Nested umbrella-shaped underground oil-water separator

Abstract

The invention discloses a nested umbrella-shaped underground oil-water separator, and relates to the field of underground oil extraction tools, and the nested umbrella-shaped underground oil-water separator comprises a centrifugal assembly used for layering mixed oil and water; the oil-water separation assembly is used for separating layered oil and water; the water pressure control assembly comprises an inner waterproof sleeve, a piston pipe arranged on the inner waterproof sleeve in a sleeving mode, a connecting sleeve arranged on the piston pipe in a sleeving mode and an umbrella type inner sleeve installed at one end of the connecting sleeve. A plurality of oil-water extraction ports are formed in the side wall of the umbrella-type inner sleeve, a first contact surface is arranged on the umbrella-type inner sleeve on the inner sides of the oil-water extraction ports, and a second contact surface matched with the first contact surface is arranged at one end, close to the umbrella-type inner sleeve, of the piston tube; the water pressure control assembly comprises an opening state and a closing state, the separated water phase pushes the piston pipe to move towards the umbrella-type inner sleeve, and when the water pressure control assembly is in the opening state, the first contact surface and the second contact surface are not in contact, and oil and water can be discharged from the oil and water extraction port; in a closed state, the first contact surface is in contact with the second contact surface, one end of the piston tube is closed by the umbrella-type inner sleeve, and oil and water cannot be discharged from the oil and water extraction port; the problems that in the prior art, an underground oil-water separator is poor in oil-water separation effect and low in efficiency are solved.

Description

Technical Field

[0001] The invention relates to the field of downhole oil production tools, in particular to a nested umbrella-shaped downhole oil-water separator. Background Art

[0002] At present, most of the domestic oil fields have entered the middle and late stages of exploitation. The water content in the wells has increased, resulting in a gradual increase in the water content in the oil well produced fluid, which often exceeds 90% in some oil fields. Therefore, a large amount of oil-water mixture will be produced during the production process of the oil fields, and the oil-water separation process occupies a very important position.

[0003] Oil-water separator is a commonly used equipment for treating oil and water with high water content. Its main function is to improve production efficiency by separating the water phase from the oil and water. However, in the analysis and research of current oil-water separators, it is found that although the above-ground oil-water separator has a good separation effect, it has the problems of large footprint and high investment cost. For traditional downhole oil-water separators, due to the narrow working scene, large equipment cannot be used, resulting in weak separation function, poor separation effect and low efficiency of the downhole oil-water separator. Summary of the invention

[0004] The invention provides a nested umbrella-shaped downhole oil-water separator to solve the problems of poor oil-water separation effect and low efficiency in the downhole oil-water separator in the prior art.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a nested umbrella-shaped downhole oil-water separator, comprising:

[0007] A centrifugal assembly for separating the mixed oil and water into separate layers;

[0008] An oil-water separation component, used to separate the oil and water after stratification;

[0009] A water pressure control assembly comprises an inner water-blocking sleeve, a piston tube sleeved on the inner water-blocking sleeve, a connecting sleeve sleeved on the piston tube, and an umbrella-shaped inner sleeve installed on one end of the connecting sleeve;

[0010] The side wall of the umbrella-shaped inner sleeve is provided with a plurality of oil and water extraction ports, the umbrella-shaped inner sleeve inside the oil and water extraction ports is provided with a first contact surface, and one end of the piston tube close to the umbrella-shaped inner sleeve is provided with a second contact surface matching the first contact surface;

[0011] The water pressure control component includes an open state and a closed state. The separated water phase pushes the piston tube to move toward the umbrella-shaped inner sleeve. When in the open state, the first contact surface and the second contact surface are not in contact, and oil and water can be discharged from the oil-water extraction port; when in the closed state, the first contact surface and the second contact surface are in contact, the umbrella-shaped inner sleeve closes one end of the piston tube, and oil and water cannot be discharged from the oil-water extraction port.

[0012] As most oil fields enter the exploitation process, the water content in the wells varies greatly and shows a gradually increasing trend, resulting in a gradual increase in the water content in the oil well produced fluid. The present invention drives the piston tube to move through the water separated from the oil and water to open or close the inner water-isolating sleeve used to transport the oil and water, thereby achieving the purpose of extracting the oil and water according to the amount of water, avoiding the extraction of oil and water with a high water content, improving the effect of oil-water separation, avoiding secondary extraction, and improving separation efficiency.

[0013] Furthermore, an outgoing water sleeve is installed at one end of the connecting sleeve away from the umbrella-type inner sleeve, a circular ring is provided on the outer wall of the piston tube, a limiting ring is provided on the inner wall of the connecting sleeve, a reset elastic member is provided between the circular ring and the limiting ring, and a limiting elastic member is provided between the circular rings at the lower end of the outgoing water sleeve.

[0014] When the water phase pushes the piston tube to fit with the umbrella-type inner sleeve, the water phase is in a discharge state. When the thrust generated by the water phase decreases, the piston tube cannot be quickly reset, which will lead to a decrease in the extraction efficiency of the oil-water separator and even cause oil and water to overflow from the outlet of the water phase. Therefore, a reset elastic member is used to provide a restoring force for the piston tube, which is used to quickly reset the piston tube when the thrust generated by the water phase is small, so as to prevent the inner water-isolating sleeve from being further blocked by the umbrella-type inner sleeve. The limiting elastic member is used to limit the moving distance of the piston tube during reset, so that the initial position of the piston tube is located at the position when the thrust generated by the limiting elastic member and the reset elastic member are equal; and under the thrust of the water phase, a force balance is achieved with the force generated by the limiting elastic member and the reset elastic member, so that the greater the thrust of the water phase, the farther the piston tube moves toward the umbrella-type inner sleeve, the greater the water output of the water phase, and the faster the thrust of the water phase decreases, thereby achieving a stable process of extracting oil and water, reducing the effects of liquid flow rate, liquid flow rate mutation, water content, water content mutation, etc. on the extraction process.

[0015] Furthermore, a plurality of drainage holes are provided on the side wall of the external water casing, and the water pressure control assembly also includes an initial state. When no water phase pushes the piston tube, the reset elastic member and the limiting elastic member are both in the initial state. At this time, the circular ring is located on the side of the drainage hole away from the umbrella-type inner casing.

[0016] The piston tube is pushed by the water phase, so that the drainage holes are gradually connected with the area where the water phase is located, and the water phase is discharged from the drainage holes. The greater the thrust of the water phase, the farther the ring on the piston tube moves, the more drainage holes are connected with the area where the water phase is located, and the faster the water phase is discharged from the drainage holes.

[0017] Furthermore, the oil-water separation component includes an oil-water separation pipe, which is connected to the inner water-isolating sleeve, and a plurality of water separation holes are formed on the side wall of the oil-water separation pipe.

[0018] Due to the density difference between the oil and water phases, under the action of centrifugal force and centripetal buoyancy, the water phase migrates to the side wall to form an outer vortex, while the oil phase is forced to migrate to the center to form an inner vortex. The water phase in the outer vortex state is thrown out through the water separation hole and the action of centrifugal force, thereby achieving the purpose of separating the water phase and the oil phase.

[0019] Furthermore, the diameter of the oil-water separation pipe gradually decreases from an end away from the inner water-blocking sleeve toward an end close to the inner water-blocking sleeve.

[0020] By changing the diameter of the oil-water separation tube, the fluid is accelerated when it enters the small diameter end from the large diameter end, which can compensate for the energy loss of the fluid during the flow process and provide power for subsequent separation.

[0021] Furthermore, the water separation holes are spirally distributed along the side wall of the oil-water separation tube.

[0022] The wall spiral distribution direction of the water separation hole is consistent with the fluid vortex direction, which can improve the throwing efficiency of the water phase in the outer vortex state.

[0023] Furthermore, the centrifugal assembly includes a spiral tube connected to the oil-water separation tube, and the spiral tube is provided with guide vanes for guiding the rotation of water flow.

[0024] The spiral tube changes the fluid flowing through into a swirl state to generate centrifugal force, without the need for an additional centrifugal device, with a simple structure and small space occupation.

[0025] Furthermore, the oil-water separation component also includes an inner water casing sleeved on the outside of the oil-water separation tube, one end of the inner water casing is sleeved on the spiral tube, and the other end is embedded in the inner side of the outer water casing, and a plurality of water outlets are opened on the inner water casing embedded in the inner side of the outer water casing.

[0026] The water phase thrown out from the water separation hole is gathered and guided through the inner water sleeve, and flows to the area where the piston tube is located through the water outlet, so that the water phase can generate thrust on the piston tube.

[0027] Furthermore, a first sealing ring is provided on the inner wall of the piston tube, and the first sealing ring is in contact with the outer wall of the inner water-blocking sleeve. A second sealing ring is provided on the inner side of the connecting sleeve, and the second sealing ring is in contact with the outer wall of the piston tube.

[0028] The first sealing ring is used to prevent the oil and water in the inner water-blocking sleeve from flowing back into the piston tube, and the second sealing ring is used to prevent the oil and water in the inner water-blocking sleeve from flowing back into between the piston tube and the connecting sleeve to affect the movement of the piston tube.

[0029] Furthermore, a plurality of drainage ports are provided on the side wall of the piston tube.

[0030] As the piston tube is pushed by the water phase, fluid will enter the piston tube, causing the movement of the piston tube to be blocked. The fluid in the piston tube can be discharged through the drain port.

[0031] One or more technical solutions provided by the present invention have at least the following technical effects or advantages:

[0032] (1) The present invention drives the piston tube to move by water separated from the oil and water to open or close the inner water-isolating sleeve for conveying the oil and water, thereby achieving the purpose of extracting the oil and water according to the amount of water, avoiding extracting the oil and water with a high water content, improving the effect of oil-water separation, avoiding secondary extraction, and improving the separation efficiency;

[0033] (2) A restoring force is provided to the piston tube through the reset elastic member, so as to quickly reset the piston tube when the thrust generated by the water phase is small, so as to prevent the inner water-isolating sleeve from being blocked by the umbrella-type inner sleeve. The limiting elastic member is used to limit the moving distance of the piston tube when it is reset, so that the initial position of the piston tube is located at the position when the thrusts generated by the limiting elastic member and the reset elastic member are equal; and under the thrust of the water phase, a force balance is achieved with the force generated by the limiting elastic member and the reset elastic member, so that the greater the thrust of the water phase, the farther the piston tube moves toward the umbrella-type inner sleeve, the greater the water output of the water phase, and the faster the thrust of the water phase decreases, thereby achieving a stable oil and water extraction process and reducing the influence of liquid flow rate, liquid flow rate mutation, water content, water content mutation, etc. on the extraction process;

[0034] (3) The amount of water in the mixture affects the driving force of the water phase on the piston tube, thereby adjusting the position of the piston tube and then adjusting the number of drainage holes. This can not only adjust the discharge rate of the water phase, but also adjust the distance between the piston tube and the umbrella-shaped inner sleeve, thereby adjusting the rate of oil phase extraction, or even preventing the extraction of the oil phase, thereby reducing the extraction of the oil phase that fails to meet the extraction standard;

[0035] (4) The oil-water separator of the present invention can directly perform oil-water separation underground, thus reducing the waste of ground space and the investment of manpower costs;

[0036] (5) By nesting the annular piston, the inner water casing, the outer water casing and other components and connecting them layer by layer, the narrow underground pipeline can be effectively utilized, thereby improving the utilization efficiency of the space. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of the present invention, and do not constitute a limitation on the embodiments of the present invention;

[0038] Figure 1 It is a cross-sectional view of the overall structure of the oil-water separator in the present invention;

[0039] Figure 2 It is a schematic diagram of the umbrella-type inner sleeve structure in the present invention;

[0040] Figure 3 It is a schematic diagram of the piston tube structure in the present invention;

[0041] Figure 4 is a cross-sectional view of the connecting sleeve in the present invention;

[0042] Figure 5 This is a schematic diagram of the structure of the external water casing in the present invention;

[0043] Figure 6 It is a schematic diagram of the structure of the oil-water separation tube in the present invention;

[0044] Figure 7 It is a schematic diagram of the structure of the inner water jacket in the present invention;

[0045] Among them, 1-inner water-isolating sleeve, 2-piston tube, 201-second contact surface, 202-circular ring, 203-first sealing ring, 204-drainage port, 3-connecting sleeve, 301-limiting ring, 302-second sealing ring, 4-umbrella-type inner sleeve, 401-oil-water extraction port, 402-first contact surface, 5-external water sleeve, 501-drainage hole, 6-reset elastic member, 7-limiting elastic member, 8-oil-water separation tube, 801-water separation hole, 9-spiral tube, 901-guide blade, 10-inner water sleeve, 1001-water outlet. DETAILED DESCRIPTION

[0046] In order to more clearly understand the above-mentioned purpose, features and advantages of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0047] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those within the scope of this description. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0048] Example 1

[0049] This embodiment provides a nested umbrella-shaped downhole oil-water separator, such as Figure 1-Figure 7 As shown, including:

[0050] A centrifugal assembly for separating the mixed oil and water into separate layers;

[0051] An oil-water separation component, used to separate the oil and water after stratification;

[0052] The water pressure control assembly comprises an inner water-blocking sleeve 1, a piston tube 2 sleeved on the inner water-blocking sleeve 1, a connecting sleeve 3 sleeved on the piston tube 2, and an umbrella-shaped inner sleeve 4 installed at one end of the connecting sleeve 3;

[0053] The side wall of the umbrella-shaped inner sleeve 4 is provided with a plurality of oil-water extraction ports 401, the umbrella-shaped inner sleeve 4 inside the oil-water extraction ports 401 is provided with a first contact surface 402, and the piston tube 2 is provided with a second contact surface 201 matching the first contact surface 402 at one end close to the umbrella-shaped inner sleeve 4;

[0054] The water pressure control component includes an open state and a closed state. The separated water phase pushes the piston tube 2 to move toward the umbrella-type inner sleeve 4. When in the open state, the first contact surface 402 and the second contact surface 201 are not in contact, and oil and water can be discharged from the oil-water extraction port 401; when in the closed state, the first contact surface 402 and the second contact surface 201 are in contact, and the umbrella-type inner sleeve 4 closes one end of the piston tube 2, and oil and water cannot be discharged from the oil-water extraction port 401.

[0055] Among them, the inner water-blocking sleeve 1, the piston tube 2, the connecting sleeve 3 and the umbrella-type inner sleeve 4 are installed coaxially. The umbrella-type inner sleeve 4 is umbrella-shaped or conical barrel-shaped, closed at the top and open at the bottom. Two or more oil-water extraction ports 401 are preferably arranged, which are evenly distributed in a ring around the side wall of the umbrella-type inner sleeve 4. The oil-water extraction port 401 to the fixed part of the umbrella-type inner sleeve 4 is partially closed, and the inner surface is the first contact surface 402. The side wall of the umbrella-type inner sleeve 4 is an inclined arc surface. Therefore, the second contact surface 201 on the piston tube 2 that matches it is also an inclined arc surface. When the first contact surface 402 and the second contact surface 201 are fitted, it is necessary to prevent oil and water from passing through. Therefore, it is preferred to arrange rubber, silicone or other waterproof materials on the surface of the second contact surface 201.

[0056] In a more preferred embodiment, an outgoing water sleeve 5 is installed at one end of the connecting sleeve 3 away from the umbrella-type inner sleeve 4, a circular ring 202 is provided on the outer wall of the piston tube 2, a limiting ring 301 is provided on the inner wall of the connecting sleeve 3, a reset elastic member 6 is provided between the circular ring 202 and the limiting ring 301, and a limiting elastic member 7 is provided at the lower end of the outgoing water sleeve 5 between the circular ring 202.

[0057] Among them, the outgoing water casing 5 is coaxial with the connecting casing 3 and is preferably threadedly connected for easy installation. The outer diameter of the ring 202 is equal to the inner diameter of the outgoing water casing 5, and the inner diameter of the limiting ring 301 is equal to the outer diameter of the piston tube 2, providing a certain sealing effect. The lower end of the inner side of the outgoing water casing 5 is provided with a groove for embedding the limiting elastic part 7. The reset elastic part 6 and the limiting elastic part 7 are preferably thrust springs. After the connecting casing 3, the outgoing water casing 5, the piston tube 2, the reset elastic part 6 and the limiting elastic part 7 are installed, the reset elastic part 6 and the limiting elastic part 7 are in a compressed state.

[0058] In a more preferred embodiment, a plurality of drainage holes 501 are provided on the side wall of the external water casing 5, and the water pressure control assembly also includes an initial state. When there is no water phase pushing the piston tube 2, the reset elastic member 6 and the limiting elastic member 7 are both in the initial state. At this time, the ring 202 is located on the side of the drainage hole 501 away from the umbrella-type inner casing 4.

[0059] Among them, after the connecting sleeve 3, the outgoing water sleeve 5 and the piston tube 2 are installed, a cavity is formed between the connecting sleeve 3, the outgoing water sleeve 5 and the piston tube 2, and the cavity is divided into two parts by the circular ring 202. The cavity accommodating the reset elastic member 6 is the circular ring activity area, and the cavity accommodating the limiting elastic member 7 is the water pressure area. In the initial state, the drainage holes 501 are all located on the side wall of the outgoing water sleeve 5 in the circular ring activity area. As the water phase enters the water pressure area, the circular ring 202 is pushed to move toward the circular ring activity area, the water pressure area gradually becomes longer, and the drainage hole 501 gradually enters the water pressure area, and the water phase in the water pressure area can be discharged from the drainage hole 501.

[0060] In a more preferred embodiment, the oil-water separation assembly includes an oil-water separation tube 8, the oil-water separation tube 8 is connected to the inner water-blocking sleeve 1, and a plurality of water separation holes 801 are opened on the side wall of the oil-water separation tube 8. The inner diameter of the connection between the oil-water separation tube 8 and the inner water-blocking sleeve 1 is equal, and the number of water separation holes 801 is arbitrary and evenly distributed along the side wall of the oil-water separation tube 8.

[0061] In a more preferred embodiment, the diameter of the oil-water separation pipe 8 gradually decreases from the end away from the inner water-blocking sleeve 1 to the end close to the inner water-blocking sleeve 1. The oil-water separation pipe 8 has a cone barrel structure.

[0062] In a more preferred embodiment, the water separation holes 801 are distributed in a spiral along the side wall of the oil-water separation tube 8. The spiral direction is the same as the rotation direction of the fluid in the oil-water separation tube 8.

[0063] In a more preferred embodiment, a first sealing ring 203 is provided on the inner wall of the piston tube 2, and the first sealing ring 203 is in contact with the outer wall of the inner waterproof sleeve 1. A second sealing ring 302 is provided on the inner side of the connecting sleeve 3, and the second sealing ring 302 is in contact with the outer wall of the piston tube 2.

[0064] In a more preferred embodiment, a plurality of drain ports 204 are provided on the side wall of the piston tube 2. The number of the drain ports 204 is arbitrary, and the fluid infiltrated into the piston tube 2 can be discharged into the annular active area and then discharged from the drain hole 501.

[0065] Example 2

[0066] On the basis of Example 1, Figure 1-Figure 7 As shown, the centrifugal assembly includes a spiral tube 9 connected to the oil-water separation tube 8, and a guide vane 901 for guiding the rotation of water flow is provided in the spiral tube 9.

[0067] Among them, the oil-water separation tube 8 and the spiral tube 9 are preferably threadedly connected, the inner diameter of the spiral tube 9 is equal to the inner diameter of the end of the oil-water separation tube 8 away from the inner water-blocking sleeve 1, the guide blades 901 are spirally distributed, and the direction of the spiral is the same as the spiral distribution direction of the water separation holes 801. The device uses a pump to pump the oil-water mixture from the spiral tube 9, and the fluid flows through the guide blades 901 to change the direction of the fluid from linear motion to rotational motion. Due to the density difference between the oil and water phases, under the action of centrifugal force and centripetal buoyancy, the water phase migrates toward the inner tube wall to form an external vortex, while the oil phase is forced to migrate to the central area to form an internal vortex.

[0068] In a more preferred embodiment, the oil-water separation component also includes an inner water casing 10 which is sleeved on the outside of the oil-water separation tube 8, one end of the inner water casing 10 is sleeved on the spiral tube 9, and the other end is embedded in the inner side of the outer water casing 5, and a plurality of water outlets 1001 are provided on the inner water casing 10 embedded in the inner side of the outer water casing 5.

[0069] Among them, the inner diameter of the inner water casing 10 is larger than the maximum outer diameter of the oil-water separation tube 8. The cavity formed between the inner water casing 10 and the oil-water separation tube 8 is used to gather and guide the flow of water, and then discharged to the water pressure zone through the water outlet 1001 to provide thrust for the piston tube 2.

[0070] In this scheme, the separation of oil and water is related to the water content in the oil-water mixture, specifically:

[0071] The oil-water mixture pumped into the oil-water separator passes through the spiral tube 9, and the oil phase forms an inner vortex flow, which is sent out through the inner water-blocking sleeve 1, the umbrella-shaped inner sleeve 4 and the oil-water extraction port 401; the water phase forms an outer vortex flow, enters the inner water-receiving sleeve 10 through the water separation hole 801, and then enters the water pressure zone through the water outlet 1001, pushing the piston tube 2 to move, and the drainage hole 501 enters the water pressure zone, and the water phase is discharged through the drainage hole 501;

[0072] The higher the water content in the oil-water mixture, the less oil phase and the more water phase, the greater the thrust of the water phase on the piston tube 2, the farther the piston tube 2 moves, the closer the piston tube 2 is to the umbrella-type inner sleeve 4, the slower the oil phase extraction speed is, and the less water phase that cannot be separated passes through the oil-water extraction port 401. At the same time, the more drainage holes 501 enter the water pressure zone, the faster the water phase is discharged through the drainage holes 501, forming a relatively stable extraction process.

[0073] When the water content in the oil-water mixture is too high and reaches a certain limit, there is less oil phase, and there is too much water phase that cannot be separated, and the oil phase extraction standard cannot be met, resulting in poor oil-water separation effect. Therefore, the oil phase extraction conditions are not met. At this time, due to the excessive water phase, the thrust of the water pressure zone on the piston tube 2 reaches a certain threshold, and the piston tube 2 is tightly attached to the umbrella-type inner sleeve 4, and the first contact surface 402 and the second contact surface 201 are attached, blocking the inner water-blocking sleeve 1 and the oil-water extraction port 401, preventing the fluid in the inner water-blocking sleeve 1 that fails to meet the oil phase extraction standard from being extracted, thereby ensuring the oil-water separation effect;

[0074] When a certain amount of water phase is discharged from the drainage hole 501, the water phase that cannot be separated in the oil phase is reduced to reach the extraction standard. At the same time, the thrust of the water pressure zone on the piston tube 2 is lower than a certain threshold, and the reset elastic member 6 pushes the piston tube 2 away from the umbrella-type inner sleeve 4, and the oil phase can be extracted through the oil-water extraction port 401.

[0075] Among them, the "certain limit" of water content, the "extraction standard" of the oil phase, the "certain threshold" of the thrust of the water pressure zone on the piston tube 2, etc. are all determined according to the device structure, user needs, etc., and this embodiment does not make specific limitations.

[0076] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0077] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A nested umbrella-shaped downhole oil-water separator, characterized in that: include: A centrifugal assembly for separating the mixed oil and water into separate layers; An oil-water separation component, used to separate the oil and water after stratification; A water pressure control assembly comprises an inner water-blocking sleeve (1), a piston tube (2) sleeved on the inner water-blocking sleeve (1), a connecting sleeve (3) sleeved on the piston tube (2), and an umbrella-shaped inner sleeve (4) installed at one end of the connecting sleeve (3); A plurality of oil-water extraction ports (401) are provided on the side wall of the umbrella-shaped inner sleeve (4); a first contact surface (402) is provided on the umbrella-shaped inner sleeve (4) inside the oil-water extraction port (401); and a second contact surface (201) matching the first contact surface (402) is provided at one end of the piston tube (2) close to the umbrella-shaped inner sleeve (4); The water pressure control component includes an open state and a closed state. The separated water phase pushes the piston tube (2) to move toward the umbrella-shaped inner sleeve (4). When in the open state, the first contact surface (402) and the second contact surface (201) are not in contact, and oil and water can be discharged from the oil-water extraction port (401); when in the closed state, the first contact surface (402) and the second contact surface (201) are in contact, the umbrella-shaped inner sleeve (4) seals one end of the piston tube (2), and oil and water cannot be discharged from the oil-water extraction port (401).

2. A nested umbrella-shaped downhole oil-water separator according to claim 1, characterized in that: An outgoing water sleeve (5) is installed at one end of the connecting sleeve (3) away from the umbrella-shaped inner sleeve (4); a circular ring (202) is provided on the outer wall of the piston tube (2); a limiting ring (301) is provided on the inner wall of the connecting sleeve (3); a reset elastic member (6) is provided between the circular ring (202) and the limiting ring (301); and a limiting elastic member (7) is provided at the lower end of the outgoing water sleeve (5) between the circular ring (202).

3. A nested umbrella-shaped downhole oil-water separator according to claim 2, characterized in that: A plurality of drainage holes (501) are provided on the side wall of the external water casing (5), and the water pressure control assembly also includes an initial state. When there is no water phase pushing the piston tube (2), the reset elastic member (6) and the limit elastic member (7) are both in the initial state. At this time, the circular ring (202) is located on the side of the drainage hole (501) away from the umbrella-shaped inner casing (4).

4. A nested umbrella-shaped downhole oil-water separator according to claim 2, characterized in that: The oil-water separation component comprises an oil-water separation pipe (8), the oil-water separation pipe (8) is connected to the inner water-blocking sleeve (1), and a plurality of water separation holes (801) are provided on the side wall of the oil-water separation pipe (8).

5. The nested umbrella-shaped downhole oil-water separator according to claim 4, characterized in that: The diameter of the oil-water separation pipe (8) gradually decreases from an end away from the inner water-blocking sleeve (1) toward an end close to the inner water-blocking sleeve (1).

6. The nested umbrella-shaped downhole oil-water separator according to claim 4, characterized in that: The water separation holes (801) are distributed in a spiral along the side wall of the oil-water separation tube (8).

7. The nested umbrella-shaped downhole oil-water separator according to claim 4, characterized in that: The centrifugal assembly comprises a spiral tube (9) connected to the oil-water separation tube (8), and a guide vane (901) for guiding the rotation of water flow is arranged inside the spiral tube (9).

8. The nested umbrella-shaped downhole oil-water separator according to claim 7, characterized in that: The oil-water separation component further comprises an inner water receiving sleeve (10) sleeved on the outside of the oil-water separation pipe (8), one end of the inner water receiving sleeve (10) being sleeved on the spiral pipe (9) and the other end being embedded in the inside of the outer water receiving sleeve (5), and a plurality of water outlets (1001) being provided on the inner water receiving sleeve (10) embedded in the inner side of the outer water receiving sleeve (5).

9. The nested umbrella-shaped downhole oil-water separator according to claim 1, characterized in that: A first sealing ring (203) is provided on the inner wall of the piston tube (2), and the first sealing ring (203) is in contact with the outer wall of the inner water-blocking sleeve (1). A second sealing ring (302) is provided on the inner side of the connecting sleeve (3), and the second sealing ring (302) is in contact with the outer wall of the piston tube (2).

10. The nested umbrella-shaped downhole oil-water separator according to claim 1, characterized in that: A plurality of drainage openings (204) are provided on the side wall of the piston tube (2).

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