A one-stage separator for oil and gas well produced fluid

Abstract

This utility model relates to a primary separation device for produced fluids from oil and gas wells. It includes a horizontal separation tank, inside which are an overflow plate, a baffle plate, gas-liquid cyclone separation components, a heating coil, rectifying coalescing packing, a first electrostatic coalescing plate assembly, a second electrostatic coalescing plate assembly, a distribution pipe, and a collection pipe. The horizontal separation tank has a settling chamber, an overflow chamber, and an electrostatic coalescing chamber, which are connected by the distribution pipe. The gas-liquid cyclone separation components, heating coil, and rectifying coalescing packing are located in the settling chamber. The first electrostatic coalescing plate assembly is located in the overflow chamber, and the second electrostatic coalescing plate assembly and the collection pipe are located in the electrostatic coalescing chamber. The collection pipe is connected to the oil outlet. This technical solution is applicable to the separation of produced fluids from various oil wells, and it requires fewer pieces of equipment, has a simplified process flow, low wellhead back pressure, low shared consumption and small footprint, and is easy to operate and maintain, effectively controlling costs and cycle time.

Description

Technical Field

[0001] This utility model applies to the technical field of oil and gas well produced fluid treatment equipment, and more specifically, it relates to a primary standard separator for oil and gas well produced fluid. Background Technology

[0002] In the surface development and production of oil and gas fields, the produced fluids from oil wells are usually multiphase mixtures containing oil, gas, water, and sand. The multiphase nature of the produced fluids stems from the immiscibility and density differences of the components. Currently, most major oil and gas fields in China have entered the middle and late stages of development, and the produced fluids from oil wells generally have the following characteristics: ① High water content, with some produced fluids having a water content exceeding 90%; ② Complex composition of the produced fluids; ③ Low wellhead flowing pressure. To address these complexities, conventional surface treatment processes typically utilize three-phase or four-phase separators in conjunction with heat exchangers, electrostatic coalescing dehydrators, and other equipment to separate the produced fluids, thereby obtaining high-purity crude oil. For example, Chinese Patent No. CN219387867U discloses an oil-water-gas separation system at the wellhead of an oil and gas well, which includes a separation tank, the upper part of which... The side wall has a liquid inlet connected to a preheater to heat the oil-water-gas mixture before it enters the separator. The top of the separator is connected to a gas storage tank, which is connected to a booster. Gas in the oil-water-gas mixture flows to the top of the separator and enters the gas storage tank. After being pressurized by the booster, it is delivered to the collection and transportation network. The lower side wall of the separator has an oil outlet connected to an oil storage tank. The lower part of the separator has a water outlet on the opposite side of the oil outlet, which is connected to a drain tank. The oil storage tank is connected to an oil pump. A separator is located at the bottom of the drain hole. A wire mesh demister is located at the top of the separator. The bottom of the separator is connected to the main drain pipe. Hot water in the preheater is provided by an electric water heater or a gas water heater. The electric water heater is connected to an energy storage battery pack, which is connected to a solar panel. The gas water heater is connected to the gas storage tank.

[0003] The problems with the aforementioned oil-water-gas separation system are that it involves a large number of devices, resulting in a lengthy process flow, high wellhead back pressure, high utility consumption, and will occupy a large area of ​​production land. At the same time, it is complex to operate, and inspection and maintenance are also difficult. This will lead to an increase in surface construction costs, production costs and construction period. Utility Model Content

[0004] In response to the above issues, and to overcome the problems of existing oil-gas-water separation systems for produced fluids in oil and gas wells involving a large number of devices, resulting in lengthy process flows, high wellhead back pressure, large shared consumption and footprint, complex operation, difficult inspection and maintenance, and increased surface construction costs, production costs and construction period, the purpose of this utility model is to provide a primary-stage oil and gas well produced fluid separator that is suitable for separating produced fluids from oil wells with different oil types and large variations in water content, with fewer devices, a simplified process flow, low wellhead back pressure, small shared consumption and footprint, and easy operation and maintenance, thereby effectively controlling the construction period and cost.

[0005] To achieve the above objectives, the technical solution of this utility model is:

[0006] A primary separation device for produced fluid in oil and gas wells includes a horizontal separation tank. The outer wall of the horizontal separation tank has a produced fluid inlet, an oil outlet, a gas outlet, a first water outlet, and a second water outlet. The interior of the horizontal separation tank includes an overflow plate, baffles, gas-liquid cyclone separation components, a heating coil, rectifying coalescing packing, a first electrostatic coalescing plate assembly, a second electrostatic coalescing plate assembly, a distribution pipe, and a collection pipe. The interior of the horizontal separation tank is sequentially divided into a settling chamber, an overflow chamber, and an electrostatic coalescing chamber by the overflow plate and baffles. The produced fluid inlet is connected to the settling chamber. A gas phase air chamber is located above the overflow plate. The settling chamber and overflow chamber are connected through the gas phase space above. The gas outlet is connected to the settling chamber and overflow chamber, and the oil outlet is connected to the electrostatic coalescence chamber. The first water outlet and the second water outlet are connected to the settling chamber and the electrostatic coalescence chamber, respectively. The overflow chamber and the electrostatic coalescence chamber are connected through a distribution pipe. The gas-liquid cyclone separator internals, heating coils and rectifying coalescence packing are sequentially arranged in the settling chamber, and the gas-liquid cyclone separator internals are connected to the produced fluid inlet. The first electrostatic coalescence plate group is arranged in the overflow chamber, and the second electrostatic coalescence plate group and the collection pipe are arranged in the electrostatic coalescence chamber. The collection pipe is connected to the oil outlet.

[0007] Preferably, the distribution pipe is located at the bottom of the electrostatic coalescing chamber and communicates with the overflow chamber, the collection pipe is located at the top of the electrostatic coalescing chamber, and the second electrostatic coalescing plate assembly is located between the distribution pipe and the collection pipe.

[0008] Preferably, the distribution pipe is provided with flow holes in sequence along its direction, and the collection pipe is provided with oil inlet holes in sequence along its direction.

[0009] Preferably, a demisting component is provided inside the air outlet. The demisting component includes an outlet air chamber and a wire mesh fog eliminator, with the wire mesh fog eliminator located inside the outlet air chamber.

[0010] Preferably, a first drain pipe and a second drain pipe are connected to the first outlet and the second outlet respectively, the first drain pipe and the second drain pipe are connected, and a check valve is provided on the second drain pipe.

[0011] Preferably, a manhole is also provided on the outer wall of the horizontal separation tank.

[0012] Preferably, a ladder platform is installed on the outer wall of the horizontal separation tank.

[0013] Compared with the prior art, the advantages of this utility model are:

[0014] This utility model separator employs inlet cyclone pre-separation, oil phase heating, and electrostatic coalescence technology to simultaneously separate the gas, oil, and water phases contained in the produced fluid of oil and gas wells in a single stage within its horizontal separation tank. It ensures that the separated crude oil meets quality standards, making it suitable for separating produced fluids from oil wells with varying water content and different oil types. Compared to traditional separation processes, the number of equipment involved in the entire separation process is significantly reduced, correspondingly reducing the land area required for production. Furthermore, it features low wellhead back pressure, a simplified separation process, and reduced utility consumption, effectively controlling surface construction costs, production costs, and construction time. Simultaneously, the process involves minimal manual intervention, making operation, inspection, and maintenance simpler. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of the separator of this utility model;

[0016] Figure 2 This is a perspective view of the internal structure of the separator of this utility model;

[0017] Figure 3 This is a utility model Figure 2 A magnified structural diagram of part A;

[0018] Figure 4 This is a perspective view of the internal structure of the separation component of this utility model;

[0019] Figure 5 This is a perspective view of the internal structure of the separator of this utility model from another angle;

[0020] Figure 6 This is a utility model Figure 5 A magnified structural diagram of part B.

[0021] As shown in the figure:

[0022] 1. Horizontal separator; 1a. Settling chamber; 1b. Overflow chamber; 1c. Electrostatic coalescence chamber; 101. Produced fluid inlet; 102. Oil outlet; 103. Gas outlet; 104. First water outlet; 105. Second water outlet; 2. Overflow plate; 3. Baffle plate; 4. Gas-liquid cyclone separator internals; 5. Heating coil; 6. Rectifying coalescence packing; 7. First electrostatic coalescence plate group; 8. Second electrostatic coalescence plate group; 9. Distribution pipe; 901. Flow passage; 10. Collection pipe; 1001. Oil inlet; 11. Demisting assembly; 1101. Outlet air manifold; 1102. Wire mesh mist eliminator; 12. First drain pipe; 13. Second drain pipe; 14. Ladder platform; 15. Check valve. Detailed Implementation

[0023] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0024] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. They are only for the purpose of simplifying the description and do not indicate or imply that the orientation is a specific orientation or specific orientation structure and operation. Therefore, they should not be construed as limiting this utility model.

[0025] like Figure 1 , Figure 2 and Figure 5As shown, this utility model relates to a primary separation device for produced fluid from oil and gas wells. It includes a horizontal separation tank 1. The outer wall of the horizontal separation tank 1 has a produced fluid inlet 101, an oil outlet 102, a gas outlet 103, a first water outlet 104, and a second water outlet 105. The produced fluid inlet 101 is connected to the collection end of the produced fluid from the oil and gas well, and is used to input the produced fluid into the interior of the horizontal separation tank 1. Inside the horizontal separation tank 1, oil, gas, water, and solid impurities are separated. The separated crude oil is discharged through the oil outlet 102, and the resulting wastewater and gas phase are discharged to the outside through the first water outlet 104, the second water outlet 105, and the gas outlet 103, respectively. The interior of the horizontal separation tank 1 is equipped with an overflow plate 2, a baffle plate 3, a gas-liquid cyclone separation internal component 4, and a heating element. The horizontal separator 1 consists of a coil 5, a rectifying coalescing packing 6, a first electrostatic coalescing plate group 7, a second electrostatic coalescing plate group 8, a distribution pipe 9, and a collection pipe 10. The internal space of the horizontal separator 1 is divided into three different chambers by an overflow plate 2 and a partition 3: a settling chamber 1a, an overflow chamber 1b, and an electrostatic coalescing chamber 1c. The produced liquid inlet 101 is located at the top of the settling chamber 1a and is connected to it. The air outlet 103 is located at the top of the overflow chamber 1b and is connected to it. The oil outlet 102 is located at the top of the electrostatic coalescing chamber 1c and is connected to it. The first water outlet 104 and the second water outlet 105 are located at the bottom of the settling chamber 1a and the electrostatic coalescing chamber 1c, respectively, and are connected to them. The overflow plate... The height of the overflow plate 2 is less than the height of the internal space of the horizontal separator 1, so that a gas phase space is formed above the overflow plate 2. The settling chamber 1a and the overflow chamber 1b are connected through the gas phase space. Here, the lower part of the settling chamber 1a and the overflow chamber 1b is defined as the liquid phase space, and the upper part is defined as the gas phase space. The baffle 3 completely separates the overflow chamber 1b and the electrostatic coalescence chamber 1c. The overflow chamber 1b and the electrostatic coalescence chamber 1c are only connected through the distribution pipe 9. Thus, a pressure difference will be formed in the horizontal separator 1 during the separation of produced fluid from the oil and gas well, ensuring the fluidity of the produced fluid from the oil and gas well. The gas-liquid cyclone separator internals 4, the heating coil 5, and the rectifying coalescence packing 6 are sequentially arranged in the settling chamber 1a, and the gas-liquid cyclone separator internals 4 are connected to the produced fluid inlet 101 to ensure that the produced fluid from the oil and gas well is directly input into the interior. The gas-liquid cyclone separator 4 converts the kinetic energy of the produced fluid from the oil and gas well into centrifugal force. Under the action of centrifugal force, the gas phase in the produced fluid is initially separated from the liquid and solid phases. The main component of the separated gas phase is natural gas, and the main components of the liquid phase are water and crude oil. The separated gas and liquid phases pass through the rectifying and coalescing packing 6. The gas phase rises into the upper gas phase space of the settling chamber 1a, and then enters the gas phase space of the overflow chamber 1b, and is finally discharged through the gas outlet 103. In the liquid phase space of the settling chamber 1a, due to the difference in density, the water phase is located in the lower layer and the oil phase is located in the upper layer. When the liquid phase passes through the rectifying and coalescing packing 6, the emulsion droplets in the liquid phase are broken up by the collision coalescing principle, so that the dispersed water droplets and dispersed oil droplets coalesce separately.Under the influence of density difference and gravity, coalesced water droplets settle into the aqueous phase, while coalesced oil droplets float into the oil phase. Heating coil 5 improves the demulsification effect. Furthermore, to fully utilize heat energy and avoid ineffective heating of the separated free water, heating coil 5 is installed in the oil phase space of settling chamber 1a. The stratified produced water is discharged to the external space through the first water outlet at the bottom of settling chamber 1a, while the stratified oil phase and emulsion overflow into overflow chamber 1b through overflow plate 2 between settling chamber 1a and overflow chamber 1b. It should be noted that the number of heating coil 5 and rectifying coalescing packing 6 is not particularly limited and can be set differently according to actual operational needs. The first electrostatic coalescing plate group 7 is located in the overflow chamber 1b, and the second electrostatic coalescing plate group 8 and the collection pipe 10 are located in the electrostatic coalescing chamber 1c. Both the first electrostatic coalescing plate group 7 and the second electrostatic coalescing plate group 8 integrate multiple electrostatic coalescing plates. The collection pipe 10 is connected to the oil outlet 102. When the oil phase and emulsion enter the overflow chamber 1b, they undergo preliminary electrostatic coalescing and dehydration by the first electrostatic coalescing plate group 7. Under the action of the electrostatic field formed by the first electrostatic coalescing plate group 7, the small water droplets rapidly coalesce into large water droplets and are deposited through the principle of gravity sedimentation, further separating the water phase. The oil phase and emulsion after preliminary electrostatic coalescing are then distributed through the distribution pipe 9 into the electrostatic coalescing chamber. In chamber 1c, secondary electrostatic coalescence dehydration is performed by the second electrostatic coalescence plate group 8, causing free water droplets in the oil phase and emulsion to coalesce and settle again, and be discharged to the outside through the second outlet 105 at the bottom, thus obtaining high-quality crude oil. The crude oil can finally flow out of the horizontal separator 1 through the collection pipe 10. It should be noted that there is no particular limitation on the number of distribution pipes 9 and collection pipes 10, and different numbers can be set according to actual operating needs. Generally, there are multiple sets of distribution pipes 9 and collection pipes 10, which can ensure the formation of a stable and uniform flow field in the electrostatic coalescence chamber 1c, thereby improving separation efficiency and collection efficiency. The separator of this utility model adopts inlet cyclone pre-separation, oil... Phase heating and electrostatic coalescence technology can simultaneously separate the gas, oil, and water phases in the produced fluid of oil and gas wells in a single stage within its horizontal separation tank 1, ensuring that the separated crude oil meets quality standards. This makes it suitable for separating produced fluids from oil wells with varying oil types and significant water content variations. Compared to traditional separation processes, the number of equipment involved in the entire separation process is greatly reduced, correspondingly reducing the land area required for production. Furthermore, it results in lower wellhead back pressure, a simplified separation process, and reduced utility consumption, effectively controlling surface construction costs, production costs, and construction time. Simultaneously, the reduced manual intervention throughout the process simplifies operation, inspection, and maintenance.

[0026] like Figure 2 and Figure 5As shown, the distribution pipe 9 is located at the bottom of the electrostatic coalescing chamber 1c and is connected to the overflow chamber 1b. The collection pipe 10 is located at the top of the electrostatic coalescing chamber 1c. Here, the lower part of the electrostatic coalescing chamber 1c is defined as the water phase space and the upper part is defined as the oil phase space. More specifically, the distribution pipe 9 is located near the oil-water interface between the oil phase space and the water phase space of the electrostatic coalescing chamber 1c, and the collection pipe 10 is located in the oil phase space of the electrostatic coalescing chamber 1c. The second electrostatic coalescing plate group 8 is located between the distribution pipe 9 and the collection pipe 10 and is located in the oil phase space of the electrostatic coalescing chamber 1c. In this way, under the action of the electrostatic field formed by the electrostatic coalescing plate, the free small water droplets can quickly coalesce and settle by gravity, thereby improving the efficiency of electrostatic coalescing dehydration.

[0027] like Figure 2 , Figure 3 , Figure 5 and Figure 6 As shown, the distribution pipe 9 has flow holes 901 sequentially opened along its direction, and the collection pipe 10 has oil inlet holes 1001 sequentially opened along its direction. More specifically, the oil inlet holes 1001 are located at the bottom of the collection pipe 10. Based on the above configuration, it can be ensured that the oil phase and emulsion from the overflow chamber 1b can flow out of the distribution pipe 9 uniformly and stably to the electrostatic coalescence chamber 1c, while ensuring that the high-quality crude oil that is finally separated can enter the collection pipe 10 uniformly and stably for unified collection.

[0028] like Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the gas phase separated from the oil and gas well produced fluid by the cyclone pre-separation internals and the gas phase flashed out in the settling chamber 1a will separate the entrained liquid when passing through the rectifying coalescing packing 6, and finally enter the gas outlet 103 through the gas phase space of the settling chamber 1a and the overflow chamber 1b. The present invention provides a demisting component 11 in the gas outlet 103. The demisting component 11 includes an outlet gas chamber 1101 and a wire mesh mist eliminator 1102. The wire mesh mist eliminator 1102 is located in the outlet gas chamber 1101. In this way, the mist-like liquid droplets entrained in the gas phase, which is mainly composed of natural gas, can be removed by the collision coalescence principle. The critical particle size of the removed mist-like liquid droplets is generally 10μm, which ultimately ensures that the liquid content of the natural gas flowing out of the separator through the gas chamber meets the standard.

[0029] like Figure 1 , Figure 2 and Figure 5As shown, a first drain pipe 12 and a second drain pipe 13 are connected to the first outlet 104 and the second outlet 105, respectively. The first drain pipe 12 and the second drain pipe 13 are connected. The extracted water separated in the settling chamber 1a and the electrostatic coalescence chamber 1c enters the first drain pipe 12 and the second drain pipe 13 through the first outlet 104 and the second outlet 105, respectively. The extracted water in the second drain pipe 13 will be collected in the first drain pipe 12 and finally flow into the water treatment equipment for treatment. A check valve 15 is provided on the second drain pipe 13 to prevent the extracted water in the first drain pipe 12 from flowing back into the second drain pipe 13 due to the pressure difference between the first drain pipe 12 and the second drain pipe 13, thus ensuring the normal discharge of the extracted water.

[0030] Furthermore, manholes are provided on the outer wall of the horizontal separator 1 to facilitate operators to conduct safety inspections and maintenance of the internal components of the horizontal separator 1. It should be noted that there can be multiple manholes, which facilitates comprehensive safety inspections and maintenance of the horizontal separator 1 when needed.

[0031] like Figure 1 , Figure 2 and Figure 5 As shown, a ladder platform 14 is installed on the outer wall of the horizontal separator 1, which facilitates the operator to inspect and maintain the produced liquid inlet 101, oil outlet 102, gas outlet 103, first water outlet 104 and second water outlet 105 on the outer wall of the horizontal separator 1, as well as the connected auxiliary pipelines, thereby reducing the difficulty of inspection and maintenance and improving work efficiency.

[0032] The embodiments and descriptions above are merely illustrative of the principles and preferred embodiments of this utility model. Various changes and modifications may be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of this utility model as claimed.

Claims

1. A one-stage separator for oil and gas well produced fluids, characterized in that, It includes a horizontal separation tank (1), the outer wall of which has a produced fluid inlet (101), an oil outlet (102), a gas outlet (103), a first water outlet (104), and a second water outlet (105). The interior of the horizontal separation tank (1) is provided with an overflow plate (2), a baffle plate (3), a gas-liquid cyclone separator (4), a heating coil (5), a rectifying coalescing packing (6), a first electrostatic coalescing plate group (7), a second electrostatic coalescing plate group (8), a distribution pipe (9), and a collection pipe (10). The interior of the horizontal separation tank (1) is divided into a settling chamber (1a), an overflow chamber (1b), and an electrostatic coalescing chamber (1c) by the overflow plate (2) and the baffle plate (3) in sequence. The produced fluid inlet (101) is connected to the settling chamber (1a). There is a gas phase space above the overflow plate (2). The settling chamber (1a) and the overflow chamber (1b) are connected to each other. The gas outlet (103) is connected to the settling chamber (1a) and the overflow chamber (1b) through the upper gas phase space, the oil outlet (102) is connected to the electrostatic coalescence chamber (1c), the first water outlet (104) and the second water outlet (105) are connected to the settling chamber (1a) and the electrostatic coalescence chamber (1c) respectively, and the overflow chamber (1b) and the electrostatic coalescence chamber (1c) are connected through the distribution pipe (9). The gas-liquid cyclone separator (4), heating coil (5) and rectifier coalescing packing (6) are sequentially arranged in the settling chamber (1a), and the gas-liquid cyclone separator (4) is connected to the produced fluid inlet (101). The first electrostatic coalescing plate group (7) is arranged in the overflow chamber (1b), the second electrostatic coalescing plate group (8) and the collection pipe (10) are arranged in the electrostatic coalescing chamber (1c), and the collection pipe (10) is connected to the oil outlet (102).

2. The one-trip separator of claim 1, wherein, The distribution pipe (9) is located at the bottom of the electrostatic coalescence chamber (1c) and is connected to the overflow chamber (1b). The collection pipe (10) is located at the top of the electrostatic coalescence chamber (1c). The second electrostatic coalescence plate group (8) is located between the distribution pipe (9) and the collection pipe (10).

3. The first-stage compliant separator for produced fluid from oil and gas wells according to claim 2, characterized in that, The distribution pipe (9) has flow holes (901) sequentially opened along its direction, and the collection pipe (10) has oil inlet holes (1001) sequentially opened along its direction.

4. A primary separation device for produced fluid from oil and gas wells according to any one of claims 1 to 3, characterized in that, The air outlet (103) is provided with a demisting component (11), which includes an outlet air chamber (1101) and a wire mesh fog catcher (1102), and the wire mesh fog catcher (1102) is located inside the outlet air chamber (1101).

5. A primary separation device for produced fluid from oil and gas wells according to claim 4, characterized in that, The first outlet (104) and the second outlet (105) are respectively connected to the first drain pipe (12) and the second drain pipe (13), the first drain pipe (12) and the second drain pipe (13) are connected, and the second drain pipe (13) is provided with a check valve (15).

6. A one-trip compliant oil and gas well produced fluid separator according to any one of claims 1, 2 or 5, characterized in that, The horizontal separation tank (1) also has a manhole on its outer wall.

7. The one-trip separator of claim 6, wherein, A ladder platform (14) is installed on the outer wall of the horizontal separation tank (1).

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