wall of the hollow rotating column 16. The exhaust holes 17 can be evenly arranged on the side wall of the hollow rotating column 16 in an array arrangement or a staggered arrangement; the foam outlet is located above the hollow rotating column 16. The first driving device is used to drive the hollow rotating column 16 to rotate.

[0035] In an optional embodiment, the reaction tank 5 is of a cylindrical structure, and the reaction tank 5 and the hollow rotating column 16 are preferably arranged horizontally, that is, the reaction tank 5 and the hollow rotating column 16 are arranged in the same length direction, and are both laid flat along the length direction. The structural arrangement is reasonable, and the hollow rotating column 16 occupies a large space in the reaction tank 5, which is conducive to the uniform distribution of bubbles; and the hollow rotating column 16 is arranged horizontally, so that the bubbles generated are basically at the same height position, the buoyancy of the bubbles is basically the same, the distribution range in the reaction tank 5 is large, and the uniformity of the size and distribution range of the bubbles generated is good.

[0036] In an optional embodiment, one end of the hollow rotating column 16 extends out of the gas inlet and the extended end of the hollow rotating column 16 is connected to the first driving device, and the other end of the hollow rotating column 16 contacts the inner wall of the reaction tank 5 or is rotationally connected to the inner wall of the reaction tank 5 through the rotating shaft 31. The extended end of the hollow rotating column 16 is matched with the gas outlet pipe 10, one end of the gas outlet pipe 10 is rotationally connected and sealed to the extended end of the hollow rotating column 16, and the other end of the gas outlet pipe 10 is used to connect to the gas supply source. Specifically, in this embodiment, the outer wall of the gas outlet pipe 10 is rotationally connected to the hollow rotating column 16, and the outer wall of the hollow rotating column 16 is rotationally connected to the gas inlet; the gas outlet pipe 10 is bent upward at the gas inlet to prevent the liquid in the reaction tank 5 from flowing back.

[0037] In an optional implementation manner, the present embodiment preferably arranges the gas inlet and the foam outlet at opposite ends of the reaction tank 5, and arranges the liquid inlet at the side wall of the reaction tank 5, such as the bottom, to facilitate the arrangement of pipelines, and arranges a foam discharge pipe 6 at the foam outlet, and a water pipe 8 at the liquid inlet, and the water pipe 8 is used to connect to a water supply source, and the water pipe 8 can be a straight pipe. The pipeline arrangement method is used to provide gas and liquid to the reaction tank 5, which is convenient for transmission and flexible in arrangement.

[0038] In an optional embodiment, the foam discharge pipe 6 includes a first bend section and a second bend section; the first bend section is connected to the foam outlet, and the first bend section is arranged along the transverse bend, and the horizontal projection is U-shaped, which is convenient for discharging foam along the horizontal plane; the second bend section is connected to the first bend section, and the second bend section is arranged to bend upward, and the projection on the longitudinal section is U-shaped, which is beneficial to reducing the transverse width occupancy, and the top of the second bend section is higher than the reaction tank 5, so that the water head of the second bend section is higher than the water head in the reaction tank 5, thereby forming a pressure difference, which has a certain blocking effect on the laterally discharged foam, avoiding the direct outflow of the foam, and also avoiding the liquid loss of the foam in the reaction tank 5.

[0039] In an optional embodiment, in order to improve the reaction efficiency, a plurality of stirring blades 40 are fixedly connected to the outer wall of the hollow rotating column 16. These stirring blades 40 fully stir the foam generating liquid and nitrogen during rotation, thereby enhancing the mixing effect of the nitrogen and foam generating liquid and accelerating the reaction rate.

[0040] In an optional embodiment, the first driving device includes a driving wheel 20, a driven ring 18 and a motor 21. When in use, the motor 21 is connected to the driving wheel 20, the driving wheel 20 and the driven ring 18 are connected by a belt 19, and the driven ring 18 is embedded in the protruding end of the hollow rotating column 16. The driving wheel 20 is driven to rotate by the motor, and the hollow rotating column 16 is driven to rotate by the belt 19 and the driven ring 18, so as to prepare foam.

[0041] When the foam generator is used to prepare nitrogen foam, the foam generating liquid is injected through the liquid inlet; nitrogen is injected through the gas inlet, and the nitrogen is dispersed into small bubbles through the multiple exhaust holes 17 arranged along the axial direction on the side wall of the hollow rotating column 16. When the small bubbles are discharged from the exhaust holes 17, the hollow rotating column 16 is driven to rotate at a high speed, and the small bubbles are broken and diffused in the foam generating liquid by centrifugal force and the cutting of the inner wall of the exhaust hole 17, so that the bubbles are fully in contact with the foam generating liquid to form foam. After the foam escapes, it can be discharged through the foam outlet and put into use. After overflowing, it needs to pass through the filter screen 45 embedded in the fixed shell 44 to enter the fixed shell 44. At the same time, the foam discharge pipe 6 is covered by the fixed shell 44, and the foam filtered by the filter screen 45 will be put into use, which can make the foam to be used more delicate, thereby achieving a better use effect. When the hollow rotating column 16 rotates, the main shaft 42 can be driven by the universal joint 41, and the scraper 46 can be driven to rotate by the universal joint 43. The scraper 46 can prevent the foam from adhering to the filter screen 45, so that the filter screen 45 maintains an efficient filtering effect.

[0042] Example 2 Based on Example 1, this example provides a nitrogen foam generating device for nitrogen foam fracturing. Figure 2-Figure 3 , including a movable frame 1, the foam generator, a nitrogen storage tank 13, a foam generating liquid storage water tank 12, an air pump 11 and a water pump 7. Among them, the nitrogen storage tank 13 is used to store nitrogen, and the nitrogen storage tank 13 is connected to the gas inlet on the foam generator reaction tank 5 through the air pump 11, and the air pump 11 is used to extract gas from the nitrogen storage tank 13; the foam generating liquid storage water tank 12 is used to store foam generating liquid, and the foam generating liquid storage water tank 12 is connected to the liquid inlet on the foam generator reaction tank 5 through the water pump 7, and the water pump 7 is used to extract foam generating liquid from the foam generating liquid storage water tank 12.

[0043] Since most foam generators are of fixed design, in order to increase their flexibility when used in oil fields, this embodiment fixes the foam generator, nitrogen storage tank 13 and foam generating liquid storage water tank 12 on one side of the top of the movable frame 1, so that the nitrogen foam generating device can be moved by tires, so that the device can be flexibly moved to the required position for operation according to different areas and operation requirements of the oil field.

[0044] Specifically, in the present embodiment, a foam generating liquid storage water tank 12 is installed at the middle part of the frame 1, a water pump 7 is installed at the head of the frame 1, the foam generating liquid storage water tank 12 and the water pump 7 are connected by a water pumping pipe 9, and the water pump 7 and the reaction tank 5 are connected by a water delivery pipe 8; in the present embodiment, a nitrogen storage tank 13 is installed at the rear part of the frame 1, and the nitrogen storage tank 13 is fixedly connected to the frame 1 through a fixing frame 14. There are two nitrogen storage tanks 13 in the present embodiment, and the two nitrogen storage tanks 13 are connected to a three-way air inlet pipe 15, and the three-way air inlet pipe 15 is connected to the input end of the air pump 11. The air pump 11 is fixedly installed on the top of the foam generating liquid storage water tank 12, and the output end of the air pump 11 is connected to the hollow rotating column 16 in the reaction tank 5 through an air outlet pipe 10; the reaction tank 5 is arranged at the head of the frame 1. An electric motor 21 is fixedly installed on the top of the reaction tank 5, and a driving wheel 20 is fixedly connected to the output end of the electric motor 21. A driven ring 18 is fixedly connected to one side of the outer wall of the hollow rotating column 16, and a belt 19 is arranged between the driven ring 18 and the driving wheel 20; a foam discharge pipe 6 is fixedly connected to the inside of the reaction tank 5; tires 3 are rotatably connected to both sides of the frame 1, and the tires 3 are arranged in a rectangular array.

[0045] When the device is used, first, the foam generating liquid storage water tank 12 is used to store the foam generating liquid, and then the foam generating liquid is extracted from the foam generating liquid storage water tank 12 by the water pump 7 using the water extraction pipe 9, and the foam generating liquid is discharged into the reaction tank 5 through the water delivery pipe 8; at the same time, the air pump 11 extracts nitrogen from the nitrogen storage tank 13 through the three-way air inlet pipe 15, and the nitrogen enters the reaction tank 5 through the air outlet pipe 10; the hollow rotating column 16 in the reaction tank 5 is driven to rotate by the motor 21 to generate foam. In this process, the efficient operation of the water pump 7 and the air pump 11 ensures the continuous supply and flow of the foam generating liquid and nitrogen, and ensures the smooth progress of the reaction.

[0046] When nitrogen enters the reaction tank 5, it will enter the hollow rotating column 16 disposed inside the reaction tank 5; during use, since the nitrogen has a sufficiently high pressure, it can be ensured that the injected foam generating liquid does not enter the hollow rotating column 16. By starting the motor 21 and driving the driving wheel 20 to rotate, the driving wheel 20 is connected to the driven ring 18 through the belt 19, thereby driving the hollow rotating column 16 to rotate. The multiple exhaust holes 17 on the hollow rotating column 16 are evenly distributed, so that the nitrogen can be evenly discharged into the foam generating liquid inside the reaction tank 5. As the hollow rotating column 16 rotates, the nitrogen quickly diffuses in the foam generating liquid.

[0047] In this way, the foam generating liquid and nitrogen react quickly to generate foam. During the foam generation process, the mixture inside the reaction tank 5 is affected by the rotation of the hollow rotating column 16 and the stirring blades 40 to form uniform and delicate foam. Finally, the foam generated by the reaction is discharged through the foam discharge pipe 6 for subsequent use. The design of the entire device not only improves the reaction efficiency, but also ensures the stability and uniformity of the generated foam, so that it can play a better role in the nitrogen foam fracturing process. In this way, the device can provide continuous, stable and efficient foam generation capabilities in actual applications, meet the use requirements under different working conditions, and provide reliable technical support for nitrogen foam fracturing.

[0048] Example 3 Based on Example 2, please refer to Figure 4-Figure 6 In this embodiment, a storage assembly is also provided at the head of the frame 1, and the storage assembly is used to connect to a vehicle, and the frame is dragged by the vehicle to realize the overall movement of the nitrogen foam generating device.

[0049] Specifically, in this embodiment, the storage assembly is installed on one side of the top of the frame 1 . The storage assembly includes a storage box 4, an opening and closing plate 22 and a braking device; the bottom of the storage box 4 is fixedly connected to the frame 1, and an opening is provided on the storage box 4 to provide a movable space for the towing vehicle, and an opening and closing plate 22 is provided at the opening to cover the opening and protect against rain and dust; one side of the top of the opening and closing plate 22 is rotatably connected to the storage box 4, and one side of the bottom of the opening and closing plate 22 is detachably connected to the storage box 4 through a fixing bolt 23, such as snap fixing, plugging, etc.; a rotating shaft 31 is rotatably connected inside the storage box 4, one end of the rotating shaft 31 extends out of the storage box 4 and the extended end is fixedly connected to the crank 24; a storage tray 28 is fixedly connected to the outer wall of the rotating shaft 31, and a traction rope 29 is fixedly connected to one side of the outer wall of the storage tray 28, and a traction hook 30 is fixedly connected to the free end of the traction rope 29; a hanging hole is provided on the side wall of the storage tray 28 for hanging the traction hook 30 to prevent the traction hook 30 from shaking; the movement state of the rotating shaft 31 is controlled by the braking device.

[0050] Further, the brake device in this embodiment includes a worm wheel 27, a worm 26, a brake pad 32 and a rotating handle 25, wherein the rotating handle 25 is connected to the worm 26, the worm 26 is connected to the worm wheel 27, the worm wheel 27 is connected to the brake pad 32, and the brake pad 32 is used to brake the rotation of the storage disk; the brake device is arranged at one end of the storage box 4 away from the crank 24. Specifically, a pair of worm wheels 27 that are symmetrical on the inner side wall of the storage box 4 are rotatably connected, and a brake pad 32 is fixedly connected to the end surface of each worm wheel 27, and the brake pad 32 can fit with the rotating shaft 31, and a worm 26 is vertically arranged between the two worm wheels 27, and the worm 26 is meshed with the two symmetrical worm wheels 27 at the same time, and the worm 26 is connected to the rotating handle 25 located outside the storage box 4 through a connecting rod, and the rotating handle 25 is arranged on the top of the storage box 4; further, in this embodiment, two opposite sides of the rotating shaft in the circumferential direction are provided with a card slot for matching with the brake pad 32.

[0051] When moving the nitrogen foam generating device, the opening and closing plate 22 is opened, and the carrier can be connected to the traction rope 29 through the traction hook 30 to ensure that the device can be towed securely. One end of the traction rope 29 is fixedly connected to the storage tray 28, and the rotating shaft 31 can be manually driven to rotate through the crank 24, thereby driving the storage tray 28 to rotate and realize the retracting and releasing operation of the traction rope 29. The design of the crank 24 allows the operator to easily adjust the length of the traction rope 29 to meet different usage requirements.

[0052] When it is necessary to control the retraction and fixing of the traction rope 29, the worm 1 26 can be driven to rotate by rotating the handle 25. The worm 1 26 is meshed with the outer wall of the worm wheel 1 27. The operation of rotating the handle 25 will drive the left-right symmetrical worm wheel 1 27 to rotate synchronously in the opposite direction. The worm wheel 1 27 is fixedly connected with a brake pad 32. During the rotation of the worm wheel 1 27, the brake pad 32 fits the outer wall of the rotating shaft 31 to generate friction, thereby controlling the motion state of the rotating shaft 31.

[0053] When the traction rope 29 needs to be locked, the handle 25 is rotated to continue to rotate the worm 26, so that the worm wheel 27 drives the brake pad 32 to move relatively, and the brake pad 32 is tightly closed on the rotating shaft 31. After the brake pad 32 is closed, the rotating shaft 31 is locked, and the storage tray 28 cannot rotate either, so that the length of the traction rope 29 can be effectively fixed to prevent the traction rope 29 from accidentally sliding or loosening.

[0054] After the traction rope 29 is stored, in order to ensure the neatness and safety of the device, the storage box 4 can be closed by the opening and closing plate 22. The opening and closing plate 22 is connected to the front side of the storage box 4 by rotation to ensure that it can be opened and closed flexibly. After closing, the opening and closing plate 22 is fixed to the outer wall of the storage box 4 using the fixing bolt 23 to ensure the sealing of the storage box 4 and the stable placement of the traction rope 29. This design not only improves the convenience of use of the device, but also ensures the safety and stability of the traction rope 29, avoiding unexpected situations that may occur during transportation and storage.

[0055] Example 4 Based on Example 2 or Example 3, in order to ensure that the nitrogen foam generating device can operate stably, this embodiment further improves the frame 1: Please refer to Figure 7-Figure 8 , the frame 1 is provided with support columns 2 on both sides, the support columns 2 are hollow structures, the support columns 2 are sleeved with threaded columns 38 inside, and the threaded columns 38 can move along the support columns 2 in the vertical direction; the bottom of the threaded columns 38 is fixedly connected with a support seat 33, the outer contour size of the support seat 33 is larger than the outer contour size of the support column 2, and is used for upper limit positioning and support; a worm gear 2 37 is provided between the support seat 33 and the support column 2, and the inner wall of the worm gear 2 37 is threadedly connected to the threaded column 38. A second driving device is fixedly connected to both sides of the bottom of the frame 1. The second driving device in this embodiment includes a double-headed motor 34, the output end of the double-headed motor 34 is fixedly connected to a connecting shaft 35, one end of the connecting shaft 35 is fixedly connected to a worm gear 2 36, and the outer wall of the worm gear 2 36 is meshed with the outer wall of the worm gear 2 37.

[0056] In an optional embodiment, a threaded column 38 is slidably connected inside the support column 2, and four limiting grooves 39 are provided on the outer wall of the threaded column 38. The four limiting grooves 39 are arranged in a circular array, and a protrusion that snaps into engagement with the limiting groove 39 is provided on the inner wall of the support column 2. The threaded column 38 is slidably connected to the support column 2 along the vertical direction.

[0057] When in use, the connecting shaft 35 can be driven to rotate by the double-headed motor 34. The output end of the double-headed motor 34 is fixedly connected to the connecting shaft 35, and one end of the connecting shaft 35 is connected to the worm 2 36. When the double-headed motor 34 is started, the connecting shaft 35 will drive the worm 2 36 to rotate, and the outer wall of the worm 2 36 is meshed with the outer wall of the worm wheel 2 37, so the rotation of the worm 2 36 will drive the worm wheel 2 37 to rotate synchronously.

[0058] The worm gear 2 37 is fixed to the bottom of the support column 2, and the movement of the threaded column 38 can be controlled by the rotation of the worm gear 2 37. The outer wall of the threaded column 38 is threadedly connected to the inside of the worm gear 2 37, and since the outer wall of the threaded column 38 is provided with a ring array of limiting grooves 39, the inner wall of the support column 2 is slidably connected with the limiting grooves 39, ensuring that the threaded column 38 can only slide up and down inside the support column 2, avoiding lateral displacement.

[0059] When the worm gear 2 37 rotates, it drives the threaded column 38 to slide downward, so that the support base 33 at the bottom of the threaded column 38 gradually contacts and supports the ground. The support base 33 provides additional stable support to ensure the stability and safety of the device during operation. Through this design, when the device needs to be moved or fixed, the operator can simply adjust the height of the support base 33 by controlling the double-headed motor 34, thereby achieving fast and reliable support and stability.

[0060] The adoption of this solution not only improves the overall stability of the device, but also enhances its adaptability under different terrains and working conditions. Through the precise control of the limit groove 39, the sliding of the threaded column 38 inside the support column 2 is smoother, avoiding the instability of the device due to unnecessary displacement. In addition, the precise engagement between the worm 36 and the worm wheel 37 makes the entire driving and supporting process efficient and reliable, ensuring the stable use of the device under various operating conditions.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A foam generator, characterized in that: It comprises a reaction tank (5), wherein the reaction tank (5) is provided with a gas inlet, a liquid inlet and a foam outlet; A hollow rotating column (16) is provided in the reaction tank (5), the hollow rotating column (16) is rotatably connected to the reaction tank (5), the hollow rotating column (16) is used for rotation, the hollow rotating column (16) is a hollow structure, the hollow rotating column (16) is connected to the gas inlet, and a plurality of exhaust holes (17) are provided on the side wall of the hollow rotating column (16) along the axial direction; The foam outlet is located above the hollow rotating column (16).

2. A foam generator according to claim 1, characterized in that: A plurality of stirring blades (40) are axially arranged on the side wall of the hollow rotating column (16).

3. A foam generator according to claim 1, characterized in that: The reaction tank (5) is of a cylindrical structure, and the reaction tank (5) and the hollow rotating column (16) are both arranged transversely.

4. A foam generator according to claim 3, characterized in that: The gas inlet is provided with an air outlet pipe (10), the foam outlet is provided with a foam discharge pipe (6), and the liquid inlet is provided with a water delivery pipe (8); The outer wall of the gas outlet pipe (10) is rotatably connected to the hollow rotating column (16), the outer wall of the hollow rotating column (16) is rotatably connected to the gas inlet, and the gas outlet pipe (10) is arranged to be bent upward at the gas inlet; The foam discharge pipe (6) comprises a first bend section and a second bend section, the first bend section is connected to the foam outlet, and the first bend section is projected in a bend on a horizontal plane; the second bend section is connected to the first bend section, and the second bend section is bent upward, and the top of the second bend section is higher than the reaction tank (5).

5. A foam generator according to any one of claims 1 to 4, characterized in that: The invention also comprises a first driving device, the first driving device being used for driving the hollow rotating column (16) to rotate; the first driving device comprising a driving wheel (20), a driven ring (18) and a motor (21), the motor (21) being connected to the driving wheel (20), the driving wheel (20) and the driven ring (18) being connected via a belt (19), a first universal shaft (41) being fixedly connected to one side of the outer wall of the hollow rotating column (16), a main shaft (42) being fixedly connected to one side of the outer wall of the first universal shaft (41), a second universal shaft (43) being fixedly connected to one end of the main shaft (42), a scraper (46) being fixedly connected to one side of the outer wall of the second universal shaft (43), a fixed shell (44) being fixedly connected to one side of the interior of the reaction tank (5), the outer wall of the scraper (46) being rotatably connected to the interior of the fixed shell (44), and a filter screen (45) being fixedly connected to the interior of the fixed shell (44).

6. A nitrogen foam generating device for nitrogen foam fracturing, characterized in that: A foam generator comprising any one of claims 1 to 5, further comprising: A nitrogen storage tank (13), the nitrogen storage tank (13) is used to store nitrogen, and the nitrogen storage tank (13) is connected to the gas inlet via an air pump (11); A foam generating liquid storage water tank (12), wherein the foam generating liquid storage water tank (12) is used to store the foam generating liquid, and the foam generating liquid storage water tank (12) is connected to the liquid inlet via a water pump (7).

7. A nitrogen foam generating device for nitrogen foam fracturing according to claim 6, characterized in that: It also includes a traversable frame (1), and the foam generating liquid storage water tank (12) and the nitrogen storage tank (13) are both fixedly mounted on the frame (1).

8. The nitrogen foam generating device for nitrogen foam fracturing according to claim 7, characterized in that: The foam generating liquid storage water tank (12) is installed at the middle of the frame (1), and the water pump (7) is located at the head of the frame (1); the nitrogen storage tank (13) is installed at the rear of the frame (1), and the air pump (11) is installed on the top of the foam generating liquid storage water tank (12); the reaction tank (5) is installed at the head of the frame (1), and the reaction tank (5) is installed above the water pump (7).

9. The nitrogen foam generating device for nitrogen foam fracturing according to claim 7, characterized in that: It also includes a storage assembly for storing a traction rope (29), the storage assembly being mounted on either end of the frame (1); the storage assembly includes a storage box (4) and a braking device; The storage box (4) is provided with an opening, and a storage tray (28) is provided inside the storage box (4). The storage tray (28) is used to wind up a traction rope (29). Both ends of the storage tray (28) are provided with a rotating shaft (31), and the rotating shaft (31) is rotatably connected to the storage box (4). One end of the rotating shaft (31) is provided with a crank (24), and the crank (24) is located outside the storage box (4); The braking device comprises a worm wheel 1 (27), a worm screw 1 (26), a brake pad (32) and a rotating handle (25), wherein the brake pad (32) is used to contact the rotating shaft (31), the brake pad (32) is fixedly connected to the end surface of the worm wheel 1 (27), the worm wheel 1 (27) is meshed with the worm screw 1 (26), the worm screw 1 (26) is connected to the rotating handle (25), and the rotating handle (25) is located outside the storage box (4).

10. A nitrogen foam generating device for nitrogen foam fracturing according to any one of claims 7 to 9, characterized in that: Support columns (2) are provided on both sides of the frame (1), and a threaded column (38) is sleeved inside the support column (2). A limit groove (39) is vertically provided on the threaded column (38), and the threaded column (38) can move relative to the support column (2) in the vertical direction; a support seat (33) is provided at the bottom end of the threaded column (38), and the outer contour size of the support seat (33) is larger than the outer contour size of the support column (2); a second worm gear (37) is provided between the support seat (33) and the support column (2), and the second worm gear (37) is threadedly connected to the threaded column (38); a second driving device is provided at the bottom of the frame (1), and the second driving device includes a second worm gear (36), and the second worm gear (36) is meshed with the second worm gear (37).

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