Sand prevention gas lift device

Abstract

The invention belongs to the technical field of oil and gas well gas production engineering, and particularly relates to a sand prevention gas lift device. The sand prevention gas lift device comprises an eccentric cylinder; the gas lift valve is arranged on the outer side of the eccentric cylinder; the filter mechanism is arranged on the outer side of the eccentric cylinder and connected with the gas lift valve, and fluid outside the eccentric cylinder sequentially passes through the filter mechanism and the gas lift valve to enter the eccentric cylinder.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil and gas well production engineering, and particularly relates to a sand-proof gas lifting device. BACKGROUND

[0002] Petroleum and natural gas development is a systematic project covering geology, drilling, well completion, production increase, collection and transportation, etc. With the rapid economic development, the demand for energy is rising sharply, and oil and gas development has changed from conventional oil and gas resources to unconventional oil and gas such as tight oil and gas, shale oil and gas, and coalbed methane. Horizontal well staged fracturing technology has become the mainstream technology. Unconventional oil and gas resources are buried deep and have small porosity, and often need to be hydraulically fractured to establish oil and gas channels in the formation. In order to improve oil and gas recovery, the construction discharge of hydraulic fracturing, the amount of pumped liquid, and the number of support agents need to be increased to crush the formation as much as possible. As oil and gas well production enters the middle and late stages, the formation energy gradually decreases, and the liquid loading in the oil and gas well increases, resulting in a rapid decline in oil and gas production. The method to solve the above technical problems is to inject high-pressure gas such as compressed natural gas and nitrogen into the well. The compressed gas is injected through the annulus or the tubing, enters through the gas lifting valve on the tubing string, reduces the density of the liquid, and is lifted out of the ground under the circulation of the fluid, thereby reducing the resistance of the liquid loading to the natural gas in the formation and releasing the production capacity.

[0003] However, the inventors of the present application found that during the fracturing flowback and late production process, part of the proppant (ceramsite, quartz) squeezed into the formation will enter the wellbore along with oil and gas and pressure-returned liquid. The conventional gas lifting device is prone to blockage of the gas lifting valve during production, affecting the efficiency of oil and gas well drainage and gas recovery. SUMMARY

[0004] In view of the above technical problems, the present application aims to provide a sand-proof gas lifting device which can prevent the gas lifting valve from being blocked, thereby improving the efficiency of oil and gas well drainage and gas recovery.

[0005] According to the present application, a sand-proof gas lifting device is provided, comprising:

[0006] an eccentric cylinder;

[0007] a gas lifting valve arranged outside the eccentric cylinder; and

[0008] a filtering mechanism arranged outside the eccentric cylinder, the filtering mechanism being connected with the gas lifting valve, and the fluid outside the eccentric cylinder entering the inside of the eccentric cylinder through the filtering mechanism and the gas lifting valve in sequence.

[0009] In one specific embodiment, the filtering mechanism comprises a second eccentric cylinder arranged in parallel outside the eccentric cylinder body, the end of the second eccentric cylinder is communicated with the gas lift valve, a first screen pipe is arranged in the second eccentric cylinder, and at least one liquid inlet hole is arranged at the side of the second eccentric cylinder corresponding to the position of the first screen pipe.

[0010] In one specific embodiment, a sand scraping ring is arranged in sliding mode between the first screen pipe and the second eccentric cylinder, the sand scraping ring is configured to reciprocate along the first screen pipe in axial direction in response to pressure fluctuation of fluid, so as to remove sundries on the surface of the first screen pipe.

[0011] In one specific embodiment, the second eccentric cylinder comprises a first sand prevention working cylinder and a second sand prevention working cylinder arranged in coaxial mode, and the first sand prevention working cylinder and the second sand prevention working cylinder are connected through a connecting hole, the diameter of the connecting hole is smaller than the inner diameter of the first screen pipe.

[0012] In one specific embodiment, a second screen pipe is arranged in the second sand prevention working cylinder.

[0013] In one specific embodiment, a conversion joint is arranged at the end of the second sand prevention working cylinder away from the connecting hole, one end of the conversion joint extends into the second sand prevention working cylinder and is connected with the second screen pipe, and the other end of the conversion joint is connected with the gas lift valve.

[0014] In one specific embodiment, the gas lift valve comprises a first eccentric cylinder arranged in parallel outside the eccentric cylinder body, a bypass hole is arranged on the outer wall of the eccentric cylinder body corresponding to the first eccentric cylinder, and a piston capable of plugging the bypass hole is arranged in the first eccentric cylinder in movable mode, the piston is configured to allow fluid to flow only from the first eccentric cylinder to the eccentric cylinder body.

[0015] In one specific embodiment, an adjusting head is arranged at the end of the first eccentric cylinder in threaded connection mode, a spring is arranged between the adjusting head and the piston, and the spring force can be adjusted through the adjusting head.

[0016] In one specific embodiment, a connecting sleeve for connecting with the filtering mechanism is arranged at the end of the first eccentric cylinder away from the adjusting head, and a limiting ring is arranged between the connecting sleeve and the piston.

[0017] In one specific embodiment, the connecting sleeve is connected with the filtering mechanism through a transition ring and a liquid transmission pipe.

[0018] Compared with the prior art, the application has the following advantages.

[0019] The present invention includes an eccentric cylinder, a gas lift valve, and a filtration mechanism. During operation, the fluid outside the eccentric cylinder needs to be filtered by the filtration mechanism before entering the eccentric cylinder through the gas lift valve, thereby preventing the gas lift valve from being blocked and improving the efficiency of drainage and gas production in oil and gas wells.

[0020] The present invention provides a movable sand scraping ring between the first screen pipe and the first sand control working cylinder. When the fluid passes through the sand scraping ring, under the pressure fluctuation of the fluid, the sand scraping ring will form an irregular reciprocating motion along the axial direction of the first screen pipe, thereby scraping off the dirt on the surface of the first screen pipe, preventing the surface of the first screen pipe from being blocked by dirt, thereby improving the efficiency of drainage and gas production in oil and gas wells. Attached Figure Description

[0021] The present invention will now be described with reference to the accompanying drawings.

[0022] Figure 1 A schematic diagram of one embodiment of the sand-control airlift device according to the present invention is shown;

[0023] Figure 2 A schematic diagram of an embodiment of the sand control air lift device according to the present invention installed in a wellbore is shown;

[0024] Figure 3 Showing Figure 1 A magnified view of part A in the middle;

[0025] Figure 4 Showing Figure 1 A magnified view of part B in the middle section;

[0026] Figure 5 Showing Figure 1 A magnified view of part C in the middle;

[0027] Figure 6 A schematic diagram of the sand-control airlift device in the vertical section is shown;

[0028] Figure 7 A schematic diagram of the sand-control airlift device in the horizontal section is shown.

[0029] In the diagram: 1. Eccentric cylinder; 11. Bypass hole; 12. First cylinder; 13. Second cylinder; 14. Eccentric flow channel; 15. Machining hole;

[0030] 2. Air lift valve; 21. First eccentric cylinder; 22. Piston; 23. Adjusting head; 24. Spring; 25. Connecting sleeve; 26. Limit ring;

[0031] 3, filter mechanism; 31, second eccentric cylinder; 311, liquid inlet hole; 312, first sand prevention working cylinder; 313, second sand prevention working cylinder; 314, connecting hole; 32, first screen pipe; 33, sand scraping ring; 34, second screen pipe; 35, conversion joint; 36, blocking ring; 37, plug;

[0032] 4, transition ring;

[0033] 5, liquid transmission pipe;

[0034] 6, protection cylinder;

[0035] 7, pipe;

[0036] 8, oil pipe;

[0037] 10, wellbore;

[0038] 100, sand prevention gas lift device.

[0039] In this application, all the drawings are schematic drawings for illustrating the principles of the present application and are not drawn according to the actual proportions. DETAILED DESCRIPTION

[0040] The present application will be described below with reference to the drawings.

[0041] It should be noted that the directional phrases or limiting words "up", "down" and the like used in this application are all with respect to the drawings referred to Figure 1 They are not used to limit the absolute position of the parts involved, but can be changed according to the specific situation.

[0042] Figure 1 The structure of the sand prevention gas lift device 100 according to the present application is shown. As shown in the figure, the sand prevention gas lift device 100 includes an eccentric cylinder 1, a gas lift valve 2 and a filter mechanism 3. Figure 1

[0043] In this embodiment, the eccentric cylinder 1 is integrally configured in a substantially cylindrical shape. An eccentric flow passage 14 is provided through the inside of the eccentric cylinder 1, the center axis of the eccentric flow passage 14 is offset from the center axis of the eccentric cylinder 1, and the center axis of the eccentric flow passage 14 is parallel to the center axis of the eccentric cylinder 1. The upper end of the eccentric cylinder 1 is provided with an upper joint for threaded connection with an oil pipe.

[0044] ​Due to the eccentric structure of the eccentric cylinder 1, there is a space on the side of the eccentric cylinder 1 that can accommodate the gas lift valve 2 and the filtering mechanism 3. The gas lift valve 2 and the filtering mechanism 3 are both arranged on the outer side of the eccentric cylinder 1, the center axes of the gas lift valve 2 and the filtering mechanism 3 are parallel to the center axis of the eccentric cylinder 1, and the center axes of the gas lift valve 2 and the filtering mechanism 3 coincide. The filtering mechanism 3 connects the outer space of the eccentric cylinder 1 with the gas lift valve 2, and the gas lift valve 2 connects the filtering mechanism 3 with the inner space of the eccentric cylinder 1. In this arrangement, the fluid outside the eccentric cylinder 1 needs to pass through the filtering mechanism 3 and the gas lift valve 2 in sequence to enter the inside of the eccentric cylinder 1, and the filtering mechanism 3 can filter the fluid to prevent the sand and other impurities carried by the fluid from clogging the gas lift valve 2.

[0045] According to the present application, the eccentric cylinder 1 comprises a first cylinder 12 and a second cylinder 13 coaxially fixedly connected, and the gas lift valve 2 and the filtering mechanism 3 are arranged on the outer sides of the first cylinder 12 and the second cylinder 13, respectively.

[0046] In the present embodiment, as shown in Figure 1 , the first cylinder 12 is arranged above the second cylinder 13, the gas lift valve 2 is arranged on the outer side of the first cylinder 12, and the filtering mechanism 3 is arranged on the outer side of the second cylinder 13. By arranging the eccentric cylinder 1 into two parts of the first cylinder 12 and the second cylinder 13, the assembly between the parts can be facilitated, and the specific assembly process is described below.

[0047] In a specific embodiment, as shown in Figure 1 and Figure 4 , the filtering mechanism 3 comprises a second eccentric cylinder 31 arranged in parallel on the outer side of the second cylinder 13, the upper end of the second eccentric cylinder 31 is in communication with the gas lift valve 2, a first screen pipe 32 is arranged in the second eccentric cylinder 31, at least one liquid inlet hole 311 is arranged on the side of the second eccentric cylinder 31 corresponding to the position of the first screen pipe 32, and a plug 37 is sealingly fixed to the lower end of the second eccentric cylinder 31. In this arrangement, the liquid inlet hole 311 connects the inner cavity of the second eccentric cylinder 31 with the outer space of the eccentric cylinder 1, the first screen pipe 32 is arranged in the inner cavity of the second eccentric cylinder 31, and the upper end of the second eccentric cylinder 31 is in communication with the gas lift valve 2. Therefore, the fluid outside the eccentric cylinder 1 can enter the inner cavity of the second eccentric cylinder 31 through the liquid inlet hole 311, and after being filtered by the first screen pipe 32, the fluid enters the eccentric flow passage 14 of the eccentric cylinder 1 through the gas lift valve 2.

[0048] In a preferred embodiment, the outer diameter of the first screen pipe 32 is smaller than the inner diameter of the second eccentric cylinder 31, that is, there is an annular space between the first screen pipe 32 and the inner wall of the second eccentric cylinder 31. The sand scraping ring 33 is movably arranged on the outer wall of the first screen pipe 32, that is, the sand scraping ring 33 can reciprocate along the axial direction in the annular space between the first screen pipe 32 and the second eccentric cylinder 31. When the fluid passes through the filtering mechanism 3, the sand scraping ring 33 can reciprocate along the axial direction of the first screen pipe 32 in response to the pressure fluctuation of the fluid, so as to remove the impurities on the surface of the first screen pipe 32, prevent the first screen pipe 32 from being blocked, and prolong the service life.

[0049] In a specific embodiment, the second eccentric cylinder 31 comprises a first sand prevention working cylinder 312 and a second sand prevention working cylinder 313 arranged coaxially, and the first sand prevention working cylinder 312 and the second sand prevention working cylinder 313 are connected through a connecting hole 314. The connecting hole 314 has a hole diameter smaller than the inner diameter of the first screen pipe 32, the first screen pipe 32 is fixed coaxially in the first sand prevention working cylinder 312, and the upper end of the first screen pipe 32 axially abuts against the connecting hole 314. A stop ring 36 is arranged between the plug 37 and the first screen pipe 32, and the lower end of the first screen pipe 32 axially abuts against the stop ring 36. A plurality of liquid inlet holes 311 are arranged on the side of the first sand prevention working cylinder 312 along the axial direction. In this arrangement, after the fluid enters the inner cavity of the first sand prevention working cylinder 312 through the liquid inlet hole 311, the fluid can only enter the inside of the first screen pipe 32 after being filtered from the side of the first screen pipe 32, and then enter the second sand prevention working cylinder 313 from the upper end of the first screen pipe 32 through the connecting hole 314.

[0050] In this embodiment, as shown in Figure 1 and Figure 4 , the second eccentric cylinder 31 and the second cylinder body 13 are integrally formed. In the production process, a hole is drilled downward along the axial direction from the upper end of the second eccentric cylinder 31 to form the second sand prevention working cylinder 313, and a hole is drilled upward along the axial direction from the lower end of the second eccentric cylinder 31 to form the first sand prevention working cylinder 312, and then a hole is drilled axially between the first sand prevention working cylinder 312 and the second sand prevention working cylinder 313 to form the connecting hole 314. The first screen pipe 32, the sand scraping ring 33, the stop ring 36 and the plug 37 are sequentially inserted from the lower end of the first sand prevention working cylinder 312, and finally the plug 37 is fixed and sealed with the first sand prevention working cylinder 312 by threaded connection. The stop ring 36 is used to install the first screen pipe 32, the first screen pipe 32 is connected with the stop ring 36 by threads, and the lower side of the stop ring 36 abuts against the plug 37. Here, the stop ring 36 actually plays a transitional role. If the first screen pipe 32 is connected with the plug 37 by threads, it is difficult to connect them together by threads due to the far center of gravity during installation.

[0051] In a preferred embodiment, a second screen pipe 34 is arranged in the second sand control working barrel 313. In this arrangement, the fluid filtered by the first screen pipe 32 in the first sand control working barrel 312 can be filtered again by the second screen pipe 34 in the second sand control working barrel 313, thereby enhancing the filtering effect on the fluid.

[0052] Further, a conversion joint 35 is arranged at the upper end of the second sand control working barrel 313. As shown in Figure 1 and 4 , the upper end of the conversion joint 35 is connected to the gas lift valve 2, the lower end of the conversion joint 35 extends into the interior of the second sand control working barrel 313, and the lower end of the conversion joint 35 is fixedly connected to the second screen pipe 34. The conversion joint 35 is fixedly connected to the second sand control working barrel 313 by means of threaded connection. When the second screen pipe 34 needs to be replaced, only the threads between the conversion joint 35 and the second sand control working barrel 313 need to be loosened, and then the conversion joint 35 is taken out from above the second sand control working barrel 313, so that the second screen pipe 34 can be taken out from the second sand control working barrel 313, thereby replacing the second screen pipe 34.

[0053] According to the present application, as shown in Figure 1 and Figure 3 , the gas lift valve 2 comprises a first eccentric cylinder 21 arranged in parallel outside the eccentric cylinder body 1, a bypass hole 11 is arranged on the outer wall of the eccentric cylinder body 1 corresponding to the first eccentric cylinder 21, a piston 22 capable of plugging the bypass hole 11 is movably arranged in the first eccentric cylinder 21, and the piston 22 is configured to allow fluid to flow only from the first eccentric cylinder 21 to the eccentric cylinder body 1.

[0054] In a specific embodiment, the first eccentric cylinder 21 is arranged outside the first cylinder body 12, the first eccentric cylinder 21 and the first cylinder body 12 are integrally formed, and a bore hole is drilled in the first eccentric cylinder 21 in the axial direction, thereby forming a space capable of accommodating the piston 22. As shown in Figure 3 , the bore hole is drilled from the right side of the first eccentric cylinder 21 to the left, thereby forming a machining hole 15 and a bypass hole 11 in the right side outer wall of the first eccentric cylinder 21 and the inner wall of the first cylinder body 12 in sequence, and then the machining hole 15 is completely plugged, for example, by welding.

[0055] The upper end of the first eccentric cylinder 21 is provided with an adjusting head 23 by means of threaded connection, an elastic element is arranged between the adjusting head 23 and the piston 22, and the position of the adjusting head 23 relative to the first eccentric cylinder 21 is adjusted by means of threads, thereby adjusting the elastic force of the elastic element. Specifically, the elastic element is configured as a spring 24, or a bellows filled with inert gas is arranged between the adjusting head 23 and the piston 22 to act as the elastic element.

[0056] In the present embodiment, as shown in Figure 3 the upper end of the piston 22 in the first eccentric cylinder 21 axially abuts the lower end of the spring 24, and in the absence of external force, the piston 22 is located at the position of the bypass hole 11, thereby blocking the bypass hole 11. The lower part of the piston 22 communicates with the outside space of the eccentric cylinder body 1 through the filtering mechanism 3, and when the pressure of the outside space of the eccentric cylinder body 1 exceeds the elastic force of the spring 24 and pushes the piston 22 to move upward, the piston 22 no longer blocks the bypass hole 11, at which time the bypass hole 11 communicates with the outside space of the eccentric cylinder body 1 through the filtering mechanism 3, and the fluid in the outside space of the eccentric cylinder body 1 can enter the eccentric flow passage 14 of the eccentric cylinder body 1 through the filtering mechanism 3 and the bypass hole 11.

[0057] In a specific embodiment, a connecting sleeve 25 for connecting with the filtering mechanism 3 is arranged at the end of the first eccentric cylinder 21 away from the adjusting head 23, and a limiting ring 26 is arranged between the connecting sleeve 25 and the piston 22. As shown in Figure 3 the limiting ring 26 is inserted into the lower end of the first eccentric cylinder 21 in a clearance fit, and a step is arranged on the limiting ring 26 which axially abuts the lower end face of the first eccentric cylinder 21, the limiting ring 26 is fitted in a clearance fit, and here it is not necessary to use a threaded connection, but to directly insert into the first eccentric cylinder 21 is the simplest installation method. The connecting sleeve 25 is fixedly arranged at the lower end of the limiting ring 26 by a threaded connection, and the upper and lower ends of the limiting ring 26 abut the piston 22 and the connecting sleeve 25, respectively. By arranging the limiting ring 26, the piston 22 can be limited, so that the piston 22 can move to the position of the bypass hole 11 under the action of the spring 24 in the absence of external force, thereby blocking the bypass hole 11.

[0058] According to the present application, the connecting sleeve 25 is connected with the filtering mechanism 3 through the transition ring 4 and the liquid transmission pipe 5. By arranging the transition ring 4 and the liquid transmission pipe 5, the present application can be easily assembled.

[0059] As shown in Figure 1 and Figure 5 a protective cylinder 6 is fixedly arranged outside the second sand prevention working cylinder 313. In the present embodiment, the central axis of the protective cylinder 6 coincides with the central axes of the first eccentric cylinder 21 and the second eccentric cylinder 31, and there is an axial spacing between the upper end of the protective cylinder 6 and the first eccentric cylinder 21, and there is an axial spacing between the lower end of the protective cylinder 6 and the second eccentric cylinder 31. The protective cylinder 6 provides a mounting base for the fixation of the liquid transmission pipe 5.

[0060] The protective cylinder 6 and the second sand prevention working cylinder 313 are integrally formed, and a bore hole is formed along the axial direction of the protective cylinder 6, thereby forming a cavity for accommodating the liquid transmission pipe 5. That is, the liquid transmission pipe 5 is arranged in the interior of the protective cylinder 6, the upper end of the liquid transmission pipe 5 extends above the protective cylinder 6, and the liquid transmission pipe 5 is connected with the connecting sleeve 25 through the transition ring 4. Specifically, the upper and lower ends of the transition ring 4 are respectively connected with the connecting sleeve 25 and the liquid transmission pipe 5 through threaded connection. The lower end of the liquid transmission pipe 5 extends below the protective cylinder 6, and is connected with the conversion joint 35 through threaded connection.

[0061] According to the present application, the assembly steps of the sand prevention gas lifting device 100 are as follows:

[0062] A sealing ring is sleeved on the piston 22, the piston 22 is pushed into the bypass hole 11 from above or below the first eccentric cylinder 21, the spring 24 is loaded from above the first eccentric cylinder 21, and the adjusting head 23 with the sealing ring is screwed;

[0063] The limiting ring 26, the connecting sleeve 25, the transition ring 4 and the like are connected into an integrated whole, and are inserted from below the first eccentric cylinder 21;

[0064] After the first screen pipe 32 is connected with the blocking ring 36, the first screen pipe 32 is inserted into the second eccentric cylinder 31, and then the plug 37 is installed;

[0065] The second screen pipe 34 is inserted from the upper side of the second eccentric cylinder 31;

[0066] The conversion joint 35 and the liquid transmission pipe 5 are connected through threaded connection, and are inserted from the upper side of the second eccentric cylinder 31;

[0067] The lower end of the conversion joint 35 is connected with the second eccentric cylinder 31 through threaded connection;

[0068] The first cylinder body 12 and the second cylinder body 13 are connected into an integrated whole through threaded connection, and during assembly, it is ensured that the first eccentric cylinder 21 and the second eccentric cylinder 31 are axially coincident;

[0069] The liquid transmission pipe 5, the transition ring 4, the connecting sleeve 25 and the limiting ring 26 are sequentially connected through threaded connection;

[0070] The threaded connection parts are loosely connected during initial assembly, and after the assembly of all the pipe fittings is completed, the threaded connection parts are tightened.

[0071] Figure 2The structure of the sand prevention gas lift device 100 after entering the wellbore 10 is shown. When the gas lift process is implemented, gas is pumped into the annulus between the sand prevention gas lift device 100 and the wellbore 10, so that the annulus liquid column is pressed to descend, the liquid column pressure is superimposed with the gas pressure, the piston 22 is pushed to overcome the spring force, the bypass hole 11 is exposed to automatically discharge water; the gas pushes the annulus liquid into the device and the pipe column, the gas flows and expands in the pipe to the ground, forming a negative pressure to take out the accumulated liquid in the pipe.

[0072] In the case of multiple-stage sand prevention gas lift devices 100 in series, when the annulus liquid column pressure is higher than the position of the first-stage sand prevention gas lift device 100, the lower multiple-stage sand prevention gas lift devices 100 will be opened to participate in the shunt hydraulic pressure. As the annulus liquid level decreases, the multiple-stage sand prevention gas lift devices 100 will automatically close from top to bottom (until the annulus liquid column pressure cannot push the piston 22 in the last-stage sand prevention gas lift device 100).

[0073] According to the present application, a gas lift process is also provided, as shown in Figure 6 and Figure 7 At least one sand prevention gas lift device 100 is first connected in series on the oil pipe 8 and lowered into the vertical section or horizontal section flooded by water in the well, at this time the bottom end of the oil pipe 8 is in a blocked state, and a pipe 7 (usually a small-size coiled tubing) is lowered into the oil pipe 8, the pipe 7 is inserted into the bottom end of the oil pipe 8, and the bottom end of the pipe 7 is in an open state.

[0074] When the formation energy is sufficient, under the action of the formation energy (formation pressure, natural gas pressure, etc.), due to the pressure difference between the inside and outside of the oil pipe 8, the accumulated liquid in the large annulus between the oil pipe 8 and the wellbore 10 is squeezed into the small annulus between the oil pipe 8 and the pipe 7 through the sand prevention gas lift device 100, and the formation compressed gas (natural gas, etc.) enters the small annulus together and moves to the ground along the oil pipe 8, the natural gas expands in the moving process, continuously taking the accumulated liquid to the ground, thereby achieving the effect of water drainage and gas production.

[0075] When the formation energy is insufficient, the liquid loading in the large annulus between the tubing 8 and the wellbore 10 can enter the small annulus between the tubing 8 and the pipe 7 through the sand control gas lift device 100, but the energy thereof is insufficient to move along the tubing 8 to the ground. When there is no liquid loading in the tubing 8, the liquid loading pressure in the large annulus can push the piston 22 to move upward to overcome the spring force, so as to communicate the bypass hole 11 with the large annulus, and the liquid loading in the large annulus can enter the tubing 8 through the bypass hole 11. As the liquid loading in the large annulus continuously enters the tubing 8, the pressure in the large annulus gradually decreases, and finally the pressure in the large annulus decreases to be insufficient to push the piston 22 to overcome the spring force, so as to make the piston 22 wall bypass hole 11. At this time, the nitrogen, natural gas or other gas is injected into the pipe 7 (or the small annulus between the pipe 7 and the tubing 8) through the ground gas lift vehicle for pressurization. Due to the pressure difference between the inside and outside of the pipe 7, the liquid loading in the tubing 8 can move to the ground from the small annulus between the pipe 7 and the tubing 8 (or the pipe 7), and the compressed gas expands in the moving process, continuously brings the liquid loading to the ground, so as to achieve the effect of drainage gas recovery.

[0076] In the description of the present application, it should be understood that the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically limited.

[0077] In the present application, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0078] In the description of the present application, the description of the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present application, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0079] Finally, it should be noted that the above only describes the preferred embodiments of the present application and does not constitute any limitation on the present application. Although the present application is described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacements to some technical features thereof. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A sand-control airlift device, characterized in that, include: Eccentric cylindrical body (1); An air lift valve (2) is installed on the outside of the eccentric cylinder (1); as well as A filter mechanism (3) is provided on the outside of the eccentric cylinder (1). The filter mechanism (3) is connected to the air lift valve (2). Fluid outside the eccentric cylinder (1) enters the interior of the eccentric cylinder (1) through the filter mechanism (3) and the air lift valve (2) in sequence.

2. The sand-control airlift device according to claim 1, characterized in that, The filtration mechanism (3) includes a second eccentric cylinder (31) arranged parallel to the outside of the eccentric cylinder body (1). The end of the second eccentric cylinder (31) is connected to the air lift valve (2). A first screen tube (32) is provided inside the second eccentric cylinder (31). At least one liquid inlet hole (311) is provided on the side of the second eccentric cylinder (31) at a position corresponding to the first screen tube (32).

3. The sand-control airlift device according to claim 2, characterized in that, A scraping ring (33) is slidably disposed between the first screen tube (32) and the second eccentric cylinder (31). The scraping ring (33) is configured to reciprocate along the axial direction of the first screen tube (32) in response to pressure fluctuations of the fluid, thereby removing impurities from the surface of the first screen tube (32).

4. The sand-control airlift device according to claim 3, characterized in that, The second eccentric cylinder (31) includes a first sand-proof working cylinder (312) and a second sand-proof working cylinder (313) arranged coaxially. The first sand-proof working cylinder (312) and the second sand-proof working cylinder (313) are connected by a connecting hole (314), and the diameter of the connecting hole (314) is smaller than the inner diameter of the first screen tube (32).

5. The sand-control airlift device according to claim 4, characterized in that, A second screen tube (34) is installed inside the second sand-proof working cylinder (313).

6. The sand-control airlift device according to claim 5, characterized in that, A conversion connector (35) is provided at the end of the second sand control working cylinder (313) away from the connection hole (314). One end of the conversion connector (35) extends into the second sand control working cylinder (313) and is connected to the second screen tube (34). The other end of the conversion connector (35) is connected to the air lift valve (2).

7. The sand-control airlift device according to any one of claims 1 to 6, characterized in that, The air lift valve (2) includes a first eccentric cylinder (21) arranged parallel to the outside of the eccentric cylinder body (1). A bypass hole (11) is provided on the outer wall of the eccentric cylinder body (1) corresponding to the first eccentric cylinder (21). A piston (22) capable of blocking the bypass hole (11) is movably arranged inside the first eccentric cylinder (21). The piston (22) is configured to allow fluid to flow from the first eccentric cylinder (21) to the eccentric cylinder body (1).

8. The sand-control airlift device according to claim 7, characterized in that, An adjusting head (23) is provided at the end of the first eccentric cylinder (21) by means of a threaded connection. A spring (24) is provided between the adjusting head (23) and the piston (22). The elastic force of the spring (24) can be adjusted by the adjusting head (23).

9. The sand-control airlift device according to claim 8, characterized in that, A connecting sleeve (25) for connecting to the filter mechanism (3) is provided at one end of the first eccentric cylinder (21) away from the adjusting head (23), and a limit ring (26) is provided between the connecting sleeve (25) and the piston (22).

10. The sand-control airlift device according to claim 9, characterized in that, The connecting sleeve (25) is connected to the filter mechanism (3) through the transition ring (4) and the liquid transfer tube (5).

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