A continuous sand filtering device

Abstract

The present invention relates to a continuous sand filtering device, comprising a water inlet section and a water outlet section, wherein a collecting mechanism is provided radially outwardly extending between the water inlet section and the water outlet section, wherein the collecting mechanism comprises a first collecting body and a second collecting body, wherein the first collecting body is connected with the water inlet section through a mud and sand buffer section, the mud and sand buffer section above the first collecting body is provided with an anti-backflow structure, and the second collecting body is connected with the first collecting body through a blocking valve; a filter screen is also installed in the water inlet section, wherein the filter screen is tiltedly arranged above the mud and sand buffer section, and a first spiral flow channel is provided on the inner wall of the water inlet section to form turbulence, so that the mud and sand attached to the filter screen are washed down under the impact of the turbulence; the present invention arranges a spiral flow channel on one side of the air inlet of the filter screen to form turbulence, impacts the mud and sand attached to the filter screen, and causes it to gradually fall into the sand storage tank under the action of gravity, thereby avoiding shutdown for replacing the filter screen, and the two-stage collecting tank can avoid shutdown for cleaning the deposited mud and sand, and the device has a simple structure and is easy to maintain.

Description

Technical Field

[0001] The invention belongs to the technical field of natural gas field development, and in particular relates to a continuous sand filtering device. Background Art

[0002] The Sulige Gas Field is a "three-low" gas field. With the continued expansion of development, low-pressure, low-yield, and water-producing wells are increasing, making drainage and gas recovery increasingly critical. Natural gas-assisted drainage technology reduces wellhead pressure (to less than the pipeline transmission pressure). This technology accelerates production and recovery, offering advantages such as high efficiency and low cost. It is an ideal drainage and recovery process for low-pressure, low-yield, water-producing gas wells.

[0003] During the natural gas assisted drainage process, the gas-liquid mixture returns from the well and enters the compressor after preliminary filtration and separation. The gas-liquid mixture entering the compressor is mainly gas, but there will still be downhole liquid entering the compressor. At this time, the mixed mud and sand will damage the compressor, affect the normal operation of natural gas assisted drainage, reduce work efficiency, and even cause damage to the compressor and lead to shutdown. Summary of the Invention

[0004] The present invention solves the technical problem by adopting the following technical solutions:

[0005] A continuous sand filtering device comprises a water inlet section and a water outlet section, wherein a collecting mechanism is provided radially outwardly extending between the water inlet section and the water outlet section, the collecting mechanism comprising a first collecting body and a second collecting body, the first collecting body being connected to the water inlet section via a mud and sand buffer section, a backflow prevention structure being installed in the mud and sand buffer section above the first collecting body, and the second collecting body being connected to the first collecting body via a blocking valve;

[0006] A filter screen is also installed in the water inlet section, and the filter screen is tilted and arranged above the mud and sand buffer section. A first spiral flow channel is opened on the inner wall of the water inlet section to form turbulence, so that under the impact of the turbulent flow, the mud and sand attached to the filter screen are washed down.

[0007] Furthermore, a second spiral flow channel and / or a baffle is provided on the water outlet section behind the filter screen, so that the water flow passing through the filter screen undergoes reverse impact, thereby preventing mud and sand from adhering to the filter screen.

[0008] Furthermore, a first baffle is provided on the water outlet section behind the filter screen, and a third spiral flow channel is provided on the inner wall of the inlet and outlet of the first baffle, so that the water flow passing through the filter screen undergoes reverse impact to prevent mud and sand from adhering to the filter screen.

[0009] Furthermore, the first collecting body and the second collecting body are detachably connected.

[0010] Furthermore, it also includes a mounting base, which is mounted on one side of the first collecting body.

[0011] Furthermore, a locking mechanism is installed on the mounting base, and the locking mechanism locks the first collecting body and the second collecting body. The locking mechanism has a triangular connecting rod, and the second collecting body and the first collecting body can be locked or loosened through the triangular connecting rod.

[0012] Furthermore, the locking mechanism includes a triangular connecting rod, a straight connecting rod, an L-shaped connecting rod and a tension spring. One end of the L-shaped connecting rod is hinged to the mounting base, and the other end is used to press the annular boss on the second collecting body to lock the second collecting body with the first collecting body; one end of the straight connecting rod is hinged to the mounting base, and the other end is hinged to the triangular connecting rod, and the triangular connecting rod is hinged at a right angle to the L-shaped connecting rod; when locked, the hinge points of the triangular connecting rod and the L-shaped connecting rod and the straight connecting rod are on the same straight line, and the self-locking of the mechanism can be achieved at this time. One end of the tension spring is connected to the mounting base, and the other end is connected to the triangular connecting rod to balance the deadweight of the triangular connecting rod and prevent the triangular connecting rod from falling by itself, causing the locking mechanism to be unlocked.

[0013] Furthermore, the first collecting body and the second collecting body are both tank structures with expanded inner diameters.

[0014] Furthermore, a sand discharge valve is installed at the bottom of the second collecting body.

[0015] The advantages and positive effects of the present invention are:

[0016] In order to prevent the filtered mud and sand from causing pipeline blockage, the present invention provides a spiral flow channel on one side of the filter inlet to form turbulence, which impacts the mud and sand attached to the filter, causing it to gradually fall into the sand storage tank under the action of gravity, thus avoiding shutdown for filter replacement; a baffle or a spiral flow channel is provided on one side of the filter outlet, so that the gas-liquid mixture passing through the filter is blocked by the baffle to generate a reverse impact water flow, thereby strengthening the oscillation of the filter and ensuring continuous operation of the compressor; and the two-stage collection tank can avoid shutdown for cleaning the deposited mud and sand, and the device has a simple structure and is easy to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that these drawings are designed for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, unless otherwise specified, these drawings are intended only to conceptually illustrate the structures described herein and are not necessarily drawn to scale.

[0018] Figure 1 A schematic cross-sectional view of a continuous sand filtering device provided by an embodiment of the present invention;

[0019] Figure 2 A structural cross-sectional view of a first collecting body and a second collecting body of a continuous sand filtering device provided in an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of the three-dimensional structure of a continuous sand filtering device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] First of all, it should be noted that the specific structure, characteristics and advantages of the present invention will be specifically described below in an exemplary manner. However, all descriptions are only used for illustration and should not be understood as limiting the present invention. In addition, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature displayed or implied in the drawings, can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned herein. In addition, in order to simplify the drawings, the same or similar technical features may be marked in only one place in the same drawing.

[0022] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0023] Example 1

[0024] like Figures 1 to 3 The present embodiment provides a continuous sand filtering device, comprising an inlet section 1 and an outlet section 3. A collecting mechanism is provided radially outwardly extending between the inlet section and the outlet section. The collecting mechanism comprises a first collecting body 6 and a second collecting body 8. The first collecting body is connected to the inlet section through a mud and sand buffer section 4. A backflow prevention structure 5 is installed in the mud and sand buffer section above the first collecting body. The second collecting body is connected to the first collecting body through a blocking valve 7.

[0025] The anti-backflow structure includes a straight channel and a curved channel. Along the direction of the falling sand, the curved channel first reverses and then falls. When reverse flow occurs, the reflux liquid flows along the straight channel and the curved channel respectively, but the flow direction of the fluid in the curved channel at the reverse outlet is the same as the falling direction of the sand, which will hinder the reverse flow of the liquid in the straight channel, that is, the flow direction of the curved channel is still the falling direction during reflux, and at the same time, the straight channel is blocked from reversing. In order to better achieve the obstruction of liquid reverse flow, it can be considered to install multiple anti-backflow structures in series.

[0026] A filter screen 2 is also installed in the water inlet section. The filter screen is tilted above the mud and sand buffer section. The tilt direction of the filter screen is from the water inlet section to the water outlet section from top to bottom. Figure 1 As shown, gravity assists the attached mud and sand to fall, and a first spiral flow channel is opened on the inner wall of the water inlet section to form turbulence, so that the mud and sand attached to the filter screen are washed down under the impact of the turbulence.

[0027] A second spiral flow channel and / or a baffle is provided on the water outlet section behind the filter screen to cause the water flow passing through the filter screen to have a reverse impact, thereby preventing mud and sand from adhering to the filter screen.

[0028] A sand discharge valve 9 is installed at the bottom of the second collecting body.

[0029] The first collecting body and the second collecting body are detachably connected; Figure 1 As shown, the first collecting body and the second collecting body are both tank structures with expanded inner diameters.

[0030] Specifically, it also includes a mounting base, which is mounted on one side of the first collecting body. A locking mechanism is installed on the mounting base, and the locking mechanism locks the first collecting body and the second collecting body. There is a triangular connecting rod on the locking mechanism, and the second collecting body can be locked or loosened with the first collecting body through the triangular connecting rod.

[0031] It should be noted that the base 11 is symmetrically arranged, and the locking mechanism 13 includes a triangular link B, a straight link C, an L-shaped link D and a tension spring 12. One end of the L-shaped link is hinged to the base 11, and the other end is used to press the annular boss on the second collecting body 8 to lock the second collecting body 8 with the first collecting body 6; one end of the straight link is hinged to the base 11, and the other end is hinged to the triangular link. The triangular link is hinged at a right angle to the L-shaped link, that is, there are two hinge points on the triangular link, which are hinged to the straight link and the L-shaped link respectively; when locking the second collecting body 8, pull the triangular link upward to drive the straight link and the L-shaped link to swing, and finally the L-shaped link presses the annular boss on the second collecting body 8. When locked, the hinge points of the triangular link and the L-shaped link and the straight link are on the same straight line. At this time, the self-locking of the mechanism can be achieved, that is, under the action of the deadweight of the second collecting body 8, the various links of the locking mechanism 13 cannot move. Figure 2 The locking mechanism 13 is shown on the left side of the middle. One end of the tension spring 12 is connected to the base 11, and the other end is connected to the triangular connecting rod. Its function is to balance the weight of the triangular connecting rod and prevent the triangular connecting rod from falling and causing the locking mechanism 13 to unlock. That is, the elastic force of the tension spring is balanced with the triangular connecting rod or keeps the triangular connecting rod in an upward swinging state to ensure the reliability of the locking.

[0032] Specifically, when it is necessary to lock the first collecting body 6 and the second collecting body 8, the locking mechanism 13 pushes the second collecting body upward to lock the second collecting body 8 with the first collecting body 6; wherein, the tension spring pulls the triangular connecting rod downward to separate the second collecting body 8 from the first collecting body 6; the function of the second collecting body 8 is a secondary cache to keep the sand removal device working continuously. After the second collecting body 8 is full of sand, it is removed for cleaning or the blocking valve 7 is closed for cleaning. The collected mud and sand are temporarily stored in the first collecting body 6 to keep the system in a closed state.

[0033] In this embodiment, the filter screen 2 is provided to ensure that the gas passes normally and the sediment is screened out, thereby ensuring the normal operation of the compressor and thus ensuring the work of water drainage and gas production; the sediment buffer section can assist in sedimentation of sediment and prevent turbulence from washing up the sediment, causing the sediment to adhere to the filter screen; the Tesla valve exists because the space below is closed and the liquid does not flow, and the sand and gravel gradually fall under the action of gravity. This valve is used to prevent the sediment from returning under the influence of turbulence; when the blocking valve 7 is closed, the sand discharge valve 9 is opened to discharge the sand, and when working, the blocking valve 7 is opened and the sand discharge valve 9 is closed;

[0034] In addition, it can also be considered that an interface can be provided on the second collecting body 8 for flushing the second collecting body 8; a second spiral flow channel and / or a baffle is provided on the water outlet section 3, and the second spiral flow channel is used for reverse flushing to flush the filter screen during maintenance; in this embodiment, a circle of baffles A is provided along the inner wall of the pipe on the water outlet section 3. The baffle A is a circular plate with a hole in the middle for water to flow through. The plate blocks water, causing the water flow passing through the filter screen to have a reverse impact, further causing the filter screen to vibrate to avoid mud and sand adhesion. The liquid must flow through the middle of the pipe, which is similar to the water flow state of the Tesla valve, but will not have a significant impact on the liquid circulation in the middle of the pipe.

[0035] Example 2

[0036] As a further improvement to the present invention, it can be considered that: a first baffle is set on the water outlet section behind the filter, and a third spiral flow channel is set on the inner wall of the inlet and outlet of the first baffle. The first baffle can play a reverse flushing role during normal filtration, and the third spiral flow channel can play a reverse flushing role when maintaining the device.

[0037] The other structures of this embodiment are the same as those in Embodiment 1 and will not be described again here.

[0038] The above embodiments describe the present invention in detail, but the contents described are only preferred embodiments of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A continuous sand filtering device, characterized in that: It includes a water inlet section and a water outlet section, a collection mechanism is provided radially extending outward between the water inlet section and the water outlet section, the collection mechanism includes a first collection body and a second collection body, the first collection body is connected to the water inlet section through a mud and sand buffer section, an anti-backflow structure is installed in the mud and sand buffer section above the first collection body, and the second collection body is connected to the first collection body through a blocking valve; A filter screen is also installed in the water inlet section. The filter screen is tilted and arranged above the mud and sand buffer section. A first spiral flow channel is opened on the inner wall of the water inlet section to form turbulent flow, so that under the impact of the turbulent flow, the mud and sand attached to the filter screen are washed away. A second spiral flow channel and / or a baffle is provided on the water outlet section behind the filter, so that the water flow passing through the filter screen is subjected to reverse impact, thereby preventing mud and sand from adhering to the filter screen; or a first baffle is provided on the water outlet section behind the filter screen, and a third spiral flow channel is provided on the inner wall of the inlet and outlet of the first baffle, so that the water flow passing through the filter screen is subjected to reverse impact, thereby preventing mud and sand from adhering to the filter screen; It also includes a mounting base, wherein the mounting base is mounted on one side of the first collecting body; A locking mechanism is installed on the mounting base, and the locking mechanism locks the first collecting body and the second collecting body. The locking mechanism has a triangular connecting rod, and the second collecting body and the first collecting body can be locked or released by the triangular connecting rod. The locking mechanism includes a triangular connecting rod, a straight connecting rod, an L-shaped connecting rod and a tension spring. One end of the L-shaped connecting rod is hinged to the mounting base, and the other end is used to press the annular boss on the second collecting body to lock the second collecting body with the first collecting body; one end of the straight connecting rod is hinged to the mounting base, and the other end is hinged to the triangular connecting rod, and the triangular connecting rod is hinged at a right angle to the L-shaped connecting rod; when locked, the hinge point of the triangular connecting rod and the L-shaped connecting rod and the straight connecting rod are on the same straight line, and the self-locking of the mechanism can be achieved at this time. One end of the tension spring is connected to the mounting base, and the other end is connected to the triangular connecting rod to balance the dead weight of the triangular connecting rod and prevent the triangular connecting rod from falling by itself, causing the locking mechanism to be unlocked.

2. A continuous sand filtering device according to claim 1, characterized in that: The first collecting body and the second collecting body are detachably connected.

3. A continuous sand filtering device according to claim 1, characterized in that: The first collecting body and the second collecting body are both tank structures with expanded inner diameters.

4. A continuous sand filtering device according to claim 1, characterized in that: A sand discharge valve is installed at the bottom of the second collecting body.

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