A single-pump suction type oil-water cyclone separation device for injection and production in the same well

Abstract

The present invention relates to a single pump suction type oil-water cyclone separation device for injection and production in the same well, which is composed of a drainage hollow cone, a drainage pipe, a tail pipe, and an outer shell. The outer shell is a sleeve with a closed upper port and an open lower port. A tangential inlet is arranged at the upper end of the outer shell, and a fixed cylinder is arranged at the axial position of the outer shell cover. The fixed cylinder has an internal thread, and the top of the solid column on the upper part of the drainage hollow cone is provided with an external thread. The drainage hollow cone is threadedly connected with the threaded cylinder, and the lower part of the drainage hollow cone is a hollow cone cylinder. A plurality of oil phase liquid inlet holes are arranged on the cone cylinder, and the inner wall of the lower port of the drainage hollow cone is threadedly connected to the drainage pipe, and the outer wall of the lower port of the drainage hollow cone is threadedly connected to the tail pipe. The drainage pipe is composed of a cone pipe and a straight pipe in one body, and pressure-stabilizing holes are evenly arranged at the corresponding parts of the tail pipe and the drainage pipe. The present invention improves the oil-water separation efficiency through the drainage hollow cone, the oil-water mixed liquid flows stably, alleviates the problem of oil phase loss from the side wall, greatly improves the economic benefit, and is convenient for installation in a small space underground.

Description

Technical Field

[0001] The invention relates to an underground oil-water separation device, in particular to an underground single-pump suction type oil-water cyclone separation device for injection and production in the same well. Background Art

[0002] At present, most of the oil-water separation cyclones adopt the method that the oil outlet and the water outlet are located on different sides of the device, and the internal flow field has cyclonic motion in multiple directions, which leads to unstable flow field, low separation efficiency, and poor removal effect on fine oil droplets. In addition, this structure with the oil outlet and the water outlet on different sides is sometimes very inconvenient when connected to related supporting process equipment, especially when used for underground operations, and the construction is very difficult.

[0003] Chinese invention patent ZL202110409969.4, a nested solid-liquid-liquid three-phase separation device, in which the solid-liquid three-phase medium enters through a tangential inlet, is swirled by the guide vanes, and under the action of centrifugal force, the water phase is thrown to the side wall and discharged from the drain port, and the oil phase aggregates at the center, moves upward, and is discharged through the oil drain port. However, the device adopts a structural form in which the oil outlet and the water outlet are on different sides. During the swirling process, multiple flow fields will be generated, resulting in an unstable overall flow field, which has a poor effect on the agglomeration and separation effect. Moreover, this structural form is also insufficient in the treatment of fine oil droplets. Under some specific working conditions in engineering, it is inconvenient to install related supporting process equipment. Summary of the invention

[0004] The purpose of the present invention is to provide a single-pump suction type oil-water cyclone separator for injection and production in the same well. The single-pump suction type oil-water cyclone separator for injection and production in the same well is used to solve the problems of unstable flow field and low separation efficiency of existing oil-water separation devices.

[0005] The technical solution adopted by the present invention to solve its technical problems is as follows: the single-pump suction type oil-water cyclone separation device for injection and production in the same well is composed of a drainage hollow cone, a drainage pipe, a tail pipe and an outer shell. The outer shell is a sleeve with a closed upper port and an open lower port. A tangential inlet is arranged at the upper end of the outer shell. A fixed cylinder is arranged at the axial position of the outer shell cover. The fixed cylinder has an internal thread. The top of the solid column at the upper part of the drainage hollow cone is provided with an external thread. The drainage hollow cone is threadedly connected with the threaded cylinder. The lower part of the drainage hollow cone is a hollow cone cylinder. A plurality of oil phase liquid inlet holes are arranged on the cone cylinder. The inner wall of the lower port of the drainage hollow cone is threadedly connected to the drainage pipe. The outer wall of the lower port of the drainage hollow cone is threadedly connected to the tail pipe. The drainage pipe is composed of a cone pipe and a straight pipe in one. Pressure stabilizing holes are evenly arranged at the corresponding positions of the tail pipe and the drainage pipe. The lower port of the tail pipe is an oil phase outlet. The annular hole between the tail pipe and the outer shell is a water phase outlet.

[0006] In the above scheme, the shell is a multi-cone segment shell which is integrally formed from top to bottom by an upper cylinder segment, a first cone segment, a second cone segment, a third cone segment and a lower cylinder segment. The ratio of the length of the first cone segment to the sum of the lengths of the second cone segment and the third cone segment is 1:5-1:7, the sum of the lengths of the second cone segment and the third cone segment is greater than the length of the drainage tube, and the ratio of the cone length of the drainage hollow cone to the length of the drainage tube is 10:25-10:30.

[0007] In the above solution, there are two tangential inlets, which are symmetrically arranged at the upper end of the shell.

[0008] In the above scheme, the upper cylinder section and the first cone section of the shell are cyclone chamber sections, the second cone section is a large cone section, and the third cone section is a small cone section. The oil-water mixture enters the cyclone chamber from the tangential inlet and rotates at a high speed under a certain pressure to form a strong cyclone field. The liquid moves downward along the cyclone chamber section, the large cone section and the small cone section. Under the action of centrifugal force, the water phase with higher density is thrown to the shell wall, rotates downward along the periphery, and is finally discharged from the water phase outlet; the oil phase with lower density is moved to the center, and the oil droplets gather near the drainage hollow cone and enter the inner cavity of the drainage hollow cone through the oil phase liquid inlet hole, and move downward along the drainage pipe under the action of the internal cyclone flow field and are discharged from the oil phase outlet. Beneficial Effects

[0009] 1. The perforated drainage hollow cone of the present invention gathers the oil phase in the middle area during the oil-water separation process, and the oil phase enters the interior through the liquid inlet hole, and realizes efficient separation while achieving the same-direction outflow function.

[0010] 2. The perforated tail pipe structure of the present invention can ensure that the pressure inside the tail pipe is balanced with the external pressure while separating the oil and water phases, thereby ensuring normal flow inside the entire device.

[0011] 3. The present invention can realize the outflow of oil and water in the same direction, which not only stabilizes the central flow field and realizes efficient separation, effectively separates fine oil droplets, but also does not allow a large number of pipelines to be connected, making it easy to install in the narrow space underground, thus solving a major problem of underground construction.

[0012] 4. The present invention has the advantages of simple structure and easy installation. By opening a hole in the drainage hollow cone, the oil phase enters the inner cavity through the oil phase inlet hole after coalescence, and flows out through the inner cavity to the oil phase outlet. The effect of separation and discharge after coalescence is better than that of the original one, which alleviates the problem of oil phase loss from the side wall and greatly improves the economic benefits. The tail pipe opening stabilizes the pressure conservation inside the entire device, facilitates the removal of the oil phase, and ensures the normal flow of the overall oil-water mixture. At the same time, the design of the oil phase and water flowing out in the same direction facilitates downhole installation and is more conducive to stabilizing the hydraulic cyclone flow field. It is a device suitable for efficient oil-water separation downhole.

[0013] 5. The present invention adopts the co-directional outflow of oil and water, the outer wall adopts multi-cone sections, and the internal structure adopts the drainage cone, which stabilizes the flow field as a whole, strengthens the coalescence effect, has a better effect on the treatment of fine oil droplets, and can solve the installation and connection difficulties of supporting process equipment, reduce pipeline junctions, and the overall process equipment is simple and light. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the overall appearance of a single-pump suction type oil-water cyclone separation device for injection and production in the same well;

[0015] Figure 2 An overall cross-sectional view of a single-pump suction type oil-water cyclone separation device for injection and production in the same well;

[0016] Figure 3 An exploded view of a single pump suction type oil-water cyclone separation device for injection and production in the same well;

[0017] Figure 4 The appearance (a) and cross-sectional view (b) of the hollow drainage cone;

[0018] Figure 5 The following are the appearance view (a) and cross-sectional view (b) of the tail pipe sleeve.

[0019] In the figure: 101-drainage hollow cone, 1011-oil phase liquid inlet, 102-drainage pipe, 103-tail pipe, 1031-pressure stabilizing hole, 1032-oil phase outlet, 104-housing, 1041-tangential inlet, 1042-water phase outlet. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings:

[0021] Combination Figure 1-Figure 5 As shown, this single-pump suction type oil-water cyclone separation device for injection and production in the same well is composed of a drainage hollow cone 101, a drainage pipe 102, a tail pipe 103, and a shell 104. The shell 104 is a sleeve with an upper port closed and a lower port open. A tangential inlet 1041 is arranged at the upper end of the shell. There are two tangential inlets, which are symmetrically arranged at the upper end of the shell. A fixed cylinder is arranged at the axial position of the shell cover. The fixed cylinder has an internal thread. The top of the solid column on the upper part of the drainage hollow cone 101 is provided with an external thread. The drainage hollow cone 101 is threadedly connected to the threaded cylinder. The lower part of the drainage hollow cone 101 is a hollow cone cylinder, and a plurality of oil phase liquid inlet holes 1011 are arranged on the cone cylinder. The inner wall of the lower port of the drainage hollow cone is threadedly connected to the drainage pipe 102, and the outer wall of the lower port of the drainage hollow cone is threadedly connected to the tail pipe 103. The drainage pipe is composed of a cone tube and a straight tube in one body. Pressure-stabilizing holes 1031 are evenly arranged at the corresponding parts of the tail pipe 103 and the drainage pipe 102. The lower port of the tail pipe 103 is the oil phase outlet 1032, and the annular hole between the tail pipe 103 and the outer shell 104 is the water phase outlet 1042.

[0022] The oil-water mixture enters the cyclone cavity from the tangential inlet, and under a certain pressure, performs high-speed rotational motion inside the device to form a strong cyclone field. The liquid moves downward along the cyclone cavity section, the large cone section and the small cone section. Under the action of centrifugal force, the water phase with higher density is thrown to the wall of the device, rotates downward along the periphery, and is finally discharged from the water phase outlet 1042; the oil phase with lower density is moved to the center, and the oil droplets gather near the drainage hollow cone section and enter the inner cavity of the cone section through the oil phase inlet hole 1011, and move downward along the drainage cone tube under the action of the internal cyclone flow field, and are discharged from the oil phase outlet 1032. The present invention is a cyclone separation device that is easy to install underground and can efficiently separate oil and water. The drainage hollow cone further improves the oil-water separation efficiency and realizes the same-direction outflow. The tail pipe opening ensures that the inner cavity and the external pressure are balanced, stabilizes the normal flow of the oil-water mixture, and the oil-water same-direction outflow eliminates the problem of pipeline junction at the oil phase outlet, which is convenient for installation in a small space underground. The oil-water co-flow structure is conducive to the stability of the flow field. A hollow drainage cone is installed in the center. The outer shell adopts a cone section design. The overall structure strengthens the coalescence of fine oil droplets and can improve the separation efficiency. The co-flow structure can solve the problem of complex equipment installation in some specific working conditions.

[0023] The outer shell 104 is a multi-cone section outer shell which is integrally formed from top to bottom by an upper cylinder section, a first cone section, a second cone section, a third cone section and a lower cylinder section. The upper cylinder section and the first cone section are swirl chamber sections, the second cone section is a large cone section, and the third cone section is a small cone section. The ratio of the length of the first cone section to the sum of the lengths of the second cone section and the third cone section is 1:5-1:7, the sum of the lengths of the second cone section and the third cone section is greater than the length of the drainage tube, and the ratio of the cone length of the drainage hollow cone 101 to the length of the drainage tube is 10:25-10:30.

[0024] Combination Figure 1-Figure 3 As shown, the device is placed vertically and is used in a vertical working state during operation. It can separate the oil-water mixed medium. The separated oil phase is discharged from the oil phase outlet 1032, and the separated water phase is discharged from the water phase outlet 1042 and re-injected into the ground. The oil-water mixed liquid enters the device through the tangential inlet 1041 of the shell 104 to form a cyclonic flow field. Under the action of the flow field and the hollow drainage cone 101, the oil phase is gathered on the surface of the hollow drainage cone and enters the interior of the drainage hollow cone 101 through the middle oil phase inlet hole 1011. The internal oil flows down into the drainage pipe 102, and is discharged into the inner cavity of the tail pipe 103 through the drainage pipe, and is discharged from the oil phase outlet 1032. The oil-water mixed liquid containing a small amount of water phase on the outside of the tail pipe 103 enters the interior through the pressure-stabilizing hole 1031 on the tail pipe 103, stabilizing the internal pressure conservation of the entire device, facilitating the removal of the oil phase, and also ensuring the normal flow of the overall oil-water mixed liquid. After that, the water phase flows out through the outlet of the shell 104, and the oil phase flows out through the tail pipe 103.

[0025] Figure 4 The appearance diagram and cross-sectional diagram of the drainage hollow cone 101 are shown. The oil-water two phases are centrifuged and acted on by the drainage cone so that the oil phase gathers in the middle area and then enters the inner cavity through the oil phase inlet hole 1011 on the hollow drainage cone.

[0026] Figure 5 The following are the appearance and cross-sectional views of the tail pipe 103. The oil-water mixture containing a small amount of water phase on the outside enters the inside through the pressure-stabilizing hole 1031 on the tail pipe 103, which can separate the oil and water phases while ensuring that the pressure in the tail pipe cavity is balanced with the external pressure, thereby ensuring normal flow inside the entire device.

[0027] The device has a compact structure and stable operation. The multi-cone shell structure and the drainage cone have obvious oil phase coalescing effect. The drainage cone is made into a hollow opening, which plays an oil-water separation role while coalescing, thereby improving the overall separation efficiency. The structure of the co-directional outflow stabilizes the flow field and has a good effect on the treatment of fine oil droplets. It can solve the difficulties of installation and construction under specific working conditions and realizes efficient separation of oil and water phases through cyclone. It has a simple structure and is easy to install. It is suitable for small underground spaces and has high practicality.

[0028] The co-flow cyclone separator combines the overall structure of the conventional cyclone, adds a central cone at the axial position, and locates the oil outlet and the water outlet on one side of the cyclone. The water outlet is designed to be tangential. This new type of oil-water separation cyclone has changed the traditional design concept and has the advantages of stabilizing the flow field, shortening the cyclone length, improving the separation efficiency of fine oil droplets and reducing the construction difficulty. It has certain guiding significance for the research work on further miniaturization and efficiency of cyclones and has considerable prospects for promotion and application.

Claims

1. A single-pump suction type oil-water cyclone separation device for injection and production in the same well, characterized by: The single-pump suction type oil-water cyclone separation device for injection and production in the same well is composed of a hollow drainage cone, a drainage pipe, a tail pipe, and an outer shell. The outer shell is a sleeve with a closed upper port and an open lower port. A tangential inlet is arranged at the upper end of the outer shell. A fixed cylinder is arranged at the axial position of the top of the outer shell. The fixed cylinder has an internal thread. The top of the solid column at the upper part of the drainage hollow cone is provided with an external thread. The drainage hollow cone is threadedly connected with the fixed cylinder. The lower part of the drainage hollow cone is a hollow cone cylinder. A plurality of oil phase liquid inlet holes are arranged on the cone cylinder. The inner wall of the lower port of the drainage hollow cone is threadedly connected to the drainage pipe. The outer wall of the lower port of the drainage hollow cone is threadedly connected to the tail pipe. The drainage pipe is composed of a cone pipe and a straight pipe in one body. Pressure stabilizing holes are evenly arranged at the corresponding parts of the tail pipe and the drainage pipe. The lower port of the tail pipe is an oil phase outlet, and the annular hole between the tail pipe and the outer shell is a water phase outlet. The shell is a multi-cone segment shell which is integrally formed from top to bottom by an upper cylinder segment, a first cone segment, a second cone segment, a third cone segment and a lower cylinder segment, the ratio of the length of the first cone segment to the sum of the lengths of the second cone segment and the third cone segment is 1:5-1:7, the sum of the lengths of the second cone segment and the third cone segment is greater than the length of the drainage tube, and the ratio of the cone length of the hollow drainage cone to the length of the drainage tube is 10:25-10:30; The upper cylinder section and the first cone section of the shell are the cyclone chamber section, the second cone section is the large cone section, and the third cone section is the small cone section. The oil-water mixture enters the cyclone chamber from the tangential inlet and rotates at a high speed under a certain pressure to form a strong cyclone field. The liquid moves downward along the cyclone chamber section, the large cone section and the small cone section. Under the action of centrifugal force, the water phase with a higher density is thrown to the shell wall, rotates downward along the periphery, and is finally discharged from the water phase outlet; The oil phase with lower density is transported to the center, and the oil droplets gather near the hollow drainage cone and enter the inner cavity of the hollow drainage cone through the oil phase inlet hole, and move downward along the drainage pipe under the action of the internal vortex flow field. The oil-water mixture containing a small amount of water phase on the outside of the tail pipe enters the inside of the tail pipe through the pressure-stabilizing hole on the tail pipe and is discharged from the oil phase outlet.

2. The single-pump suction type oil-water cyclone separation device for injection and production in the same well according to claim 1 is characterized in that: There are two tangential inlets, which are symmetrically arranged at the upper end of the shell.

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