Multi-stage composite defoaming synergistic enhancement CO2 oil recovery produced liquid-gas-liquid separation unit

Abstract

The application relates to a multistage composite defoaming synergistic enhancement type CO2 flooding oil production liquid gas-liquid separation device, which comprises a cyclone separation tank, the cyclone separation tank is divided into a bottom tank, a cyclone separation cavity, a gas phase tank and a hot water tank from bottom to top, a jet defoamer communicating with the hot water tank is arranged at the top of the cyclone separation cavity, the cyclone separation cavity communicates with the gas phase tank through a first-stage static defoamer, the cyclone separation cavity is provided with a central shaft, at least two-stage dynamic defoamers are arranged on the central shaft, a first-stage static defoamer is arranged below each-stage dynamic defoamer, the dynamic defoamer comprises a plurality of defoaming blades which are installed around the central shaft in a horizontal radiation mode, a plurality of defoaming holes are uniformly arranged in each defoaming blade, each defoaming blade is connected with the central shaft through upper and lower connecting rings, the multiphase mixed liquid is subjected to porous defoaming and jet defoaming, water resource self-circulation utilization is realized while the multiphase mixed liquid is subjected to step-by-step defoaming and cyclone separation. The jet defoaming, the dynamic defoaming and the static defoaming are complementary to each other, and the separation efficiency is high.

Description

Technical Field

[0001] This invention relates to the field of gas-liquid separation equipment technology, specifically to a multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid gas-liquid separation device. Background Technology

[0002] During oilfield development, especially in the later stages, production wells commonly face issues such as bubbles caused by carbon dioxide foam accompanying the produced fluid, and incomplete defoaming. During production, carbon dioxide liquid transforms into carbon dioxide foam under pressure, easily leading to low separation efficiency and insufficient gas phase recovery. This not only reduces oil and gas well recovery rates but may also cause equipment failure due to insufficient throttling control precision, affecting the continuity of production.

[0003] To address the challenge of gas-liquid separation at wellheads, Chinese patent document CN202521348816.3 designed a gas-liquid cyclone separator. This device, using a combination of a gas escape pipe and a baffle plate, along with an internal return pipe and a filter, improved the reliability of bubble separation. However, this solution lacked a dynamic defoaming device and did not perform secondary treatment on difficult-to-separate bubbles, resulting in low gas-liquid separation efficiency. Furthermore, during gas circulation, the gas phase was only discharged through a single escape pipe, leading to insufficient recovery. Chinese patent document CN202521153895.2 designed a gas-liquid separator using a combination of a filter and a U-shaped discharge pipe. It included an inlet pipe and a U-shaped discharge pipe, with a filter installed at the lower end of one side of the U-shaped discharge pipe. This facilitated disassembly and maintenance and provided a certain degree of separation reliability under stable operating conditions. However, this solution lacked self-circulation and dynamic filter installation, and relied on a single-path flow and a single exhaust structure, making it prone to secondary gas-liquid entrainment and gas phase retention, resulting in limited separation purity and recovery efficiency.

[0004] Meanwhile, existing wellhead separation devices generally suffer from serious water waste and low separation efficiency. Some devices use a large amount of water in their structure to improve separation efficiency, but they do not achieve self-recycling of water resources, and they are not modularly designed for the source of warm water, requiring hot water to be input from the outside; most separation devices do not have a combined static and dynamic defoaming system, and a single separation device cannot effectively separate air bubbles.

[0005] Therefore, there is an urgent need for a wellhead gas-liquid separation device that integrates self-circulation and high-efficiency separation functions and has a compact structure, in order to solve the problems of low separation efficiency, insufficient gas phase recovery and serious water resource consumption in the existing technology, and meet the exploitation needs of high gas-bearing wells. Summary of the Invention

[0006] The purpose of this invention is to provide a multi-stage composite defoaming synergistic enhancement CO2 flooding produced fluid gas-liquid separation device. This multi-stage composite defoaming synergistic enhancement CO2 flooding produced fluid gas-liquid separation device is used to solve the problems of low separation efficiency, insufficient gas phase recovery, and serious water resource consumption in the prior art.

[0007] The technical solution adopted by this invention to solve its technical problem is as follows: This multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device includes a cyclone separator, which is divided from bottom to top into a bottom tank, a cyclone separation chamber, a gas phase tank, and a hot water tank. A double tangential inlet is provided at the upper end of the cyclone separation chamber. A heating wire is installed inside the hot water tank. A jet defoamer connected to the hot water tank is located at the top of the cyclone separation chamber. The cyclone separation chamber and the gas phase tank are connected through a first-stage static defoamer. A central shaft is provided inside the cyclone separation chamber, driven by a motor located below the cyclone separator. At least two stages of dynamic defoamers are provided on the central shaft, and a first-stage static defoamer is provided below each stage of dynamic defoamer. The dynamic defoamers include multiple water-soluble... The defoaming blades are installed radially around the central shaft. Each defoaming blade has several defoaming holes evenly distributed. Each defoaming blade is connected to the central shaft through an upper and lower connecting ring. Each stage of static defoamer is fixed and has several defoaming holes. The cyclone separation chamber and the bottom tank are connected through a first-stage static defoamer set on the bottom plate of the cyclone separation chamber. The multiphase mixture passes through the porous defoaming and jet defoaming treatment in sequence, forming a graded defoaming path of jet defoaming, static defoaming and dynamic defoaming. The bottom tank is equipped with a baffle. The upper part of the bottom tank is equipped with an oil outlet and the lower part is equipped with a water outlet. One of the water outlets of the bottom tank is connected to the hot water tank through a pump and a self-circulation pipe. While performing graded defoaming and cyclone separation, the self-circulation of water resources is realized.

[0008] In the above scheme, a first-stage dynamic defoamer is installed at the upper end of the central shaft, and a second-stage static defoamer is installed below the first-stage dynamic defoamer. The second-stage static defoamer is a circular plate with several defoaming holes, which divides the cyclone separation chamber into two chambers. The two chambers are connected through the several defoaming holes of the circular plate. A second-stage dynamic defoamer is installed on the central shaft between the second-stage static defoamer and the bottom plate of the cyclone separation chamber. A third-stage static defoamer is installed below the second-stage dynamic defoamer. The third-stage static defoamer is a cylindrical body with an open lower end and several defoaming holes. The third-stage static defoamer is fixed above the central hole of the bottom plate of the cyclone separation chamber. A first baffle is fixed below the central hole. The first baffle is a cylindrical body with open ends. The inner diameter of the third-stage static defoamer is equal to that of the first baffle and they are coaxial. The fluid after being defoamed by the second-stage dynamic defoamer can only enter the bottom tank after being defoamed by the third-stage static defoamer.

[0009] In the above scheme, a second baffle is provided at the bottom of the bottom tank, and the lower port of the first baffle extends into the second baffle which is coaxially arranged.

[0010] In the above scheme, the partition between the hot water tank and the gas phase tank is the top of the gas phase tank, and the partition between the gas phase tank and the cyclone separation chamber is the bottom of the gas phase tank. The first-stage static defoamer is a cylindrical body with open ends and several defoaming holes. The upper port of the first-stage static defoamer is closed through the top of the gas phase tank, and the lower port of the first-stage static defoamer is fixed at the center hole at the bottom of the gas phase tank. The fluid from the cyclone separation chamber can only enter the gas phase tank after being defoamed by the first-stage static defoamer and is discharged from the gas outlet of the gas phase tank.

[0011] In the above scheme, the bottom of the cyclone separator is equipped with a bottom support, and the bottom of the cyclone separator sits on the bottom support. The pump and motor are located below the cyclone separator.

[0012] In the above scheme, the outlet of the bottom tank is connected to the pump through an internal water inlet pipe, the pump is connected to the self-circulation pipe, and the self-circulation pipe is connected to the hot water tank.

[0013] In the above scheme, the central shaft is formed by welding the first central shaft and the second central shaft together. The second central shaft is connected to the bottom of the cyclone separator by an upper bearing, a bearing protective shell, and a lower bearing. The second central shaft is located outside the tank and connected to the motor.

[0014] Beneficial effects: 1. This invention's multi-stage defoamer addresses the complex situation of densely packed, irregularly shaped, and difficult-to-separate carbon dioxide bubbles in wellhead produced fluid. It innovatively combines static defoaming, dynamic defoaming, jet defoaming, and weak vortex separation into a single defoaming method. Precise defoaming is achieved through the synergistic cooperation of different defoaming modes. The inlet is a double-tangential inlet, allowing the liquid to form a weak vortex within the tank. Each stage of the defoaming plate has evenly distributed defoaming holes. Carbon dioxide bubbles entering the vortex separation chamber first undergo hot water scattering defoaming treatment by the jet defoamer, which uses fully automatic physical jetting to quantitatively spray hot water through gravity and spring energy accumulation. Simultaneously, the dynamic defoamer generates downward thrust during rotation, forcing carbon dioxide bubbles through its defoaming holes. The static defoamer further defoams the carbon dioxide bubbles, reducing their proportion. This sequentially interleaved defoaming combination solves the pain points of existing defoamers, such as incomplete defoaming, difficulty in separating large numbers of bubbles, and the use of a single static or dynamic defoamer. More importantly, a new type of defoaming method, jet defoamer, has been added, which enhances the defoaming efficiency to a certain extent. The combination of multiple defoaming methods and weak vortex phase avoids insufficient separation caused by excessive bubbles.

[0015] 2. This invention innovatively develops a synergistic structure of hot water self-circulation and scattering to achieve efficient gas-liquid separation and full hot water recovery. Hot water in the hot water tank is scattered downwards by a jet defoamer, which evenly sprays the hot water into the cyclone separation chamber. The impact force of high-speed droplets eliminates foam, effectively removing some carbon dioxide bubbles. The liquid phase water, after multiple separations, enters the pump through the bottom outlet pipe and then re-enters the hot water tank through the self-circulating water pipe. The heating wire in the hot water tank ensures a consistent water temperature, allowing for re-entry into the circulation system. This process requires no external lifting or control equipment and enables internal self-circulation, solving the problems of hot water source and water resource reuse. It is more environmentally friendly and practical, achieving integrated internal water recycling and further enhancing the practicality and reliability of the device.

[0016] 3. This invention is a defoaming device integrating a multi-stage defoaming combination. When the gas-liquid mixture enters the separation tank, it enters the first-stage separation combination, which includes a top static defoamer, a middle static defoamer, a dynamic defoamer, and a jet defoamer. A large number of carbon dioxide bubbles are first defoamed by the jet defoamer, which removes large-volume bubbles from high-speed droplets. Simultaneously, the dynamic defoaming plate defoams during its rotation, generating a downward thrust to further eliminate bubbles. The mixture then flows downward through the static defoamer for further defoaming. After passing through the first-stage separation combination, the gas-liquid mixture enters the second-stage separation combination, which includes a dynamic defoamer and a static defoamer. The dynamic defoaming plate defoams during its rotation, simultaneously generating a downward thrust to guide the mixture downward into the static defoamer for further defoaming. The synergistic effect of the first and second-stage separation combinations effectively eliminates carbon dioxide bubbles, reducing the presence of bubbles that could lead to unsatisfactory separation processes and results. Through multi-stage defoaming, better separation of carbon dioxide bubbles is achieved.

[0017] 4. This invention is an integrated defoaming equipment separation device comprising a jet defoamer, dynamic and static defoaming, and water resource self-recycling. It achieves deep synergy between throttling and separation, constructing a complete process of "stage-by-stage defoaming - vortex separation - self-recycling." The mixture of gas, oil, and water undergoes porous defoaming combined with jet defoaming, achieving precise separation through jet defoaming, static defoaming, and dynamic defoaming, thus stabilizing the separation efficiency. Subsequently, the water used by the jet defoamer re-enters the hot water pipe for heating via a self-circulating water pipe, and then passes through the jet defoamer again for carbon dioxide defoaming. This process eliminates the need for external lifting, control, or other auxiliary equipment, achieving integrated operation through modular assembly. It simplifies operational procedures, reduces maintenance costs, and solves the problems of existing technologies requiring step-by-step operation, narrow adaptability, and high operational complexity. Furthermore, the trigger logic design of the multi-stage defoaming and self-recycling structure is reasonable, ensuring that the defoaming plates are triggered stage by stage, avoiding blockage, and further enhancing the practicality and reliability of the device. This novel carbon dioxide gas bubble separation equipment utilizes a physically driven jet defoamer to achieve uniform droplet size and heating, enhancing separation efficiency and equipment reliability. The integrated process enables collaborative operation, with jet, dynamic, and static defoaming working in tandem. This addresses the shortcomings of existing technologies, such as low separation efficiency, poor water resource utilization, and weak resistance to operating condition fluctuations. It significantly improves oil and gas well recovery rates, reduces operating and maintenance costs, and is compatible with various separation processes, including drainage gas production and same-well injection and production. It can be widely applied to carbon dioxide separation operations at the wellhead of gas wells with high gas content and large operating condition fluctuations, significantly improving oil and gas well recovery rates and production economics.

[0018] 5. This invention is applicable to situations where carbon dioxide foam accumulates due to the vaporization of liquid carbon dioxide caused by low pressure during the production process, making efficient separation difficult. It can achieve efficient separation of gas and liquid two-phase media and is suitable for various extraction processes such as drainage gas production and injection-production in the same well. Attached image description: Figure 1 Cross-sectional view of the present invention; Figure 2 This is an exploded view of the entire invention; Figure 3 This is an exploded view of the outer casing of the present invention; Figure 4 This is a schematic diagram of a dynamic defoaming group, where (a) is a three-dimensional view of the dynamic defoaming group; and (b) is a front view of the dynamic defoaming group. Figure 5 An exploded view of the dynamic defoaming group; Figure 6 This is a structural diagram of a hot water circulation system; Figure 7 This is an exploded view of the entire hot water circulation system; Figure 8 Schematic diagram of adding an outer shell to a static defoaming unit; Figure 9 Exploded view of the static defoaming group with an outer shell; Figure 10 Add an exploded view to the schematic diagram of the middle part of the outer shell; Figure 11 This is an exploded view of the static defoaming group. Figure 12 This is the front view of the present invention; Figure 13 This is a side view of the present invention; Figure 14 This is a side sectional view of the present invention; Figure 15 This is an exploded view of the central axis connection.

[0019] In the diagram: 101 - Outer shell end cap; 102 - Heating wire; 103 - Hot water tank; 104 - Hot water tank bottom plate; 105 - Jet defoamer; 106 - Internal water pipe; 107 - Pump; 108 - Self-circulating water pipe; 201 - First-stage static defoamer; 202 - Static defoamer bearing; 203 - Second-stage static defoamer; 204 - Third-stage static defoamer upper end cap; 205 - Third-stage static defoamer; 206 - First baffle; 207 - Second baffle; 301 - First-stage dynamic defoamer; 3011 - First-stage dynamic defoamer upper connecting ring. 3012 Lower connecting ring of the first-stage dynamic defoamer; 302-Second-stage dynamic defoamer; 3021-Upper connecting ring of the second-stage dynamic defoamer; 3022-Lower connecting ring of the second-stage dynamic defoamer; 303-First central shaft; 304-Bearing protective shell; 3041-Upper bearing; 3042-Lower bearing; 305-Second central shaft; 306-Motor; 401-Gas phase tank; 402-Gas phase tank bottom plate; 403-Double tangential cyclone separator; 404-Cyclone separator bottom plate; 405-Bottom tank; 406-Outer sleeve bottom plate; 407-Bottom support. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings: See Figures 1-15This multi-stage composite defoaming synergistic enhancement CO2-driven oil recovery liquid-gas-liquid separation device includes a cyclone separator, which is divided from bottom to top into a bottom tank 405, a cyclone separation chamber, a gas phase tank 401, and a hot water tank 103. The upper end of the cyclone separation chamber has a double tangential inlet. A heating wire 102 is installed inside the hot water tank 103. A jet defoamer 105, connected to the hot water tank 103, is located at the top of the cyclone separation chamber. The cyclone separation chamber and the gas phase tank 401 are connected via a first-stage static defoamer 201. A central shaft is installed inside the cyclone separation chamber, driven by a motor located below the cyclone separator. At least two stages of dynamic defoamers are installed on the central shaft, and a static defoamer is installed below each stage of dynamic defoamers. The dynamic defoamer includes multiple defoaming blades arranged horizontally radially around the central shaft. Each defoaming blade has several defoaming holes evenly distributed. Each defoaming blade is connected to the central shaft via an upper and lower connecting ring. Each stage of the static defoamer is fixed and has several defoaming holes. The cyclone separation chamber and the bottom tank 405 are connected via a first-stage static defoamer located on the bottom plate 404 of the cyclone separation chamber. The multiphase mixture sequentially undergoes porous defoaming and jet defoaming treatments, forming a graded defoaming path of jet defoaming, static defoaming, and dynamic defoaming. The bottom tank is equipped with a baffle plate, an oil outlet at the top, and a water outlet at the bottom. One water outlet of the bottom tank is connected to a hot water tank via a pump 107 and a self-circulation pipe 108. The bottom of the cyclone separator is supported by a bottom support 407, and the bottom of the cyclone separator sits on the bottom support 407. The pump 107 and the motor 306 are located below the cyclone separator.

[0021] In this embodiment, a first-stage dynamic defoamer 301 is installed at the upper end of the central shaft. Below the first-stage dynamic defoamer 301, a second-stage static defoamer 203 is installed. The second-stage static defoamer 203 is a circular plate with several defoaming holes. The circular plate divides the cyclone separation chamber into two chambers, which are connected through the defoaming holes. A second-stage dynamic defoamer 302 is installed on the central shaft between the second-stage static defoamer 203 and the bottom plate of the cyclone separation chamber. The mixture needs to be defoamed again by the second-stage static defoamer 203 before flowing down to the second-stage dynamic defoamer 302. A third-stage static defoamer 205 is installed below the first-stage dynamic defoamer 302. The third-stage static defoamer 205 is a cylindrical body with an open lower end and several defoaming holes. The third-stage static defoamer is fixed above the central hole of the bottom plate of the cyclone separation chamber. A first baffle 206 is fixed below the central hole. The first baffle 206 is a cylindrical body with open ends. The inner diameter of the third-stage static defoamer 205 and the first baffle 206 are equal and coaxial. The fluid after being defoamed by the second-stage dynamic defoamer 302 can only enter the bottom tank 405 after being defoamed by the third-stage static defoamer 205. A second baffle 207 is installed at the bottom of the bottom tank 405, and the lower end of the first baffle 206 extends into the coaxially installed second baffle 207.

[0022] A jet defoamer 105 is connected to the bottom of the hot water tank, and a self-circulating water pipe 108 is connected to the tank wall, which in turn connects to a pump 107 at the bottom of the outer cylinder. The gas-liquid mixture enters the cyclone separation chamber through a double tangential inlet. In the cyclone separation chamber, it undergoes hot water scattering defoaming through two jet defoamers, and then sequentially passes through the defoaming holes of the first-stage dynamic defoamer, the defoaming holes of the second-stage static defoamer plate, the defoaming holes of the second-stage dynamic defoamer, and the defoaming holes of the third-stage static defoamer.

[0023] The partition between the hot water tank 103 and the gas phase tank 401 is the top of the gas phase tank, and the partition between the gas phase tank 401 and the cyclone separation chamber is the bottom of the gas phase tank. The first-stage static defoamer 201 is a cylindrical body with open ends and several defoaming holes. The upper port of the first-stage static defoamer is closed through the top of the gas phase tank, and the lower port of the first-stage static defoamer is fixed at the center hole at the bottom of the gas phase tank. The fluid from the cyclone separation chamber can only enter the gas phase tank after being defoamed by the first static defoamer and is discharged from the gas outlet of the gas phase tank.

[0024] The static defoaming structure is composed of a first-stage static defoamer 201, a second-stage static defoamer 203, bearings, a third-stage static defoamer 205, and baffles. The defoamers have evenly distributed defoaming holes. The first-stage static defoamer 201 is located in the gas phase tank 401, and its upper port is sealed by the top of the gas phase tank. The second-stage static defoamer 203 is connected to the central shaft via bearings, preventing multiphase flow from flowing downwards from the bearings. The diameter of the second-stage static defoamer 203 is the same as the inner diameter of the cyclone separation chamber, and it is a circular plate. The third-stage static defoamer 205 is located at the bottom of the cyclone separation chamber. The cylinder and upper cover of the third-stage static defoamer 205 are evenly distributed with defoaming holes, and all multiphase flow must pass through these holes.

[0025] The dynamic defoaming structure is composed of a first-stage dynamic defoamer 301, a first central shaft 303, a second-stage dynamic defoamer 302, bearings, a bearing protective shell 304, a second central shaft 305, and a motor 306. The first-stage dynamic defoamer 301 is connected to the central shaft by an upper and lower connecting ring and is located at the top of the central shaft; the second-stage dynamic defoamer 302 is connected to the central shaft by two upper and lower connecting rings and is located in the middle of the central shaft; the first central shaft 303 and the second central shaft 305 can be welded together as one piece. The central shaft is connected to the bottom of the cyclone separator by two bearings and a bearing protective shell. The second central shaft 305 is located outside the tank and connected to the motor.

[0026] The hot water tank 103, heating wire 102, jet defoamer 105, bottom outlet pipe, pump 107, and self-circulating water pipe 108 constitute a hot water self-circulation structure. The heating wire 102 is located inside the hot water tank 103, and the heating wire support is connected to the bottom plate of the hot water tank. The bottom plate of the hot water tank is connected to the hot water tank 103. The jet defoamer 105 is connected to the bottom plate of the hot water tank. The hot water inside the hot water tank is evenly sprayed to the lower vortex separation chamber through the jet defoamer 105. The bottom outlet pipe is connected to the bottom of the tank. The water passes through the pump 107 and then enters the self-circulating water pipe 108, and is transported to the hot water tank 103.

[0027] The present invention is described in more detail below: This invention involves sequentially treating a mixture of multiple liquids using porous defoaming and jet defoaming processes, forming a precise, graded defoaming path of "jet defoaming—static defoaming—dynamic defoaming," thus stabilizing separation efficiency. Simultaneously, the water used by the jet defoamer is returned to the hot water pipe via a self-circulating water pipe for reheating, and then supplied to the jet defoamer for carbon dioxide defoaming. This constructs a complete process of "step-by-step defoaming—cyclone separation—self-recycling," achieving a deep synergy between water conservation and separation. This invention employs modular assembly, integrating multiple precise defoaming and water resource self-recycling functions into one unit. It eliminates the need for external lifting, control, or other auxiliary equipment, enabling integrated operation, effectively simplifying procedures, reducing maintenance costs, and overcoming the shortcomings of existing technologies such as step-by-step operation, narrow adaptability, and high operational complexity. Furthermore, the rationally designed trigger logic of the multi-stage defoaming and self-recycling structure ensures orderly step-by-step triggering of the defoaming plates, preventing blockages and further enhancing practicality and reliability.

[0028] The dynamic defoaming structure includes a first-stage dynamic defoamer 301, an upper connecting ring 3011 for the first-stage dynamic defoamer, a lower connecting ring 3012 for the first-stage dynamic defoamer, a second-stage dynamic defoamer 302, an upper connecting ring 3021 for the second-stage dynamic defoamer, a lower connecting ring 3022 for the second-stage dynamic defoamer, a first central shaft 303, a bearing protective shell 304, an upper bearing 3041, a lower bearing 3042, a second central shaft 305, and a motor 306.

[0029] The upper connecting ring 3011 of the first-stage dynamic defoamer is connected to the upper end of the first-stage dynamic defoamer 301; the lower connecting ring 3012 of the first-stage dynamic defoamer is connected to the lower end of the first-stage dynamic defoamer 301; the upper connecting ring 3021 of the second-stage dynamic defoamer is connected to the upper end of the second-stage dynamic defoamer 302; the lower connecting ring 3022 of the second-stage dynamic defoamer is connected to the lower end of the second-stage dynamic defoamer 302; the first-stage dynamic defoamer 301 and the second-stage dynamic defoamer 302 are connected to the first central shaft 303. 01 is located at the top of the first central shaft 303, and the second-stage dynamic defoamer 302 is located in the middle of the first central shaft 303; the first central shaft 303 is connected to the bearing protective shell 304, the second central shaft 305, and the motor 306; wherein, the first central shaft 303 is connected to the bearing protective shell 304, the upper bearing 3041, the lower bearing 3042, and the second central shaft 305, and the bottom of the first central shaft 303 is connected to the upper bearing 3041; the second central shaft 305 is connected to the lower bearing 3042; the second central shaft 305 is connected to the motor 306.

[0030] After connection, multiple liquids enter through the tangential inlet and undergo first-stage dynamic defoaming through the holes of the first-stage dynamic defoamer 301. During rotation, a downward thrust is generated, causing the liquids to enter the holes of the second-stage dynamic defoamer 302 for second-stage dynamic defoaming.

[0031] The static defoaming structure includes a first-stage static defoamer 201, a static defoamer bearing 202, a second-stage static defoamer 203, a third-stage static defoamer upper cover 204, a third-stage static defoamer tank 205, a first baffle plate 206, and a second baffle plate 207.

[0032] The static defoamer bearing 202 is connected to the second-stage static defoamer 203, which has evenly distributed defoaming holes. The upper cover 204 of the third-stage static defoamer is connected to the third-stage static defoamer tank 205, which also has evenly distributed defoaming holes. The first baffle 206 and the second baffle 207 are aligned on a central axis. After the mixture is defoamed by the second-stage static defoamer 203, it enters the defoaming group composed of the upper cover 204 and the third-stage static defoamer tank 205, and finally passes through the first baffle 206 and the second baffle 207. The top is reinforced with evenly distributed defoaming holes from the first-stage static defoamer 201 to prevent incomplete separation at the top.

[0033] The hot water circulation system includes an outer casing end cap 101, a heating wire 102, a hot water tank 103, a hot water tank bottom plate 104, a jet defoamer 105, an internal water pipe 106, a pump 107, and a self-circulating water pipe 108.

[0034] The lower end of the outer casing 101 is connected to the upper end of the hot water tank 103; the lower end of the hot water tank 103 is connected to the upper end of the hot water tank base plate 104; the bracket of the heating wire 102 is connected to the upper end of the hot water tank base plate 104; the upper end of the jet defoamer 105 is connected to the lower end of the hot water tank base plate 104; the internal water pipe 106 is connected to the pump 107; the pump 107 is connected to the lower end of the self-circulating water pipe 108; the upper end of the self-circulating water pipe 108 is connected to the hot water tank 103.

[0035] After connection, water enters the hot water tank 103, where it is heated and kept warm by the heating wire 102. The hot water is diffused and defoamed by the jet defoamer 105. After a series of defoaming processes, the water enters the internal water pipe 106 and then the pump, where it is recycled by the self-circulating water pipe 108. Finally, it enters the hot water tank 103 again for heating and recycling.

[0036] The outer casing assembly includes a gas phase tank 401, a gas phase tank bottom plate 402, a double tangential cyclone separator 403, a cyclone separator bottom plate 404, a bottom tank 405, an outer casing bottom plate 406, and a bottom support 407. The outer casing end cap 101, hot water tank 103, and hot water tank bottom plate 104 are auxiliary devices.

[0037] The lower end of the outer casing end cap 101 is connected to the upper end of the hot water tank 103; the lower end of the hot water tank 103 is connected to the upper end of the hot water tank bottom plate 104; the lower end of the hot water tank bottom plate 104 is connected to the upper end of the gas phase tank 401; the lower end of the gas phase tank 401 is connected to the upper end of the gas phase tank bottom plate 402; the lower end of the gas phase tank bottom plate 402 is connected to the upper end of the double tangential cyclone separator 403; the lower end of the double tangential cyclone separator 403 is connected to the upper end of the cyclone separator bottom plate 404; the lower end of the cyclone separator bottom plate 404 is connected to the upper end of the bottom tank 405; the lower end of the bottom tank 405 is connected to the upper end of the outer casing bottom plate 406; and the outer casing bottom plate 406 is connected to the bottom support 407.

[0038] In operation, the gas-oil-water mixture enters through a tangential inlet and is tangentially introduced into the cyclone separator 403 via two symmetrically arranged tangential inlets, forming a strong swirling field. Under centrifugal force, the gas and liquid achieve efficient centrifugal stratification. The incoming gas-oil-water mixture first undergoes defoaming via a first-stage dynamic defoamer 301, generating a downward thrust. Simultaneously, the jet defoamer 105 uses a physical drive to regularly and uniformly scatter droplets for hot water jet defoaming at the upper end. The gas-oil-water mixture then undergoes a second... The water undergoes defoaming in the first-stage static defoamer 203; then, it undergoes rotational dynamic defoaming in the second-stage dynamic defoamer 302, flows downward through the third-stage static defoamer for defoaming, and then enters the first baffle 206 and the second baffle 207 in the bottom tank 405 for the final defoaming process; the water in the bottom tank 405 enters the pump 107 through the inner water pipe 106 passing through the bottom plate 406 of the outer sleeve, and then enters the hot water tank 103 through the self-circulating water pipe 108 connected to the pump 107 for reheating and then flows through the jet defoamer 105 again for defoaming.

[0039] This invention features a simple structure and convenient assembly. Through a multi-stage defoaming module separation path consisting of static, dynamic, and jet defoaming, along with a water self-circulation device, it effectively solves the technical defects of existing carbon dioxide gas separation devices, such as low separation efficiency, weak water resource utilization, and weak resistance to operating condition fluctuations. It can be widely applied to carbon dioxide separation operations at the wellhead of gas wells with high gas content and large operating condition fluctuations, significantly improving the recovery rate and economic efficiency of oil and gas wells.

Claims

1. A multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device, characterized in that: This multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device includes a cyclone separator, which is divided from bottom to top into a bottom tank, a cyclone separation chamber, a gas phase tank, and a hot water tank. The upper end of the cyclone separation chamber has a double tangential inlet. A heating wire is installed inside the hot water tank. A jet defoamer connected to the hot water tank is located at the top of the cyclone separation chamber. The cyclone separation chamber and the gas phase tank are connected through a first-stage static defoamer. A central shaft is installed inside the cyclone separation chamber, driven by a motor located below the cyclone separator. At least two stages of dynamic defoamers are installed on the central shaft, and a first-stage static defoamer is installed below each stage of dynamic defoamers. The dynamic defoamers include multiple units installed horizontally radially around the central shaft. The defoaming blades outside the mandrel are each evenly equipped with several defoaming holes. Each defoaming blade is connected to the central shaft through an upper connecting ring and a lower connecting ring. Each stage of static defoamer is fixed and has several defoaming holes. The cyclone separation chamber and the bottom tank are connected through a first-stage static defoamer set on the bottom plate of the cyclone separation chamber. The multiphase mixture passes through the porous defoaming and jet defoaming treatment in sequence, forming a graded defoaming path of jet defoaming, static defoaming and dynamic defoaming. The bottom tank is equipped with a baffle plate, an oil outlet at the top and a water outlet at the bottom. One of the water outlets of the bottom tank is connected to the hot water tank through a pump and a self-circulation pipe. While performing graded defoaming and cyclone separation, the water resources are self-circulated.

2. The multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device according to claim 1, characterized in that: A first-stage dynamic defoamer is installed at the upper end of the central shaft. A second-stage static defoamer is installed below the first-stage dynamic defoamer. The second-stage static defoamer is a circular plate with several defoaming holes. The circular plate divides the cyclone separation chamber into two chambers, which are connected by the several defoaming holes of the circular plate. A second-stage dynamic defoamer is installed on the central shaft between the second-stage static defoamer and the bottom plate of the cyclone separation chamber. A third-stage static defoamer is installed below the second-stage dynamic defoamer. The third-stage static defoamer is a cylindrical body with an open lower end and several defoaming holes. The third-stage static defoamer is fixed above the central hole of the bottom plate of the cyclone separation chamber. A first baffle is fixed below the central hole. The first baffle is a cylindrical body with open ends. The inner diameter of the third-stage static defoamer is equal to that of the first baffle and they are coaxial. The fluid after being defoamed by the second-stage dynamic defoamer can only enter the bottom tank after being defoamed by the third-stage static defoamer.

3. The multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device according to claim 2, characterized in that: The bottom of the tank is provided with a second baffle, and the lower port of the first baffle extends into the second baffle which is coaxially arranged.

4. The multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device according to claim 3, characterized in that: The partition between the hot water tank and the gas phase tank is the top of the gas phase tank, and the partition between the gas phase tank and the cyclone separation chamber is the bottom of the gas phase tank. The first-stage static defoamer is a cylindrical body with open ends and several defoaming holes. The upper port of the first-stage static defoamer is closed through the top of the gas phase tank, and the lower port of the first-stage static defoamer is fixed at the center hole at the bottom of the gas phase tank. The fluid from the cyclone separation chamber can only enter the gas phase tank after being defoamed by the first-stage static defoamer and is discharged from the gas outlet of the gas phase tank.

5. The multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device according to claim 4, characterized in that: The bottom of the cyclone separator is provided with a bottom support, and the bottom of the cyclone separator sits on the bottom support. The pump and motor are located below the cyclone separator.

6. The multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device according to claim 5, characterized in that: The outlet of the bottom tank is connected to a pump via an internal water inlet pipe. The pump is connected to a self-circulation pipe, which in turn is connected to a hot water tank.

7. The multi-stage composite defoaming synergistic enhancement CO2 flooding produced liquid-gas-liquid separation device according to claim 6, characterized in that: The central shaft is formed by welding a first central shaft and a second central shaft together. An upper bearing, a bearing protective shell, and a lower bearing are provided between the second central shaft and the bottom of the cyclone separator. The second central shaft is located outside the tank and connected to a motor.

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