Oil-water separation device for oil field produced liquid

Abstract

The invention belongs to the technical field of oilfield exploitation, and particularly relates to an oilfield produced liquid oil-water separation device which comprises a cyclone separation tank, a blow-off pipe is arranged at the bottom of the cyclone separation tank, and a continuous blow-off assembly is arranged at the bottom of the blow-off pipe; the continuous blowdown assembly comprises a circular shell with a blowdown pipe fixed, the upper side of the circular shell is communicated with the blowdown pipe, a blowdown port is formed in the lower side of the circular shell, a circular block is rotationally installed in the circular shell, the side wall of the circular block makes contact with the inner wall of the circular shell, and dirt collecting grooves are formed in the upper end and the lower end of the circular block; according to the continuous blowdown assembly, continuous blowdown of the cyclone separation tank in the normal working process is achieved through cooperation of a circular block and a circular shell, dirt collecting grooves in the circular block are alternately communicated with and blocked from a blowdown pipe, the continuity and high efficiency of blowdown are guaranteed, and complex blowdown operation is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield exploitation, and in particular relates to an oil-water separation device for oilfield produced fluid. Background Art

[0002] During oilfield production, crude oil extracted from the well typically carries large amounts of free water, silt, and mechanical impurities. These impurities not only reduce the quality of the crude oil and increase the difficulty and cost of subsequent processing, but can also cause wear and corrosion to pipelines, storage facilities, and refining equipment, shortening their service life and impacting production safety. Therefore, initial oil-water separation and decontamination treatment of produced fluids is an essential step in oilfield production.

[0003] The use of cyclone separators can be mainly used for solid-liquid separation and liquid-liquid separation in the oil production process. Its core function is to efficiently remove solid particles (such as sand and rock chips) and free water in crude oil through centrifugal force, thereby protecting downstream equipment, improving oil quality and reducing processing costs.

[0004] The cyclone separator is a dirt remover that uses the principle of centrifugal separation to remove impurities. The liquid inlet pipe is installed at the eccentric position of the cylinder. When working, after the liquid enters the cyclone separator from the water inlet pipe, it first forms a surrounding fluid that is obliquely downward along the tangential direction of the cylinder. The liquid water flow rotates and moves downward. When the liquid water flow reaches the bottom, it turns upward along the axis of the cylinder, is filtered by the central tube filter, and is discharged from the top water pipe. Under the action of the fluid inertia centrifugal force and its own gravity, the debris falls along the bottom wall into the lower sewage outlet of the equipment. After working for a period of time, manually open the sewage valve and the separated debris can be discharged from the dirt remover.

[0005] In the existing structure, when the cyclone separator is discharging sewage, the equipment needs to be shut down and the sewage valve needs to be manually opened to discharge the sewage. This is not only complicated to operate, but also time-consuming and labor-intensive, affecting production efficiency. Summary of the Invention

[0006] The purpose of the present invention is to provide an oil-water separation device for oilfield produced fluid, so as to solve the problems raised in the background technology.

[0007] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows: An oil-water separation device for oilfield produced fluid comprises a cyclone separation tank, the bottom of the cyclone separation tank being conical, a liquid inlet pipe being provided on the right side of the cyclone separation tank, a central tube being fixed at the central axis of the cyclone separation tank, the upper end of the central tube passing through the cyclone separation tank and connected to a liquid outlet, a sewage pipe being provided at the bottom of the cyclone separation tank, and a continuous sewage discharge assembly being provided at the bottom of the sewage pipe; The continuous sewage discharge assembly includes a circular shell to which the sewage pipe is fixed, the upper side of the circular shell is connected to the sewage pipe, the lower side of the circular shell is provided with a sewage outlet, a circular block is rotatably installed in the circular shell, the side wall of the circular block contacts the inner wall of the circular shell, and the upper and lower ends of the circular block are provided with sewage collection grooves; A shell is fixed to the side wall of the liquid inlet pipe, and the shell is connected to the inside of the liquid inlet pipe. A rotating shaft is rotatably installed in the middle of the shell, and a plurality of push plates are fixed to the side wall of the rotating shaft. The push plate close to the side of the liquid inlet pipe extends into the inside of the liquid inlet pipe, and a transmission part is provided between the rotating shaft and the circular block.

[0008] The transmission member includes a first transmission shaft connected to the lower end of the rotating shaft, a second transmission shaft is fixed at the center of the circular block, and the cyclone separation tank is equipped with a reduction gearbox, the first transmission shaft is connected to the input end of the reduction gearbox, and the second transmission shaft is connected to the output end of the reduction gearbox.

[0009] A collecting box located below the sewage pipe is provided at the bottom of the cyclone separation tank.

[0010] The dirt collection trough is V-shaped, and a cleaning assembly for cleaning the dirt collection trough is installed on the side wall of the collection box. The cleaning assembly includes a strip shell arranged on one side of the sewage outlet, a slide is provided for sliding inside the strip shell, a first spring is provided between the slide and the bottom of the strip shell, a scraper is fixed to the upper end of the slide that slides out of the strip shell, and the end of the scraper abuts against the inner wall of the dirt collection trough.

[0011] The lower end of the central tube is provided with a filter screen.

[0012] The lower end of the central tube is rotatably mounted with a ring via a rotating rod. The filter screen is hemispherical and mounted on the lower side of the ring. The upper end of the central tube is mounted with an arcuate shell. The left end of the arcuate shell is connected to a waste liquid pipe. The waste liquid pipe is connected to the central tube through the arcuate shell. A rotating shaft is rotatably mounted on the upper side of the inner side of the arcuate shell. A baffle is fixed to the rotating shaft. The baffle vertically blocks the waste liquid pipe downward. A motor is mounted on the rear side of the arcuate shell. The output shaft of the motor is connected to the rotating shaft.

[0013] The side wall of the central tube is provided with a mounting groove, the rotating rod extends into the mounting groove and is connected to the first gear, the mounting groove is rotatably installed with a second gear meshing with the first gear, a slider is slidingly provided in the mounting groove, the lower side of the slider is connected to a rack meshing with the second gear, a fixing block is fixed to the mounting groove, a second spring is provided between the lower side of the slider and the fixing block, the upper end of the slider is connected to a push rod, the upper end of the push rod extends into the arc shell, and the upper end of the push rod abuts against the lower end of the baffle, and the upper end of the push rod is processed with a bevel.

[0014] The device of the present invention forms a stable double-helix flow field through a cyclone separation tank, and utilizes density differences to achieve efficient separation of crude oil from free water, mud and mechanical impurities. The crude oil forms an internal vortex in the middle of the cyclone separation tank and is discharged upward, while high-density materials are discharged downward along the wall spiral, effectively reducing the load on subsequent dehydration equipment.

[0015] The continuous sewage discharge component of the present invention realizes continuous sewage discharge in the normal working process of the cyclone separation tank through the cooperation of the circular block and the circular shell. The sewage collection groove on the circular block is alternately connected to and blocked with the sewage pipe, ensuring the continuity and efficiency of sewage discharge, avoiding complicated sewage discharge operations, and utilizing the flow rate of crude oil to drive the push plate to rotate, thereby driving the circular block to rotate. No additional power source is required, thereby reducing energy consumption and operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention is further illustrated by means of the following non-limiting examples.

[0017] Figure 1 This is a structural schematic diagram of an embodiment of an oil-water separation device for oilfield produced fluid according to the present invention; Figure 2 This is a schematic cross-sectional view of an embodiment of an oil-water separation device for oilfield produced fluid according to the present invention. Figure 1 ; Figure 3 Based Figure 2 A schematic diagram of the structure at point A in the middle; Figure 4 This is a schematic cross-sectional view of an embodiment of an oil-water separation device for oilfield produced fluid according to the present invention. Figure 2 ; Figure 5 This is a schematic cross-sectional view of an embodiment of an oil-water separation device for oilfield produced fluid according to the present invention. Figure 3 ; Figure 6 Based Figure 5 A magnified schematic diagram of the structure at B in the middle; Figure 7 Based Figure 5 A magnified schematic diagram of the structure at C in the middle; Figure 8 This is a schematic cross-sectional view of an embodiment of an oil-water separation device for oilfield produced fluid according to the present invention. Figure 4 ; Figure 9 Based Figure 8 Enlarged schematic diagram of the structure at D in the middle.

[0018] The main component symbols are described as follows: Cyclone separation tank 1, liquid inlet pipe 11, central tube 12, liquid outlet 13, sewage pipe 14, circular shell 2, sewage outlet 21, circular block 22, sewage collection tank 23, shell 3, rotating shaft 31, push plate 32, first transmission shaft 311, second transmission shaft 221, reduction gear box 33, collection box 34, strip shell 35, slide plate 36, first spring 37, scraper 38, filter screen 4, circular ring 41, arc-shaped shell 42, waste liquid pipe 43, rotating shaft 44, baffle 45, motor 46, mounting slot 5, first gear 51, second gear 52, slider 53, rack 54, second spring 55, and push rod 56. DETAILED DESCRIPTION

[0019] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and embodiments.

[0020] like Figure 1-9 As shown, an oil-water separation device for oilfield produced liquid of the present invention includes a cyclone separation tank 1, the bottom of the cyclone separation tank 1 is conical, a liquid inlet pipe 11 is provided on the right side of the cyclone separation tank 1, a central pipe 12 is fixed at the middle axis of the cyclone separation tank 1, the upper end of the central pipe 12 passes through the cyclone separation tank 1 and is connected to a liquid outlet 13, a sewage pipe 14 is provided at the bottom of the cyclone separation tank 1, and a continuous sewage discharge assembly is provided at the bottom of the sewage pipe 14; The continuous sewage discharge assembly includes a circular shell 2 fixed with a sewage pipe 14. The upper side of the circular shell 2 is connected to the sewage pipe 14. The lower side of the circular shell 2 is provided with a sewage outlet 21. A circular block 22 is rotatably installed in the circular shell 2. The side wall of the circular block 22 contacts the inner wall of the circular shell 2. The upper and lower ends of the circular block 22 are provided with sewage collection grooves 23. A shell 3 is fixed to the side wall of the liquid inlet pipe 11, and the shell 3 is connected to the inside of the liquid inlet pipe 11. A rotating shaft 31 is rotatably installed in the middle of the shell 3, and a plurality of push plates 32 are fixed to the side wall of the rotating shaft 31. The push plate 32 close to the side of the liquid inlet pipe 11 extends into the interior of the liquid inlet pipe 11, and a transmission part is provided between the rotating shaft 31 and the circular block 22.

[0021] When crude oil is extracted from an oil well, it usually carries free water, sediment, and mechanical impurities. The cyclone separator can initially separate the free water from the oil-water mixture (the effect is significant when the water content is >30%), thereby reducing the load on subsequent dehydration equipment. The crude oil is connected to the liquid inlet pipe 11 and enters the cyclone separation tank 1 at a high speed in a tangential direction, forcing a rotating flow field. The flow rate at the inlet of the liquid inlet pipe 11 is 3-8m / s. The crude oil forms a stable double-helix flow field in the middle of the cyclone separation tank 1 (the outer vortex is downward and the inner vortex is upward). High-density materials (partial free water, sediment and mechanical impurities) spiral downward along the wall and are discharged through the bottom flow port. Low-density materials (crude oil) spiral upward along the center pipe 12 and are discharged through the liquid outlet 13. When crude oil flows into the cyclone separation tank 1 from the liquid inlet pipe 11, the push plate 32 installed in the shell 3 is extended into the liquid inlet pipe 11 by the rotation of the rotating shaft 31. Therefore, the flow of crude oil can push the push plate 32 to rotate rapidly, driving the rotating shaft 31 to rotate, and transmitting power to the circular block 22 through the transmission member, so that the circular block 22 rotates in the circular shell 2. This design can drive the circular block 22 to rotate continuously when crude oil is input into the cyclone separation tank 1; when the dirt collection tank 23 of the circular block 22 faces upward, it will be connected to the sewage pipe 14, and the mud, mechanical impurities and free water at the bottom of the cyclone separation tank 1 will fall downward into the dirt collection tank 23 When the circular block 22 rotates, the dirt collecting trough 23 will move away from the drain pipe 14, and the bottom of the drain pipe 14 will be blocked by the side wall of the circular block 22 until the other dirt collecting trough 23 moves to the upper side. The dirt collecting trough 23 with the dirt collected faces the lower side and automatically falls downward due to its own weight. Therefore, the circular block 22 can continuously clean the dirt at the bottom of the cyclone separation tank 1 under continuous rotation, so that the drain pipe 14 can simultaneously perform the sewage discharge work during the normal operation of the cyclone separation tank 1, avoiding time-consuming and labor-intensive complicated operations, and utilizing the flow rate of crude oil to drive the push plate 32 to rotate, thereby driving the circular block 22 to rotate, without the need for additional power; The side wall of the circular block 22 abuts against the inner wall of the circular shell 2 , thereby ensuring the sealing between the circular block 22 and the circular shell 2 .

[0022] The transmission member includes a first transmission shaft 311 connected to the lower end of the rotating shaft 31, a second transmission shaft 221 is fixed at the center of the circular block 22, and a reduction gearbox 33 is installed on the cyclone separation tank 1. The first transmission shaft 311 is connected to the input end of the reduction gearbox 33, and the second transmission shaft 221 is connected to the output end of the reduction gearbox 33; the reduction gearbox is a mechanical transmission device, which is mainly used to reduce the rotation speed and increase the output torque at the same time. The core component of the reduction gearbox is a gear set, which usually includes a driving wheel (input wheel) and a driven wheel (output wheel). The number of teeth on the driving wheel is less than that on the driven wheel. When the driving wheel rotates, the driven wheel is driven to rotate through the meshing of the gears. Since the driven wheel has more teeth, its rotation speed will decrease, but the torque will increase accordingly. Therefore, when the rotating shaft 31 rotates, it can drive the first transmission shaft 311 to rotate, and transmit power to the second transmission shaft 221 through the deceleration and amplification of the reduction gear box 33, driving the circular block 22 to rotate, thereby realizing power transmission.

[0023] A collecting box 34 is provided at the bottom of the cyclone separation tank 1 and is located below the sewage pipe 14 ; the collecting box 34 is used to collect sewage discharged from the sewage pipe 14 .

[0024] The dirt collection trough 23 is V-shaped, and a cleaning assembly for cleaning the dirt collection trough 23 is installed on the side wall of the collection box 34. The cleaning assembly includes a strip shell 35 arranged on one side of the sewage outlet 21. A slide plate 36 is slidably provided in the strip shell 35. A first spring 37 is provided between the slide plate 36 and the bottom of the strip shell 35. A scraper 38 that slides out of the strip shell 35 is fixed to the upper end of the slide plate 36. The end of the scraper 38 abuts against the inner wall of the dirt collection trough 23.

[0025] When the dirt collecting trough 23 of the circular block 22 abuts against the scraper 38, the first spring 37 is compressed. When the dirt collecting trough 23 of the circular block 22 rotates to the scraper 38, the scraper 38 extends into the dirt collecting trough 23 under the elastic force of the first spring 37. Since the dirt collecting trough 23 is V-shaped, the scraper 38 will abut against the side wall of the dirt collecting trough 23. During the rotation of the circular block 22, the scraper 38 will move toward the center along the side wall of the dirt collecting trough 23 until it moves to the bottom of the dirt collecting trough 23 and then abuts against the other side wall of the dirt collecting trough 23, pushing the scraper 38 to move toward the inside of the strip shell 35, causing the first spring 37 to be compressed again, and finally causing the scraper 38 to leave the dirt collecting trough 23. Therefore, whenever the dirt collecting trough 23 rotates to the lower side, the scraper 38 can be used to clean the side wall of the dirt collecting trough 23 to prevent dirt from adhering to the dirt collecting trough 23.

[0026] A filter screen 4 is provided at the lower end of the central tube 12 ; the filter screen 4 is used to filter small particles of impurities or suspended matter in the crude oil, preparing for the subsequent fine oil-water separation of the crude oil.

[0027] A circular ring 41 is rotatably installed at the lower end of the central tube 12 through a rotating rod. The filter screen 4 is hemispherical and is installed on the lower side of the circular ring 41. An arc-shaped shell 42 is installed at the upper end of the central tube 12. The left end of the arc-shaped shell 42 is connected to a waste liquid pipe 43. The waste liquid pipe 43 is connected to the central tube 12 through the arc-shaped shell 42. A rotating shaft 44 is rotatably installed on the upper side of the arc-shaped shell 42. A baffle 45 is fixed to the rotating shaft 44. The baffle 45 vertically blocks the waste liquid pipe 43 downward. A motor 46 is installed on the rear side of the arc-shaped shell 42. The output shaft of the motor 46 is connected to the rotating shaft 44.

[0028] A mounting groove 5 is provided on the side wall of the central tube 12, and a rotating rod extends into the mounting groove 5 and is connected to a first gear 51, and a second gear 52 meshing with the first gear 51 is rotatably installed in the mounting groove 5, and a slider 53 is slidingly provided in the mounting groove 5, and a rack 54 meshing with the second gear 52 is connected to the lower side of the slider 53, and a fixed block is fixed to the mounting groove 5, and a second spring 55 is provided between the lower side of the slider 53 and the fixed block, and a push rod 56 is connected to the upper end of the slider 53, and the upper end of the push rod 56 extends into the arc shell 42, and the upper end of the push rod 56 abuts against the lower end of the baffle 45, and the upper end of the push rod 56 is processed with a bevel.

[0029] In the initial state, the baffle 45 is vertically downward, blocking the waste liquid pipe 43. At this time, the upper end of the central tube 12 is normally connected to the liquid outlet 13, and the lower end of the baffle 45 is in contact with the upper end of the push rod 56. At this time, the opening of the hemispherical filter 4 is facing upward, and its entirety is located below the central tube 12. The hemispherical filter 4 is used to filter crude oil. When the device is used for a long time, excessive impurities will adhere to the surface of the filter 4, which may easily cause the filter 4 to become clogged. The motor 46 is then started again to turn the baffle 45 downwards and reset it. The baffle 45 moves downwards and abuts against the inclined surface of the push rod 56, thereby pushing the push rod 56 downwards and reset it. The crude oil with impurities collected by the waste liquid pipe 43 can be processed separately to avoid waste; With this design, when the device is in continuous use, the filter screen 4 can be turned over to backwash the filter screen 4, and the cyclone separation tank 1 can work normally without stopping.

[0030] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. An oil-water separation device for oilfield produced fluid, comprising a cyclone separator, the bottom of the cyclone separator being conical, a liquid inlet pipe being provided on the right side of the cyclone separator, a central tube being fixed at the central axis of the cyclone separator, the upper end of the central tube passing through the cyclone separator and connected to a liquid outlet, and a sewage pipe being provided at the bottom of the cyclone separator, characterized in that: A continuous sewage discharge assembly is provided at the bottom of the sewage pipe; The continuous sewage discharge assembly includes a circular shell to which the sewage pipe is fixed, the upper side of the circular shell is connected to the sewage pipe, the lower side of the circular shell is provided with a sewage outlet, a circular block is rotatably installed in the circular shell, the side wall of the circular block contacts the inner wall of the circular shell, and the upper and lower ends of the circular block are provided with sewage collection grooves; A shell is fixed to the side wall of the liquid inlet pipe, and the shell is connected to the inside of the liquid inlet pipe. A rotating shaft is rotatably installed in the middle of the shell, and a plurality of push plates are fixed to the side wall of the rotating shaft. The push plate close to the side of the liquid inlet pipe extends into the inside of the liquid inlet pipe, and a transmission part is provided between the rotating shaft and the circular block.

2. The oil-water separation device for oilfield produced fluid according to claim 1, characterized in that: The transmission member includes a first transmission shaft connected to the lower end of the rotating shaft, a second transmission shaft is fixed at the center of the circular block, and the cyclone separation tank is equipped with a reduction gearbox, the first transmission shaft is connected to the input end of the reduction gearbox, and the second transmission shaft is connected to the output end of the reduction gearbox.

3. The oil-water separation device for oilfield produced fluid according to claim 1, characterized in that: A collecting box located below the sewage pipe is provided at the bottom of the cyclone separation tank.

4. The oil-water separation device for oilfield produced fluid according to claim 3, characterized in that: The dirt collection trough is V-shaped, and a cleaning assembly for cleaning the dirt collection trough is installed on the side wall of the collection box. The cleaning assembly includes a strip shell arranged on one side of the sewage outlet, a slide is provided for sliding inside the strip shell, a first spring is provided between the slide and the bottom of the strip shell, a scraper is fixed to the upper end of the slide that slides out of the strip shell, and the end of the scraper abuts against the inner wall of the dirt collection trough.

5. The oil-water separation device for oilfield produced fluid according to claim 1, characterized in that: The lower end of the central tube is provided with a filter screen.

6. The oil-water separation device for oilfield produced fluid according to claim 5, characterized in that: The lower end of the central tube is rotatably mounted with a ring via a rotating rod. The filter screen is hemispherical and mounted on the lower side of the ring. The upper end of the central tube is mounted with an arcuate shell. The left end of the arcuate shell is connected to a waste liquid pipe. The waste liquid pipe is connected to the central tube through the arcuate shell. A rotating shaft is rotatably mounted on the upper side of the inner side of the arcuate shell. A baffle is fixed to the rotating shaft. The baffle vertically blocks the waste liquid pipe downward. A motor is mounted on the rear side of the arcuate shell. The output shaft of the motor is connected to the rotating shaft.

7. The oil-water separation device for oilfield produced fluid according to claim 6, characterized in that: The side wall of the central tube is provided with a mounting groove, the rotating rod extends into the mounting groove and is connected to the first gear, the mounting groove is rotatably installed with a second gear meshing with the first gear, a slider is slidingly provided in the mounting groove, the lower side of the slider is connected to a rack meshing with the second gear, a fixing block is fixed to the mounting groove, a second spring is provided between the lower side of the slider and the fixing block, the upper end of the slider is connected to a push rod, the upper end of the push rod extends into the arc shell, and the upper end of the push rod abuts against the lower end of the baffle, and the upper end of the push rod is processed with a bevel.

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