CN116104464A

CN116104464A - Sand control oil-gas separator based on centrifugal separation effect

Info

Publication number: CN116104464A
Application number: CN202211546903.0A
Authority: CN
Inventors: 罗伟燚; 黄涛; 肖扬
Original assignee: Zhejiang Ocean University ZJOU
Current assignee: Zhejiang Ocean University ZJOU
Priority date: 2022-12-01
Filing date: 2022-12-01
Publication date: 2023-05-12

Abstract

The invention relates to the technical field of petroleum exploitation, in particular to a sand prevention oil-gas separator based on centrifugal separation; the oil-gas separation device comprises a separator, wherein the separator is arranged at the bottom of an oil-well pump through a plurality of connecting plates and comprises a sleeve and an outer tube, the sleeve is vertical, the top of the outer tube is communicated with the bottom of the oil-well pump, the bottom of the outer tube is closed, the upper end of the outer tube is provided with a plurality of liquid inlet holes which are radially arranged, the sleeve is sleeved outside the outer tube, a centrifugal filtering mechanism is arranged between the sleeve and the outer tube, and the top of the sleeve is provided with an oil-gas separation assembly for discharging gas; according to the oil well pump, the separator is arranged at the bottom of the oil well pump, the centrifugal separation mechanism in the separator can enable petroleum to rise, gravel is thrown to the inner wall of the sleeve, then accumulated into blocks and finally settled back to the shaft due to the action of gravity, and gas is discharged through the oil-gas separation component above, so that separation of petroleum, gravel and gas in petroleum is achieved.

Description

Sand control oil-gas separator based on centrifugal separation effect

Technical Field

The invention relates to the technical field of oil exploitation, in particular to a sand prevention oil-gas separator based on centrifugal separation.

Background

Sand production from oil and gas wells is a phenomenon often encountered in oil recovery production. Sand production of oil and gas wells can bring great influence to normal production. Sand production from an oil well is a phenomenon that sand stratum structures near perforation tunnels or in a bottom hole zone are damaged due to loose cementing of a reservoir stratum, low strength and flushing of fluid in the oil and gas exploitation process, so that sand grains are moved out of the oil layer along with the fluid. In the last 30 th century, people recognize that the sand production in the stratum can bring harm to the oil and gas exploitation, sand prevention measures must be adopted to improve the output of oil and gas wells and prevent accidents. With the high-speed development of the world petroleum industry, the sand control technology is continuously perfected and gradually matured, and a sand control comprehensive matching technology system is gradually formed. The gravel packing sand control method is adopted in the 30 s, and the chemical sand fixation method is adopted in the 40 s on a large scale. The method for mainly researching chemical sand prevention is carried out in the 60 th year of the last century, the mechanical sand prevention is researched in the 70 th year of the last century, and the research and application of the wire-wrapped screen gravel packing technology are carried out in the 80 th year of the last century. With the continuous improvement of sand control technology, people have studied more about the mechanism of sand production of the stratum, prediction of sand production and various measures for sand production; the existing sand prevention technology is to add a sand prevention device, crude oil enters an oil-gas separator through the sand prevention device, so that most of the oil-gas separators do not have sand prevention performance or are not particularly simple, and for oil-gas wells with serious sand production or after fracturing, the oil-gas separator without the sand prevention device supplies liquid flow containing a large amount of sand to an electric submersible pump, so that the electric submersible pump is easy to clamp.

Chinese patent CN110485970B discloses an exhaust sand control device of an oil pump, which can filter gravel in oil by gravity through a plurality of gravity settling drums, can separate gravel in oil through a centrifugal sand setting device, and can separate gas in oil through an exhaust separator, however, the application does not disclose the following technical problems:

1. in the prior art, the gravity settling cylinder and the centrifugal sand setting device can filter and separate the sand in the petroleum, but the sand is accumulated in the sand setting cavity and accumulated for a long time, so that the separation effect is affected;

2. in the prior art, the gas separator can be arranged in the middle of the oil pump, so that a sealing area cannot be formed in the petroleum pump, and when the petroleum pump works, the piston in the oil pump cannot smoothly pump petroleum into the upper part.

Disclosure of Invention

According to the sand prevention oil-gas separator based on centrifugal separation, the separator is arranged at the bottom of the oil pump, sand in oil can be filtered by the separator, the sand can be thrown to the inner wall of the sleeve in the ascending process of the oil by the centrifugal separation mechanism, then accumulated into blocks and finally settled back to the shaft due to the action of gravity, and gas is discharged through the oil-gas separation component above, wherein the self-sealing component can realize automatic sealing in the oil pumping process, so that the separation of the oil from the sand and the gas in the oil is realized, and the automatic sealing effect in the oil pumping process is realized, so that the smooth running of the oil pump is ensured.

In order to solve the problems in the prior art, the invention adopts the following technical scheme:

the utility model provides a sand control oil-gas separator based on centrifugal separation effect, including the oil-well pump, the inside ball valve that is equipped with of oil-well pump, the bottom of oil-well pump is equipped with the separator that is used for sand control and carries out oil-gas separation, the separator is installed in the bottom of oil-well pump through a plurality of connecting plates, the separator is including being vertical form sleeve and outer tube, the top of outer tube and the bottom intercommunication of oil-well pump, the bottom of outer tube is closed form, the upper end of outer tube is equipped with a plurality of feed liquor holes that are radial setting, the outside at the outer tube is established to the sleeve cover, be equipped with centrifugal filter mechanism between sleeve and the outer tube, telescopic top is equipped with the oil-gas separation subassembly that is used for exhaust gas.

Preferably, the diameter of the inlet opening is smaller than the diameter of the gravel.

Preferably, the inside of the outer tube is provided with a vertical central tube, the top of the central tube is arranged in the outer tube through a sealing block, the height of the sealing block is higher than that of the liquid inlet, and the bottom of the central tube is provided with an opening.

Preferably, the centrifugal filter mechanism is a spiral sheet, the spiral sheet being mounted between the sleeve and the outer tube.

Preferably, the top of the flight is lower than the bottom of the feed opening.

Preferably, the bottom of the sleeve is provided with a setback end, and the setback end is provided with a first filter plate for filtering gravel in the petroleum.

Preferably, a second filter plate in a circular ring shape is further arranged in the sleeve, and the second filter plate is horizontally arranged in the sleeve and is positioned between the spiral sheet and the liquid inlet.

Preferably, the oil and gas separation assembly comprises a mist catcher; the mist catcher is annular and is arranged between the outer tube and the sleeve, and the mist catcher is positioned above the liquid inlet hole; the self-sealing mechanism capable of automatically sealing the mist catcher during oil pumping is arranged on the mist catcher and is arranged at the top of the mist catcher and is in transmission connection with the spherical valve.

Preferably, the self-sealing mechanism comprises a connecting disc, a connecting block and a sealing assembly;

the connecting disc is disc-shaped and horizontally arranged above the mist catcher, the bottom of the connecting disc is communicated with the mist catcher, and a plurality of exhaust holes are annularly arranged at the top of the connecting disc;

the connecting block is horizontally arranged in the oil pump and is connected with the top of the spherical valve;

the sealing assembly is the same as the exhaust holes in number and corresponds to the exhaust holes one by one, the top of the sealing assembly is connected with the connecting block, and the bottom of the sealing assembly is abutted with the bottom of the exhaust holes in the working state.

Preferably, the sealing assembly comprises a sealing ball, a connecting rod and a limiting ring;

the sealing ball is arranged in the connecting disc and positioned below the exhaust hole, and is connected with the connecting block through the connecting rod;

the limiting ring sleeve is arranged on the connecting rod and is positioned on one side of the oil pump close to the connecting disc.

Compared with the prior art, the beneficial effects of this application are:

1. the invention uses centrifugal separation to remove sand and separate oil from water, without adding sand control device, without increasing cost. Meanwhile, the oil-gas separation and oil-sand separation processes are integrated, the separation efficiency is high, the separation effect is good, and the subsequent treatment process is simple;

2. the invention combines spiral separation and separation with changing the flow direction of liquid flow, and carries out oil-gas separation twice, thus having thorough separation and good effect;

3. the invention can effectively remove sand, prevent the pump from being blocked, effectively protect the electric submersible pump from being damaged and prolong the service life of the electric submersible pump;

4. the invention has thorough oil-gas separation, and effectively prevents the occurrence of air lock phenomenon and gas blocking circulation phenomenon.

Drawings

FIG. 1 is a schematic perspective view of a sand control oil-gas separator based on centrifugal separation;

FIG. 2 is a perspective structural cross-sectional view of a sand control oil and gas separator based on centrifugal separation;

FIG. 3 is a partially exploded view of a three-dimensional structure of a sand control oil and gas separator based on centrifugal separation;

FIG. 4 is a schematic diagram of a partial perspective view of a sand control oil-gas separator based on centrifugal separation;

FIG. 5 is a partial perspective sectional view of a sand control oil and gas separator based on centrifugal separation;

FIG. 6 is a schematic diagram of a partial perspective view of a sand control oil-gas separator based on centrifugal separation.

The reference numerals in the figures are:

1-an oil pump; 11-ball valve;

2-connecting plates;

3-separator; 31-sleeve; 311-a first filter plate; 312-second filter plates; 32-an outer tube; 321-liquid inlet holes; 33-a central tube; 331-sealing block; 34-a centrifugal filtration mechanism; 341-spiral sheet;

4-an oil-gas separation assembly; 41-a mist catcher; 42-a self-sealing mechanism; 421-connecting disc; 4211-exhaust holes; 422-connecting blocks; 423-a seal assembly; 4231-sealing ball; 4232-connecting rod; 4233-stop collar.

Detailed Description

The invention will be further described in detail with reference to the drawings and the detailed description below, in order to further understand the features and technical means of the invention and the specific objects and functions achieved.

Referring to fig. 1 to 6, a sand prevention oil-gas separator based on centrifugal separation effect comprises an oil-well pump 1, a ball valve 11 is arranged in the oil-well pump 1, a separator 3 used for sand prevention and oil-gas separation is arranged at the bottom of the oil-well pump 1, the separator 3 is arranged at the bottom of the oil-well pump 1 through a plurality of connecting plates 2, the separator 3 comprises a vertical sleeve 31 and an outer tube 32, the top of the outer tube 32 is communicated with the bottom of the oil-well pump 1, the bottom of the outer tube 32 is in a closed shape, a plurality of liquid inlet holes 321 which are radially arranged are arranged at the upper end of the outer tube 32, the sleeve 31 is sleeved outside the outer tube 32, a centrifugal filtering mechanism 34 is arranged between the sleeve 31 and the outer tube 32, and an oil-gas separation assembly 4 used for discharging gas is arranged at the top of the sleeve 31.

In the oil exploitation process, in order to improve the quality of oil and prevent the sand from being pumped into the oil pump 1 to cause the damage of the oil pump 1, sand prevention measures are required to be taken, the bottom of the oil pump 1 is provided with a separator 3, the separator 3 comprises a vertical sleeve 31 and an outer tube 32, a centrifugal filter mechanism 34 is arranged between the sleeve 31 and the outer tube 32, the top of the sleeve 31 is provided with an oil-gas separation component 4 for discharging gas, when oil is pumped into the separator 3 from the bottom of the sleeve 31, the oil firstly passes through the centrifugal filter mechanism 34, the centrifugal filter mechanism 34 can filter sand in the oil, at the moment, part of gas exists in the oil, the gas in the oil can be discharged from the oil-gas separation component 4 above, the oil can flow into the outer tube 32 from the inside of the liquid inlet 321, and finally can be pumped into the oil pump from the outer tube 32, thereby realizing the filtration of the sand in the oil, and the gas in the oil can be discharged, and the damage of the oil pump caused by pumping the sand and the gas in the oil into the inside of the oil pump in the oil pumping process can be avoided.

Referring to fig. 2, the diameter of the inlet 321 is smaller than the diameter of the gravel.

In order to prevent that the gravel with smaller diameter from being pumped into the petroleum pump when petroleum is pumped, the diameter size of the liquid inlet 321 can play a role in filtering, and meanwhile, the liquid inlet 321 is provided with a plurality of liquid inlets, so that the speed of petroleum pumping is not influenced when the gravel is filtered, meanwhile, the liquid inlet 321 can play a role in filtering residual gravel in the petroleum when the petroleum flows into the outer tube 32, when the petroleum passes through the centrifugal filtering mechanism 34, a small part of gravel can be remained, and therefore, when the residual gravel in the petroleum is filtered, the diameter of the liquid inlet 321 is smaller than the diameter of the gravel, so that the effect of filtering the residual gravel can be played when the petroleum passes through the liquid inlet 321.

Referring to fig. 2, a central tube 33 is provided in the outer tube 32, the top of the central tube 33 is mounted in the outer tube 32 by a sealing block 331, the sealing block 331 is higher than the liquid inlet 321, and an opening is provided at the bottom of the central tube 33.

When gas in petroleum needs to be cleared again, through being equipped with center tube 33 in the inside of outer tube 32, the top of center tube 33 passes through sealing block 331 and installs in the inside of outer tube 32 and sealing block 331 highly is higher than the height of feed liquor hole 321, the bottom of center tube 33 is equipped with the opening simultaneously, when petroleum flows in the inside of outer tube 32 from feed liquor hole 321 of outer tube 32 upper end, petroleum can descend to the bottom of outer tube 32, because gas and liquid density's difference, residual gas in the petroleum can rise, finally follow the rising to feed liquor hole 321 department and flow from oil-gas separation subassembly 4, thereby the setting of center tube 33 can change the direction that the petroleum flowed in, take out again after making the petroleum flow down, thereby realized getting rid of residual gas in the petroleum, avoided gas to get into the airlock phenomenon that leads to oil-well pump 1 in the oil-well pump 1.

Referring to fig. 2 to 3, the centrifugal filter mechanism 34 is a spiral sheet 341, and the spiral sheet 341 is installed between the sleeve 31 and the outer tube 32.

In the process of oil extraction, when the sand in the oil needs to be filtered, the screw sheets 341 are arranged between the sleeve 31 and the outer tube 32, and because the density of the sand is different from that of the oil, the centrifugal force received by the screw sheets 341 is inconsistent to achieve the purpose of sand removal, and because the density of the solid sand is higher, the oil can spiral along the screw sheets 341 in the process of oil extraction, the solid sand can be thrown onto the inner wall of the sleeve 31 due to the centrifugal force when rotating, and then accumulated into blocks and finally subsided back to the lower side due to the action of gravity, thereby achieving the purpose of sand removal.

Referring to fig. 2 to 3, the top of the spiral piece 341 is lower than the bottom of the liquid inlet 321.

In the spiral rising process of the oil, in order to ensure that the oil smoothly flows in from the liquid inlet 321, the top of the spiral piece 341 is arranged below the liquid inlet 321, when the oil passes through the spiral piece 341, the gravel and the oil can move to the inner wall of the sleeve 31 due to centrifugal force, but due to the fact that the density of the gravel is high, the gravel can be thrown to the inner wall of the sleeve 31 due to centrifugal force, finally, the gravel can be accumulated to form a block and settle back to the bottom, the oil can move upwards along one side close to the sleeve 31, after the oil passes through the spiral piece 341, the gravel and the oil can be separated, the oil flows into the liquid inlet 321 due to the action of the oil pump 1, and if the spiral piece 341 is arranged above the liquid inlet 321, the oil can move upwards continuously, so that the inflow efficiency of the oil from the liquid inlet 321 is affected.

Referring to figure 3, the bottom of the sleeve 31 is provided with a recessed end on which is provided a first filter plate 311 for filtering gravel from the oil.

In the oil extraction process, in order to increase the filtering effect, through being equipped with first filter 311 in the bottom of sleeve 31, first filter 311 is the bottom of horizontal form installation at sleeve 31, in the oil exploitation process, oil gas well goes out sand and can bring very big influence for normal production, oil well goes out sand is because reservoir cementation loose, intensity is low, fluid wash and lead to near perforation tunnel or well bottom area sandstone layer structure to be destroyed in the oil exploitation process for the phenomenon that the sand grain moves out along with the fluid from the oil reservoir, first filter 311 can filter great grit in the oil well of stone in the exploitation process, thereby can accomplish preliminary filtration when oil suction separator 3, thereby can avoid a large amount of grit to enter into separator 3 and influence the filtering effect.

Referring to fig. 2 to 3, a second filter plate 312 having a circular ring shape is further disposed in the sleeve 31, and the second filter plate 312 is horizontally installed inside the sleeve 31 and between the spiral piece 341 and the liquid inlet.

When the oil is filtered by the spiral sheet 341, most of the gravel in the oil rises spirally along the inner wall of the sleeve 31 due to centrifugal force, then accumulated into blocks and finally settled to the bottom due to gravity operation, at this time, most of the gravel is separated, but a small amount of gravel still exists in the oil, so that in order to prevent the gravel from flowing into the outer tube 32 from the liquid inlet 321 together with the oil, a second filter plate 312 is arranged at the top of the spiral sheet 341, when the oil is filtered by the spiral sheet 341, the gravel is filtered again by the second filter plate 312, the second filter plate 312 can filter out a small amount of gravel existing in the oil, meanwhile, the second filter plate 312 can break up gas in the oil, the broken gas can rise and be filtered and discharged from the oil-gas separation assembly 4, and the filtered oil can flow into the inner portion of the outer tube 32 from the liquid inlet 321, thereby realizing the separation of oil and preventing the gravel from being pumped into the inner portion of the oil pump 1.

Referring to fig. 2 to 5, the oil and gas separation assembly 4 includes a mist catcher 41; the mist catcher 41 is annular and is arranged between the outer tube 32 and the sleeve 31, and the mist catcher 41 is positioned above the liquid inlet 321; the mist catcher 41 is provided with a self-sealing mechanism 42 which can automatically complete sealing of the mist catcher 41 during oil pumping, and the self-sealing mechanism 42 is arranged on the top of the mist catcher 41 and is in transmission connection with the ball valve 11.

When gas discharge is required to be completed, a mist catcher 41 is arranged above a cavity formed between the sleeve 31 and the outer tube 32, and gas passes through a bending channel of the mist catcher to separate liquid drops entrained in gas flow under the action of inertia force and gravity: the gas flows through the demister at a certain speed, the movement direction of the gas is changed rapidly and continuously, the fog drops in the gas are impacted on the demister blades and captured due to the centrifugal force and inertia, the fog drops are collected to form water flow, and the water flow falls into the slurry pool due to the gravity, so that gas-liquid separation is realized, the gas flowing through the demister is discharged, meanwhile, the self-sealing mechanism 42 can seal the mist catcher 41 when the oil pump 1 is in an upstroke, the oil pump 1 is only communicated with an oil well when the oil pump 1 is in an oil pumping mode, the efficiency when the oil pump 1 is in a downstroke is improved, and the self-sealing mechanism 42 can open the mist catcher 41 to be communicated with the outside so as to realize the discharge of the gas.

Referring to fig. 5-6, the self-sealing mechanism 42 includes a connecting disc 421, a connecting block 422, and a sealing assembly 423;

the connecting disc 421 is disc-shaped and horizontally arranged above the mist catcher 41, the bottom of the connecting disc 421 is communicated with the mist catcher 41, and a plurality of exhaust holes 4211 are annularly arranged at the top of the connecting disc 421;

the connection block 422 is horizontally installed inside the oil pump 1 and connected with the top of the ball valve 11;

the number of the sealing assemblies 423 is the same as that of the exhaust holes 4211 and corresponds to that of the exhaust holes 4211 one by one, the top of the sealing assemblies 423 is connected with the connecting block 422, and the bottom of the sealing assemblies 423 is abutted with the bottom of the exhaust holes 4211 in the working state.

When the sealing area is required to be formed by controlling the upper part of the mist catcher 41, the connecting disc 421 is arranged above the mist catcher 41, a plurality of exhaust holes 4211 are formed in an annular array at the top of the connecting disc 421, the sealing assemblies 423 are in same number and in one-to-one correspondence with the exhaust holes 4211, the sealing assemblies 423 are in transmission connection with the spherical valves 11 through the connecting blocks 422, when the oil pump 1 is in an upward stroke, the spherical valves 11 move upwards due to pressure, so that the connecting blocks 422 can drive the sealing assemblies 423 to move upwards, the sealing of the exhaust holes 4211 is realized by the upward movement of the sealing assemblies 423, the sealing of the mist catcher 41 by the connecting disc 421 is realized, the smooth running of oil pumping can be ensured, and when the oil pump 1 is in a downward stroke, the spherical direction is reset downwards, so that the connecting blocks 422 can drive the sealing assemblies 423 to move downwards, the sealing state of the connecting disc 421 is opened, and the mist catcher 41 is communicated with the outside, so that the exhaust effect is achieved.

Referring to fig. 6, the seal assembly 423 includes a seal ball 4231, a connecting rod 4232, and a stop collar 4233;

the sealing ball 4231 is disposed in the connection disc 421 and below the exhaust hole 4211, and the sealing ball 4231 is connected to the connection block 422 through the connection rod 4232;

the limiting ring 4233 is sleeved on the connecting rod 4232 and is positioned on one side of the oil pump 1 close to the connecting disc 421.

When the upward movement of the connection block 422 makes the sealing assembly 423 move upward, and the sealing effect on the exhaust hole 4211 on the connection disc 421 needs to be completed, the connection block 422 is connected with the connection block 4232, the bottom of the connection block 4232 is connected with the sealing ball 4231, the sealing ball 4231 is arranged below the exhaust hole 4211, when the connection block 422 moves upward, the connection block 4232 can make the sealing ball 4231 move upward, so that the sealing ball 4231 can block the lower part of the exhaust hole 4211, and the sealing effect on the exhaust hole 4211 is realized, and when the connection block 422 moves downward, the exhaust hole 4211 needs to be opened, and the downward movement of the connection block 422 makes the connection block 4232 drive the sealing ball 4231 to move downward, so that the sealing ball 4231 is separated from the exhaust hole 4211, and the exhaust effect is achieved; the limiting ring 4233 is arranged on the connecting rod 4232 and is positioned on one side of the oil pump 1 close to the connecting disc 421, when the oil pump 1 is in an upward stroke, the limiting ring 4233 is abutted with the bottom of the oil pump 1, at the moment, the sealing ball 4231 just can seal the exhaust hole 4211, the limiting ring 4233 is arranged to avoid the damage of the connecting disc 421 caused by the upward movement of the sealing assembly 423, and meanwhile, the upward movement of the spherical valve 11 is avoided.

The foregoing examples merely illustrate one or more embodiments of the invention, which are described in greater detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. The utility model provides a sand control oil and gas separator based on centrifugal separation effect, including oil-well pump (1), oil-well pump (1) inside is equipped with ball valve (11), its characterized in that, oil-well pump (1)'s bottom is equipped with and is used for sand control and carries out oil and gas separation's separator (3), separator (3) are installed in oil-well pump (1)'s bottom through a plurality of connecting plates (2), separator (3) are including being vertical form sleeve (31) and outer tube (32), the top of outer tube (32) communicates with oil-well pump (1)'s bottom, the bottom of outer tube (32) is closed form, the upper end of outer tube (32) is equipped with a plurality of feed liquor holes (321) that are radial setting, sleeve (31) cover is established in the outside of outer tube (32), be equipped with centrifugal filter mechanism (34) between sleeve (31) and outer tube (32), the top of sleeve (31) is equipped with oil and gas separation subassembly (4) that are used for exhaust gas.

2. The centrifugal separation-based sand-control oil-gas separator according to claim 1, wherein the diameter of the liquid inlet hole (321) is smaller than the diameter of the gravel.

3. The sand-prevention oil-gas separator based on centrifugal separation according to claim 1, wherein a vertical central tube (33) is arranged in the outer tube (32), the top of the central tube (33) is arranged in the outer tube (32) through a sealing block (331), the height of the sealing block (331) is higher than that of the liquid inlet hole (321), and an opening is arranged at the bottom of the central tube (33).

4. The sand control oil and gas separator based on centrifugal separation according to claim 1, characterized in that the centrifugal filter mechanism (34) is a spiral sheet (341), the spiral sheet (341) being mounted between the sleeve (31) and the outer tube (32).

5. The centrifugal separation-based sand control oil and gas separator according to claim 4, wherein the top of the spiral sheet (341) is lower than the bottom of the liquid inlet hole (321).

6. A sand control oil and gas separator based on centrifugal separation according to claim 1, characterized in that the bottom of the sleeve (31) is provided with a setback end, on which is provided a first filter plate (311) for filtering sand in oil.

7. The sand-preventing oil-gas separator based on centrifugal separation according to claim 6, wherein a second filter plate (312) in a circular ring shape is further arranged in the sleeve (31), and the second filter plate (312) is horizontally arranged in the sleeve (31) and is positioned between the spiral sheet (341) and the liquid inlet.

8. The sand control oil and gas separator based on centrifugal separation according to claim 1, characterized in that the oil and gas separation assembly (4) comprises a mist catcher (41); the mist catcher (41) is in a circular ring shape and is arranged between the outer tube (32) and the sleeve (31), and the mist catcher (41) is positioned above the liquid inlet hole (321); the mist catcher (41) is provided with a self-sealing mechanism (42) capable of automatically sealing the mist catcher (41) during oil pumping, and the self-sealing mechanism (42) is arranged at the top of the mist catcher (41) and is in transmission connection with the spherical valve (11).

9. The centrifugal separation based sand control oil and gas separator of claim 8 wherein the self-sealing mechanism (42) comprises a connecting disc (421), a connecting block (422) and a sealing assembly (423);

the connecting disc (421) is disc-shaped and horizontally arranged above the mist catcher (41), the bottom of the connecting disc (421) is communicated with the mist catcher (41), and a plurality of exhaust holes (4211) are annularly arranged at the top of the connecting disc (421);

the connecting block (422) is horizontally arranged in the oil pump (1) and is connected with the top of the spherical valve (11);

the number of the sealing assemblies (423) is the same as that of the exhaust holes (4211) and corresponds to that of the exhaust holes one by one, the top of the sealing assemblies (423) is connected with the connecting block (422), and the bottom of the sealing assemblies (423) is abutted with the bottom of the exhaust holes (4211) in the working state.

10. The centrifugal separation based sand control oil and gas separator of claim 9 wherein the seal assembly (423) comprises a seal ball (4231), a connecting rod (4232) and a stop collar (4233);

the sealing ball (4231) is arranged in the connecting disc (421) and is positioned below the exhaust hole (4211), and the sealing ball (4231) is connected with the connecting block (422) through the connecting rod (4232);

the limiting ring (4233) is sleeved on the connecting rod (4232) and is positioned on one side of the oil pump (1) close to the connecting disc (421).