Three-phase separation equipment for treating oilfield produced liquid

Abstract

The utility model provides three-phase separation equipment for oil field produced liquid treatment, which comprises a horizontally arranged tank body, a gas-liquid separation area, an oil-water separation area, a water chamber and an oil chamber are sequentially arranged in the tank body along the length direction, the gas-liquid separation area and the oil-water separation area are separated by a rectifying filler, and an oil separation weir plate is arranged between the oil-water separation area and the water chamber. The bottom of the oil separation weir plate is hollowed out, the oil-water separation weir plate is arranged between the water chamber and the oil chamber, the oil separation weir plate is higher than the oil-water separation weir plate, a horizontal section is arranged at the top end of the oil separation weir plate and crosses the oil-water separation weir plate, a gas phase outlet is formed in the top of the oil chamber, and demisting filler is arranged at the gas phase outlet in the tank body. The oil-water separation filler is arranged in the oil-water separation area, and the three-phase mixed liquid inlet is formed in the top of the gas-liquid separation area. The cyclone separator, the rectifying filler and the demisting filler are arranged, so that the liquid content of exhausted gas is low. The oil-water separation filler, the oil separation weir plate and the oil-water separation weir plate are arranged, so that the water content of discharged oil is low.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and natural gas processing, in particular to a three-phase separation device for oilfield produced liquid processing. Background Art

[0002] Oil, gas and water separation is the main process of oil and gas gathering and transportation in oil and gas fields. Its purpose is to separate the oil, gas and water mixture into liquid and natural gas under certain operating conditions, and to separate the liquid into crude oil and free water. If necessary, solid mechanical impurities must be separated for further processing. The technical means of oil, gas and water three-phase separation include equilibrium separation and mechanical separation. Equilibrium separation is the formation of oil, gas and water layers under certain pressure and temperature, and then preliminary separation; mechanical separation is to use external force to separate oil, gas and water mechanically (such as centrifugal force). There are three common oil, gas and water three-phase separation processes: single separation, continuous separation and multi-stage separation.

[0003] The main equipment for oil, gas and water separation is the three-phase separator. The three-phase separator is one of the key equipment for oilfield surface engineering. It is usually the first equipment to process produced fluid at the wellhead and is the key to economical and stable crude oil extraction. Improving the separation efficiency of the three-phase separator has always been the focus of oilfield surface engineering research. Its internal component design and process design have a great influence on the separation efficiency.

[0004] The design principle of the internal structure of the three-phase separator is to promote the gas-liquid equilibrium state and strengthen the oil-gas-water separation, so as to minimize the equipment size of the separator under the premise of the specified processing capacity and separation effect. The internal components of the three-phase separator include the inlet diverter, wave-breaking plate, defoaming plate, vortex preventer, sandblasting nozzle, sand discharge pipe, mist collector, etc., which are mainly divided into the inlet diverter area, liquid collection area, gravity settling area, and mist collector area according to the functional area. The inlet diverter area will separate the gas and liquid by absorbing the kinetic energy of the liquid and changing its flow direction. The liquid collection area provides sufficient residence time for the entrained gas to escape from the gravity settling area. When the gas enters the gravity settling area, its speed decreases, and the tiny droplets carried by the gas and not yet separated by the inlet separator are separated by gravity and fall to the gas-liquid surface. Before the gas leaves the container, it must first pass through the gathering area and mist collector, which use coalescing elements that can provide a large contact area to remove small droplets. When the gas passes through the gathering structure, it will change the flow direction rapidly. Due to the large accumulation of the gathering structure, the droplets cannot keep up with the change of the gas flow direction, so they collide with the gathering structure and fall into the liquid gathering area. Mist collectors are used to eliminate droplets and solid particles in the air flow. Wave-breaking plates are some porous baffles or plates installed in the liquid collecting area of ​​the separator perpendicular to the flow direction to reduce the fluctuations caused by the entry of liquid. Defoaming plates are used to provide a larger surface area so that possible foams can be gathered and burst to maintain normal operation of the device. Vortex breakers are used to prevent swirl and suppress the tendency of vortex formation. Sandblasting nozzles and sand discharge pipes are used to remove solid particles without interfering with the separation process.

[0005] The main process of the three-phase separator is that the oil-water-gas mixture enters the feed chamber from the feed port, enters the gravity separation section after being stabilized by the flow stabilizer, and separates the gas by using the density difference between gas and oil and water. The oil and water vapor entrained in the gas are further separated by the separation element, and the oil-water mixture enters the sewage chamber, and the oil with lower density enters the oil chamber through the overflow plate, thereby achieving the purpose of oil-water separation. Finally, the oil-gas-water three-phase mixture is separated into three separate fluids of gas phase, oil phase and water phase at the outlet.

[0006] How to efficiently design the components and processes of the three-phase separator is the key to affecting the effect of the three-phase separator.

[0007] Generally, the design of a three-phase separator can be a horizontal tank or a vertical tank. The advantage of a horizontal tank is that the direction of liquid movement is perpendicular to the direction of gravity, which is conducive to sedimentation separation, small liquid level fluctuation, and good liquid level stability; its disadvantage is that the gas-liquid separation space is small, it is not suitable for occasions requiring a large buffer volume, it occupies a large area, and it is inconvenient to install it at a high position. The advantage of a vertical tank is that the gas-liquid separation space is large, there is enough vertical height, it is conducive to the continuous separation of the intermediate mixed layer, it occupies a small area, and it is convenient to install it at a high position; its disadvantage is that the liquid flow direction is opposite to gravity, which is not conducive to sedimentation, the liquid level fluctuates greatly, and the liquid level stability is worse than that of a horizontal tank. Utility Model Content

[0008] In order to solve the problem that both the horizontal tank and the vertical tank of the three-phase separator in the above-mentioned prior art have disadvantages and the three-phase separator has low diversion efficiency.

[0009] The utility model proposes a three-phase separation device for oilfield produced liquid treatment. The utility model is realized through the following technical solutions:

[0010] The utility model comprises a tank body, which is horizontally arranged. A gas-liquid separation zone, an oil-water separation zone, a water chamber and an oil chamber are sequentially arranged inside the tank body along the length direction. The gas-liquid separation zone and the oil-water separation zone are separated by a rectifying filler. An oil separation weir is arranged between the oil-water separation zone and the water chamber. The bottom of the oil separation weir is hollowed out. The oil-water separation weir is arranged between the water chamber and the oil chamber. The oil separation weir is higher than the oil-water separation weir. A horizontal section is provided at the top of the oil separation weir. The horizontal section crosses the oil-water separation weir. A gas phase outlet is arranged at the top of the oil chamber. A demisting filler is arranged at the gas phase outlet in the tank body. The oil-water separation filler is arranged in the oil-water separation zone. A three-phase mixed liquid inlet is arranged at the top of the gas-liquid separation zone. A mixed liquid feed pipeline is connected to the three-phase mixed liquid inlet. A cyclone separator is arranged inside the tank body and connected to the three-phase mixed liquid inlet. A water phase outlet is arranged at the bottom of the water chamber. An oil phase outlet is arranged at the bottom of the oil chamber.

[0011] Furthermore, a backwash port and a backwash drain port are also provided at the bottom of the tank body.

[0012] Furthermore, a first backwash port and a first backwash drain port are arranged at the bottom of the gas-liquid separation zone, a second backwash port and a second backwash drain port are arranged at the bottom of the oil-water separation zone, a third backwash port and a third backwash drain port are arranged at the bottom of the oil chamber, the flushing water pipe is respectively connected to the first backwash port, the second backwash port and the third backwash port, and the sewage pipe is respectively connected to the first backwash drain port, the second backwash drain port and the third backwash drain port.

[0013] Furthermore, a first vortex breaker is provided at the water phase outlet, and a second vortex breaker is provided at the oil phase outlet.

[0014] Furthermore, a pressure sensor is provided on the top of the tank body, a gas phase outlet pipe is provided at the gas phase outlet, a pressure control valve is provided on the gas phase outlet pipe, and the pressure sensor and the pressure control valve are interlocked. A gas-liquid interface level meter is provided in the oil-water separation area, a water phase level meter is provided in the water chamber, an oil phase level meter is provided in the oil chamber, a water phase outlet pipe is provided at the water phase outlet, a water phase level control valve is provided on the water phase outlet pipe, and the water phase level meter and the water phase level control valve are interlocked, and an oil phase outlet pipe is provided at the oil phase outlet, an oil phase level control valve is provided on the oil phase outlet pipe, and the oil phase level meter and the oil phase level control valve are interlocked.

[0015] Furthermore, the demisting filler is of blade type.

[0016] Furthermore, the oil separation weir plate and the oil-water separation weir plate are height-adjustable.

[0017] Compared with the prior art, the beneficial effects of the utility model are:

[0018] 1. A cyclone separator, a rectifying filler and a demisting filler are provided to reduce the liquid content in the exhaust gas.

[0019] 2. The oil-water separation filler and the oil separation weir plate and oil-water separation weir plate of special structure are set, so that the equipment's drainage water has low oil content and low water content in the discharged oil.

[0020] 3. Flushing pipes, backwashing components and sewage pipes are set up to enable the equipment to remove sand and foam online.

[0021] 4. The overall pressure drop of the whole equipment is small and not easy to be damaged.

[0022] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments, which are given as examples only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0024] Figure 2 It is a schematic diagram of the three-phase flow direction of the utility model.

[0025] Indicated in the figure:

[0026] 1. Three-phase mixed liquid inlet; 2. Cyclone separator; 3. Rectification filler; 4. Oil-water separation filler; 5. Oil separation weir plate; 6. Oil-water separation weir plate; 7. Demisting filler; 8. Gas phase outlet; 9. First vortex breaker; 10. Water phase outlet; 11. Second vortex breaker; 12. Oil phase outlet; 13. First backwash outlet; 14. First backwash drain outlet; 15. Second backwash outlet; 16. Second backwash drain outlet; 17. Third Backwash port; 18. Third backwash drain port; 19. Tank body; 20. Mixed liquid feed pipeline; 21. Pressure sensor; 22. Gas phase outlet pipeline; 23. Pressure control valve; 24. Gas-liquid interface level meter; 25. Water phase level meter; 26. Oil phase level meter; 27. Water phase outlet pipeline; 28. Water phase level control valve; 29. ​​Oil phase outlet pipeline; 30. Oil phase level control valve; 31. Flushing water pipeline; 32. Sewage pipeline. DETAILED DESCRIPTION

[0027] The present application is further described below in conjunction with the accompanying drawings and embodiments.

[0028] like Figure 1 and Figure 2 As shown, the utility model provides a three-phase separation device for oilfield produced liquid treatment, including a tank body 19, the tank body 19 is horizontally arranged, and a gas-liquid separation zone, an oil-water separation zone, a water chamber and an oil chamber are sequentially arranged inside the tank body 19 along the length direction. The gas-liquid separation zone and the oil-water separation zone are separated by a rectifying filler 3. The oil separation weir plate 5 is arranged between the oil-water separation zone and the water chamber, and the oil-water separation weir plate 6 is arranged between the water chamber and the oil chamber. The oil separation weir plate 5 is higher than the oil-water separation weir plate 6, and there is a horizontal section at the top of the oil separation weir plate 5, and the horizontal section crosses the oil-water separation weir plate 6. A gas phase outlet 8 is arranged at the top of the oil chamber, and a demisting filler 7 is arranged at the gas phase outlet 8 in the tank body 19. The oil-water separation filler 4 is arranged in the oil-water separation zone. The three-phase mixed liquid inlet 1 is arranged at the top of the gas-liquid separation zone, and the cyclone separator 2 is arranged inside the tank body 19 and connected to the three-phase mixed liquid inlet 1. The three-phase mixture of oil, gas and water enters the cyclone separator 2 from the three-phase mixed liquid inlet 1 to achieve preliminary separation of gas and liquid. The liquid phase enters the gas-liquid separation zone at the bottom of the cyclone separator 2, and the gas phase enters the gas-liquid separation zone from the top of the cyclone separator 2. After the gas phase is separated, the large particle droplets in the gas phase are separated by the rectifying filler 3, and then pass through the top cavity in the tank body 19 to the demisting filler 7 to achieve separation of small particle droplets in the gas phase, and leave the tank body 19 at the gas phase outlet 8. The oil-water mixture first passes through the rectifying filler 3 to reduce the turbulence of the liquid phase, enters the oil-water separation zone, and separates and stratifies the oil phase and the water phase under the action of the oil-water separation filler 4 and gravity sedimentation. The oil separation weir plate 5 and the oil-water separation weir plate 6 of the utility model are both overflow type, wherein the bottom of the oil separation weir plate 5 is hollowed out to allow the water phase to flow. After the oil-water mixture passes through the oil-water separation filler 4, stratification and preliminary separation have been achieved. At this time, the water phase is at the bottom due to its high density, and the oil phase is at the top due to its low density. The water phase at the bottom enters the water chamber from the hollow section at the bottom of the oil separation weir plate 5, and the oil phase at the top is guided to the oil chamber from the horizontal section of the oil separation weir plate 5. In order to discharge the water phase in the water chamber out of the tank body 19, a water phase outlet 10 is provided at the bottom of the water chamber, and the oil phase in the oil chamber is discharged out of the tank body 19, and an oil phase outlet 12 is provided at the bottom of the oil chamber; the water phase entering the water chamber leaves the tank body 19 from the water phase outlet 10, and the oil phase entering the oil chamber leaves the tank body 19 from the oil phase outlet 12. A backwash port and a backwash drain port are also provided at the bottom of the tank body 19; a first backwash port 13 and a first backwash drain port 14 are provided at the bottom of the gas-liquid separation zone, a second backwash port 15 and a second backwash drain port 16 are provided at the bottom of the oil-water separation zone, and a third backwash port 17 and a third backwash drain port 18 are provided at the bottom of the oil chamber. The backwash ports and backwash drain ports of the gas-liquid separation zone and the oil chamber are relatively independent, and the oil-water separation zone and the water chamber share a set of backwash ports and backwash drain ports. At the same time, a first vortex breaker 9 is provided at the water phase outlet 10 , and a second vortex breaker 11 is provided at the oil phase outlet 12 .

[0029] The oil-gas-water three-phase mixed liquid comes from outside the boundary and enters the tank body 19 through the mixed liquid feed pipe 20 connected to the three-phase mixed liquid inlet 1. A pressure sensor 21 is arranged on the top of the tank body 19, and a gas phase outlet pipe 22 is arranged at the gas phase outlet 8. A pressure control valve 23 is arranged on the gas phase outlet pipe 22. The pressure sensor 21 and the pressure control valve 23 are interlocked, and the operating pressure in the tank body 19 is controlled by the exhaust rate and the exhaust pressure. The oil-water separation zone is provided with a gas-liquid interface level meter 24, the water chamber is provided with a water phase level meter 25, the oil chamber is provided with an oil phase level meter 26, a water phase outlet pipe 27 is provided at the water phase outlet 10, a water phase level control valve 28 is provided on the water phase outlet pipe 27, the water phase level meter 25 and the water phase level control valve 28 are interlocked, and the water phase level is controlled by controlling the water phase discharge rate; an oil phase outlet pipe 29 is provided at the oil phase outlet 12, an oil phase level control valve 30 is provided on the oil phase outlet pipe 29, the oil phase level meter 26 and the oil phase level control valve 30 are interlocked, and the oil phase level is controlled by controlling the oil phase discharge rate; since the water chamber and the oil-water separation zone are connected, the gas-liquid interface of the oil-water separation zone can also be controlled by the water phase level control valve 28. The flushing water pipe 31 is respectively connected to the first backwash port 13, the second backwash port 15 and the third backwash port 17, and the sewage pipe 32 is respectively connected to the first backwash drain port 14, the second backwash drain port 16 and the third backwash drain port 18. When backwashing operation is required, flushing water comes from outside and enters the bottom of the tank body 19 through the flushing water pipe 31 for backwashing, and the impurities flushed out are discharged from the three-phase separator through the sewage pipe 32.

[0030] In the three-phase separation device, the three-phase mixture of produced fluid, oil, gas and water enters the three-phase separation device body through the inlet. The inlet device can be an inlet baffle, a semi-open pipe, a blade-type inlet device or a cyclone-type inlet device. The blade-type inlet device and the cyclone-type inlet device can fully handle the fluid at the inlet nozzle and maximize the gas-liquid separation. Other inlet devices may lead to poor gas-liquid distribution and increase gas-liquid entrainment. Therefore, the utility model preferably uses a blade-type inlet device or a cyclone-type inlet device. Figure 1For example, cyclone separator 2 is selected. The advantages of this liquid inlet device are: lower kinetic energy of the fluid entering the tank; better gas phase distribution; elimination of foam on the liquid surface; removal of solid particles entrained by the feed. The high-momentum cyclone separator 2 is based on the centrifugal principle to achieve efficient gas-liquid separation. Through a specially designed low-shear inlet section, the produced liquid mixture is introduced into the cyclone separator 2 from the inlet pipe. Inside the cyclone separator 2, the gas and liquid are separated under the action of centrifugal force, the liquid enters the liquid section of the three-phase separation equipment downward, and the gas is discharged through the top of the cyclone separator 2 for the next step of deep demisting. The low-shear design and moderate centrifugal force of the high-momentum cyclone separator 2 can also minimize the generation of foam in the produced liquid mixture. Cyclone separator 2 is particularly suitable for produced liquids containing solid impurities, wax hydrocarbons, asphaltene and other impurities. The advantages of cyclone separator 2 include: high inlet kinetic energy and large liquid processing capacity; large volume separation of gas and liquid, high efficiency; low shear design, enhanced oil-water separation; and a certain defoaming effect.

[0031] For three-phase separation, the produced liquid introduced into the tank 19 is violently turbulent at the inlet of the three-phase separation equipment through a low-impact blade inlet or a high-momentum cyclone separator 2. In order to maximize the efficiency of liquid-liquid separation, the flow of the liquid needs to be evenly distributed over the entire cross-section of the container liquid section. To further enhance the liquid-liquid separation, the use of agglomerating fillers can not only reduce the size of the three-phase separation equipment, but also increase the produced liquid processing volume under the premise of maintaining the overall separation efficiency. Figure 1 For example, a rectifying filler 3 and an oil-water separation filler 4 are used respectively. When the gas and liquid enter the tank body 19, the flow rate is relatively high. Only when the fluid is evenly distributed in the entire available cross-section of the three-phase separation device can a good flow state be achieved and an ideal separation effect be achieved. For a three-phase separation device equipped with a blade-type inlet device, the fluid is introduced more evenly and the flow velocity is also lower, so a relatively uniform fluid distribution can be achieved. However, for the tank body 19 equipped with a cyclone separator 2, the gas is separated in the jet and the liquid needs to be redistributed. At this time, the design and arrangement of the distribution baffle and the distribution rectifying filler 3 are quite necessary and important. The advantages of the rectifying filler 3 include: the separated gas phase contains a small amount of droplets; the drainage oil content and the drainage oil water content are low; and the pressure drop is reduced. The rectifying filler 3 is used to slow down the violent turbulence of the oil-gas-water three-phase mixture entering the three-phase separation device body, providing conditions for further oil-water separation. The oil-water separation filler 4 is used to enhance the rapid and efficient separation of oil and water. If there is no wax or other dirt in the produced fluid, the oil-water separation filler 4 can be used to increase the liquid handling capacity of the gravity separation section, and the coalescer condenses small droplets (mainly oil droplets or water droplets here) into large droplets. The oil-water separation filler 4 can be a wire mesh type or a blade type.

[0032] A demisting filler 7 is provided at the gas phase outlet 8 of the three-phase separation device. The basic principle of the demisting filler 7: each phase of different density in the fluid has different momentum. If the two-phase flow suddenly changes direction, the heavy fluid particles with larger momentum cannot turn as quickly as the light fluid, so separation will occur. The momentum method is usually used for the separation of two-phase flow in flow. If the gravity acting on the droplets is greater than the resistance of the airflow acting on the droplets, the droplets will settle out of the gas phase. Very small droplets cannot actually be separated by gravity. These droplets can be coalesced into larger droplets and then settle by gravity. The coalescing device in the separation device forces the gas to pass through a tortuous path, and the momentum of the droplets causes them to collide with each other or with the aggregation device to form larger droplets, which can settle out of the gas by gravity. The demisting filler 7 includes a wire mesh type and a blade type. Its function is to coalesce the small droplets that still exist in the gas phase after the initial separation into large droplets, so that they fall from the rising gas phase by their own gravity. Blade demister: Blade demister is a highly efficient demister, which is mainly composed of an irregular arrangement of parallel plates. Due to the design of the blades, the liquid-containing gas in the blade bundle is forced to change direction several times, and the heavier droplets are thrown onto the wet wall, thereby achieving deep gas-liquid separation. It is suitable for environments with and without dirt. The blade demister is made of curved parallel plates to collect and discharge the separated liquid, and can be disassembled through the manhole. The advantages of the blade demister include: it can adapt to the treatment of components prone to scaling.

[0033] The design of the oil-water two-phase separation weir plate has the greatest impact on the oil-water separation efficiency. There are two types of separation weir plates: immersion type and overflow type. The immersion type design is prone to gas-liquid interface fluctuations, while the overflow type design has a more stable gas-liquid interface. Considering the fluctuations in the flow rate of the oil-water two-phase fluid, an adjustable separation weir plate is used to control the oil-water two-phase interface, which is easy to control the liquid level. The oil separation weir plate 5 and the oil-water separation weir plate 6 of the utility model are both overflow type, wherein the bottom of the oil separation weir plate 5 is hollowed out for the water phase to flow, the oil separation weir plate 5 is higher than the oil-water separation weir plate 6, and the oil separation weir plate 5 has a horizontal section, which spans the oil-water separation weir plate 6. After the oil-water mixture passes through the oil-water separation filler 4, stratification and preliminary separation have been achieved. At this time, the water phase is at the bottom due to its high density, and the oil phase is at the top due to its low density. The water phase at the bottom enters the water chamber from the hollow section at the bottom of the oil separation weir plate 5, and the oil phase at the top is guided to the oil chamber from the horizontal section of the oil separation weir plate 5. The height of the oil separation weir plate 5 and the oil-water separation weir plate 6 is made adjustable. According to the changes in the properties of oil and water, the changes in the processing volume and the separation effect, the height can be adjusted at any time to change the position of the oil-water interface in the oil-water settling chamber so that the separator works in the best state.

[0034] In oil fields with large amounts of sand, the three-phase separation equipment needs to be equipped with a backwash system (or sandblasting system), which consists of a flushing water pipe 31, backwashing internals and a sewage pipe 32. The backwashing system (sandblasting system) fluidizes the solid particles deposited at the bottom of the tank 19 into mud by injecting flushing water, and discharges the mud into the sand treatment / produced water system for reprocessing. The sandblasting system can inject purified water into the bottom of the separator. Several nozzles are arranged on the distribution pipe of the sandblasting system according to the size of the separator. Since the distance between the nozzles is very close, the jets of purified water will overlap well, and the silt in a specific area will be fluidized, thereby promoting the discharge of gas from the sand discharge port. The produced sewage containing silt can be further treated in depth in the subsequent water treatment system. The advantages of the sandblasting system include: effective jet distribution; good sand removal ability; excellent scale inhibition performance; low pressure drop.

[0035] In addition to the above embodiments, the present application may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present application.

Claims

1. A three-phase separation device for oilfield produced liquid treatment, comprising a tank body (19), wherein the tank body (19) is arranged horizontally, and is characterized in that: The tank body (19) is provided with a gas-liquid separation zone, an oil-water separation zone, a water chamber and an oil chamber in sequence along the length direction. The gas-liquid separation zone and the oil-water separation zone are separated by a rectifying filler (3). An oil separation weir plate (5) is provided between the oil-water separation zone and the water chamber. The bottom of the oil separation weir plate (5) is hollowed out. The oil-water separation weir plate (6) is provided between the water chamber and the oil chamber. The oil separation weir plate (5) is higher than the oil-water separation weir plate (6). The top of the oil separation weir plate (5) has a horizontal section, which crosses the oil-water separation weir plate ( 6), a gas phase outlet (8) is arranged at the top of the oil chamber, a demisting filler (7) is arranged at the gas phase outlet (8) in the tank body (19), an oil-water separation filler (4) is arranged in the oil-water separation area, a three-phase mixed liquid inlet (1) is arranged at the top of the gas-liquid separation area, a mixed liquid feed pipeline (20) is connected to the three-phase mixed liquid inlet (1), a cyclone separator (2) is arranged inside the tank body (19) and connected to the three-phase mixed liquid inlet (1), a water phase outlet (10) is arranged at the bottom of the water chamber, and an oil phase outlet (12) is arranged at the bottom of the oil chamber.

2. The three-phase separation equipment for oilfield produced fluid treatment according to claim 1, characterized in that: The bottom of the tank body (19) is also provided with a backwashing port and a backwashing drain port.

3. The three-phase separation equipment for oilfield produced fluid treatment according to claim 2, characterized in that: A first backwash port (13) and a first backwash drain port (14) are arranged at the bottom of the gas-liquid separation zone, a second backwash port (15) and a second backwash drain port (16) are arranged at the bottom of the oil-water separation zone, a third backwash port (17) and a third backwash drain port (18) are arranged at the bottom of the oil chamber, a flushing water pipeline (31) is respectively connected to the first backwash port (13), the second backwash port (15) and the third backwash port (17), and a sewage pipeline (32) is respectively connected to the first backwash drain port (14), the second backwash drain port (16) and the third backwash drain port (18).

4. The three-phase separation equipment for oilfield produced fluid treatment according to claim 1, characterized in that: A first vortex breaker (9) is provided at the water phase outlet (10), and a second vortex breaker (11) is provided at the oil phase outlet (12).

5. The three-phase separation equipment for oilfield produced fluid treatment according to claim 1, characterized in that: A pressure sensor (21) is arranged on the top of the tank body (19), a gas phase outlet pipe (22) is arranged at the gas phase outlet (8), a pressure control valve (23) is arranged on the gas phase outlet pipe (22), and the pressure sensor (21) and the pressure control valve (23) are interlocked.

6. The three-phase separation equipment for oilfield produced fluid treatment according to claim 1, characterized in that: The oil-water separation zone is provided with a gas-liquid interface level meter (24), the water chamber is provided with a water phase level meter (25), the oil chamber is provided with an oil phase level meter (26), a water phase outlet pipe (27) is provided at the water phase outlet (10), a water phase level control valve (28) is provided on the water phase outlet pipe (27), the water phase level meter (25) and the water phase level control valve (28) are interlocked, an oil phase outlet pipe (29) is provided at the oil phase outlet (12), an oil phase level control valve (30) is provided on the oil phase outlet pipe (29), the oil phase level meter (26) and the oil phase level control valve (30) are interlocked.

7. The three-phase separation equipment for oilfield produced fluid treatment according to claim 1, characterized in that: The demisting filler (7) is of blade type.

8. The three-phase separation equipment for oilfield produced fluid treatment according to claim 1, characterized in that: The oil separation weir plate (5) and the oil-water separation weir plate (6) are height-adjustable.

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