Oil, gas and water three-phase separator with air supplementing device

Abstract

The utility model discloses a kind of oil-gas-water three-phase separators with air supplementing device, more specifically related to three-phase separator technical field, comprising: separator shell, the liquid inlet pipe being fixedly arranged with its inside being communicated in separator shell one end, separation baffle and fixed baffle are fixedly arranged in the inside of separator shell, the drain pipe and oil outlet pipe being fixedly arranged with its inside being communicated in the bottom end of separator shell, mist eliminator is fixedly arranged in the inside top end of separator shell, the exhaust pipe is fixedly arranged in the top end of separator shell;External gas source, the air outlet end of external gas source is fixedly arranged with air supplementing pipeline, pressure detection instrument is fixedly arranged in the top end of separator shell, controller is fixedly arranged in the front end of separator shell.The utility model not only solves inherent problem on pressure fluctuation and interface control of traditional separator, but also significantly improves the overall performance, adaptability and reliability of equipment through intelligent control.

Description

Technical Field

[0001] This utility model relates to the field of three-phase separator technology, specifically to an oil-gas-water three-phase separator with a gas replenishment device. Background Technology

[0002] During oil and gas field development, the fluid produced from oil wells is typically a mixture of crude oil, natural gas, and water. To meter, process, and recover these three components, a three-phase separator is required. Its basic principle relies on effects such as gravity settling and collision coalescence to separate the mixed fluid into three layers of gas, oil, and water within a container under specific pressure and temperature.

[0003] Traditional three-phase separators are typically equipped with a back pressure regulating valve to control the separator's operating pressure. However, in actual operating conditions, especially in the later stages of oilfield development or at well sites with unstable production, severe gas production shortages may occur. When the gas produced within the separator is insufficient to maintain the minimum pressure required by the back pressure valve, it causes a sudden drop in internal pressure, leading to a series of problems: 1. Deterioration of separation effect: The pressure reduction will cause a large amount of dissolved gas in the crude oil to escape, forming small bubbles, which will hinder the settling of oil droplets and water droplets, resulting in an unclear oil-water interface and both the oil content in the effluent and the water content in the effluent exceeding the standard.

[0004] 2. Pump inlet cavitation: If the pressure is too low, the inlet pressure of the downstream delivery pump will be insufficient, which can easily lead to cavitation and damage the pump body.

[0005] 3. Process interruption: To ensure processing quality, the control system may be triggered to shut down due to excessively low pressure, affecting the continuity of production.

[0006] Therefore, there is an urgent need for a technical solution that can automatically maintain the internal pressure of the separator when its own gas production is insufficient. Utility Model Content

[0007] The purpose of this invention is to provide an oil-gas-water three-phase separator with a gas replenishment device to address the aforementioned shortcomings in the technology.

[0008] To achieve the above objectives, this utility model provides the following technical solution: an oil-gas-water three-phase separator with a gas replenishment device, comprising: A separator housing has an inlet pipe fixedly connected to its interior at one end. Inside the separator housing, a separation baffle and a fixed partition are fixedly installed. The separation baffle is located on one side of the end of the inlet pipe. At the bottom of the separator housing, a drain pipe and an oil drain pipe are fixedly connected to its interior, respectively located on both sides of the fixed partition. A mist eliminator is fixedly installed at the top of the separator housing. An exhaust pipe is fixedly installed at the top of the mist eliminator, and a back pressure regulating valve is fixedly installed on the exhaust pipe. An external air source is provided, with a replenishment line fixedly installed at the outlet end of the external air source. One end of the replenishment line passes through the top of the separator housing and extends to the gas phase distribution area inside the separator housing. A replenishment regulating valve is fixedly installed on the replenishment line. A pressure detection instrument is fixedly installed at the top of the separator housing, with the detection end of the pressure detection instrument extending to the gas phase area. A controller is fixedly installed at the front end of the separator housing. The pressure detection instrument and the replenishment regulating valve are respectively connected to the input and output ends of the controller.

[0009] Preferably, the external gas source can be an external natural gas pipeline, a nitrogen cylinder group, or an on-site nitrogen generation device.

[0010] Preferably, the connection point of the gas replenishment line is located at the front end of the exhaust pipe to ensure that the replenished gas can be fully mixed and act on the gas phase region.

[0011] Preferably, the top of the fixed partition has an adjustment groove, and an adjustment partition is provided inside the adjustment groove. The adjustment partition and the inner wall of the adjustment groove of the separator housing are sealed together by a sealing gasket. A threaded rod is provided inside the adjustment groove. The bottom end of the threaded rod passes through the bottom end of the fixed partition and the bottom end of the separator housing and extends to the bottom end of the separator housing. The threaded rod and the bottom end of the fixed partition are rotatably connected by a sealed bearing. The bottom end of the adjustment partition has a threaded groove, and the top end of the threaded rod extends into the threaded groove and is threadedly connected to the threaded groove. A motor is fixedly provided at the bottom end of the separator housing. The output shaft of the motor is fixedly connected to the bottom end of the threaded rod. The motor is connected to the output end of the controller. A protective frame is fixedly provided at the bottom end of the separator housing, and the motor is located inside the protective frame.

[0012] Preferably, the adjusting baffle has a lifting groove on the side near the aqueous phase zone, a lifting block is provided inside the lifting groove, and a float is fixed on one side of the lifting block. The density of the float is less than the density of water and greater than the density of oil. The float floats in water and sinks to the bottom in oil. The float is located at the oil-water separation surface.

[0013] Preferably, a first tactile switch and a second tactile switch are fixedly provided at the top and bottom of the lifting groove, respectively. Both the first tactile switch and the second tactile switch are connected to the input terminal of the controller. A first touch block and a second touch block are fixedly provided at the top and bottom of the lifting block, respectively. The first touch block is located at the bottom of the first tactile switch, and the second touch block is located at the top of the second tactile switch.

[0014] Preferably, a guide groove is provided on each of the two inner side walls of the lifting groove, and a guide slider is provided inside the guide groove. The two guide sliders are respectively fixedly connected to the front and rear sides of the lifting block.

[0015] The technical effects and advantages provided by this utility model in the above technical solution are as follows: 1. Regarding pressure stability: Ensuring separation efficiency: The automatic gas replenishment device can accurately maintain the internal pressure of the separator when the gas production is insufficient, effectively preventing the escape of dissolved gas and oil-water emulsification caused by sudden pressure drop, thereby ensuring the separation efficiency and quality of the oil, gas and water phases.

[0016] Ensuring production continuity: It avoids system shutdowns triggered by excessively low pressure, making it particularly suitable for oil fields with low gas-oil ratios or unstable production conditions, and greatly improving the continuity and stability of the production process.

[0017] Protecting downstream equipment: Stable system pressure prevents cavitation in the delivery pump and extends the service life of pumps and other downstream equipment.

[0018] 2. Regarding separation efficiency: Improved separation quality: Through the automatically adjustable baffle and floating interface detection mechanism, it can dynamically respond to changes in the oil-water interface, optimize the water phase outflow channel in real time, effectively prevent oil-water cross-contamination, and significantly improve the purity of the exported crude oil and produced water.

[0019] Strong self-adaptability: This automatic adjustment system enables the separator to adapt to changes in the inlet flow rate and oil-water ratio, achieving efficient separation under different operating conditions and broadening the application range of the equipment.

[0020] Achieving intelligent operation: By linking interface detection and mechanical adjustment through a controller, the oil-water separation process is automated and intelligent, reducing reliance on manual operation.

[0021] 3. In terms of overall performance: High integration and reliability: It integrates two major functions, namely gas replenishment and pressure stabilization and automatic interface adjustment, to ensure the high performance and operational reliability of the separator under complex working conditions.

[0022] High degree of automation: Pressure regulation and interface regulation are both completed automatically through sensors, controllers and actuators, with rapid response and precise control, effectively reducing the labor intensity of operators.

[0023] In summary, this invention not only solves the inherent problems of pressure fluctuation and interface control in traditional separators, but also significantly improves the overall performance, adaptability and reliability of the equipment through intelligent control. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the overall three-dimensional sectional structure of the present invention. Figure 1 ; Figure 3 This is a schematic diagram of the overall three-dimensional sectional structure of the present invention. Figure 2 ; Figure 4 This is a three-dimensional sectional view of the fixed partition and the adjustable partition of this utility model. Figure 1 ; Figure 5 This is a three-dimensional sectional view of the fixed partition and the adjustable partition of this utility model. Figure 2 ; Figure 6 For the present utility model Figure 5 A schematic diagram of the enlarged structure of A in the middle.

[0026] Explanation of reference numerals in the attached figures: 1. Separator housing; 2. Inlet pipe; 3. Separation baffle; 4. Fixed partition; 5. Drain pipe; 6. Oil drain pipe; 7. Mist eliminator; 8. Exhaust pipe; 9. Back pressure regulating valve; 10. External air source; 11. Air replenishment line; 12. Air replenishment regulating valve; 13. Pressure measuring instrument; 14. Controller; 15. Adjustment groove; 16. Adjustment partition; 17. Threaded rod; 18. Threaded groove; 19. Motor; 20. Protective frame; 21. Lifting groove; 22. Lifting block; 23. Float; 24. First tactile switch; 25. Second tactile switch; 26. First contact block; 27. Second contact block; 28. Guide slide; 29. ​​Guide slider. Detailed Implementation

[0027] To enable those skilled in the art to better understand the technical solution of this utility model, the following description is provided in conjunction with the appendix. Figure 1-6 The present invention provides a more detailed description of the specific implementation of an oil-gas-water three-phase separator with a gas replenishment device.

[0028] I. Overall Structure and Workflow The oil-gas-water three-phase separator with a gas replenishment device described in this utility model has a horizontal, tank-shaped separator shell 1 as its core body. The oil-gas-water mixture enters the separator at high speed through the inlet pipe 2, first impacting the separation baffle 3 for initial gas-liquid separation and kinetic energy reduction. The liquid falls into the lower part of the separator under gravity and gradually separates into layers due to the density difference between oil and water as it flows towards the fixed baffle 4, with oil on top and water at the bottom. The fixed baffle 4 divides the lower part of the separator into a water phase zone and an oil phase zone. The separated clean water is discharged through the drain pipe 5, and the separated crude oil is discharged through the oil drain pipe 6. The separated natural gas rises to the top of the separator, where it passes through the mist eliminator 7 to capture any liquid droplets it carries, becoming dry gas that is discharged through the exhaust pipe 8. The back pressure regulating valve 9 is used to control the system's operating pressure.

[0029] II. Implementation Method of the Gas Injection Device 1. Composition and Connection: The core components of the air replenishment device include an external air source 10, an air replenishment pipeline 11, an air replenishment regulating valve 12, a pressure detection instrument 13, and a controller 14.

[0030] External gas source 10: Preferably a nitrogen cylinder group or on-site nitrogen generator, as nitrogen is an inert gas that improves safety. It can also be connected to an external natural gas pipeline.

[0031] Pressure detection instrument 13: It adopts an industrial-grade pressure transmitter, whose probe extends to the gas phase space at the top of the separator for real-time monitoring of pressure values.

[0032] Controller 14: It can be a PLC (Programmable Logic Controller) or DCS (Distributed Control System) module. Its input is connected to the pressure transmitter and its output is connected to the air supply regulating valve 12.

[0033] The connection point of the supplementary gas line 11 is located at the front end of the exhaust pipe 8 (i.e. upstream of the airflow), ensuring that the supplementary gas can be fully mixed with the original gas in the separator before being discharged through the exhaust pipe 8, thereby effectively maintaining the system pressure.

[0034] 2. Working principle and beneficial effects: Under normal operating conditions, the wellhead fluid carries a sufficient amount of natural gas, and the pressure value detected by the pressure transmitter remains within the normal set range (e.g., 0.4 MPa). The controller 14 does not issue any commands, and the gas supply regulating valve 12 is in the closed state.

[0035] When the wellhead gas production is insufficient, causing the pressure transmitter to detect a pressure drop to a preset first pressure threshold (e.g., 0.35 MPa), the controller 14 immediately outputs an opening signal to the gas supply regulating valve 12 (which can be a pneumatic or electric regulating valve, such as those from Fisher or Samson). Gas from the external gas source 10 is injected into the top of the separator through the gas supply line 11, and the system pressure begins to rise.

[0036] When the pressure rises back to the second pressure threshold (e.g., 0.38 MPa), the controller 14 outputs a shut-off signal, the gas supply regulating valve 12 closes, and gas supply stops.

[0037] This implementation method specifically solves the problem in the prior art where insufficient gas production leads to a sudden drop in separator pressure, resulting in deterioration of separation performance, pump cavitation, and production interruption. Its advantages include the ability to automatically and accurately maintain separation pressure, ensuring separation performance and production continuity, while also featuring a simple structure and a high degree of automation.

[0038] III. Implementation Methods for Automatic Adjustment of Oil-Water Interface 1. Mechanical adjustment structure: An adjustment groove 15 is provided at the top of the fixed partition 4, and an adjustable partition 16 is provided inside. A dynamic seal is achieved between the adjustable partition 16 and the groove wall via a PTFE gasket. A threaded rod 17 (such as a T-type lead screw) passes through the bottom of the fixed partition 4 and the separator housing 1 via a sealed bearing (brands such as SKF or NSK are optional), and is connected to the output shaft of a motor 19 (an explosion-proof servo motor or stepper motor from Siemens or ABB is optional). The motor 19 is equipped with a protective frame 20 to prevent damage. A threaded groove 18 is provided at the bottom of the adjustable partition 16, into which the top of the threaded rod 17 is screwed. By controlling the forward and reverse rotation of the motor 19 via the controller 14, the adjustable partition 16 can be precisely raised and lowered, thereby changing the height of the oil-water two-phase overflow channel.

[0039] 2. Interface testing and feedback mechanism: A lifting groove 21 is provided on the side of the regulating baffle 16 near the aqueous phase zone, and a lifting block 22 is installed inside it. A float 23 is fixed to one side of the float 21. The float 23 is made of a material with a density between oil and water (e.g., a density of 0.85-0.99 g / cm³). 3 It is made of a high-molecular composite material, which allows it to always float on the oil-water interface.

[0040] A first tactile switch 24 and a second tactile switch 25 (optional Omron or Schneider miniature limit switches) are fixed at the top and bottom of the lifting slot 21, respectively. A first contact block 26 and a second contact block 27 are fixed at the corresponding positions of the lifting block 22.

[0041] To ensure the smooth movement of the lifting block 22, guide grooves 28 are provided on both sides of the inner side wall of the lifting groove 21, and the guide slider 29 (which can be made of self-lubricating copper-based or polymer material) is fixedly connected to the lifting block 22.

[0042] 3. Automatic control logic and beneficial effects: Excessive Interface Level (Too Much Aqueous Phase): When the oil-water interface level rises, the float 23 causes the lifting block 22 to move upwards. When the interface level is too high, the first contact block 26 touches the first tactile switch 24, and the switch signal is transmitted to the controller 14. The controller 14 then starts the motor 19 to rotate forward, raising the adjusting baffle 16, increasing the outflow channel of the aqueous phase, and causing the interface level to drop.

[0043] Low interface (too much oil phase): When the oil-water interface drops, the float 23 drives the lifting block 22 to move downward. When the interface is too low, when the second touch block 27 touches the second touch switch 25, the controller 14 starts the motor 19 to reverse, lowers the adjusting baffle 16, reduces the water phase outflow channel, and causes the interface to rise again.

[0044] This implementation method specifically solves the problem that traditional fixed baffles cannot adapt to oil-water mixtures with fluctuating flow and proportions, leading to incomplete separation or oil-water cross-contamination. Its advantages lie in achieving automatic detection and adjustment of the oil-water interface height, dynamically optimizing the separation space, significantly improving oil-water separation efficiency and processing quality, and realizing intelligent control.

[0045] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A three-phase oil-gas-water separator with a gas replenishment device, characterized in that, include: A separator housing (1) is provided with an inlet pipe (2) connected to its interior at one end. A separation baffle (3) and a fixed partition (4) are fixed inside the separator housing (1). The separation baffle (3) is located on one side of the end of the inlet pipe (2). A drain pipe (5) and an oil drain pipe (6) connected to its interior are fixed at the bottom of the separator housing (1). The drain pipe (5) and the oil drain pipe (6) are respectively located on both sides of the fixed partition (4). A mist eliminator (7) is fixed at the top inside the separator housing (1). An exhaust pipe (8) is fixed at the top of the separator housing (1). The exhaust pipe (8) is located at the top of the mist eliminator (7). A back pressure regulating valve (9) is fixed on the exhaust pipe (8). An external air source (10) is provided with a gas supply line (11) at the outlet end of the external air source (10). One end of the gas supply line (11) passes through the top of the separator housing (1) and extends to the gas phase distribution area inside the separator housing (1). A gas supply regulating valve (12) is fixedly provided on the gas supply line (11). A pressure detection instrument (13) is fixedly provided at the top of the separator housing (1). The detection end of the pressure detection instrument (13) extends to the gas phase area. A controller (14) is fixedly provided at the front end of the separator housing (1). The pressure detection instrument (13) and the gas supply regulating valve (12) are respectively connected to the input end and the output end of the controller (14).

2. The oil-gas-water three-phase separator with a gas replenishment device according to claim 1, characterized in that: The external gas source (10) is an external nitrogen cylinder.

3. The oil-gas-water three-phase separator with a gas replenishment device according to claim 1, characterized in that: The connection point of the gas supply line (11) is located at the front end of the exhaust pipe (8) to ensure that the supplemented gas can be fully mixed and act on the gas phase region.

4. The oil-gas-water three-phase separator with a gas replenishment device according to claim 1, characterized in that: The fixed partition (4) has an adjustment groove (15) at its top. An adjustment partition (16) is provided inside the adjustment groove (15). The adjustment partition (16) is sealed to the inner wall of the adjustment groove (15) of the separator housing (1) by a sealing gasket. A threaded rod (17) is provided inside the adjustment groove (15). The bottom end of the threaded rod (17) passes through the bottom end of the fixed partition (4) and the bottom end of the separator housing (1) and extends to the bottom end of the separator housing (1). The threaded rod (17) is rotatably connected to the bottom end of the fixed partition (4) by a sealed bearing. Next, the bottom end of the adjusting partition (16) is provided with a threaded groove (18), the top end of the threaded rod (17) extends into the threaded groove (18) and is connected to the threaded groove (18) by a thread. The bottom end of the separator housing (1) is fixedly provided with a motor (19), the output shaft of the motor (19) is fixedly connected to the bottom end of the threaded rod (17), the motor (19) is connected to the output end of the controller (14), the bottom end of the separator housing (1) is fixedly provided with a protective frame (20), and the motor (19) is located inside the protective frame (20).

5. The oil-gas-water three-phase separator with a gas replenishment device according to claim 4, characterized in that: The regulating baffle (16) has a lifting groove (21) on the side near the water phase zone. The lifting groove (21) has a lifting block (22) inside. A float (23) is fixed on one side of the lifting block (22). The density of the float (23) is less than that of water and greater than that of oil. The float (23) floats in water and sinks in oil. The float (23) is located at the oil-water separation surface.

6. The oil-gas-water three-phase separator with a gas replenishment device according to claim 5, characterized in that: The top and bottom of the lifting groove (21) are respectively fixedly provided with a first tactile switch (24) and a second tactile switch (25). The first tactile switch (24) and the second tactile switch (25) are both connected to the input terminal of the controller (14). The top and bottom of the lifting block (22) are respectively fixedly provided with a first touch block (26) and a second touch block (27). The first touch block (26) is located at the bottom of the first tactile switch (24), and the second touch block (27) is located at the top of the second tactile switch (25).

7. The oil-gas-water three-phase separator with a gas replenishment device according to claim 5, characterized in that: The lifting groove (21) has a guide groove (28) on each of its two inner side walls. The guide groove (28) has a guide slider (29) inside. The two guide sliders (29) are fixedly connected to the front and rear sides of the lifting block (22) respectively.

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