Double-tubular-column closed type gas lift liquid collecting and discharging device

Abstract

The utility model relates to a double-tubular-column closed gas-lift liquid production and drainage device which mainly comprises an oil pipe, an outer pipe hanger, an inner pipe hanger, an inner tubular column, an outer tubular column, a jet pump, a U-shaped joint or an integrated U-shaped joint, an aeration control valve, a setting cylinder and a one-way valve, wherein the outer tubular column is formed by connecting the oil pipe with the outer pipe hanger and the setting cylinder; the upper end of the outer pipe column is an outer pipe hanger, the lower part of the outer pipe column is a setting cylinder, the outer pipe hanger fixes the outer pipe column on a wellhead in a hanging manner, the inner pipe column is formed by connecting an oil pipe with an inner pipe hanger, a U-shaped joint or an integrated U-shaped joint, an aeration control valve, a jet pump and a one-way valve, the upper end of the inner pipe column is an inner pipe hanger, and the lower part of the inner pipe column is a jet pump and a one-way valve. And the inner pipe hanger is used for hanging and fixing the inner pipe column on a hanging seat on a wellhead.

Description

Technical Field:

[0001] The present invention relates to machinery for gas-lift production and drainage of liquids, and is particularly applicable to fields such as oil extraction in the petroleum, natural gas, and coalbed methane industries, gas drainage and gas production from natural gas wells, gas drainage and gas production from coalbed methane wells, and groundwater extraction in industrial, agricultural production, and daily life. Background Art:

[0002] The existing methods for gas-lift oil production and liquid drainage are mainly the gas-lift oil production and drainage processes widely used in oil extraction. The process is to quickly carry out the liquid by injecting compressed gas into the wellbore, and there are two main methods: continuous gas lift and intermittent gas lift. In intermittent gas lift, there is a chamber gas lift method, which uses air pressure to open the gas lift valve at the upper part of the liquid collection chamber in the well, so that the gas acts on the liquid surface in the chamber and quickly pushes the liquid into the liquid production pipe for lifting. It is used for oil wells with low bottom hole pressure and high liquid production index. However, it has the disadvantages of complex structure, large gas consumption in a short time, serious liquid slippage, low efficiency, poor effectiveness in sand-producing wells and foam emulsion wells, difficulty in lifting viscous liquids, and difficulty in removing wax and scale. In particular, the gas lift valve is prone to failure, and special operations are required for fishing and other work, and the production maintenance cost is relatively high. In the section on gas pumps on page 550 of Volume 2 <Lower> of "Oil Production Technology by Lifting Method" edited by K.E. Brown of the United States and published by the Petroleum Industry Press in 1985, a gas pump is described. The method is to alternately inject gas into the bottom well gathering chamber to discharge the liquid, and then discharge the gas to make the liquid fill the gathering chamber again. Generally speaking, the gas pressure in oil wells is not high enough, so this method can only be used to lift shallow oil layers. At the same time, there is a time delay between gas charging and discharging, which limits this method to low-production wells and still has difficulty in solving the problems of serious liquid slippage and low efficiency. In my invention patents "A Method and Device for Gas-Lift Liquid Production and Drainage Using a U-Shaped Tube (ZL201610040485.6)", "A Method and Device for Gas-Lift Liquid Production (Patent No. 201210453381.X)", "A Chamber Gas Production and Drainage Liquid Device (Patent Application No. 202211681138.3)", and utility model patents "A U-Shaped Joint (Patent No. 202222669528.0)", "An Integrated U-Shaped Joint (Patent Application No. 202420944959.X)", and "An Aeration Control Valve (Patent Application No. 202420726934.2)", improvements have been made to solve the above problems, enabling convenient production and transportation of fluids at any depth, with the characteristics of small gas consumption and easy maintenance, and well solving the problem of serious liquid slippage. However, there are still disadvantages such as low efficiency in the production of oil and gas wells with low production and low formation pressure, especially in the gas drainage and gas production of low-pressure coalbed methane and shale gas wells. At the same time, it is also difficult to apply to wells with poor wellbore quality or leakage. Summary of the Invention:

[0003] One of the objectives of the present invention is to further innovate, improve and perfect the above-mentioned prior invention of the inventor, and control the production of the production well by adjusting the gas injection time or gas injection volume of the surface equipment according to the liquid output of the production well. A double-tubular column closed gas lift liquid production and drainage device composed of an outer tube, an inner tube, a jet pump, a check valve, etc. is provided. When a U-shaped joint and an air admixture control valve are connected to the inner tube of the device, it can lift the liquid or fluid deep in the well with a lower air pressure and a smaller gas volume, and does not generate backpressure on the formation and reduces the flowing pressure, achieving the purpose of increasing production. The U-shaped joint prevents liquid slippage, and the multi-stage chambers formed by multiple U-shaped joints retain the upward gas in the tubular column, reducing the average density of the fluid in the tubular column and facilitating the lifting of liquid with a low air pressure. Its air admixture control valve also has the function of automatically adjusting the density of the fluid, keeping the gas injection volume and the liquid production volume optimal at all times. The gas consumption of the double-tubular column closed gas lift liquid production and drainage device is only 15-20% of that of the traditional gas lift method, meeting the production requirements of oil production in low-energy oil wells or gas drainage and gas production in gas wells, especially the drainage and gas production in low-pressure coalbed methane and shale gas wells. The device can conveniently control the production of the production well by adjusting the gas injection time or gas injection volume of the surface equipment.

[0004] Another objective of the present invention is to provide a double-tubular column closed gas lift liquid production and drainage device that integrates gas gathering lift, gas lift jet and gas push, which has a simple structure, convenient construction, reliable operation, easy operation, low energy consumption, high efficiency, long service life, wide application range, can be used at any depth and for any property, and is not restricted by the environment. In particular, it can be applied to wells with poor wellbore quality or leakage, and does not generate backpressure on the formation.

[0005] The invention is realized as follows:

[0006] In a dual - string closed - type gas - lift liquid production and drainage device mainly composed of an oil pipe, an outer pipe hanger (2), an inner pipe hanger (3), an inner pipe string (6), an outer pipe string (7), a jet pump (10), a U - shaped joint (8) or an integrated U - shaped joint (26), an aeration control valve (9), a packer barrel (11), a check valve (16), etc.: The outer pipe string (7) is composed of connecting an oil pipe to the outer pipe hanger (2), the packer barrel (11), etc. The upper end of the outer pipe string (7) is the outer pipe hanger (2), and the lower part of the outer pipe string (7) is the packer barrel (11). The outer pipe hanger (2) suspends and fixes the outer pipe string (7) on the wellhead (1); The inner pipe string (6) is composed of connecting an oil pipe to the inner pipe hanger (3), the U - shaped joint (8) or the integrated U - shaped joint (26), the aeration control valve (9), the jet pump (10), the check valve (16), etc. The upper end of the inner pipe string (6) is the inner pipe hanger (3), and the lower part of the inner pipe string (6) is the jet pump (10) and the check valve (16). The inner pipe hanger (3) suspends and fixes the inner pipe string (6) on the suspension seat (30) on the wellhead (1), and at the same time, the inner pipe hanger (3) seals the inner pipe string (6) on the packer barrel (11) at the lower part of the outer pipe string (7); The inner pipe string (6) and the outer pipe string (7) are sleeved to form an annular space. The high - pressure fluid on the ground enters this annular space from the fluid injection port (31) and then enters the jet pump (10), sucks the fluid in the wellbore (5) and is lifted to the ground through the inner pipe string (6).

[0007] The outer pipe string (7) formed by connecting the outer pipe hanger (2) and the packer barrel (11) with an oil pipe is a channel for transporting the power fluid.

[0008] The outer pipe string (7) formed by connecting the outer pipe hanger (2) and the packer barrel (11) with an oil pipe is suspended on the wellhead (1) by the outer pipe hanger (2) connected to its upper end.

[0009] The inner pipe string (6) formed by connecting the inner pipe hanger (3), the jet pump (10), and the check valve (16) with an oil pipe is a channel for transporting the fluid to be produced.

[0010] The inner pipe string (6) formed by connecting the inner pipe hanger (3), the U - shaped joint (8) or the integrated U - shaped joint (26), the jet pump (10), and the check valve (16) with an oil pipe is a channel for transporting the fluid to be produced.

[0011] The inner pipe string (6) formed by connecting the inner pipe hanger (3), the U - shaped joint (8) or the integrated U - shaped joint (26), the aeration control valve (9), the jet pump (10), and the check valve (16) with an oil pipe is a channel for transporting the fluid to be produced.

[0012] The interval between the U - shaped joint (8) or the integrated U - shaped joint (26) on the inner pipe string (6) is dozens of meters.

[0013] The aeration control valves (9) connected to the inner pipe string (6) are spaced tens of meters apart.

[0014] The aeration control valve (9) on the inner pipe string (6) is provided with a hole (29) for communicating the space inside and outside the inner pipe string (6).

[0015] The inner pipe string (6) is suspended and fixed on the suspension seat (30) on the wellhead (1) by the inner pipe hanger (3) connected to the upper end. At the same time, the inner pipe hanger (3) seals the inner pipe string (6) on the sealing cylinder (11) at the lower part of the outer pipe string (7).

[0016] The jet pump (10) is composed of a throat pipe (12), a nozzle (13), a base (14), etc. The throat pipe (12) is connected to the base (14) by a thread, and the nozzle (13) is connected to the base (14) by a thread. The jet pump (10) is connected to the lower part of the inner pipe string (6) by the thread of the throat pipe (12). The high-pressure fluid outside the jet pump (10) enters through the first channel (24), sprays out through the nozzle (12), generates a negative pressure at the throat pipe (12) to suck the well fluid into the inner pipe string (6) through the check valve (16) and lift it to the ground.

[0017] A check valve (16) is installed at the fluid inlet of the jet pump (10), and the check valve (16) is connected to the jet pump (10) by a compression joint (17).

[0018] The outer pipe hanger (2) is the joint at the upper end of the outer pipe string (7), and its function is to suspend and fix the outer pipe string (7) on the ground wellhead (1) and be sealed by the seal in the second sealing groove (21).

[0019] The inner pipe hanger (3) is the joint at the upper end of the inner pipe string (6), and its function is to suspend and fix the inner pipe string (6) on the suspension seat (30) on the wellhead (1) and be sealed by the seal in the third sealing groove (23). It is used to communicate the external with the annular channel between the inner pipe string (6) and the outer pipe string (7), facilitating the fluid to enter the annular space formed by the inner pipe string (6) and the outer pipe string (7) from the fluid injection port (31). At the same time, the inner pipe hanger (3) seals the inner pipe string (6) on the sealing cylinder (11) at the lower part of the outer pipe string (7) and is sealed by the seal in the first sealing groove (15).

[0020] The suspension seat (30) is sealed on the wellhead (1). The suspension seat (30) is provided with a fluid injection port (31), and the fluid injection port (31) is the inlet of the power fluid.

[0021] The sealing cylinder (11) is composed of a first joint (18), a sealing ring (19), and a second joint (20). Its function is to seal the inner pipe string (6) in the outer pipe string (7), so that the outer pipe string (7) and the inner pipe string (6) form a closed space, facilitating the high-pressure fluid entering this closed space from the ground to enter the jet pump (10).

[0022] The U-joint (8) consists of two U-shaped channels connected in series vertically, forming a U-shaped or annular structure. The U-joint (8) can also be an annular structure or an integral U-joint (26). Its structure enables the fluid to form a channel that goes upward ↑, then turns back downward ↓, and then turns back upward ↑, creating a structure where gas seals the falling liquid and liquid seals the upward surging gas. A U-joint (8) or an integral U-joint (26) is connected to the inner pipe string (6) at intervals of dozens of meters, usually connecting a U-joint (8) or an integral U-joint (26) every 1 to 12 or more than 12 tubing strings, that is: connecting a U-joint (8) or an integral U-joint (26) every other 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12 tubing strings, etc. The function of the U-joint (8) or the integral U-joint (26) is to prevent the liquid from slipping and form multiple cavity segments on the inner pipe string (6), separating the upward-flowing fluid in the inner pipe string (6) into multiple fluid segments where gas pushes the liquid and liquid pushes the gas, so as to reduce the flow pressure and facilitate the production of liquid extraction and drainage.

[0023] The holes (29) on the gas injection control valve (9) are used to communicate the annular space formed by the nesting of the inner pipe string (6) and the outer pipe string (7) with the fluid channel inside the inner pipe string (6). The holes (29) of the gas injection control valve (9) are inclined upward, with an inclination angle less than 30 degrees. The number of gas injection control valves (9) on the inner pipe string (6) is 0 to 8. Usually, the number of gas injection control valves (9) on the inner pipe string (6) is 0, 1, 2, 3, 4, 5, or 6. When the number is more than 2, the interval is dozens of meters. The gas injection control valve (9) is a hole (29) or a slit. The function of the gas injection control valve (9) is to inject gas into the inner pipe string (6) to adjust and reduce the density of the fluid inside the inner pipe string (6).

[0024] The inner pipe string (6) and the outer pipe string (7) are also channels for injecting chemical agents or steam for other measures such as wax and scale removal.

[0025] The check valve (16) is installed at the fluid inlet of the jet pump (10), and its function is to prevent the fluid from flowing back into the wellbore (5).

[0026] The features of the present invention are:

[0027] a. Simple structure, reliable operation, long service life, and low cost for maintaining production.

[0028] In the present invention, a simple and reliable air injection control valve (9) replaces the complex and malfunction-prone conventional gas lift valve, which not only simplifies, makes reliable and long-lived the downhole structure, but also makes the surface equipment and operation simpler and more flexible. It can either lift liquid intermittently or continuously, and can also produce automatically when the formation has a certain amount of energy. Therefore, the requirements for surface gas supply equipment are greatly reduced. Due to its unique closed structure, it will not generate backpressure on the formation. The jet structure of its jet pump (10) also has a suction effect. The combination of the U-shaped joint (8) or the integral U-shaped joint (26) with the jet pump (10), the check valve (16) and the air injection control valve (9) in the invention is very effective for the exploitation of low-pressure oil and gas wells, shale gas wells and coalbed methane wells, and is more convenient for the production of horizontal wells.

[0029] b. High efficiency and low energy consumption.

[0030] According to the liquid output of the production well, by adjusting the gas injection time or gas injection volume of the surface equipment, the output of the production well is controlled. By adopting the unique U-shaped structure with air-liquid mutual sealing and pushing and the characteristic of reducing density by air injection, the gas consumption is only 15-20% of the traditional gas lift method. Its air injection control valve (9) simultaneously has the functions of automatic regulation and reducing the density of the fluid, so that the gas injection volume and the liquid production volume are always kept in the best match to meet the requirements of oil production in oil wells with lower energy or liquid drainage in natural gas wells, shale gas and coalbed methane drainage and gas production, and enables the oil and gas wells to resume normal production.

[0031] c. Wide application range.

[0032] The present invention is not limited by the properties of the fluid to be exploited, and can exploit viscous liquids, emulsions and liquids with high water content, sand content and gas content. It is not limited by the quality of the wellbore and can be used in wells with bent wellbores and damaged casings. It is not limited by the environment of the fluid to be exploited and can be used for liquid production in onshore and offshore oil and water wells, liquid drainage and gas production in natural gas wells and horizontal well exploitation, and is convenient for wax cleaning and scale removal. Brief description of the drawings:

[0033] Figure 1 This is a schematic diagram of a double-tubular column closed gas lift liquid production and drainage device composed of an outer tubular column (7) formed by connecting an outer pipe hanger (2) and a setting cylinder (11) with a tubing and an inner tubular column (6) formed by connecting an inner pipe hanger (3), a jet pump (10), a check valve (16), etc. with a tubing. The check valve (16) prevents the high-pressure fluid on the ground from entering the wellbore from the fluid injection port (31), and at the same time reduces the liquid slippage by using the fluid velocity of the thinner tubular column.

[0034] Figure 2In this embodiment, it is a schematic diagram of a double-tubular closed gas lift liquid production and drainage device composed of an outer tubular string (7) formed by connecting an outer tubing hanger (2) and a setting cylinder (11) with tubing and an inner tubular string (6) formed by connecting an inner tubing hanger (2), a U-joint (8) or an integrated U-joint (26) or an air injection control valve (9), a jet pump (10), a check valve (16), etc. with tubing. The check valve (16) prevents high-pressure fluid on the ground from entering the wellbore through the fluid injection port (31). At the same time, the U-joint (8) or the integrated U-joint (26) or the air injection control valve (9) is used to prevent liquid slippage, and the fluid is pushed to the ground with a lower air pressure.

[0035] Figure 3 It is a schematic structural diagram of the air injection control valve (9) in this embodiment.

[0036] Figure 4 It is an assembly structure diagram of the jet pump (10) in this embodiment.

[0037] Figure 5 It is an assembly structure diagram of the setting cylinder (11) in this embodiment.

[0038] Figure 6 It is a structural diagram of the outer tubing hanger (2) in this embodiment.

[0039] Figure 7 It is a structural diagram of the inner tubing hanger (3) in this embodiment.

[0040] Figure 8 It is a structural diagram of the throat tube (12) of the jet pump (10) in this embodiment.

[0041] Figure 9 It is a structural diagram of the nozzle (13) of the jet pump (10) in this embodiment.

[0042] Figure 10 、 Figure 11 It is a structural diagram of the base (14) of the jet pump (10) in this embodiment.

[0043] Figure 12 It is a structural diagram of the compression joint (17) of the check valve (16) in this embodiment.

[0044] Figure 13 It is a structural diagram of the joint one (18) of the setting cylinder (11) in this embodiment.

[0045] Figure 14 It is a structural diagram of the setting ring (19) of the setting cylinder (11) in this embodiment.

[0046] Figure 15 It is a structural diagram of the joint two (20) of the setting cylinder (11) in this embodiment.

[0047] Figure 16 This is the structural diagram of the check valve (16) in this embodiment.

[0048] Figure 17 、 Figure 18 This is the schematic structural diagram of the integral U-shaped joint (26) in this embodiment.

[0049] Figure 19 、 Figure 20 This is the schematic structural diagram of the U-shaped joint (8) in this embodiment.

[0050] Names in the figure:

[0051] 1. Wellhead, 2. Outer pipe hanger, 3. Inner pipe hanger, 4. Production port, 5. Wellbore, 6. Inner pipe string, 7. Outer pipe string, 8. U-shaped joint, 9. Aeration control valve, 10. Jet pump, 11. Setting cylinder, 12. Throat pipe, 13. Nozzle, 14. Base, 15. Seal groove 1, 16. Check valve, 17. Compression joint, 18. Joint 1, 19. Setting ring, 20. Joint 2, 21. Seal groove 2, 23. Seal groove 3, 24. Channel 1, 25. Channel 2, 26. Integral U-shaped joint, 27. Channel 3, 28. Channel 4, 29. Hole, 30. Suspension seat, 31. Fluid injection port. Specific implementation manners:

[0052] The invention will be further described in detail below with reference to the accompanying drawings:

[0053] Refer to Figure 1 :

[0054] A double-pipe string closed gas lift liquid production and drainage device is composed of an outer pipe string (7) formed by connecting an outer pipe hanger (2) and a setting cylinder (11) with a tubing, and an inner pipe string (6) formed by connecting an inner pipe hanger (3), a jet pump (10), a check valve (16), etc. with a tubing. The upper end of the outer pipe string (7) is the outer pipe hanger (2), and the lower part of the outer pipe string (7) is the setting cylinder (11). The outer pipe string (7) is suspended on the wellhead (1) by the outer pipe hanger (2). The upper part of the inner pipe string (6) is the inner pipe hanger (3), and the lower part of the inner pipe string (6) is the jet pump (10). While the inner pipe string (6) is suspended on the outer pipe hanger (2) on the wellhead (1) by the inner pipe hanger (3), the inner pipe string (6) is also set on the setting cylinder (11) at the lower part of the outer pipe string (7). This nested inner pipe string (6) and outer pipe string (7) form an annular space. High-pressure fluid on the ground enters through the fluid injection port (31), passes through this annular space and enters the jet pump (10), sucks the fluid in the wellbore (5) and then pushes it to the ground through the inner pipe string (6). The gas in the wellbore (5) is produced from the production port (4). In this device, the check valve (16) prevents the high-pressure fluid on the ground from entering the wellbore through the fluid injection port (31), and at the same time reduces the liquid slippage by using the fluid velocity of the thinner pipe string.

[0055] Working principle: When the external fluid enters from the fluid injection port (31) into the annular space formed by the outer pipe column (7) and the inner pipe column (6) nested with each other, and then enters through the first channel (24) and is ejected through the nozzle (12), a negative pressure is generated at the throat (12) to suck the well fluid into the outer pipe column (7) through the one-way valve (16) and lift it to the ground.

[0056] Refer to Figure 2 :

[0057] The double-pipe column closed gas lift liquid production and drainage device is composed of an outer pipe column (7) connected by tubing to an outer pipe hanger (2) and a packer barrel (11), and an inner pipe column (6) connected by tubing to an inner pipe hanger (3), a U-shaped joint (8) or an integrated U-shaped joint (26), an air injection control valve (9), etc. The upper end of the outer pipe column (7) is the outer pipe hanger (2), and the lower part of the outer pipe column (7) is the packer barrel (11). The outer pipe column (7) is suspended on the wellhead (1) by the outer pipe hanger (2). The upper end of the inner pipe column (6) is the inner pipe hanger (3), and the lower part of the inner pipe column (6) is the jet pump (10). While the inner pipe column (6) is suspended on the outer pipe hanger (2) on the wellhead (1) by the inner pipe hanger (3), the inner pipe column (6) is also sealed on the packer barrel (11) at the lower part of the outer pipe column (7). The nested inner pipe column (6) and outer pipe column (7) form an annular space. The high-pressure fluid on the ground enters this annular space from the fluid injection port (31) and enters the jet pump (10), sucks the fluid in the wellbore (5) and then lifts it to the ground through the inner pipe column (6). The gas in the wellbore (5) is produced from the production port (4). In this device, the one-way valve (16) prevents the high-pressure fluid on the ground from entering the wellbore from the fluid injection port (31), and at the same time uses the U-shaped joint (8) or the integrated U-shaped joint (26) or the air injection control valve (9) to prevent the slippage of the liquid and lift the fluid to the ground with a lower air pressure.

[0058] Working principle: When the external fluid enters from the fluid injection port (31) into the annular space formed by the outer pipe column (7) and the inner pipe column (6) nested with each other, and then enters through the first channel (24) and is ejected through the nozzle (12), a negative pressure is generated at the throat (12) to suck the well fluid into the outer pipe column (7) through the one-way valve (16) and lift it to the ground. During this period, the U-shaped joint (8) or the integrated U-shaped joint (26) not only prevents the slippage of the liquid but also retains the gas in the inner pipe column (6), reducing the average density of the fluid in the inner pipe column (6). The air injection control valve (9) continuously injects air, reducing the density of the fluid in the inner pipe column (6) and making it easier to lift to the ground. The gas in the wellbore (5) is produced from the production port (4).

Claims

1. Double-tubing closed gas lift fluid production and drainage device. In the double-tubing closed gas lift fluid production and drainage device mainly composed of tubing, outer tubing hanger (2), inner tubing hanger (3), inner tubing string (6), outer tubing string (7), jet pump (10), U-joint (8) or integral U-joint (26), gas injection control valve (9), setting cylinder (11), check valve (16): The outer tubing string (7) is composed of tubing connecting the outer tubing hanger (2) and the setting cylinder (11). The upper end of the outer tubing string (7) is the outer tubing hanger (2), and the lower part of the outer tubing string (7) is the setting cylinder (11). The outer tubing hanger (2) suspends and fixes the outer tubing string (7) on the wellhead (1). The inner tubing string (6) is composed of tubing connecting the inner tubing hanger (3), U-joint (8) or integral U-joint (26), gas injection control valve (9), jet pump (10), check valve (16). The upper end of the inner tubing string (6) is the inner tubing hanger (3), and the lower part of the inner tubing string (6) is the jet pump (10) and the check valve (16). The inner tubing hanger (3) suspends and fixes the inner tubing string (6) on the suspension seat (30) on the wellhead (1). At the same time, the inner tubing hanger (3) seals the inner tubing string (6) on the setting cylinder (11) at the lower part of the outer tubing string (7). The inner tubing string (6) and the outer tubing string (7) are sleeved to form an annular space. The high-pressure fluid on the ground enters this annular space from the fluid injection port (31) and then enters the jet pump (10), sucks the fluid in the wellbore (5) and is pushed to the ground through the inner tubing string (6).

2. The double-tubular column closed gas lift liquid production and drainage device according to claim 1 is characterized in that: The inner tubing string (6) connected by tubing, inner tubing hanger (3), jet pump (10), and check valve (16) forms a channel for transporting the fluid to be produced.

3. The double-tubular column closed gas lift liquid production and drainage device according to claim 1, characterized in that: The inner tubing string (6) connected by tubing, inner tubing hanger (3), U-joint (8) or integral U-joint (26), jet pump (10), and check valve (16) forms a channel for transporting the fluid to be produced.

4. The double-tubular column closed gas lift liquid production and drainage device according to claim 1 is characterized in that: The inner tubing string (6) connected by tubing, inner tubing hanger (3), U-joint (8) or integral U-joint (26), gas injection control valve (9), jet pump (10), and check valve (16) forms a channel for transporting the fluid to be produced.

5. The double-tubular column closed gas lift liquid production and drainage device according to claim 1, characterized in that: The interval between the U-joint (8) or integral U-joint (26) on the inner tubing string (6) is dozens of meters.

6. The double-tubular column closed gas lift liquid production and drainage device according to claim 1 is characterized in that: The interval between the gas injection control valves (9) connected to the inner tubing string (6) is dozens of meters.

7. The double-tubular column closed gas lift liquid production and drainage device according to claim 1, characterized in that: The gas injection control valve (9) on the inner tubing string (6) is provided with a hole (29) for communicating the inner and outer spaces of the inner tubing string (6).

8. The double-tubular column closed gas lift liquid production and drainage device according to claim 1, characterized in that: A check valve (16) is installed at the fluid inlet of the jet pump (10).

9. The double-tubular column closed gas lift liquid production and drainage device according to claim 1 is characterized in that: The base (14) of the jet pump (10) is an integral part, and a channel one (24) and a channel two (25) are simultaneously opened on this integral part.

10. The double-tubular column closed gas lift liquid production and drainage device according to claim 1 is characterized in that: The opening of the hole (29) of the gas injection control valve (9) slopes upward, and the inclination angle is less than 30 degrees.

11. The double-tubular column closed gas lift liquid production and drainage device according to claim 1 is characterized in that: The U-joint (8) is two U-shaped channels connected in series up and down, forming a U-shaped or annular structure.

12. The double-tubular column closed gas lift liquid production and drainage device according to claim 1 is characterized in that The integral U-joint (26) is an integral U-shaped channel formed by casting or 3D printing.

13. The double-tubular column closed gas lift liquid production and drainage device according to claim 1 is characterized in that: The number of gas injection control valves (9) is 0 or 1 or 2 or 3 or 4 or 5 or 6.

Images