An oil-water cyclone separation device for injection and production in the same well and same direction drainage

Abstract

The present invention relates to a same-well injection and production downhole same-direction drainage type oil-water cyclone separation device, which is composed of a hollow spiral flow channel, a hollow drainage cone, a drainage pipe, and a tail pipe coaxially arranged in an outer shell. The outer shell is a multi-cone section outer shell composed of a flow channel section, a drainage cone section, a drainage pipe cone section, and a tail pipe section from top to bottom. Both ends of the outer shell are open, and the upper port of the outer shell is an axial inlet. The hollow spiral flow channel is arranged in the flow channel section of the outer shell, and a plurality of first oil phase liquid inlet holes are arranged on the hollow column; the hollow drainage cone is fixed at the lower port of the hollow spiral flow channel, and the second oil phase liquid inlet holes are evenly arranged around the hollow drainage cone; the lower port of the hollow drainage cone is connected to the drainage pipe and the tail pipe. The present invention has a stable flow field and high separation efficiency. The spiral flow channel and the hollow drainage cone are hollowly arranged, which shortens the oil-water two-phase separation time and improves the separation accuracy. The structure of the oil-water two-phase outlet on the same side solves the problem of the inconvenience of installing the bidirectional cyclone with related supporting process equipment under specific working conditions.

Description

Technical Field

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

[0002] The existing hydrocyclones have a long separation time and are not effective in treating fine oil droplets. In particular, the oil phase outlet and the water phase outlet are located at different positions, resulting in multiple flow fields, which leads to unstable flow fields and affects the separation efficiency. Conventional hydrocyclones require a large number of pipe connections during installation, which affects the oil phase output efficiency and is very inconvenient to connect with related supporting process equipment, especially when used in underground operations. Therefore, it is necessary to design a hydrocyclone that can complete the same-direction outflow underground and reduce the separation time, and solve the problem of process equipment installation.

[0003] Chinese invention patent: A three-phase cyclone separator with a guide cone in the center, patent number ZL202110609024.7, the patent includes a solid-liquid cyclone separation section and a liquid-liquid cyclone separation section. In the solid-liquid cyclone separation section, the solid phase is thrown to the side wall and discharged through the double-cut solid discharge outlet. The light oil and water phases gather toward the central area and move downward along the liquid-liquid cyclone separation section. Under the action of centrifugal force, the heavy water phase is thrown to the side wall and discharged downward, and the oil phase gathers at the center position and is discharged. The device structure adopts a solid guide cone, the oil phase flow process is longer, the oil-water separation time is long, and the outer shell adopts a single cone section structure, which has a poor effect on the coalescence of the oil and water phases. Summary of the invention

[0004] The purpose of the present invention is to provide a same-well injection and production downhole co-directional discharge type oil-water cyclone separator, which is used to solve the problems of long oil-water separation time and poor agglomeration effect in the existing co-directional outflow structure.

[0005] The technical solution adopted by the present invention to solve the technical problem is as follows: the same-well injection and production downhole same-direction liquid discharge type oil-water cyclone separation device is composed of a hollow spiral flow channel, a hollow drainage cone, a drainage pipe, and a tail pipe coaxially arranged in an outer shell, the outer shell is a multi-cone section outer shell composed of a flow channel section, a drainage cone section, a drainage pipe cone section, and a tail pipe section from top to bottom, the two ends of the outer shell are open, the upper port of the outer shell is an axial inlet, the hollow spiral flow channel is arranged in the flow channel section of the outer shell, the upper part of the hollow spiral flow channel is a solid column, the solid column is located at the axis of the flow channel section, and the lower part of the hollow spiral flow channel is a hollow column The outer wall of the hollow column is a spiral flow channel, and a plurality of first oil phase liquid inlet holes are arranged on the hollow column; the hollow drainage cone is fixed at the lower port of the hollow spiral flow channel, the hollow drainage cone is a hollow cone, and the second oil phase liquid inlet holes are evenly arranged around the hollow drainage cone; the inner wall of the lower port of the hollow drainage cone is threadedly connected to the drainage tube, and the outer wall of the lower port of the hollow drainage cone is threadedly connected to the tail pipe, the drainage tube is a cone tube, and pressure-stabilizing holes are evenly arranged in the middle and upper part of the tail pipe, the lower port of the tail pipe is the oil phase outlet, and the annular hole between the tail pipe and the outer shell is the water phase outlet; the hollow spiral flow channel, the hollow drainage cone, and the drainage tube constitute an inner cavity.

[0006] In the above solution, the top of the solid column of the hollow spiral flow channel is flush with the upper port of the shell, and a gradually shrinking annular space is formed between the solid column and the shell.

[0007] In the above scheme, the second oil phase liquid inlet holes on the hollow drainage cone are arranged in rows, and each row has a plurality of second oil phase liquid inlet holes.

[0008] In the above solution, the pressure-stabilizing holes on the tail pipe are arranged in rows, and each row has a plurality of pressure-stabilizing holes.

[0009] The method for oil-water separation in the same-well injection and production downhole co-directional liquid discharge type oil-water cyclone separation device in the above scheme is as follows: the oil-water mixed medium enters the outer shell from the axial inlet, generates centrifugal force through the hollow spiral flow channel, and under the joint action of the outer shell and the hollow drainage cone, the oil phase agglomerates and adheres to the surface of the hollow drainage cone, and enters the inner cavity from the second oil phase inlet hole and the second oil phase inlet hole. The oil in the inner cavity enters the tail pipe cavity under the drainage of the drainage pipe and is discharged through the oil phase outlet; when the separated oil-water mixture from the drainage cone section of the outer shell flows through the tail pipe, part of the oil phase enters the tail pipe cavity through the pressure-stabilizing hole on the tail pipe. At this time, while continuing to separate the oil and water phases, it is also ensured that the pressure in the tail pipe cavity is balanced with the external pressure, ensuring that normal flow is achieved inside the same-well injection and production downhole co-directional liquid discharge type oil-water cyclone separation device, and the oil phase also flows out from the oil phase outlet, and the water phase is thrown to the side wall by centrifugal force and flows out from the water phase outlet. Beneficial Effects

[0010] 1. The present invention innovatively designs a spiral flow channel and a hollow drainage cone with an oil phase inlet hole. The oil-water mixture enters the device and is aggregated in the middle under the combined action of the centrifugal force generated by the spiral flow channel, the multi-cone segment shell and the drainage cone. At the same time, the oil phase can enter the spiral flow channel and the inner cavity of the hollow drainage cone through the oil phase inlet hole, thereby achieving the preliminary separation of the oil and water phases.

[0011] 2. The present invention utilizes a co-directional outflow structure, with the oil phase outlet and the water phase outlet located on the same side, to avoid multiple flow fields generated during the cyclone separation process due to the outlets being located on different sides, thereby causing unstable flow and reducing separation efficiency, and eliminating the complex problem of pipeline junctions required during the installation of conventional hydrocyclones.

[0012] 3. The present invention innovatively utilizes a perforated tail pipe, which can separate the oil and water phases while ensuring that the pressure inside the tail pipe is balanced with the external pressure, thus ensuring the normal flow inside the entire device.

[0013] 4. The present invention has the advantages of simple structure, stable flow field, high separation efficiency, etc. The structure of multi-cone shell plus drainage cone strengthens the oil phase coalescence effect and improves separation accuracy. The oil and water phases are efficiently separated by opening holes on the wall to coalesce and separate at the same time. The tail pipe is provided with a pressure-stabilizing hole to stabilize the flow field inside the device and the normal discharge of the oil phase separated from the tail pipe cavity. The structural design on the same side of the oil and water phase outlet solves the problem of inconvenient installation of the bidirectional cyclone with related supporting process equipment under specific working conditions. It is a multi-phase medium efficient separation device suitable for underground wells.

[0014] 5. According to statistics, the axial flow guide vane cyclone has better separation performance than the tangential inlet cyclone. The axial guide vane cyclone of the present invention has a spiral flow channel to generate swirl, and the hollow drainage cone is provided with an oil phase inlet hole. The oil phase attached to the wall of the drainage cone flows into the inner cavity, shortening the separation time, and the multi-cone section plus drainage cone structure has a better coalescing effect.

[0015] 6. The co-directional outflow structure of the present invention can solve the problem that a large number of pipelines are required to connect during the installation of conventional hydrocyclones, which increases the complexity of the equipment. The multi-conical sections of the outer shell plus the internal drainage cone structure are adopted to enhance the oil phase coalescence effect, the oil and water phases are axially fed, the spiral flow channel creates centrifugal force, the spiral flow channel and the hollow drainage cone are provided with oil phase inlet holes for oil and water phase separation, shortening the oil and water phase separation time, and the co-directional outflow structure of oil and water is adopted to enhance oil phase coalescence and improve separation efficiency. The present invention has a simple structure, high separation efficiency, can achieve efficient separation of oil and water phases, and is a co-directional liquid discharge type oil-water cyclone separation device suitable for injection and production in the same well. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the overall appearance of a downhole same-direction liquid-discharging type oil-water cyclone separation device for injection and production in the same well;

[0017] Figure 2 It is an exploded view of an oil-water cyclone separation device for the same well injection and production in the same direction;

[0018] Figure 3 It is an overall cross-sectional view of an oil-water cyclone separation device for the same-well injection and production and the same-direction liquid discharge type;

[0019] Figure 4 The outer shell appearance (a) and cross-sectional view (b) are shown;

[0020] Figure 5 The appearance (a) and cross-sectional view (b) of the spiral flow channel;

[0021] Figure 6 The appearance (a) and cross-sectional view (b) of the hollow drainage cone.

[0022] In the figure, 101-hollow spiral flow channel, 1011-first oil phase liquid inlet hole, 102-hollow drainage cone, 1021-second oil phase liquid inlet hole, 103-drainage pipe, 104-tail pipe, 1041-pressure stabilizing hole, 1042-oil phase outlet, 105-housing, 1051-axial inlet, 1052-water phase outlet. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings:

[0024] Combination Figure 1-Figure 6As shown, this downhole same-direction liquid discharge type oil-water cyclone separation device for injection and production in the same well is composed of a hollow spiral flow channel 101, a hollow drainage cone 102, a drainage pipe 103, and a tail pipe 104 coaxially arranged in a shell 105. The shell 105 is a multi-cone section shell composed of a flow channel section, a drainage cone section, a drainage pipe cone section, and a tail pipe section from top to bottom. Both ends of the shell are open, and the upper port of the shell is an axial inlet 1051. The hollow spiral flow channel 101 is arranged in the flow channel section of the shell 105. The upper part of the hollow spiral flow channel 101 is a solid column, which is located at the axis of the flow channel section. The top of the solid column of the hollow spiral flow channel is flush with the upper port of the shell, and a gradually shrinking annular space is formed between the solid column and the shell; the lower part of the hollow spiral flow channel 101 is A hollow column, the outer wall of the hollow column is a spiral flow channel, and a plurality of first oil phase liquid inlet holes 1011 are arranged on the hollow column; a hollow drainage cone 102 is fixed at the lower port of the hollow spiral flow channel 101, the hollow drainage cone is a hollow cone, and second oil phase liquid inlet holes 1021 are evenly arranged around the hollow drainage cone 102; the inner wall of the lower port of the hollow drainage cone is threadedly connected to the drainage tube 103, and the outer wall of the lower port of the hollow drainage cone is threadedly connected to the tail pipe 104, the drainage tube is a cone tube, and pressure-stabilizing holes 1041 are evenly arranged in the middle and upper part of the tail pipe 104, the lower port of the tail pipe 104 is the oil phase outlet 1042, and the annular hole between the tail pipe and the outer shell is the water phase outlet 1052; the hollow spiral flow channel 101, the hollow drainage cone 102, and the drainage tube 103 constitute an inner cavity.

[0025] In this embodiment, four rows of second oil phase inlet holes are arranged on the hollow drainage cone 102, each row having a plurality of second oil phase inlet holes 1021; four rows of pressure stabilizing holes 1041 are arranged on the tail pipe 104, each row having a plurality of pressure stabilizing holes.

[0026] The oil-water mixture of the present invention enters the device through an axial inlet, and is swirled in a hollow spiral flow channel. The oil phase flows through the spiral flow channel and coalesces with the drainage cone, and at the same time enters the inner cavity through the oil phase liquid inlet hole to complete separation. The outer shell 105 adopts a multi-cone section structure, which can also improve the coalescence effect during the swirling process of the oil-water mixture. The tail pipe 104 is provided with a pressure-stabilizing hole 1041 to ensure the conservation of pressure between the inner cavity and the outside, ensure the stable outflow of the oil phase, and play a role in stabilizing the normal flow of the oil-water mixture. The pressure-stabilizing hole 1041 on the tail pipe 104 can also realize secondary separation of oil and water by having the oil phase flow in. The separated water phase is injected back into the underground through the water phase outlet on the outer wall, and the oil phase is discharged through the oil tank outlet at the tail pipe. This device innovatively designs a multi-cone section co-directional oil-water separation device that can achieve the separation of oil and water in the same direction. Through the combined effect of the multi-cone section and the drainage cone, the agglomeration effect of the oil phase is enhanced and the separation efficiency is improved. Conventional hydrocyclones require a large number of pipeline connections during installation, and the oil phase is not discharged smoothly. The co-directional outflow can solve the installation problem of related equipment under specific working conditions.

[0027] Combination Figure 1-Figure 3As shown, the present invention is placed vertically and is used in a vertical working state during operation. The oil-water two phases are separated and the separated oil phase is discharged through the tail pipe oil phase outlet, and the water phase is discharged through the outer wall water phase outlet 1052 and injected back into the ground. The oil-water mixed medium enters the device through the axial inlet 1051, and generates centrifugal force through the hollow spiral flow channel 101. Under the joint action of the outer shell 105 and the hollow drainage cone 102, the oil phase aggregates and adheres to the surface of the hollow drainage cone 102, and enters the inner cavity from the second oil phase inlet hole 1021 and the first oil phase inlet hole 1011. The oil in the inner cavity enters the tail pipe inner cavity downward under the drainage of the drainage pipe 103, and is discharged through the oil phase outlet 1042. The separated oil-water mixture flows through the tail pipe 104, and part of the oil phase enters the inner cavity through the pressure-stabilizing hole 1041 on the tail pipe 104. While separating the oil-water two phases, it can also ensure that the pressure in the tail pipe inner cavity is balanced with the external pressure, and ensure the normal flow inside the entire device. The oil phase flows out from the oil phase outlet 1042 of the tail pipe 104, and the water phase is thrown to the side wall by centrifugal force and flows out from the water phase outlet 1052.

[0028] See also Figure 4 The outer shell adopts a multi-cone section structure to enhance the agglomeration effect and improve the separation efficiency.

[0029] See also Figure 5 The hollow spiral channel 101 is used to generate vortex, and the outer wall is provided with a first oil phase liquid inlet hole 1011, so that the oil attached to the wall surface is separated during the vortex generation process, thereby reducing the separation time and improving the time efficiency.

[0030] See also Figure 6 The coalesced oil adheres to the outer wall of the cone, and enters the inner cavity along the second oil phase inlet hole 1021 to complete the oil-water separation.

[0031] The co-directional outflow structure can solve the problem that a large number of pipe connections are required during the installation of conventional hydrocyclones, which increases the complexity of the equipment. The multi-conical sections of the outer shell plus the internal drainage cone structure are adopted to enhance the oil phase coalescence effect. The oil and water phases are axially fed, and the spiral flow channel creates centrifugal force. The spiral flow channel and the hollow drainage cone are provided with oil phase inlet holes for oil and water phase separation, which shortens the oil and water phase separation time. The oil and water co-directional outflow structure is adopted to enhance the oil phase coalescence and improve the separation efficiency. The invention has a simple structure, high separation efficiency, and can achieve efficient separation of the oil and water phases.

[0032] The present invention utilizes the effects of multiple cone sections, spiral centrifugal and drainage cones to enhance the agglomeration effect of the oil phase, and oil phase liquid inlet holes are provided in the spiral flow channel and the hollow drainage cone to complete separation during the agglomeration process, thereby greatly reducing the separation time. The present invention has a simple structure, short separation time and high separation efficiency, and is a small-scale oil-water high-efficiency separation device suitable for underground wells, and is an oil-water high-efficiency separation device used in the fields of underground oilfield exploitation and injection and production in the same well.

Claims

1. A downhole same-direction liquid discharge type oil-water cyclone separation device for injection and production in the same well, characterized by: The same-well injection and production downhole same-direction liquid discharge type oil-water cyclone separation device is composed of a hollow spiral flow channel, a hollow drainage cone, a drainage pipe, and a tail pipe coaxially arranged in an outer shell. The outer shell is a multi-cone section outer shell composed of a flow channel section, a drainage cone section, a drainage pipe cone section, and a tail pipe section from top to bottom. Both ends of the outer shell are open, and the upper port of the outer shell is an axial inlet. The hollow spiral flow channel is arranged in the flow channel section of the outer shell. The upper part of the hollow spiral flow channel is a solid column, which is located at the axis of the flow channel section. The lower part of the hollow spiral flow channel is a hollow column, and the outer wall of the hollow column is a spiral flow channel. The hollow column is provided with a plurality of first oil phase liquid inlet holes; the hollow drainage cone is fixed at the lower port of the hollow spiral flow channel, the hollow drainage cone is a hollow cone, and the second oil phase liquid inlet holes are evenly arranged around the hollow drainage cone; the inner wall of the lower port of the hollow drainage cone is threadedly connected to the drainage pipe, the outer wall of the lower port of the hollow drainage cone is threadedly connected to the tail pipe, the drainage pipe is a cone pipe, and the middle and upper parts of the tail pipe are evenly provided with pressure stabilizing holes, the lower port of the tail pipe is the oil phase outlet, and the annular hole between the tail pipe and the shell is the water phase outlet; the hollow spiral flow channel, the hollow drainage cone, and the drainage pipe constitute an inner cavity.

2. The same-well injection and production downhole same-direction liquid discharge type oil-water cyclone separation device according to claim 1 is characterized in that: The top of the solid column of the hollow spiral flow channel is flush with the upper port of the shell, and a gradually shrinking annular space is formed between the solid column and the shell.

3. The same-well injection and production downhole same-direction liquid discharge type oil-water cyclone separation device according to claim 2 is characterized by: The second oil phase liquid inlet holes on the hollow drainage cone are arranged in rows, and each row has a plurality of second oil phase liquid inlet holes.

4. The same-well injection and production downhole same-direction liquid discharge type oil-water cyclone separation device according to claim 3 is characterized by: The pressure-stabilizing holes on the tail pipe are arranged in rows, and each row has a plurality of pressure-stabilizing holes.

5. The same-well injection and production downhole same-direction liquid discharge type oil-water cyclone separation device according to claim 4 is characterized in that: The method for separating oil and water by the same-well injection and production downhole co-directional drainage type oil-water cyclone separation device is as follows: the oil-water mixed medium enters the outer shell from the axial inlet, generates centrifugal force through the hollow spiral flow channel, and under the joint action of the outer shell and the hollow drainage cone, the oil phase aggregates and adheres to the surface of the hollow drainage cone, and enters the inner cavity from the first oil phase inlet hole and the second oil phase inlet hole, the oil in the inner cavity enters the tail pipe cavity under the drainage of the drainage pipe, and is discharged through the oil phase outlet; when the separated oil-water mixture from the drainage cone section of the outer shell flows through the tail pipe, part of the oil phase enters the tail pipe cavity through the pressure-stabilizing hole on the tail pipe, at this time, while continuing to separate the oil and water phases, it is also ensured that the pressure in the tail pipe cavity is balanced with the external pressure, after the oil and water are separated, the oil phase also flows out from the oil phase outlet, and the water phase is thrown to the side wall by centrifugal force and flows out from the water phase outlet.

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