An automatic backwashing de-oiling and sand removal device for injection and production in the same well

Abstract

The present invention relates to a kind of downhole automatic backwashing de-oiling and sand removal device for injection and production in the same well, the upper and middle part of its oil-water separation module is located in the sand removal module, the sand removal module includes an upper channel and a lower channel, the oil-water separation module includes an oil cylinder, a cyclone, and a spiral flow channel; the lower channel is arranged in the upper channel and forms a lower annular cavity with the lower part of the upper channel, the oil cylinder is fastened to the inner wall of the upper annular cavity and the inner wall of the lower annular cavity respectively, the upper channel, the oil cylinder, and the lower channel are surrounded by a jacket, the oil cylinder liquid inlet is communicated with the jacket, the outer wall of the upper annular cavity is provided with a mixed phase inlet, the outer wall of the lower annular cavity is provided with a backwashing port, a sand net and a sand net partition are provided in the upper annular cavity, a filter layer is provided in the sand net, a plurality of central cylinders are fixed under the sand net along the circumferential direction, each central cylinder is provided with a backwashing partition, and the backwashing partition corresponds to the backwashing port. The present invention can automatically remove sand and backwash and finely perform three-phase separation, and the backwashing function is controlled by the weight of the blocked deposited sand phase, and the separation efficiency is high.

Description

Technical Field

[0001] The invention relates to an oil-water-sand three-phase medium separation and backwashing device used in the field of underground same-well injection and production, and specifically relates to an underground automatic backwashing de-oiling and sand removal device for the same-well injection and production. Background Art

[0002] In many areas of my country, pipe wells have a series of pipe well operation problems due to excessive sand content in the oil wells, which leads to damage to pumping equipment, sinking of the pump house foundation, bending and even breaking of the well pipes. Some pipe wells are scrapped after a short period of use, which not only causes economic losses, but also affects normal production and life. Some underground filters are used to remove sand, but over time, the filters will be blocked by sand accumulation, which is not conducive to underground sand removal. Therefore, measures must be taken to remove the accumulated sand. Backwashing is a common measure that can solve this problem. In view of the high sand content in the underground oil field, most of the existing technologies use a high-pressure multi-valve method to remove sand and backwash. The Chinese utility model patent with announcement number CN217681850U discloses an underground high-pressure backwashing device, which uses a high-pressure multi-valve method for multi-phase sand removal and backwashing. It can be seen from the content disclosed in the document that the structural equipment used needs to add a complex structure of high-pressure water purification, which is not conducive to cost control, and there is a situation where the pressure of high-pressure water purification is insufficient. Summary of the invention

[0003] The purpose of the present invention is to provide an automatic backwashing deoiling and sand removal device for injection and production in the same well. This automatic backwashing deoiling and sand removal device for injection and production in the same well is used to solve the problem that the high-pressure multi-valve method for multi-phase sand removal backwashing in the prior art has a complex structure and is not conducive to cost control.

[0004] The technical solution adopted by the present invention to solve its technical problems is: this downhole automatic backwashing deoiling and sand removal device for injection and production in the same well includes a sand removal module and an oil-water separation module, the upper and middle parts of the oil-water separation module are located in the sand removal module, the sand removal module includes an upper channel and a lower channel, the oil-water separation module includes an oil cylinder, a cyclone, and a spiral flow channel, the cyclone is arranged in the oil cylinder, the spiral flow channel is placed in the cyclone cavity of the cyclone, the spiral flow channel is fixedly connected to the oil cylinder through a flange at its top, the upper channel is an open cylinder with an upper annular cavity, the lower channel is an open cylinder with an outer eaves at the bottom, the lower channel is arranged in the upper channel and connected to the lower part of the upper channel The upper annular cavity is constituted by the oil cylinder, which is respectively fastened to the inner wall of the upper annular cavity and the inner wall of the lower annular cavity; the upper channel, the oil cylinder and the lower channel are surrounded by a jacket; the liquid inlet of the oil cylinder is communicated with the jacket; the outer wall of the upper annular cavity is provided with a mixed phase inlet; the outer wall of the lower annular cavity is provided with a backwashing port; a sand net and a sand net partition are provided in the upper annular cavity; a filter layer is provided in the sand net; a plurality of central cylinders are fixed under the sand net along the circumferential direction; each central cylinder is provided with a backwashing partition, and the backwashing partition corresponds to the backwashing port; each central cylinder extends into a bottom cylinder and is slidably connected to the bottom cylinder; each central cylinder is connected to the bottom cylinder by a spring.

[0005] In the above scheme, the upper channel has an upper liquid inlet clamping ring, which is threadedly connected to the oil barrel and is placed above the first clamping ring of the oil barrel; the upper end of the lower channel has a lower liquid inlet clamping ring, which has an internal thread, the lower channel is threadedly connected to the oil barrel, and the lower liquid inlet clamping ring is placed below the second clamping ring of the oil barrel; the interval between the upper liquid inlet clamping ring of the upper channel and the lower liquid inlet clamping ring of the lower channel corresponds to the oil barrel liquid inlet port of the oil barrel.

[0006] In the above scheme, the filter layer is a circular secondary filter layer with coarse filtration on the outside and fine filtration on the inside. The sand mesh partition is used to open or close the liquid inlet of the oil cylinder. There are four cylindrical threaded grooves in a circumferential array in the filter layer, and the inner side of the cylindrical threaded groove is threaded. Each cylindrical threaded groove is connected to the top thread of a central cylinder and axially matched.

[0007] The upper end and the middle and lower parts of the central cylinder of the above scheme are both threaded, the upper end thread is connected to the filter layer thread, the lower thread is connected to the partition thread, a sliding convex ring is set at the bottom of the central cylinder, the sliding convex ring is nested and connected with the central cylinder connecting hole at the top of the bottom cylinder, and there are four central cylinders.

[0008] In the above scheme, the backwashing baffle is in the shape of a ring, and has four circular holes in a circumferential array, the inner side of the circular holes is threaded, and the baffle is threadedly connected to each central cylinder; the backwashing baffle is used to open or close the backwashing port.

[0009] In the above scheme, there are four springs, which are respectively placed inside the four bottom cylinders. Both ends of the springs are flat bottom surfaces. The top flat bottom surface is in contact with and fixed to the bottom surface of the central cylinder, and the bottom flat bottom surface is in contact with and welded to the groove surface of the lower channel.

[0010] In the above scheme, the bottom cylinder is a hollow cylinder with threads on the bottom, and the threads on the bottom are connected to the thread grooves of the oil cylinder of the lower channel through threads.

[0011] In the above scheme, the top of the spiral flow channel is a flange, the center of the flange is an overflow port, the flange has four spiral flow channel fixing holes in a circumferential array, threads are opened in the spiral flow channel fixing holes, the threads of the screws fix the flange and the oil cylinder together, and the spiral flow channel cooperates with the cyclone and the axis of the oil cylinder.

[0012] In the above scheme, the oil cylinder is a cylinder with threads on the outer top, the inner middle and upper part, and the outer bottom. The oil cylinder includes an oil cylinder outlet and an oil cylinder liquid inlet. The outer walls of the oil cylinder on the upper and lower sides of the oil cylinder liquid inlet are respectively provided with a first clamping ring and a second clamping ring, the first clamping ring is clamped with the upper channel, and the second clamping ring is clamped with the lower channel; the inner wall of the oil cylinder is provided with a third clamping ring, and the third clamping ring is used to fix the cyclone. The cyclone and the spiral flow channel are placed in the cavity of the oil cylinder.

[0013] In the above scheme, the cyclone is a shaft-entered cyclone, which is threadedly connected to the inner wall of the oil cylinder. The cyclone, the oil cylinder, and the spiral flow channel are axially matched, and the top surface of the cyclone coincides with the lower surface of the third clamping ring of the oil cylinder, which plays a role in fixing the cyclone. Beneficial Effects

[0014] 1. The overall configuration of the present invention is innovative, enriching the structure of the multiphase separation device. It can achieve three-phase separation of oil, water and sand from top to bottom by adopting a vertical working mode, while meeting the high flow processing capacity and automatic flow stabilization function.

[0015] 2. The upper part of the present invention is a sand removal module. When the oil-water-sand three-phase mixture enters the device, the mixture passes through the sand screen, and the sand phase is filtered and blocked to the upper part by the sand screen. The remaining oil-water mixture passes through the filter layer, thereby achieving solid-liquid separation of the sand phase and the oil-water phase in the sand removal module.

[0016] 3. The sand phase of the present invention can be automatically discharged from the device. When the sand phase is deposited too much and causes a low pressure state, the sand screen, the central cylinder, and the partition begin to move downward as a whole, and the spring begins to compress. Then the sand screen blocks the cyclone inlet, and the backwash port is opened. The high-pressure fluid enters the device through the backwash port, and the sand phase is flushed out of the device through the liquid inlet along with the fluid, thereby achieving the backwash function of the sand screen.

[0017] 4. The sand removal module of the present invention is uniquely designed, and the device can automatically restore to its initial state after the sand discharge is completed. When the sand phase is discharged from the mixed phase inlet, the spring gravity is less than its elastic force, pushing the sand net, the central cylinder and the partition as a whole to move upward and return to the initial position, completing a solid-liquid separation and sand discharge cycle. The free switching between sand discharge and backwashing functions can be realized, and the recycling has a high use value.

[0018] 5. When the present invention is working, when the sand phase is deposited too much and causes a low pressure state, the sand screen, the central cylinder, and the partition begin to move downward as a whole, and the spring begins to compress. Then the sand screen blocks the cyclone inlet, and the backwash port is opened. The high-pressure fluid enters the device through the backwash port, and the sand phase rushes out of the device through the mixed phase inlet along with the fluid, thereby achieving the backwash function of the sand screen. After the backwash is completed, the spring automatically rebounds, and the device returns to the initial state, completing a working cycle.

[0019] 6. The present invention integrates three-phase separation, fine sand removal and backwashing functions in one. The sand particles are finely separated by a secondary sand screen with external coarse filtration and internal fine filtration. The sand screen and the partition are connected as a whole through the thread of the central cylinder by a unique design structure. In the initial state, the sand screen opens the cyclone inlet and the partition closes the backwashing port to achieve a sand phase blocking state. When the weight of the sand phase deposited above the sand screen is too much to push the whole downward, the sand screen closes the cyclone inlet and the partition opens the backwashing port to start the backwashing function, realizing the free switching between sand settling and backwashing, which greatly enhances the applicability.

[0020] 7. The present invention is a three-phase separation device capable of automatic sand removal, backwashing and fine separation. The backwashing function is controlled by the weight of the blocked sediment sand phase, and the secondary sand screen finely separates the sand phase, thereby realizing automatic switching between sand removal and backwashing and enhancing the degree of sand removal by the device. It has high separation efficiency and strong practicality, and will be widely recognized and applied in multi-phase separation fields such as petroleum and desanding. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is the appearance diagram of a three-phase separation device for injection, production, sand removal and backwashing in the same well.

[0022] Figure 2 This is an overall exploded view of a three-phase separation device for injection, production, sand removal and backwashing in the same well.

[0023] Figure 3 This is an overall cross-sectional view of a three-phase separation device for injection, production, sand removal and backwashing in the same well.

[0024] Figure 4 This is the exploded view of the sand removal module.

[0025] Figure 5 This is a cross-sectional view of the sand removal module.

[0026] Figure 6 This is the appearance diagram of the oil-water separation module.

[0027] Figure 7 This is the exploded diagram of the oil-water separation module.

[0028] Figure 8 This is a cross-sectional view of the oil-water separation module.

[0029] Fig. 9 This is an enlarged view of the oil cylinder retaining ring.

[0030] Fig.10 This is a cross-sectional view comparing the state before and after backwashing.

[0031] Fig.11 This is a cross-sectional view of the sand screen filter layer.

[0032] In the figure, 1-sand removal module, 101-sand screen, 102-center cylinder, 103-backwash baffle, 104-spring, 105-bottom cylinder, 106-upper channel, 107-lower channel, 201-cyclone, 202-spiral flow channel, 203-oil cylinder, 204-screw, 1011-filter layer, 1012-cylindrical thread groove, 1061-mixed phase inlet, 1062-backwash port, 1063-liquid inlet upper clamping ring, 1071-liquid inlet lower clamping ring, 2012-bottom flow port, 2022-overflow port, 2031-first clamping ring, 2032-second clamping ring, 2033-third clamping ring, 2034-oil cylinder liquid inlet. DETAILED DESCRIPTION

[0033] The present invention will be further described below in conjunction with the accompanying drawings:

[0034] Combination Figure 1-Figure 11 As shown, this three-phase separation device for sand removal and backwashing in the same well includes a sand removal module 1 and an oil-water separation module. The sand removal module includes a sand net 101, a central cylinder 102, a backwashing baffle 103, a spring 104, a bottom cylinder 105, an upper channel 106, and a lower channel 107; the filter layer 1011 of the sand net 101 is a circular secondary filter layer with a coarse filter on the outside and a fine filter on the inside, which is used to block the sand phase. The sand net baffle is used to open or close the oil cylinder inlet 2034. The filter layer 1011 is provided with four cylindrical thread grooves 1012 in a circumferential array, and the inner side of the groove is threaded, which is connected to the top threads of the four central cylinders 102 and axially matched.

[0035] The center cylinder 102 has threads on the top and the middle and bottom. The top threads are threadedly connected to the filter layer 1011, the bottom threads are threadedly connected to the backwashing baffle 103, and the sliding convex ring at the bottom is nested and connected to the center cylinder connection hole of the bottom cylinder 105. The center cylinder 102 is matched with the groove of the sand screen 101 and the axis of the bottom cylinder 105.

[0036] The backwashing baffle 103 is annular and has four circular holes in a circumferential array. The inner side of the circular holes is threaded and is threadedly connected to the central cylinder 102. The backwashing baffle 103 is used to open or close the backwashing port 1062 and slide between the backwashing port 1062 and the lower part of the port. The backwashing baffle 103 is axially matched with the central cylinder 102.

[0037] The spring 104 is placed inside the four bottom cylinders 105, and its two ends are flat bottomed. The top flat bottom surface is fixed to the bottom surface of the center cylinder 102, and the bottom flat bottom surface is fixed to the groove surface of the lower channel 107 by welding. The spring 104 is matched with the inner axis of the bottom cylinder 105.

[0038] The bottom cylinder 105 is a hollow cylinder with threads at the bottom. The central cylinder connection hole at the top of the bottom cylinder 105 is nested with the sliding convex ring at the bottom of the central cylinder 102, and the threads at the bottom of the fixing spring 104 and the central cylinder 102 are connected with the oil cylinder thread groove of the lower channel 107 by threads.

[0039] The upper channel 106 constitutes the exterior of the sand removal module. The upper channel 106 is matched with the axis of the oil barrel 203 and is connected with threads, and the upper liquid inlet snap ring 1063 is placed above the first snap ring 2031 of the oil barrel 203. The lower channel 107 constitutes the exterior of the sand removal module. The lower channel 107 is matched with the axis of the oil barrel 203 and is connected with threads, and the lower liquid inlet snap ring 1071 is fixed below the second snap ring 2032 of the oil barrel 203. The gap between the upper liquid inlet snap ring 1063 of the upper channel 106 and the lower liquid inlet snap ring 1071 of the lower channel 107 is used for the liquid inlet of the oil barrel 203.

[0040] The oil-water separation module includes a cyclone 201, a spiral flow channel 202, an oil cylinder 203, and a screw 204. The cyclone 201 is a shaft-entry cyclone. The spiral flow channel 202 is placed in the cyclone cavity, and then the cyclone 201 is placed in the cavity of the oil cylinder 203 and connected with the internal thread of the oil cylinder 203. The cyclone 201 is axially matched with the oil cylinder 203 and the spiral flow channel 202. The top surface of the cyclone 201 coincides with the lower surface of the third clamping ring 2033 of the oil cylinder 203, which plays a role in fixing the cyclone 201.

[0041] The top of the spiral channel 202 is a flange plate, which is used to fix the oil cylinder 203. The center of the flange plate is an overflow port 2022, and there are four spiral channel fixing holes in a circumferential array, and the holes are threaded. The threads of the screw 204 fix the flange plate of the spiral channel 202 and the oil cylinder 203 together. The spiral channel 202 is axially matched with the cyclone 201, the oil cylinder 203, and the screw 204.

[0042] The oil cylinder 203 is a cylinder with threads on the outer top, inner middle and upper part, and outer bottom. It is the central part of the device, and all other parts are fixed around it. Its main structure includes the oil cylinder outlet, the oil cylinder liquid inlet 2034, and the upper and lower first clamping rings 2031, the second clamping ring 2032, and the third clamping ring 2033. The outer first clamping ring 2031 is used to fix the upper channel 106, while the second clamping ring 2032 is used to fix the position of the lower channel 107; the inner third clamping ring 2033 is used to fix the cyclone 201. The thread of the screw 204 fixes the flange of the spiral flow channel 202 and the oil cylinder 203 together. The cyclone 201 and the spiral flow channel 202 are placed in the cavity of the oil cylinder. The oil cylinder 203 is axially matched with the spiral flow channel 202, the cyclone 201, the screw 204, the upper channel 106, and the lower channel 107.

[0043] The present invention is used in a vertical working state, and can filter and backwash the sand phase of a multiphase medium mixture, and finely separate and separately collect the oil phase and the water phase. The appearance of the device is composed of an upper channel 106 and a lower channel 107. Figure 3 As shown, the three-phase medium mixture enters the sand removal module through the mixed phase inlet 1061 to achieve the separation of the sand phase and the oil-water phase. The separated sand phase is blocked above the sand net 101. The oil-water phase separated by the sand removal module continues to enter the oil-water separation module 2 through the oil cylinder inlet 2034, and the oil phase and the water phase are separated therein. The oil phase is discharged from the overflow port 2022 and the water phase is discharged from the bottom flow port 2012. When the blocked sand phase is deposited too much, the gravity presses the sand net 101, the central cylinder 102 and the backwashing partition 103 to slide downward as a whole, so that the backwashing port 1062 is opened, and the high-pressure fluid enters the device through the backwashing port 1062. The sand phase rushes out of the device with the fluid through the mixed phase inlet 1061, thereby achieving the backwashing function of the sand net 101. After the backwashing is completed, the spring 104 automatically rebounds, the device returns to the initial state, and a working cycle is completed.

[0044] See also Figure 4 , Figure 5 After the three-phase mixed liquid enters the channel composed of the upper channel 106 and the lower channel 107 through the mixed phase inlet 1061, the sand phase is blocked to the top by the filter layer 1011 of the sand screen 101, and the remaining oil-water mixture passes through the sand screen 101 to complete the solid-liquid two-phase separation.

[0045] See also Figure 7 , Figure 8 After the sand phase is filtered out, the remaining oil-water phase enters the oil-water separation module 2 through the oil cylinder liquid inlet 2034, and then passes through the separation effect of the cyclone 201. The oil phase is discharged from the upper overflow port 2022, and the water phase is discharged from the lower bottom flow port 2012. Finally, the water phase is directly reinjected and the oil phase is lifted to the ground.

[0046] Fig. 9 This is an enlarged view of the oil cylinder clamping ring. In the right figure, the first clamping ring 2031 clamps the upper liquid inlet clamping ring 1063 above it, thereby fixing the upper channel 106; the second clamping ring 2032 clamps the lower bayonet of the oil cylinder below it, thereby fixing the lower channel 107; the third clamping ring 2033 clamps the cyclone 201 below it, thereby fixing the cyclone 201.

[0047] Fig.10 The left figure is a cross-sectional view before and after the backwashing state. The left figure is the state before backwashing, and the right figure is the state of backwashing. When the sand phase is deposited too much, the sand screen 101, the central cylinder 102, and the backwashing baffle 103 start to move downward as a whole due to excessive weight, and move downward relative to the position in the left figure, and the spring 104 starts to compress. The sand screen 101 originally located on the oil cylinder inlet 2034 in the left figure blocks the oil cylinder inlet 2034 in the right figure, and the backwashing port 1062 is opened, and the high-pressure fluid enters the device through the backwashing port 1062, and the sand phase rushes out of the device with the fluid through the mixed phase inlet 1061, thereby achieving the backwashing function of the sand screen 101. After the backwashing is completed, the sand phase has been removed. At this time, the elastic force is upward, and the spring 104 automatically rebounds, pulling the sand net 101, the center cylinder 102, and the backwashing baffle 103 upward as a whole. The sand net 101 is placed above the oil cylinder liquid inlet 2034, and the backwashing baffle 103 is placed at the backwashing port 1062. After completing a working cycle, the device returns to its initial state and prepares for the next sand removal.

[0048] Fig.11 It is a cross-sectional view of the sand mesh filter layer. The filter layer 1011 of the sand mesh 101 is a circular secondary filter layer with a coarse filter on the outside and a fine filter on the inside, which is used for finely blocking the sand phase.

[0049] The mixed phase first enters the sand removal module 1 to achieve fine separation of the sand phase by the secondary sand screen, and then passes through the oil-water separation module to separate the oil phase and the water phase. The separated oil phase is lifted to the ground, and the separated water phase is directly injected back into the ground. When there is too much sand phase deposited above the sand screen 101, the sand screen 101, the central cylinder 102, and the backwash baffle 103 begin to move downward as a whole due to excessive weight, and the spring 104 begins to compress, and then the sand screen 101 blocks the cyclone inlet, and the backwash port 1062 opens. High-pressure fluid enters the device through the backwash port 1062, and the sand phase rushes out of the device with the fluid through the mixed phase inlet, achieving the backwash function of the sand screen 101. After the backwash is completed, the spring 104 automatically rebounds, and the device automatically returns to its original state and can be recycled. It is suitable for industrial multiphase medium separation and has high practical value.

Claims

1. An automatic backwashing de-oiling and de-sanding device for injection and production in the same well, characterized by: The automatic backwashing de-oiling and sand removal device for injection and production in the same well comprises a sand removal module and an oil-water separation module. The upper and middle parts of the oil-water separation module are located in the sand removal module. The sand removal module comprises an upper channel and a lower channel. The oil-water separation module comprises an oil cylinder, a cyclone and a spiral flow channel. The cyclone is arranged in the oil cylinder. The spiral flow channel is placed in the cyclone cavity of the cyclone. The spiral flow channel is fixedly connected to the oil cylinder through a flange at the top thereof. The upper channel is an open cylinder with an upper annular cavity. The lower channel is an open cylinder with an outer eave at the bottom. The lower channel is arranged in the upper channel and forms a lower annular cavity with the lower part of the upper channel. The oil cylinder They are respectively fastened together with the inner wall of the upper annular cavity and the inner wall of the lower annular cavity, the upper channel, the oil cylinder and the lower channel are surrounded by a jacket, the oil cylinder liquid inlet is communicated with the jacket, the outer wall of the upper annular cavity is provided with a mixed phase inlet, the outer wall of the lower annular cavity is provided with a backwashing port, a sand net and a sand net partition are provided in the upper annular cavity, a filter layer is provided in the sand net, a plurality of central cylinders are fixed under the sand net along the circumferential direction, each central cylinder is provided with a backwashing partition, the backwashing partition corresponds to the backwashing port, each central cylinder extends into a bottom cylinder and is slidably connected with the bottom cylinder, and each central cylinder is connected to the bottom cylinder through a spring; The oil cylinder is a cylinder with threads on the outer top, the inner middle and upper part, and the outer bottom. The oil cylinder includes an oil cylinder outlet and an oil cylinder liquid inlet. The outer walls of the oil cylinder on the upper and lower sides of the oil cylinder liquid inlet are respectively provided with a first clamping ring and a second clamping ring, the first clamping ring is clamped with the upper channel, and the second clamping ring is clamped with the lower channel; the inner wall of the oil cylinder is provided with a third clamping ring, and the third clamping ring is used to fix the cyclone. The cyclone and the spiral flow channel are placed in the cavity of the oil cylinder.

2. The automatic backwashing de-oiling and de-sanding device for injection and production in the same well according to claim 1 is characterized in that: The upper channel is provided with an upper liquid inlet clamping ring, which is threadedly connected to the oil cylinder and is placed above a first clamping ring of the oil cylinder; the upper port of the lower channel is provided with a lower liquid inlet clamping ring, which has an internal thread, the lower channel is threadedly connected to the oil cylinder, and the lower liquid inlet clamping ring is placed below a second clamping ring of the oil cylinder; the interval between the upper liquid inlet clamping ring of the upper channel and the lower liquid inlet clamping ring of the lower channel corresponds to the oil cylinder liquid inlet port of the oil cylinder.

3. The automatic backwashing de-oiling and de-sanding device for injection and production in the same well according to claim 2 is characterized in that: The filter layer is a circular secondary filter layer with coarse filtration on the outside and fine filtration on the inside. The sand mesh partition is used to open or close the liquid inlet of the oil cylinder. There are four cylindrical thread grooves in a circumferential array in the filter layer, and threads are opened on the inner side of the cylindrical thread grooves. Each cylindrical thread groove is connected to the top thread of a central cylinder and axially matched.

4. The automatic backwashing de-oiling and de-sanding device for injection and production in the same well according to claim 3 is characterized by: The top and the middle and lower parts of the central cylinder are both provided with threads, the top threads are threadedly connected to the cylindrical thread grooves, the lower threads are threadedly connected to the backwash baffles, a sliding convex ring is arranged at the bottom of the central cylinder, the sliding convex ring is nestedly connected to the central cylindrical connecting hole at the top of the bottom cylinder, and there are four central cylinders.

5. The automatic backwashing de-oiling and de-sanding device for injection and production in the same well according to claim 4 is characterized in that: The backwashing baffle is in a circular ring shape and has four circular holes in a circumferential array. The inner sides of the circular holes are provided with threads. The backwashing baffle is threadedly connected to each central cylinder. The backwashing baffle is used to open or close the backwashing port.

6. The automatic backwashing de-oiling and de-sanding device for injection and production in the same well according to claim 5 is characterized in that: There are four springs, which are respectively placed inside four bottom cylinders. Both ends of the springs are flat bottom surfaces. The top flat bottom surface is in contact with and fixed to the bottom surface of the central cylinder, and the bottom flat bottom surface is in contact with and welded to the groove surface of the lower channel.

7. The automatic backwashing de-oiling and de-sanding device for injection and production in the same well according to claim 6 is characterized by: The bottom cylinder is a hollow cylinder with threads on the bottom, and the threads on the bottom are connected to the oil cylinder thread grooves of the lower channel through threads.

8. The automatic backwashing de-oiling and de-sanding device for injection and production in the same well according to claim 7 is characterized in that: The top of the spiral flow channel is a flange, the center of the flange is an overflow port, the flange has four spiral flow channel fixing holes in a circumferential array, threads are opened in the spiral flow channel fixing holes, the threads of the screws fix the flange and the oil cylinder together, and the spiral flow channel cooperates with the cyclone and the axis of the oil cylinder.

9. The automatic backwashing de-oiling and de-sanding device for injection and production in the same well according to claim 8 is characterized in that: The cyclone is a shaft-entered cyclone, which is threadedly connected to the inner wall of the oil cylinder. The cyclone, the oil cylinder, and the spiral flow channel are axially matched, and the top surface of the cyclone coincides with the lower surface of the third clamping ring of the oil cylinder, which plays a role in fixing the cyclone.

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