A foam generator and a nitrogen foam generating device for nitrogen foam fracturing

Abstract

The present invention relates to the technical field of petrochemical engineering, and particularly relates to a foam generator and a nitrogen foam generating device for nitrogen foam fracturing. In the present invention, gas is injected into the foam generating liquid in a rotating manner through a hollow rotating column. The gas can not only increase the nitrogen filling range along the circumferential direction of the hollow rotating column by centrifugal force, but also be distributed along the axial direction of the hollow rotating column. The uniformity of the bubble distribution and particle size is good, the nitrogen utilization rate is high, the waste of nitrogen resources is small, the energy consumption of the equipment is small, and the preparation efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical engineering, and particularly 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. The nitrogen foam generating device plays a key role in this technology. It can generate nitrogen foam to improve the fracturing effect. Such a device usually consists of a nitrogen supply system, a foam generator, a control system, etc. The nitrogen supply system provides high-pressure nitrogen for the foam generator. The foam generator is a key device for generating foam, which forms foam by stirring and 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, the foam generator generally uses a stirring impeller to rotate at a high speed to stir the injected nitrogen, liquid medicine and water. The stirring efficiency is low, and there are problems such as coarse bubble diameter and low uniformity. The formation of foam is not stable enough, which affects the quality and performance of the foam. The patent document with the publication number CN206053919U in the prior art proposes a new type of intelligent high-pressure large-displacement nitrogen foam device. In this scheme, a gas-liquid mixing chamber is arranged at the front end of the inner cavity of the foam generator, and a non-powered stirring impeller is arranged at the rear end. In the gas-liquid mixing chamber, gas directly enters the distribution pipe through the gas inlet and is dispersed into small bubbles. The liquid enters in a rotating manner and drives the gas to mix. Then, the preliminarily mixed foam liquid passes through the first spiral stirring impeller and the second spiral stirring impeller, changes direction multiple times and generates stirring with water to crush the gas and form micro-bubbles in water. Although this scheme improves the quality and performance of the generated foam to a certain extent by preparing foam in stages - first pre-treating to achieve the mixing of liquid and gas, and then crushing the gas through stirring, the foam preparation time is long, and the way that the liquid enters in a rotating manner (the gas-liquid mixing cavity is filled with liquid) has high energy consumption for the equipment. At the same time, since the gas is driven to mix by the liquid in a rotating manner, the stirring efficiency is low, which easily leads 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 preparing nitrogen foam in the prior art.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present invention is as follows:

[0006] A foam generator, characterized in that it includes a reaction tank, and the reaction tank is provided with a gas inlet, a liquid inlet and a foam outlet; a hollow rotating column is arranged in the reaction tank, the hollow rotating column is rotationally connected to the reaction tank, the hollow rotating column is used for rotation, the hollow rotating column is of a hollow structure, the hollow rotating column is communicated with the gas inlet, and is used for introducing gas into the hollow rotating column at the gas inlet, and a plurality of exhaust holes are arranged axially on the side wall of the hollow rotating column; the foam outlet is located above the hollow rotating column.

[0007] When preparing nitrogen foam by using the above-mentioned foam generator, 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 axially on the side wall of the hollow rotating column. While the small bubbles are discharged from the exhaust holes, by driving the hollow rotating column to rotate at a high speed, the small bubbles are broken and diffused in the foam generating liquid by using the centrifugal force and the cutting of the inner wall of the exhaust holes, so that the bubbles are in full contact with the foam generating liquid to form foam. After the foam rises, it can be discharged through the foam outlet and put into use.

[0008] In this solution, the gas is injected into the foam generating liquid in a rotating manner through the hollow rotating column. The gas can not only increase the nitrogen filling range along the circumferential direction of the hollow rotating column by centrifugal force, but also be distributed along the axial direction of the hollow rotating column, so as to facilitate the rapid generation of a large amount of foam. The distribution and particle size of the bubbles are good. Compared with the method of directly introducing the gas, the nitrogen utilization rate is greatly improved, and the waste of nitrogen resources is reduced; and compared with the prior art in which the liquid is injected in a rotating manner, the resistance of the gas rotating into the liquid is smaller, which is beneficial to reducing the energy consumption of the equipment.

[0009] In addition, in this solution, the gas-liquid mixing and the hollow rotating column for high-speed stirring are arranged in the same working space, and the operation sequence is synchronized. Compared with the prior art in which the gas-liquid mixing chamber and the unpowered stirring impeller are arranged in the front and rear poles in the inner cavity of the foam generator, the foam generator provided by this solution has a more compact structure, higher space utilization rate, and higher preparation efficiency, which is beneficial to reducing the economic cost.

[0010] In this solution, both ends of the hollow rotating column can be rotatably connected to the reaction tank simultaneously, 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 it is open, the open end should be as close as possible to or in direct contact with the inner wall of the reaction tank. If necessary, the rotation of this end can be supported by setting bearings or brackets on the inner wall of the reaction tank, etc., 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 drain holes on its side wall, the rotation speed of the hollow rotating column, and other parameters are determined according to the high-precision requirements for oil extraction fracturing.

[0011] As a preferred solution of the present invention, a plurality of stirring blades are arranged axially on the side wall of the hollow rotating column. By stirring the foam generating liquid with the stirring blades, it is beneficial to further improve the contact efficiency between the foam generating liquid and nitrogen, accelerate the reaction, and further increase the uniformity of their mixing.

[0012] As a preferred solution of the present invention, the reaction tank has a cylindrical structure, and both the reaction tank and the hollow rotating column are arranged horizontally, that is, the length directions of the reaction tank and the hollow rotating column are the same, and they are both placed flat along the length direction. The structure layout is reasonable, and the hollow rotating column occupies a large space in the reaction tank, which is beneficial to the uniform distribution of bubbles. Moreover, by arranging the hollow rotating column horizontally, the generated bubbles 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 generated bubbles is good.

[0013] 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, and the air outlet pipe is bent upward at the gas inlet, which is beneficial to avoid the liquid reflux in the reaction tank; a foam discharge pipe is provided at the foam outlet, the foam discharge pipe includes a first return bend section and a second return bend section, the first return bend section is connected to the foam outlet, the projection of the first return bend section on the horizontal plane is in a return bend setting, which is convenient for discharging foam along the horizontal plane, the second return bend section is connected to the first return bend section, the second return bend section is bent upward and the top of the second return bend section is higher than the reaction tank, so that the water head of the second return bend section is higher than the water head in the reaction tank to form a pressure difference, which plays a certain blocking role on the laterally discharged foam, avoids the direct outflow of foam, and also avoids the liquid loss of the foam in the reaction tank; a water delivery pipe is provided at the liquid inlet for injecting liquid into the reaction tank. This solution uses a pipeline layout method to supply gas and liquid to the reaction tank, with convenient transmission and flexible layout.

[0014] As other implementable ways, a communicating chamber can also be hermetically arranged corresponding to the gas inlet / foam outlet / liquid inlet, and gas / liquid injection or foam discharge can be realized by pressurizing or pumping the communicating chamber; the structure of the reaction tank is not limited to a circular cross-section, and can also adopt a square cross-section, a gourd-shaped cross-section, a spherical structure, etc.; the ways of the gas inlet, the foam outlet, and the liquid inlet can also be flexibly arranged according to specific working conditions, not limited to the above examples.

[0015] As a preferred embodiment of the present invention, it further includes a first driving device, and the first driving device 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, the driving wheel and the driven ring are connected by a belt, and the driven ring is arranged on the extending end of the hollow rotating column; wherein, the extending end of the hollow rotating column can be the end close to the gas outlet or the end far from the gas outlet. The motor drives the driving wheel to rotate, and the belt and the driven ring drive the hollow rotating column to rotate, so as to prepare foam.

[0016] As other implementable ways, the first driving device can also adopt a gear transmission method to drive the hollow rotating column to rotate. For example, the first driving device includes a motor and a driving gear connected to the motor, and a driven gear is arranged on the extending end of the hollow rotating column, and the driving gear and the driven gear are meshed, not limited to the above examples.

[0017] The present invention also provides a nitrogen foam generating device for nitrogen foam fracturing, which includes any one of the above foam generators, and further includes:

[0018] A nitrogen storage tank for storing nitrogen. The nitrogen storage tank is connected to the gas inlet through an air pump, and the air pump is used to extract gas from the nitrogen storage tank.

[0019] A foam generating liquid storage water tank for storing foam generating liquid. The foam generating liquid storage water tank is connected to the liquid inlet through a water pump, and the water pump is used to extract foam generating liquid from the foam generating liquid storage water tank.

[0020] In this solution, the pre-prepared foam generating liquid is stored in the foam generating liquid storage water tank. The water pump extracts the foam generating liquid in the foam generating liquid storage water tank and transports it into the reaction tank. At the same time, the air pump extracts 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 the gas, which is beneficial to ensuring the smooth progress of the reaction, with good stability and uniformity of the generated foam. At the same time, it is also convenient to control the preparation process of the foam through the air pump and the water pump, improving the preparation efficiency and nitrogen utilization rate.

[0021] As a preferred solution of the present invention, the present invention further includes a travelable vehicle frame, and both the foam generating liquid storage water tank and the nitrogen storage tank are fixedly installed on the vehicle frame, which is convenient for movement and improves the use flexibility.

[0022] As a preferred solution of the present invention, the foam generating liquid storage water tank is installed in the middle of the vehicle frame, and the water pump is located at the head of the vehicle frame; the nitrogen storage tank is installed at the tail of the vehicle 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 vehicle frame and is installed above the water pump. The overall structure is compactly arranged, with high space utilization rate and convenient pipeline layout.

[0023] As a preferred solution of the present invention, the present invention further includes a storage component for storing a towing rope. The storage component is installed at any end of the vehicle frame; the storage component includes a storage box and a braking device; the storage box is provided with an opening, and a storage tray is arranged inside the storage box. The storage tray is used for winding and setting the towing rope. Both ends of the storage tray are provided with rotating shafts, and the rotating shafts are rotatably connected to the storage box. One end of the rotating shaft is provided with a crank, and the crank is located outside the storage box for convenient manual operation; the braking device includes a first worm gear, a first worm, a brake pad, and a rotating handle. The brake pad is used to contact the rotating shaft, and the brake pad is fixedly connected to the end face of the first worm gear. The first worm gear meshes with the first worm, and the first worm is connected to the rotating handle. The rotating handle is located outside the storage box.

[0024] In this solution, a storage component is provided at the head of the frame for connecting to a vehicle, and the device is towed by the vehicle to achieve movement. In the storage component, an opening on the storage box allows the towing rope to pass through. The winch handle is used to drive the storage disc to rotate, so as to wind and unwind the towing rope. The rotary handle controls the rotation of the first worm, which drives the rotation of the first worm gear. The first worm gear drives the brake pad to rotate, realizing the approach and separation from the rotating column, thereby controlling the extension length of the towing rope and the placement stability. The device is towed by the towing rope, solving the problem that the device is inconvenient to move and improving its flexibility in use.

[0025] As a preferred solution of the present invention, support columns are provided on both sides of the frame. A threaded column is sleeved inside the support column. A limiting groove is vertically provided on the threaded column. Correspondingly, a protrusion or roller and other structures that cooperate with the limiting groove are provided on the inner side wall of the support column. The protrusion can be a continuous structure or multiple protrusions can be arranged at intervals in the vertical direction, so that the threaded column can move relative to the support column in the vertical direction, and at the same time, circumferential limitation can be achieved through the limiting groove. A support seat is provided at the bottom end of the threaded column. The outer contour size of the support seat is larger than the outer contour size of the support column, for limiting and supporting. A second worm gear is provided between the support seat and the support column. The second worm gear is threadedly connected to the threaded column. A second driving device is provided at the bottom of the frame. The second driving device includes a second worm. The second worm meshes with the second worm gear. By driving the second worm to rotate the second worm gear, the threaded column is driven to move up and down along the support column. When the above nitrogen foam generating device reaches the designated position, the support seat is driven to support on the ground, solving the problem that the nitrogen foam generating device is unstable during use and improving the stability and safety of the device in use.

[0026] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are:

[0027] 1. For the foam generator provided by the present invention, gas is injected into the foam generating liquid in a rotating manner through the hollow rotating column to prepare foam. The gas can not only increase the nitrogen filling range along the circumference of the hollow rotating column through centrifugal force, but also be distributed along the axial direction of the hollow rotating column. The bubble distribution and particle size are good, the nitrogen utilization rate is high, the waste of nitrogen resources is small, the energy consumption of the equipment is small, and the preparation efficiency is high.

[0028] 2. The nitrogen foam generating device provided by the present invention stores the pre-prepared foam generating liquid in the foam generating liquid storage water tank, pumps the foam generating liquid in the foam generating liquid storage water tank into the reaction tank through a water pump, and at the same time, pumps nitrogen in the nitrogen storage tank into the reaction tank by an air pump. 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 generated foam has good stability and uniformity. At the same time, it is also convenient to control the preparation process of the foam through the water pump and the air pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic cross-sectional structure diagram of a foam generator provided by the present invention;

[0030] Figure 2 is a three-dimensional Figure 1 ;

[0031] Figure 3 is a three-dimensional of a nitrogen foam generating device for nitrogen foam fracturing provided by the present invention Figure 2 ;

[0032] Figure 4 is a schematic structure diagram of the storage component;

[0033] Figure 5 is a schematic internal structure of the storage component Figure 1 ;

[0034] Figure 6 is a schematic internal structure of the storage component Figure 2 ;

[0035] Figure 7 is a schematic structure diagram of the vehicle frame;

[0036] Figure 8 is a schematic cross-sectional structure diagram of the support column.

[0037] Icons: 1 - Frame; 2 - Support column; 3 - Tire; 4 - Storage box; 5 - Reaction tank; 6 - Foam discharge pipe; 7 - Water pump; 8 - Water delivery pipe; 9 - Water suction pipe; 10 - Air outlet pipe; 11 - Air pump; 12 - Foam generating liquid storage water tank; 13 - Nitrogen storage tank; 14 - Fixed frame; 15 - Three-way intake pipe; 16 - Hollow rotating column; 17 - Exhaust hole; 18 - Driven ring; 19 - Belt; 20 - Driving wheel; 21 - Motor; 22 - Opening and closing plate; 23 - Fixed bolt; 24 - Crank; 25 - Rotating handle; 26 - Worm 1; 27 - Worm gear 1; 28 - Storage tray; 29 - Towing rope; 30 - Towing hook; 31 - Rotating shaft; 32 - Brake pad; 33 - Support seat; 34 - Double-headed motor; 35 - Connecting shaft; 36 - Worm 2; 37 - Worm gear 2; 38 - Threaded column; 39 - Limit groove; 40 - Stirring blade; 41 - Universal shaft 1; 42 - Main shaft; 43 - Universal shaft 2; 44 - Fixed shell; 45 - Filter screen; 46 - Scraper. Detailed implementation mode

[0038] The present invention will be further described in detail below in conjunction with specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present invention to the following embodiments. All technologies implemented based on the content of the present invention belong to the scope of the present invention.

[0039] In the description of the specific embodiments of the present invention, without special explanation, the expression terms indicating the orientation or positional relationship such as "upper", "lower", "left", "right", "center", "inner", "outer", etc. are all based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship when the invention product / device / equipment is usually used and placed. These terms of orientation or positional relationship are only for the convenience of describing the solution of the present invention or simplifying the description in the specific embodiments, so as to facilitate technicians to quickly understand the solution, rather than indicating or implying that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific positional relationship. Therefore, it should not be construed as a limitation to the present invention.

[0040] In addition, when terms such as "horizontal", "vertical", "hanging", "parallel" appear, it does not mean that the corresponding device / component / element is required to be absolutely horizontal or vertical or hanging or parallel, but it can be slightly inclined or deviated. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and it does not mean that the structure must be completely horizontal, but it can be slightly inclined. Or, it can be simply understood that the corresponding device / component / element is arranged in directions such as "horizontal", "vertical", "hanging", "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%, more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still perform its function in the solution of the present invention.

[0041] In addition, when expressions such as "first", "second", "third", etc. appear in the terms, they are only 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.

[0042] In addition, in the description of the embodiments of the present invention, "several", "multiple", "a plurality of" represent at least 2. It can be any situation such as 2, 3, 4, 5, 6, 7, 8, 9, etc., and even can be a situation exceeding 9.

[0043] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / limited, when terms such as "set", "installed", "connected", "coupled", "provided with", "laid", "arranged" appear, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be connection means commonly used in the art such as welding, riveting, bolting, threaded connection, etc. Such a connection can be a mechanical connection, an electrical connection or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements.

[0044] Embodiment 1

[0045] As Figure 1 、 Figure 2 shown, this embodiment provides a foam generator, which includes a reaction tank 5 and a first driving device.

[0046] 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 for injecting gas, the liquid inlet is used for injecting liquid, and the foam outlet is used for discharging excess nitrogen and foam. A hollow rotating column 16 is provided in the reaction tank 5. The hollow rotating column 16 is rotationally connected to the reaction tank 5 and is used for rotation. The hollow rotating column 16 has a hollow structure and is communicated with 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 uniformly 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.

[0047] In an alternative embodiment, the reaction tank 5 has a cylindrical structure. Both the reaction tank 5 and the hollow rotating column 16 are preferably arranged horizontally, that is, the length directions of the reaction tank 5 and the hollow rotating column 16 are the same and are laid flat along the length direction. The structural arrangement is reasonable. 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 generated bubbles 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 generated bubbles is good.

[0048] In an alternative 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. The other end of the hollow rotating column 16 contacts the inner side wall of the reaction tank 5 or is rotationally connected to the inner wall of the reaction tank 5 through a rotating shaft 31. An outlet pipe 10 is connected in a matching manner at the extended end of the hollow rotating column 16. One end of the outlet pipe 10 is rotationally connected and hermetically fitted with the extended end of the hollow rotating column 16, and the other end of the outlet pipe 10 is used to connect to a gas supply source. Specifically, in this embodiment, the outer wall of the 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 outlet pipe 10 is bent upward at the gas inlet to prevent the liquid in the reaction tank 5 from flowing back.

[0049] In an alternative embodiment, in this embodiment, it is preferably set that the gas inlet and the foam outlet are respectively located at opposite ends of the reaction tank 5, and the liquid inlet is located on the side wall of the reaction tank 5, such as the bottom, which is convenient for arranging pipelines. A foam discharge pipe 6 is provided at the foam outlet, and a water delivery pipe 8 is provided at the liquid inlet. The water delivery pipe 8 is used to connect to a water supply source, and the water delivery pipe 8 can be a straight pipe. The pipeline arrangement method is used to supply gas and liquid to the reaction tank 5, and the transmission is convenient and the arrangement is flexible.

[0050] In an alternative embodiment, the foam discharge pipe 6 includes a first bent section and a second bent section; the first bent section is connected to the foam outlet, and the first bent section is bent horizontally, with a U-shaped horizontal projection, facilitating the discharge of foam along the horizontal plane; the second bent section is connected to the first bent section, and the second bent section is bent upward, with a U-shaped projection in the longitudinal section, which helps to reduce the lateral width occupation. The top of the second bent section is higher than the reaction tank 5, so that the water head of the second bent section is higher than the water head in the reaction tank 5 to form a pressure difference, which plays a certain role in blocking the laterally discharged foam, preventing the foam from flowing out directly and also preventing liquid loss of the foam in the reaction tank 5.

[0051] In an alternative embodiment, in order to improve the reaction efficiency, a plurality of stirring blades 40 are also fixedly connected to the outer wall of the hollow rotating column 16. During rotation, these stirring blades 40 fully stir the foam generating liquid and nitrogen, enhancing the mixing effect of nitrogen and the foam generating liquid and accelerating their reaction rate.

[0052] In an alternative embodiment, the first driving device includes a driving wheel 20, a driven ring 18, and a motor 21. During 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 and fixed on the protruding end of the hollow rotating column 16. The driving wheel 20 is rotated by the motor, and the hollow rotating column 16 is driven to rotate through the belt 19 and the driven ring 18, thereby preparing foam.

[0053] When preparing nitrogen foam using the above foam generator, the foam generating liquid is injected through the liquid inlet; nitrogen is injected through the gas inlet. The nitrogen is dispersed into small bubbles through a plurality of exhaust holes 17 arranged axially on the side wall of the hollow rotating column 16. While the small bubbles are discharged from the exhaust holes 17, by driving the hollow rotating column 16 to rotate at a high speed, the small bubbles are broken and diffused in the foam generating liquid by using centrifugal force and the cutting of the inner wall of the exhaust holes 17, so that the bubbles are in full contact with the foam generating liquid to form foam. After the foam overflows, it can be discharged through the foam outlet for use. After the foam overflows, it needs to pass through the filter screen 45 embedded in the fixed shell 44 to enter the interior of the fixed shell 44. At the same time, the foam discharge pipe 6 is covered by the fixed shell 44, so the foam filtered by the filter screen 45 will be put into use, making the foam for use finer and thus achieving a better use effect. When the hollow rotating column 16 rotates, the main shaft 42 can be driven by the universal shaft one 41, and then the scraper 46 is driven to rotate by the universal shaft two 43. The scraper 46 can prevent foam from adhering to the filter screen 45, thus keeping the filter screen 45 with an efficient filtering effect.

[0054] Embodiment 2

[0055] Based on Embodiment 1, this embodiment provides a nitrogen foam generating device for nitrogen foam fracturing. Please refer to Figure 2 - Figure 3, including a drivable vehicle frame 1, the above-mentioned foam generator, nitrogen storage tank 13, foam generating liquid storage water tank 12, air pump 11 and water pump 7. Among them, the nitrogen storage tank 13 is used to store nitrogen. The nitrogen storage tank 13 is connected to the gas inlet on the reaction tank 5 of the foam generator 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 the foam generating liquid, and the foam generating liquid storage water tank 12 is connected to the liquid inlet on the reaction tank 5 of the foam generator through the water pump 7, and the water pump 7 is used to extract the foam generating liquid from the foam generating liquid storage water tank 12.

[0056] Since most foam generators are of fixed design, but when used in oil fields, to increase their flexibility, in this embodiment, the foam generator, nitrogen storage tank 13 and foam generating liquid storage water tank 12 are all fixedly installed on one side of the top of the drivable vehicle frame 1, so that the nitrogen foam generating device can be moved through the 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.

[0057] Specifically, in this embodiment, the foam generating liquid storage water tank 12 is installed in the middle of the vehicle frame 1, the water pump 7 is installed at the head of the vehicle frame 1, the foam generating liquid storage water tank 12 and the water pump 7 are connected by a water suction pipe 9, and the water pump 7 and the reaction tank 5 are connected by a water delivery pipe 8; in this embodiment, the nitrogen storage tank 13 is installed at the tail of the vehicle frame 1, and the nitrogen storage tank 13 is fixedly connected to the vehicle frame 1 through a fixing frame 14. The number of nitrogen storage tanks 13 in this embodiment is two, and the two nitrogen storage tanks 13 are connected to a three-way inlet pipe 15, and the three-way 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 vehicle frame 1. A motor 21 is fixedly installed on the top of the reaction tank 5, the output end of the motor 21 is fixedly connected with a driving wheel 20, 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 inside the reaction tank 5; tires 3 are rotatably connected to both sides of the vehicle frame 1, and the tires 3 are arranged in a rectangular array.

[0058] When the device is in use, first, the foam generating liquid storage water tank 12 is used to store the foam generating liquid. Then, the water pump 7 uses the suction pipe 9 to extract the foam generating liquid from the foam generating liquid storage water tank 12, and discharges the foam generating liquid 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 inlet air pipe 15, and the nitrogen enters the reaction tank 5 through the 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, guaranteeing the smooth progress of the reaction.

[0059] When nitrogen enters the reaction tank 5, the nitrogen will enter the hollow rotating column 16 arranged inside the reaction tank 5. During use, due to the sufficiently large pressure of nitrogen, it can ensure that the injected foam generating liquid does not enter the inside of 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, enabling nitrogen to be evenly discharged into the foam generating liquid inside the reaction tank 5. As the hollow rotating column 16 rotates, nitrogen rapidly diffuses in the foam generating liquid.

[0060] 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 blade 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, enabling it to achieve better results during the nitrogen foam fracturing process. In this way, the device can provide continuous, stable, and efficient foam generating capacity in practical applications, meet the usage requirements under different working conditions, and provide reliable technical support for nitrogen foam fracturing.

[0061] Embodiment 3

[0062] Based on Embodiment 2, please refer to Figure 4 - Figure 6 , in this embodiment, a storage component is further provided at the head of the vehicle frame 1. The storage component is used to connect to the vehicle carrier, and the entire nitrogen foam generating device is moved by towing the vehicle frame through the vehicle carrier.

[0063] Specifically, in this embodiment, the storage component is installed on one side of the top of the vehicle frame 1. The storage component 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 vehicle frame 1, and an opening is provided on the storage box 4 to provide a moving space for pulling the vehicle. An opening and closing plate 22 is arranged at the opening to cover the opening and prevent 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 fixation, plug-in connection, etc.; a rotating shaft 31 is rotatably connected inside the storage box 4, and one end of the rotating shaft 31 extends out of the storage box 4 and a crank 24 is fixedly connected to the extending end; a storage disk 28 is fixedly connected to the outer wall of the rotating shaft 31, a traction rope 29 is fixedly connected to one side of the outer wall of the storage disk 28, and a traction hook 30 is fixedly connected to the free end of the traction rope 29; hanging holes are provided on the side wall of the storage disk 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.

[0064] Further, the braking device in this embodiment includes a first worm gear 27, a first worm 26, a brake pad 32, and a rotating handle 25. The rotating handle 25 is connected to the first worm 26, the first worm 26 is connected to the first worm gear 27, and the first worm gear 27 is connected to the brake pad 32. The brake pad 32 is used for braking the rotation of the storage disk; the braking device is arranged at one end of the storage box 4 away from the crank 24. Specifically, a pair of left-right symmetric first worm gears 27 are rotatably connected to the inner side wall of the storage box 4, and a brake pad 32 is fixedly connected to the end face of each first worm gear 27. The brake pad 32 can be attached to the rotating shaft 31. A first worm 26 is vertically arranged between the two first worm gears 27. The first worm 26 meshes with the two left-right symmetric first worm gears 27 at the same time. The first 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, clamping grooves for cooperating with the brake pad 32 are provided on the opposite sides in the circumferential direction of the rotating shaft.

[0065] When moving the nitrogen foam generating device, open the opening and closing plate 22, and a vehicle can be connected to the traction hook 30 through the traction rope 29 to ensure that the device can be stably towed. One end of the traction rope 29 is fixedly connected to the storage disk 28. The rotating shaft 31 can be manually driven to rotate through the crank 24, thereby driving the storage disk 28 to rotate and realizing the winding and unwinding operation of the traction rope 29. The design of the crank 24 enables the operator to conveniently adjust the length of the traction rope 29 to meet different usage requirements.

[0066] When it is necessary to control the retraction, extension and fixation of the traction rope 29, the worm 26 can be driven to rotate by rotating the handle 25. The worm 26 meshes with the outer wall of the worm gear 27. The operation of rotating the handle 25 will drive the left and right symmetrical worm gears 27 to rotate in reverse synchronously. The worm gear 27 is fixedly connected with a brake pad 32. During the rotation of the worm gear 27, the brake pad 32 fits against the outer wall of the rotating shaft 31 to generate frictional force, thereby controlling the motion state of the rotating shaft 31.

[0067] When it is necessary to lock the traction rope 29, the worm 26 is continuously rotated by rotating the handle 25, so that the worm gear 27 drives the brake pad 32 to perform relative movement, 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 disc 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.

[0068] After the traction rope 29 is stored, in order to ensure the cleanliness 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 rotationally connected to the front side of the storage box 4 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 by 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 using the device, but also ensures the safety and stability of the traction rope 29, avoiding possible accidents during transportation and storage.

[0069] Embodiment 4

[0070] Based on Embodiment 2 or Embodiment 3, in order to ensure that the above nitrogen foam generating device can operate stably, in this embodiment, the vehicle frame 1 is further improved: Please refer to Figure 7 - Figure 8 , on both sides of the vehicle frame 1, support columns 2 are integrally provided. The support columns 2 are of hollow structure. A threaded column 38 is sleeved inside the support column 2. The threaded column 38 can move along the support column 2 in the vertical direction; a support seat 33 is fixedly connected to the bottom of the threaded column 38. The outer contour size of the support seat 33 is larger than the outer contour size of the support column 2 for upper limit and support; a worm gear 37 is provided between the support seat 33 and the support column 2. The inner wall of the worm gear 37 is threadedly connected to the threaded column 38. On both sides of the bottom of the vehicle frame 1, a second driving device is fixedly connected. 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 with a connecting shaft 35. One end of the connecting shaft 35 is fixedly connected with a worm 36. The outer wall of the worm 36 meshes with the outer wall of the worm gear 37.

[0071] In an alternative embodiment, a threaded column 38 is slidably connected inside the support column 2. Four limiting grooves 39 are formed on the outer wall of the threaded column 38, and the four limiting grooves 39 are arranged in a circular array. Protrusions that are snap-fitted with the limiting grooves 39 are provided on the inner wall of the support column 2. The threaded column 38 and the support column 2 are slidably connected in the vertical direction.

[0072] During 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 with a second worm 36. When the double-headed motor 34 is started, the connecting shaft 35 will drive the second worm 36 to rotate, and the outer wall of the second worm 36 meshes with the outer wall of the second worm gear 37. Therefore, the rotation of the second worm 36 will drive the second worm gear 37 to rotate synchronously.

[0073] The second worm gear 37 is fixed at the bottom of the support column 2. By rotating the second worm gear 37, the movement of the threaded column 38 can be controlled. The outer wall of the threaded column 38 is threadedly connected inside the second worm gear 37, and since the outer wall of the threaded column 38 is provided with limiting grooves 39 arranged in a circular array, 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.

[0074] When the second worm gear 37 rotates, it will drive 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 force 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 control the double-headed motor 34 to adjust the height of the support base 33, thereby achieving fast and reliable support and stability.

[0075] Adopting this solution not only improves the overall stability of the device, but also enhances its adaptability to different terrains and working conditions. Through the precise control of the limiting grooves 39, the sliding of the threaded column 38 inside the support column 2 is more stable, avoiding the instability of the device caused by unnecessary displacement. In addition, the precise meshing between the second worm 36 and the second worm gear 37 makes the entire driving and supporting process efficient and reliable, ensuring the stable use of the device under various operating conditions.

[0076] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention should be included within 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); a foam discharge pipe (6) is provided at the foam outlet; 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, the second bend section is bent upward, and the top of the second bend section is higher than the reaction tank (5); the water head of the second bend section is higher than the water head in the reaction tank (5), thereby forming a pressure difference.

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 a gas outlet pipe (10), and the liquid inlet is provided with a water delivery pipe (8); The outer wall of the air 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 air outlet pipe (10) is arranged to be bent upward at the gas inlet.

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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