Wellhead closed desanding device

Abstract

The invention provides a wellhead closed desanding device which comprises a tank body constructed to be of a closed structure, at least one sand discharging opening formed in the bottom of the tank body, a separation piece arranged in the tank body and a connector arranged on the separation piece and used for receiving sand-containing fluid from a wellhead. The separation part comprises a first outlet and a second outlet, a first part of the sand-containing fluid sequentially passes through the first outlet and the sand discharge port to flow to the outside, a second part of the sand-containing fluid flows out of the second outlet, and the sand discharge port is communicated with the first outlet. And the sand flows to the sand discharge port through the baffle plate. The method can better meet the requirements of continuous production, safety and environmental protection of an oil field.

Description

Technical Field

[0001] The invention relates to the field of oil and gas gathering, transportation and processing, and in particular to a wellhead closed sand removal device. Background Art

[0002] Generally, sand production in oil wells will cause pipe blockage, increased pipeline friction, pump wear, and damage to metering instruments, which will seriously affect the normal production and gathering and transportation of crude oil.

[0003] The basic principles of crude oil desanding equipment and processes in the prior art are mainly divided into three categories, namely, filtration separation, sedimentation separation and centrifugal separation.

[0004] Filtration separation mainly separates sand of different particle sizes by controlling the mesh size of the filter. Therefore, the filter medium needs to be regularly and repeatedly flushed to fully discharge the filter material. Therefore, it is obviously not suitable for continuous production operations, and the sand-containing produced fluid will cause serious wear on the filter device when using this process, so it is rarely used in oil fields.

[0005] Sedimentation separation, i.e. large tank sedimentation and sand removal, mainly achieves the effect of sedimentation separation through density difference. When crude oil enters the sand settling tank, it takes a long enough time for the oil, water and sand to separate. Therefore, it is obviously not suitable for continuous production operations, and most of these sand settling tanks are open tanks, and the gas generated is very easy to escape, thereby polluting the environment. In addition, after the sedimentation is completed, it is necessary to manually enter the tank or use an excavator to clean up the mud and sand, which seriously reduces work efficiency and slows down the construction progress.

[0006] Centrifugal separation is divided into two categories: centrifuge and hydrocyclone. High-speed centrifuge is a dynamic device, which will cause high energy consumption during the production process, thereby increasing the burden of production costs.

[0007] At present, due to the low precision required for oilfield sand removal, conventional cyclone desanders can meet the operational requirements. However, the following problems still exist in the application of oilfields in the prior art. First, the desander device in the prior art needs to stop production and release pressure to remove sand, which will lead to waste of production capacity of the cyclone desander. Second, the prior art removes sand manually, so there is a problem of high maintenance cost, and there is also the problem of gas leakage and environmental pollution.

[0008] Therefore, it is desired in the art to provide a wellhead closed sand removal device to solve the above technical problems. Summary of the invention

[0009] The purpose of the present invention is to propose a wellhead closed sand removal device, which can separate the sand-containing fluid at the wellhead into three phases of gas, liquid and solid, and at the same time has the functions of continuous sand removal, automatic intermittent sand discharge, backwashing and environmental protection, so as to better adapt to the needs of continuous production and safety and environmental protection in oil fields.

[0010] According to the present invention, a wellhead closed sand removal device is provided, comprising a tank body constructed in a closed structure, at least one sand discharge port is provided at the bottom of the tank body,

[0011] A separation member is arranged in the tank body, and an interface for receiving sand-containing fluid from a wellhead is arranged on the separation member, and

[0012] An inclined baffle is arranged in the tank body,

[0013] Wherein, the separation element comprises a first outlet and a second outlet,

[0014] The first part of the sand-containing fluid flows to the outside through the first outlet and the sand discharge port in sequence, and the second part of the sand-containing fluid flows out from the second outlet and flows to the sand discharge port through the baffle.

[0015] In one embodiment, the wellhead closed sand removal device also includes a backwashing mechanism, which includes a sand flushing plate arranged in the tank body and below the separator, a sand flushing pipeline constructed in a Japanese-shaped structure, and a pump body arranged on the sand flushing pipeline, wherein a first end of the sand flushing pipeline is connected to the tank body to receive the liquid in the tank body, and a second end extends into the tank body and is connected to the sand flushing plate.

[0016] In one embodiment, the first part of the sand-containing fluid is sand, and a plurality of sand flushing holes are provided on the top end surface and the bottom end surface of the sand flushing plate, and the plurality of sand flushing holes are equidistantly distributed in the transverse and longitudinal directions.

[0017] In one embodiment, a switch valve is provided on the sand discharge port.

[0018] The wellhead closed sand removal device comprises a controller arranged on the sand flushing plate for monitoring the height of the sand surface, and the controller is configured to control the opening and closing of the sand discharge port through the switch valve.

[0019] In one embodiment, the wellhead closed sand removal device also includes a first discharge member and a second discharge member arranged on the tank body, wherein the fluid in the second part of the sand-containing fluid is separated into gas and liquid under the action of gravity, and the separated gas is discharged through the first discharge member, and the separated liquid is discharged through the second discharge member.

[0020] In one embodiment, a blocking structure is provided on the baffle plate, and the baffle plate is configured to extend the time for the sand in the second part of the sand-containing fluid to reach the sand discharge port through the blocking structure.

[0021] In one embodiment, the blocking structure comprises a plurality of steps arranged at intervals on the baffle, and the inclination of the steps is smaller than the inclination of the baffle.

[0022] In one embodiment, the wellhead closed sand removal device further comprises a guide pipe member configured in a U-shaped structure and arranged at the top end of the separator, and the second outlet is arranged at the free end of the guide pipe member and faces the baffle.

[0023] In one embodiment, the separation element is a hydrocyclone desander, and the interface is radially arranged on the hydrocyclone desander.

[0024] In one embodiment, the wellhead closed sand removal device further includes a safety valve arranged on the tank body, and a liquid level meter arranged on the tank body and used for monitoring the liquid level.

[0025] Compared with the prior art, the advantages of the present invention are:

[0026] The present invention can separate the three phases of gas, liquid and solid for the sand-containing fluid at the wellhead, and has the functions of continuous sand removal, automatic intermittent sand discharge, backwashing and environmental protection, so as to better meet the needs of continuous production and safety and environmental protection in oil fields. The following is a detailed introduction.

[0027] First, the controller in the present invention can monitor the sand surface height in real time and can judge the sand surface height in real time, so as to control the opening and closing of the sand discharge port through the switch valve to realize the functions of continuous sand removal and automatic intermittent sand discharge, thereby improving the working efficiency of the entire device and reducing maintenance costs.

[0028] Secondly, the present invention can perform selective backwashing on the bottom of the tank body and the sand discharge port through the sand blasting holes arranged on the top end surface and the bottom end surface of the sand blasting plate, so that the sand in the tank body can be smoothly discharged to the outside through the sand discharge port, thereby effectively eliminating the influence of the sand removal effect caused by the blockage of the sand discharge port.

[0029] Third, the present invention is a sealed structure as a whole, so that the gas and liquid can be uniformly recovered and cleaned, so as to improve the environmental friendliness of the wellhead closed sand removal device, thereby improving the ability to protect the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The present invention will be described in detail below with reference to the accompanying drawings, in which:

[0031] Figure 1 The structure of the closed wellhead sand removal device according to the present invention is schematically shown.

[0032] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale.

[0033] The meanings of the reference numerals in the accompanying drawings are as follows:

[0034] 1 tank body, 11 sand discharge ports,

[0035] 2 separation piece, 21 interface, 22 guide pipe, 201 first outlet, 202 second outlet,

[0036] 31 sand flushing plate, 311 controller, 32 sand flushing pipeline, 33 pump body,

[0037] 4 baffles,

[0038] 5. The first discharge element,

[0039] 6 The second discharge piece,

[0040] 71 safety valve, 72 liquid level gauge. DETAILED DESCRIPTION

[0041] In order to make the technical solutions and advantages of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0042] The present invention will be further described below in conjunction with the accompanying drawings.

[0043] Figure 1 The structure of a closed wellhead sand removal device 100 according to the present invention is schematically shown.

[0044] like Figure 1 As shown, the wellhead closed sand removal device 100 according to the present invention includes a tank body 1. The tank body 1 is constructed as a closed structure, so that the gas produced during the separation process can be uniformly recovered and cleaned through the first discharge member 5 (described below), thereby effectively eliminating the problem of environmental pollution caused by gas escape. Preferably, the generated gas generally enters the oil field gas gathering system through the first discharge member 5 or is burned for self-use.

[0045] According to the present invention, Figure 1As shown, the wellhead closed sand removal device 100 also includes a separator 2. Preferably, the separator 2 is a hydrocyclone desander. The separator 2 is arranged in the tank 1 and can fully separate the sand-containing fluid from the wellhead to ensure that the gas, liquid and solid phases in the sand-containing fluid can be discharged smoothly.

[0046] It is easy to understand that in a hydrocyclone desander, due to the density difference between solids and liquids, the two will generate different inertial centrifugal forces. Usually, solid particles (sand) with higher density are thrown toward the inner wall of the hydrocyclone desander, and move downward in a spiral along the inner wall, and are discharged from the first outlet 201 (described below); liquid with lower density is close to the center of the hydrocyclone desander, so the liquid will rotate at high speed to form a low-pressure spiral upward flow, so that most of the liquid and a small amount of solid particles rise with it and are discharged from the second outlet 202 (described below) of the hydrocyclone desander. This is well known in the art, so it will not be repeated.

[0047] In one embodiment, Figure 1 As shown, an interface 21 is provided on the separator 2. The interface 21 can extend through the tank body 1 and be connected to an external wellhead, so that the sand-containing fluid from the wellhead can be more easily received for subsequent sand removal work.

[0048] In a specific embodiment, the interface 21 is radially arranged on the separator 2, so that the sand-containing fluid at the wellhead can be smoothly guided into the tank body 1 at a faster speed for subsequent sand removal.

[0049] In a specific embodiment, Figure 1 As shown, the separator 2 comprises a first outlet 201 and a second outlet 202. The first outlet 201 is arranged at the bottom of the hydrocyclone desander so as to discharge the first part of the sand-containing fluid, and the second outlet 202 is arranged at the top of the hydrocyclone desander so as to discharge the second part of the sand-containing fluid.

[0050] Preferably, the first part of the sand-containing fluid is sand and the second part of the sand-containing fluid comprises fluid and a small amount of sand.

[0051] In a specific embodiment, Figure 1 As shown, at least one sand discharge port 11 is provided at the bottom of the tank body 1 , so as to ensure that the sand in the tank body 1 can be discharged smoothly through the sand discharge port 11 .

[0052] According to one embodiment of the present invention, the first part of the sand-containing fluid can flow directly to the outside through the first outlet 201 and the sand discharge port 11 in sequence, while the second part of the sand-containing fluid can flow out from the second outlet 202 and can flow to the sand discharge port 11 with a time delay through the baffle 4 (described below). The content is described below.

[0053] It is easy to understand that the sand in the sand-containing fluid can be separated under the action of the separator 2, so that most of the sand can flow directly to the sand discharge port 11 through the first outlet 201, while a small part of the sand can fall on the baffle 4 after a delay through the second outlet 202, and this part of the sand can be delayed again to reach the sand discharge port 11 under the action of the baffle 4, so that the sand discharge port 11 can smoothly perform the sand discharge work, thereby improving the sand discharge efficiency.

[0054] In one embodiment, Figure 1 As shown, the wellhead closed sand removal device 100 also includes a first discharge member 5 arranged on the tank body 1. Preferably, the fluid in the second part of the sand-containing fluid is separated into gas and liquid under the action of gravity, and the separated gas is discharged into the oilfield gas gathering system through the first discharge member 5 for unified recovery or self-use combustion, thereby effectively eliminating the problem of environmental pollution caused by gas escape.

[0055] In one embodiment, Figure 1 As shown, the wellhead closed sand removal device 100 also includes a second discharge member 6 arranged on the tank body 1. Preferably, the fluid in the second part of the sand-containing fluid is separated into gas and liquid under the action of gravity, and the separated liquid enters the oilfield gathering and transportation system through the second discharge member 6 for unified recovery or is discharged into a tank truck for transportation and elimination.

[0056] According to the present invention, Figure 1 As shown, the wellhead closed sand removal device 100 also includes a backwashing mechanism. The backwashing mechanism includes a sand flushing plate 31. The sand flushing plate 31 is arranged in the tank body 1 and below the separator 2, so as to facilitate the subsequent real-time monitoring of the sand at the bottom of the tank body 1.

[0057] It is easy to understand that the sand flowing out through the first outlet 201 of the separator 2 will directly flow into the bottom of the tank body 1, and the sand flushing plate 31 will not have any impact on it during this process.

[0058] In one embodiment, Figure 1 As shown, the backwashing mechanism further includes a sand flushing pipeline 32. Preferably, the sand flushing pipeline 32 is configured in a Japanese-shaped structure. The first end of the sand flushing pipeline 32 is connected to the tank body 1, so as to receive liquid from the tank body 1; the second end of the sand flushing pipeline 32 can extend into the tank body 1, so as to be connected to the sand flushing plate 31 in the tank body 1.

[0059] Thus, the sand flushing pipeline 32 can backwash the sand in the tank body 1 through the sand flushing plate 31 with the liquid in the tank body 1 under the action of the pump body 33 (described below). Thus, the sand accumulated in the tank body 1 can be fully decomposed, thereby ensuring that the sand in the tank body 1 can be smoothly discharged to the outside through the sand discharge port 11.

[0060] In a specific embodiment, Figure 1 As shown, the backwashing mechanism further includes a pump body 33. The pump body 33 is arranged on the sand flushing pipeline 32, so that the liquid in the tank body 1 can be more easily backwashed through the sand flushing plate 31, thereby improving the working efficiency of the sand removal work.

[0061] In addition, the present invention recycles and reuses the liquid in the tank body 1 through a backwashing mechanism, so that the sand accumulated in the tank body 1 can be fully decomposed through the recovered liquid, thereby making the wellhead closed sand removal device 100 environmentally friendly.

[0062] Compared with the prior art, the present invention adopts a fully mechanized operation, thereby improving the working efficiency of the entire device and reducing the maintenance cost. In addition, under the action of the backwashing mechanism of the present invention, it can ensure that the sand in the tank body 1 is smoothly discharged to the outside through the sand discharge port 11, thereby effectively improving the utilization rate of the separation element 2 (hydraulic cyclone desander), further improving the desanding effect and improving the working efficiency.

[0063] In one embodiment, a plurality of sand blasting holes (not shown) are provided on the top and bottom surfaces of the sand blasting plate 31. In this way, the liquid ejected from the sand blasting holes on the sand blasting plate 31 can fully flush the bottom of the tank body 1 and the sand discharge port 11, thereby fully breaking up the sand at the bottom of the tank body 1 and the sand discharge port 11, so that the sand in the tank body 1 can be smoothly discharged to the outside through the sand discharge port 11.

[0064] In addition, since sand flushing holes are provided on the top and bottom surfaces of the sand flushing plate 31, the liquid sprayed through the sand flushing holes can quickly and comprehensively flush the bottom of the tank body 1 and the sand discharge port 11, thereby effectively avoiding blockage of the sand discharge port 11 and further improving the working efficiency of the wellhead closed sand removal device 100.

[0065] In a specific embodiment, the plurality of sand flushing holes are equally spaced in the horizontal and vertical directions. In this way, the spray range of the liquid is effectively increased, so that the liquid sprayed through the sand flushing holes can be sprayed at multiple angles, and the sand at the bottom of the tank body 1 and the sand discharge port 11 can be quickly crushed, so that the sand in the tank body 1 can be smoothly discharged to the outside through the sand discharge port 11.

[0066] In a preferred embodiment, the sand flushing holes on the top and bottom surfaces of the sand flushing plate 31 in the present invention can be selectively opened. In other words, the present invention can select to open only the sand flushing holes on the top surface of the sand flushing plate 31, only open the sand flushing holes on the bottom surface of the sand flushing plate 31, or open both the sand flushing holes on the top and bottom surfaces of the sand flushing plate 31. Thus, the wellhead closed sand removal device 100 can perform more accurate flushing of the sand inside the tank body 1.

[0067] In one embodiment, Figure 1 As shown, the wellhead closed sand removal device also includes a controller 311. The controller 311 is arranged on the sand flushing plate 31, and the controller 311 can monitor the height of the sand surface in real time. Preferably, the controller 311 is a high-frequency radar level meter. It can determine the height of the sand surface according to the different wavelength frequencies reflected by different materials, which is well known to those skilled in the art.

[0068] In one embodiment, a switch valve (not shown) is provided on the sand discharge port 11, and the controller 311 is connected to the switch valve. Preferably, the controller 311 can determine the height of the sand surface, and can control the opening and closing of the sand discharge port 11 through the switch valve, so that the wellhead closed sand removal device 100 can achieve the functions of continuous sand removal and automatic intermittent sand removal.

[0069] According to the present invention, Figure 1 As shown, the wellhead closed sand removal device 100 further includes a baffle 4 disposed in the tank body 1. The baffle 4 is arranged obliquely in the tank body 1, so as to smoothly receive the second part of the sand-containing fluid from the second outlet 202, and to delay the sand in the second part of the sand-containing fluid to reach the sand discharge port 11.

[0070] It is easy to understand that both the baffle plate 4 and the blocking structure have smooth surfaces, thereby allowing the sand to slide on the baffle plate 4 .

[0071] In a specific embodiment, a blocking structure is provided on the baffle 4, and the baffle 4 is configured to extend the time for the sand in the second part of the sand-containing fluid to reach the sand discharge port 11 through the blocking structure. In this way, a time difference is generated between the sand in the second part of the sand-containing fluid and the first part of the sand-containing fluid reaching the sand discharge port 11, thereby ensuring that the sand in the tank body 1 can be smoothly discharged to the outside through the sand discharge port 11, further improving the sand discharge efficiency of the wellhead closed sand removal device 100.

[0072] In one embodiment, the blocking structure includes a plurality of steps (not shown) arranged at intervals on the baffle 4, and the inclination of the steps is smaller than the inclination of the baffle 4. In this way, when the sand in the second part of the sand-containing fluid falls onto the baffle 4 under the action of gravity, it can gradually move to the sand discharge port 11 on the inclined steps, thereby generating a time difference with the first part of the sand-containing fluid reaching the sand discharge port 11.

[0073] In another embodiment, the blocking structure includes a plurality of protrusions (not shown) arranged at intervals on the baffle 4, and the protrusions are configured as a smooth cambered structure, thereby effectively reducing the movement speed of the sand in the second part of the sand-containing fluid on the baffle 4.

[0074] In one embodiment, the wellhead closed sand removal device 100 further includes a guide pipe 22. The guide pipe 22 is disposed at the top end of the separation element 2, so as to effectively guide the second part of the sand-containing fluid.

[0075] Preferably, the guide pipe 22 is configured as a U-shaped structure. Therefore, the fixed end of the guide pipe 22 is fixedly connected to the separator 2, so as to receive the second part of the sand-containing fluid from the separator 2. The free end of the guide pipe 22 faces the baffle 4, so as to ensure that the sand in the second part of the sand-containing fluid can move smoothly to the baffle 4.

[0076] In a specific embodiment, the second outlet 202 is disposed at a free end of the guide tube 22 .

[0077] In one embodiment, the wellhead closed sand removal device 100 further includes a safety valve 71 disposed on the tank body 1. Preferably, the safety valve 71 is disposed on the top of the tank body 1, so as to ensure that the air pressure in the wellhead closed sand removal device 100 is stable.

[0078] In one embodiment, the wellhead closed sand removal device 100 further includes a liquid level gauge 72 disposed on the tank body 1. Preferably, the liquid level gauge 72 is disposed at the side end of the tank body 1, so that the liquid level in the tank body 1 can be observed through the liquid level gauge 72, and the overall situation in the tank body 1 can be understood in real time.

[0079] The present invention provides a wellhead closed sand removal device 100, which can perform three-phase separation of gas, liquid and solid for the sand-containing fluid at the wellhead, and at the same time has the functions of continuous sand removal, automatic intermittent sand discharge, backwashing, etc., so as to better adapt to the needs of continuous production and safety and environmental protection in oil fields, thereby improving the working efficiency of the entire device and reducing maintenance costs. In addition, the controller 311 in the present invention can monitor the sand surface height in real time, and can judge the sand surface height in real time, so as to control the opening and closing of the sand discharge port 11 through the switch valve to realize the functions of continuous sand removal and automatic intermittent sand discharge, thereby effectively eliminating the influence of the sand removal effect caused by the blockage of the sand discharge port. In addition, the present invention can selectively backwash the bottom of the tank body 1 and the sand discharge port 11 through the sand flushing holes set on the top and bottom surfaces of the sand flushing plate 31, so that the sand in the tank body 1 can be smoothly discharged to the outside through the sand discharge port 11. The present invention is a sealed structure as a whole, so that gas and liquid can be uniformly recovered and cleaned, so as to improve the environmental friendliness of the wellhead closed sand removal device 100, thereby improving the ability to protect the environment.

[0080] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0081] In the present invention, unless otherwise clearly stipulated and limited, terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements.

[0082] For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0083] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art can easily make changes or modifications within the disclosure scope of the present invention, and such changes or modifications should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A wellhead closed sand removal device, comprising: A tank body (1) configured as a closed structure, with at least one sand discharge port (11) provided at the bottom of the tank body (1), A separating member (2) disposed within the tank body (1), having an interface (21) on the separating member (2) for receiving sand-containing fluid from the wellhead, and An inclined baffle (4) disposed within the tank body (1), Wherein, the separating member (2) includes a first outlet (201) and a second outlet (202), A first portion of the sand-containing fluid flows to the outside successively through the first outlet (201) and the sand discharge port (11), and a second portion of the sand-containing fluid flows out from the second outlet (202) and flows to the sand discharge port (11) through the baffle (4).

2. The wellhead closed sand removal device according to claim 1, characterized in that: The wellhead closed sand removal device further includes an anti-flushing mechanism, which includes a sand flushing plate (31) disposed within the tank body (1) and below the separating member (2), a sand flushing pipeline (32) configured as a daily character structure, and a pump body (33) disposed on the sand flushing pipeline (32), wherein a first end of the sand flushing pipeline (32) communicates with the tank body (1) to receive the liquid within the tank body (1), and a second end extends into the tank body (1) and is connected to the sand flushing plate (31).

3. The wellhead closed sand removal device according to claim 2, characterized in that: The first portion of the sand-containing fluid is sand, and a plurality of sand flushing holes are provided on both the top surface and the bottom surface of the sand flushing plate (31), and the plurality of sand flushing holes are equidistantly distributed both horizontally and vertically.

4. The wellhead closed sand removal device according to claim 3, characterized in that: A switch valve is provided on the sand discharge port (11), The wellhead closed sand removal device includes a controller (311) disposed on the sand flushing plate (31) for monitoring the height of the sand surface, and the controller (311) is configured to control the opening and closing of the sand discharge port (11) through the switch valve.

5. The wellhead closed sand removal device according to claim 4, characterized in that: The wellhead closed sand removal device further includes a first discharge member (5) and a second discharge member (6) provided on the tank body (1), wherein, in the second portion of the sand-containing fluid, the fluid realizes gas-liquid separation under the action of gravity, and the separated gas is discharged through the first discharge member (5), and the separated liquid is discharged through the second discharge member (6).

6. The wellhead closed sand removal device according to claim 5, characterized in that: A blocking structure is provided on the baffle (4), and the baffle (4) is configured to be able to extend the time for the sand in the second portion of the sand-containing fluid to reach the sand discharge port (11) through the blocking structure.

7. The wellhead closed sand removal device according to claim 6, characterized in that: The blocking structure includes a plurality of spaced steps provided on the baffle (4), and the inclination of the steps is smaller than the inclination of the baffle (4).

8. The wellhead closed sand removal device according to claim 7, characterized in that: The wellhead closed sand removal device further includes a guiding pipe fitting (22) configured as a U-shaped structure provided at the top end of the separating member (2), and the second outlet (202) is provided at the free end of the guiding pipe fitting (22) and faces the baffle (4).

9. The wellhead closed sand removal device according to any one of claims 1 to 8, characterized in that: The separating member (2) is a hydrocyclone sand remover, and the interface (21) is radially provided on the hydrocyclone sand remover.

10. The closed wellhead sand removal device according to any one of claims 1 to 8, characterized in that: The wellhead closed sand removal device further comprises a safety valve (71) arranged on the tank body (1), and a liquid level meter (72) arranged on the tank body (1) and used for monitoring the liquid level.

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