Automatic gas-driven drainage downhole tool

Abstract

The invention discloses an automatic gas-driven drainage downhole tool, and relates to the technical field of downhole operation tools, the automatic gas-driven drainage downhole tool comprises an accumulated liquid collection assembly, a liquid accumulation cylinder and a shell sleeve, the liquid accumulation assembly comprises a screen pipe, a plurality of liquid guide holes are formed in the screen pipe, a liquid accumulation cavity is formed in the liquid accumulation cylinder, one end of the liquid accumulation cylinder is provided with a gas source connector, and the other end of the liquid accumulation cylinder is provided with a gas outlet; the other end of the liquid accumulation cylinder is communicated with the screen pipe, the liquid accumulation cylinder is provided with a first one-way valve and a second one-way valve, a liquid drainage channel is formed in the liquid accumulation cylinder and used for communicating the liquid accumulation cavity with the outside, the liquid accumulation cylinder is located in the shell sleeve and detachably connected with the shell sleeve, and fixing heads are installed at the two ends of the shell sleeve and used for fixing the position of the liquid accumulation cylinder. According to the device, the liquid drainage efficiency can be remarkably improved, the negative influence of accumulated liquid on gas well production is reduced, the operation complexity and cost are reduced, and the device has high universality.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole operation tools, and more specifically, to an automatic gas-driven downhole tool for draining water. Background Art

[0002] During the production process of oilfield gas wells, when the water content in the well exceeds the standard and needs to be drained to the ground, the well fluid needs to be discharged. The main purpose is to restore or increase the production capacity of the oil well by removing the accumulated fluid in the wellbore or formation, thereby ensuring the efficient development of the oilfield. Common drainage methods include gas lift drainage, pump drainage, foam drainage, coiled tubing drainage, chemical drainage, and mechanical drainage, etc. Gas lift drainage injects high-pressure gas into the wellbore and uses the gas to push the liquid out, which is suitable for medium and deep oil wells; pump drainage uses downhole pumps such as electric submersible pumps, screw pumps, or plunger pumps to force the liquid out, which is suitable for oil wells with high liquid volume or low gas-liquid ratio; foam drainage injects a foaming agent to form a foam mixture of liquid and gas, reducing the liquid density and facilitating the gas to carry it out, which is suitable for low-production liquid wells or gas wells; coiled tubing drainage uses coiled tubing to pump liquid from the bottom of the wellbore, which is suitable for deep wells or horizontal wells; chemical drainage injects chemical agents such as surfactants to reduce the surface tension of the liquid and improve the drainage efficiency; mechanical drainage uses mechanical devices such as a plunger lift system to periodically lift the liquid, which is suitable for oil wells with intermittent liquid production. These methods have their own characteristics, and it is necessary to select a suitable drainage method according to the well conditions. When it is necessary to adopt the gas drainage method, this method uses gas to push the liquid to move from the bottom of the well to the wellhead, thereby increasing the gas well production.

[0003] At present, the commonly used method in oilfields is gas-driven drainage, and the commonly used tools include gas-driven pumps, gas lift valves, and coiled tubing, etc. The gas-driven pump forms a gas-liquid mixture by injecting gas, reducing the liquid density and making it easy to discharge; the gas lift valve is installed on the tubing to control the gas injection point and optimize the gas lift efficiency; the coiled tubing is used to inject gas into the bottom of the well to ensure full mixing of gas and liquid. This method is suitable for low-producing gas wells or gas wells with serious liquid accumulation and can effectively restore the production capacity of gas wells.

[0004] However, at present, the structure of the downhole liquid accumulation gas drainage device is complex and the operation is also complex, which requires a lot of manual intervention and greatly affects the drainage efficiency.

[0005] In summary, how to provide an automatic gas-driven downhole tool for efficiently draining the downhole liquid accumulation is an urgent problem to be solved by those skilled in the art at present. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an automatic gas-driven downhole tool, which can significantly improve the drainage efficiency, reduce the negative impact of liquid accumulation on the production of gas wells, and does not require manual intervention, reducing the operation complexity and cost.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] An automatic gas-driven downhole tool for draining liquid, comprising:

[0009] A liquid accumulation collection component, the liquid accumulation component includes a screen pipe, and a number of liquid guiding holes are provided on the screen pipe;

[0010] A liquid accumulation cylinder, the openings at both ends of the liquid accumulation cylinder are in a converging shape, a liquid accumulation cavity is provided inside the liquid accumulation cylinder, a gas source connector is installed at one end of the liquid accumulation cylinder, the other end of the liquid accumulation cylinder is communicated with the screen pipe, a first one-way valve that only opens towards the liquid accumulation cavity is installed at one end of the liquid accumulation cylinder close to the gas source connector, a second one-way valve that only opens towards the liquid accumulation cavity is installed at the other end of the liquid accumulation cylinder away from the first one-way valve, a liquid discharge channel is provided on the liquid accumulation cylinder, and the liquid discharge channel is used to communicate the liquid accumulation cavity with the outside;

[0011] An outer shell sleeve, the liquid accumulation cylinder is located inside the outer shell sleeve and is detachably connected to the outer shell sleeve, fixing heads are installed at both ends of the outer shell sleeve, the fixing heads are used to fix the position of the liquid accumulation cylinder, and the screen pipe is connected to the outer shell sleeve through the fixing heads.

[0012] Further, the liquid accumulation cylinder is of a multi-section structure and is detachably connected by means of threads or buckles. When the multi-section liquid accumulation cylinders are assembled and installed, the liquid accumulation cavity is formed.

[0013] Further, the present invention further includes:

[0014] A sealing member, the sealing member is located inside the liquid accumulation cavity, and the sealing member is used to seal the openings at both ends of the liquid accumulation cylinder.

[0015] Further, the sealing member is of a spherical structure, the sealing member moves freely inside the liquid accumulation cavity, and the gravity of the sealing member is less than the buoyancy force, so that the sealing member moves along with the liquid level inside the liquid accumulation cavity.

[0016] Further, funnel-shaped grooves are provided at both ends of the liquid accumulation cylinder, and the openings of the two grooves face each other.

[0017] Further, when the liquid accumulation cylinder is installed inside the outer shell sleeve, a communication cavity is formed between the outer shell sleeve and the liquid accumulation cylinder. The liquid discharge channel includes a first channel, a second channel and a third channel. The first channel is located on the side of the liquid accumulation cylinder close to the gas source connector, and the first channel is used to communicate the communication cavity with the outside. The second channel is located on the side of the liquid accumulation cylinder away from the first channel, and the first channel is used to communicate the liquid accumulation cavity with the screen pipe. The third channel is located in the liquid accumulation cylinder and is used to communicate the first channel and the communication cavity.

[0018] Further, in the present invention, the second one-way valve is installed in the second channel.

[0019] Further, in the present invention, the liquid accumulation collection assembly further includes:

[0020] A plug, which is installed at one end of the screen pipe away from the outer casing sleeve.

[0021] Further, in the present invention, a plurality of liquid guiding holes are provided on the side wall of the screen pipe.

[0022] Further, in the present invention, the plug is of a hollow cylindrical structure, and the diameter of the plug is greater than the diameter of the screen pipe.

[0023] When the automatic gas-driven drainage downhole tool provided by the present invention is in use, the liquid accumulation cylinder is placed inside the outer casing sleeve and its position is fixed by two fixing heads. Both ends of the liquid accumulation cylinder are in a converging and opening shape. There is a liquid accumulation cavity inside the liquid accumulation cylinder. A gas source connector is installed at one end of the liquid accumulation cylinder and is connected to a high-pressure gas source. The other end of the liquid accumulation cylinder is connected to the screen pipe. A first one-way valve that only opens towards the liquid accumulation cavity is installed at one end of the liquid accumulation cylinder close to the gas source connector. A second one-way valve that only opens towards the liquid accumulation cavity is installed at the other end of the liquid accumulation cylinder away from the first one-way valve. A liquid discharge channel is provided on the liquid accumulation cylinder, and the liquid discharge channel is used to communicate the liquid accumulation cavity with the outside. That is to say, this device uses the formation pressure to automatically collect the well fluid into the liquid accumulation cylinder, and then the ground gas source station pressurizes to discharge the well fluid in the liquid accumulation cylinder to the ground. There are two one-way valves inside the liquid accumulation cavity, which respectively control the one-way flow of gas and liquid, ensuring that the liquid can only enter the liquid accumulation cavity from the wellbore and is discharged through the liquid discharge channel, avoiding liquid backflow. This device can significantly improve the liquid discharge efficiency, reduce the negative impact of liquid accumulation on the production of gas wells, eliminate the need for manual intervention, reduce the operation complexity and cost. At the same time, the gas-driven drainage method can adapt to different well depths and pressure conditions, and has strong versatility. Description of the Drawings

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the provided drawings.

[0025] Figure 1 It is a schematic structural diagram of the whole device provided by the present invention when in use;

[0026] Figure 2 It is a schematic structural diagram of the outer casing sleeve provided by the present invention;

[0027] Figure 3Schematic diagram of the liquid accumulation cylinder provided by the present invention;

[0028] Figure 4 Schematic diagram of the structure after the liquid accumulation cylinder and the outer shell sleeve provided by the present invention are installed.

[0029] Figures 1-4 Among them, the reference numerals include:

[0030] Liquid accumulation collection component 1, screen pipe 101, plug 102, liquid guiding hole 103, liquid accumulation cylinder 2, liquid accumulation cavity 201, gas source joint 202, first one-way valve 203, second one-way valve 204, sealing member 205, groove 206, liquid discharge channel 3, second channel 301, first channel 302, communication cavity 303, third channel 304, outer shell sleeve 4, fixed head 5. Specific implementation manner

[0031] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] The core of the present invention is to provide an automatic gas-driven downhole drainage tool, which can significantly improve the liquid drainage efficiency, reduce the negative impact of liquid accumulation on gas well production, and does not require manual intervention, reducing the operation complexity and cost.

[0033] Please refer to Figures 1-4 , an automatic gas-driven downhole drainage tool, including a liquid accumulation collection component 1, a liquid accumulation cylinder 2 and an outer shell sleeve 4. The liquid accumulation component includes a screen pipe 101, and a plurality of liquid guiding holes 103 are provided on the screen pipe 101. The openings at both ends of the liquid accumulation cylinder 2 are in a converging shape. A liquid accumulation cavity 201 is provided inside the liquid accumulation cylinder 2. A gas source joint 202 is installed at one end of the liquid accumulation cylinder 2. The other end of the liquid accumulation cylinder 2 is communicated with the screen pipe 101. A first one-way valve 203 that only opens in the direction of the liquid accumulation cavity 201 is installed at one end of the liquid accumulation cylinder 2 close to the gas source joint 202. A second one-way valve 204 that only opens in the direction of the liquid accumulation cavity 201 is installed at the other end of the liquid accumulation cylinder 2 away from the first one-way valve 203. A liquid discharge channel 3 is provided on the liquid accumulation cylinder 2. The liquid discharge channel 3 is used to communicate the liquid accumulation cavity 201 with the outside. The liquid accumulation cylinder 2 is located inside the outer shell sleeve 4 and is detachably connected to the outer shell sleeve 4. Fixed heads 5 are installed at both ends of the outer shell sleeve 4. The fixed heads 5 are used to fix the position of the liquid accumulation cylinder 2. The screen pipe 101 is connected to the outer shell sleeve 4 through the fixed head 5.

[0034] It should be noted that the fixed head 5 in the embodiments of the present invention is a hollow cylindrical structure.

[0035] In addition, in the embodiment of the present invention, a boss is provided on the fixed head 5, and a corresponding boss is provided on the liquid accumulation cylinder 2, and the position of the liquid accumulation cylinder 2 is fixed through the boss.

[0036] In the above embodiment, the fixed head 5 and the outer shell sleeve 4 are connected by threads or an opening connection. Through the precisely machined threads or snap fits, a tight connection can be achieved, ensuring the sealing and stability of the tool in a high-pressure environment. The threaded connection has the advantages of simple installation and convenient disassembly.

[0037] In addition, in the embodiment of the present invention, the gas source connector 202 adopts a ferrule type quick-connect fitting, which realizes quick connection and disconnection through an internal ferrule mechanism and is applicable to high-pressure gas pipelines. Its characteristics are good sealing performance and pressure bearing

[0038] Optionally, in some embodiments, a filter screen is provided on the screen pipe 101 for filtering the liquid accumulated in the screen pipe 101 through the liquid guide holes 103.

[0039] In the above embodiment, an air supply pipe is provided on the outer shell sleeve 4, and the air supply pipe is communicated with the screen pipe 101. After long-term use, the liquid guide holes 103 may be blocked. At this time, high-pressure gas is introduced into the screen pipe 101, and the liquid guide holes 103 are cleaned by means of back blowing.

[0040] In some other embodiments, a valve is provided on the liquid discharge channel 3, and the second one-way valve 204 is replaced with a solenoid valve. When the liquid guide holes 103 need to be cleaned, the valve is closed, and the liquid discharge channel 3 remains closed. At this time, high-pressure gas enters the liquid accumulation cavity 201, and the accumulated liquid is squeezed back into the screen pipe 101, and the liquid guide holes 103 can be cleaned by means of high pressure.

[0041] Optionally, in some embodiments, both the first one-way valve 203 and the second one-way valve 204 adopt one-way ball valves.

[0042] During use, place the liquid accumulation cylinder 2 inside the outer casing sleeve 4 and fix its position through two fixing heads 5. Both ends of the liquid accumulation cylinder 2 are in a converging and opening shape. There is a liquid accumulation cavity 201 inside the liquid accumulation cylinder 2. A gas source connector 202 is installed at one end of the liquid accumulation cylinder 2, and the gas source connector 202 is connected to a high-pressure gas source. The other end of the liquid accumulation cylinder 2 is connected to the screen pipe 101. A first one-way valve 203 that only opens towards the liquid accumulation cavity 201 is installed at one end of the liquid accumulation cylinder 2 close to the gas source connector 202. A second one-way valve 204 that only opens towards the liquid accumulation cavity 201 is installed at the other end of the liquid accumulation cylinder 2 away from the first one-way valve 203. A liquid discharge channel 3 is provided on the liquid accumulation cylinder 2, and the liquid discharge channel 3 is used to connect the liquid accumulation cavity 201 with the outside. That is to say, this device automatically collects well fluid into the liquid accumulation cylinder 2 using formation pressure, and then discharges the well fluid in the liquid accumulation cylinder 2 to the ground by pressurization from a ground gas source station. There are two one-way valves inside the liquid accumulation cavity 201, which respectively control the one-way flow of gas and liquid, ensuring that the accumulated liquid can only enter the liquid accumulation cavity 201 from the wellbore and is discharged through the liquid discharge channel 3, avoiding liquid backflow. This device can significantly improve the liquid discharge efficiency, reduce the negative impact of accumulated liquid on gas well production, eliminate the need for manual intervention, reduce the operation complexity and cost. At the same time, the gas-driven drainage method can adapt to different well depths and pressure conditions, and has strong versatility.

[0043] Optionally, in some embodiments, the liquid accumulation cylinder 2 is of a multi-section structure and is detachably connected by threads or snap-fasteners. After the multi-section liquid accumulation cylinder 2 is assembled and installed, a liquid accumulation cavity 201 for collecting accumulated liquid is formed. That is to say, with the multi-section liquid accumulation cylinder 2, when used for different well depths, adjust the number of sections of the liquid accumulation cylinder 2, so as to adapt to different well depths, which is beneficial to improving the versatility of the device.

[0044] Optionally, in some embodiments, each section of the liquid accumulation pipe is connected by threads or snap-fasteners, and the outer casing is fixed by flanges or welding. The main effect of this structure is to be able to achieve segmented liquid accumulation and drainage, adapt to the liquid accumulation distribution at different depths in the wellbore, and improve the liquid discharge efficiency. At the same time, the segmented design facilitates the installation, disassembly and maintenance of the tool, and can flexibly adjust the tool length and configuration according to the well conditions.

[0045] In some other embodiments, a sliding sleeve device is provided between the liquid accumulation pipe and the outer casing. The opening and closing of the sliding sleeve are controlled hydraulically or mechanically to achieve segmented liquid accumulation and drainage. There are multiple liquid accumulation cavities 201 inside the liquid accumulation pipe, and each liquid accumulation cavity 201 is connected to the outer casing through the sliding sleeve. The effect of this structure is to be able to dynamically adjust the liquid accumulation and drainage points, adapt to the change of the liquid accumulation distribution in the wellbore, and improve the liquid discharge efficiency. The sliding sleeve design enhances the flexibility and adaptability of the tool, and is suitable for gas wells with uneven liquid accumulation distribution or complex well conditions.

[0046] Please refer to Figures 1-4, in some embodiments, it further includes a sealing member 205. The sealing member 205 is located in the liquid accumulation cavity 201, and the sealing member 205 is used to seal the openings at both ends of the liquid accumulation cylinder 2. That is to say, by controlling the flow of liquid and gas in the liquid accumulation cavity 201 through the sealing member 205, liquid can be prevented from entering the gas source, which is beneficial to avoiding damage to the equipment.

[0047] Optionally, in some embodiments, the sealing member 205 has a spherical structure. The sealing member 205 moves freely in the liquid accumulation cavity 201, and the gravity of the sealing member 205 is less than the buoyancy force, so that the sealing member 205 moves along with the liquid level in the liquid accumulation cavity 201. Specifically, a floating ball can be used as the sealing member 205, and the floating ball rises and falls with the liquid level to achieve the sealing of the liquid accumulation cavity 201.

[0048] In the above embodiments, in order to further improve the automation degree during the use of the liquid drainage device, a liquid level gauge can be installed at the top of the liquid accumulation cavity 201 to monitor the liquid level height in the liquid accumulation cavity 201 through the liquid level gauge. And there is also a control box. The liquid level gauge and the air pump are both electrically connected to the control box. When the liquid level gauge detects that the liquid reaches the preset height, the control box controls the air pump to work, so that air is supplied to the liquid accumulation cavity 201 to discharge the liquid. When the liquid level drops to the preset height, the control box controls the air pump to stop working, thereby realizing the automation of the device.

[0049] In some other embodiments, in order to further improve the convenience during the use of the device and reduce the use of underground cables, a barometer is installed on the air pump pipeline. The barometer is electrically connected to the control box. The air pump can be selected with a forward and reverse structure. That is, a certain negative pressure can be generated in the liquid accumulation cavity 201, so that the liquid accumulation cavity 201 sucks the liquid into it to improve the liquid collection efficiency. When the liquid enters the liquid accumulation cavity 201, it continuously pushes the floating ball upward. When the floating ball moves to the top of the liquid accumulation cavity 201 and seals the top opening, the pressure on the air pump pipeline continuously decreases, triggering the control box to control the air pump to rotate forward and start pressurizing the liquid accumulation cavity 201 to squeeze out the liquid from the liquid accumulation cavity 201. When the floating ball contacts and seals the bottom opening of the liquid accumulation cavity 201, the pressure in the liquid accumulation cavity 201 continuously increases, triggering the control box to control the air pump to stop working, thereby realizing the automatic operation of the device, reducing the use of underground cables at the same time, and improving the stability of the device.

[0050] Please continue to refer to Figures 1-4 , in some embodiments, funnel-shaped grooves 206 are provided at both ends of the liquid accumulation cylinder 2. The two grooves 206 face each other. That is to say, through the two grooves 206, after the floating ball enters the groove 206, it automatically moves to the lowest point of the groove 206, and the openings of the liquid accumulation cavity 201 are both located at the lowest point of the groove 206, so that the floating ball can completely seal the openings.

[0051] Optionally, in some embodiments, a rubber layer is provided at the groove 206. The provided rubber layer is made of a soft material, so that the sealing effect can be enhanced when the floating ball contacts it.

[0052] Please continue to refer to Figure 1 , in some embodiments, when the liquid accumulation cylinder 2 is installed in the outer shell sleeve 4, a communication cavity 303 is formed between the outer shell sleeve 4 and the liquid accumulation cylinder 2. The drain channel 3 includes a first channel 302, a second channel 301, and a third channel 304. The first channel 302 is located on the side of the liquid accumulation cylinder 2 close to the gas source connector 202. The first channel 302 is used to communicate the communication cavity 303 with the outside. That is to say, the liquid can be drained to the outside through the first channel 302. The second channel 301 is located on the side of the liquid accumulation cylinder 2 away from the first channel 302. The first channel 302 is used to communicate the liquid accumulation cavity 201 with the sieve tube 101. The third channel 304 is located in the liquid accumulation cylinder 2 and is used to communicate the first channel 302 and the communication cavity 303. That is to say, when squeezing and discharging the liquid in the liquid accumulation cavity 201, the liquid first flows to the second channel 301, but a second one-way valve 204 is provided there. Therefore, the liquid flows into the communication cavity 303 formed between the outer shell sleeve 4 and the liquid accumulation cylinder 2 through the third channel 304, and then is discharged to the outside through the first channel 302, realizing the discharge of the liquid.

[0053] In the above embodiment, the first channel 302 penetrates the side wall of the liquid accumulation cylinder 2 to achieve the purpose of communicating it with the outside.

[0054] Optionally, in some embodiments, the first channel 302 and the third channel 304 can be provided on the side wall of the liquid accumulation cylinder 2.

[0055] In some other embodiments, a connecting pipe is provided in the communication cavity 303 for connecting the third channel 304 and the first channel 302.

[0056] Optionally, in some embodiments, the second one-way valve 204 is installed in the second channel 301.

[0057] In some other embodiments, the second one-way valve 204 can also be installed at the opening of the liquid accumulation cylinder 2.

[0058] Please continue to refer to Figures 1-4 , in some embodiments, the liquid collection assembly 1 further includes a plug 102. The plug 102 is installed at one end of the sieve tube 101 away from the outer shell sleeve 4. The plug 102 is used to block the end of the sieve tube 101 to prevent the liquid guide holes 103 from being blocked when the sieve tube 101 penetrates deep into the well.

[0059] In some other embodiments, the end of the sieve tube 101 can be set to a blocked shape, and at the same time, no liquid guide holes 103 are provided on the side of the sieve tube 101 away from the liquid accumulation cylinder 2 to prevent the liquid guide holes 103 on the sieve tube 101 from being blocked.

[0060] Optionally, in some embodiments, a plurality of liquid guiding holes 103 are provided on the side wall of the screen pipe 101. Arranging them on the side wall of the screen pipe 101 can reduce the blockage of the liquid guiding holes 103 when the screen pipe 101 moves in the well.

[0061] Optionally, in some embodiments, a fixing column is fixedly installed inside the screen pipe. The fixing column is hollow, and a plurality of through holes communicating with the hollow position are provided on the fixing column. A thimble is slidably installed in the through holes, and the thimbles correspond to the positions of the liquid guiding holes one by one. Therefore, when it is necessary to clean the liquid guiding holes, only need to control a plurality of thimbles to slide so that they penetrate into the corresponding liquid guiding holes, and the cleaning of the liquid guiding holes can be realized.

[0062] Optionally, in some embodiments, a push shaft is slidably installed in the hollow position of the fixing column. One end of the push shaft is a pointed structure. When the push shaft moves downward, a plurality of thimbles can be pushed out of the through holes.

[0063] Optionally, in some embodiments, a reset member for driving each of the plurality of thimbles to slide in the direction of the hollow interior of the fixing column is provided on each of the plurality of thimbles. The reset member can be a spring.

[0064] Optionally, in some embodiments, a piston is slidably installed in the fixing column, and the hollow of the fixing column is communicated with an air pump. The push shaft is fixedly connected to the piston. When cleaning is required, the air pump supplies air to cause the piston to move, and then the push shaft moves to realize the cleaning of the liquid guiding holes.

[0065] Optionally, in some embodiments, a solenoid valve is provided on the pipeline connecting the air pump and the fixing column.

[0066] Optionally, in some embodiments, a reset member for resetting the push shaft is provided on the fixing column. The reset member can be a spring.

[0067] Optionally, in some embodiments, the plug 102 is a hollow cylindrical structure, and the diameter of the plug 102 is larger than the diameter of the screen pipe 101. By increasing the diameter of the plug 102, the plug 102 protects the screen pipe 101, so that when the screen pipe 101 penetrates into the well, the contact between the screen pipe 101 and the well wall is reduced, which is conducive to reducing the blockage of the liquid guiding holes 103.

[0068] That is to say, the key point of the embodiment of the present invention lies in: the cooperation of the liquid accumulation cylinder 2 and the outer shell sleeve 4 is adopted. One end of the liquid accumulation cylinder 2 is provided with a gas source connector 202, and the gas source connector 202 is communicated with a high-pressure gas source. The other end of the liquid accumulation cylinder 2 is communicated with the screen pipe 101. A first one-way valve 203 that only opens towards the liquid accumulation cavity 201 is installed at one end of the liquid accumulation cylinder 2 close to the gas source connector 202. A second one-way valve 204 that only opens towards the liquid accumulation cavity 201 is installed at the end of the liquid accumulation cylinder 2 far from the first one-way valve 203. A liquid discharge channel 3 is provided on the liquid accumulation cylinder 2, and the liquid discharge channel 3 is used to communicate the liquid accumulation cavity 201 with the outside. That is to say, this device automatically collects well fluid into the liquid accumulation cylinder 2 by using the formation pressure, and then discharges the well fluid in the liquid accumulation cylinder 2 to the ground by pressurization from a ground gas source station. Two one-way valves are arranged inside the liquid accumulation cavity 201 to respectively control the one-way flow of gas and liquid, ensuring that the accumulated liquid can only enter the liquid accumulation cavity 201 from the wellbore and is discharged through the liquid discharge channel 3, avoiding liquid backflow. This device can significantly improve the liquid discharge efficiency, reduce the negative impact of accumulated liquid on gas well production, and does not require manual intervention, reducing the operation complexity and cost. At the same time, the gas-driven drainage method can adapt to different well depths and pressure conditions and has strong versatility.

[0069] The various embodiments in this specification are described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other.

[0070] The above has introduced in detail an automatic gas-driven drainage downhole tool provided by the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present invention, several improvements and modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the present invention.

Claims

1. An automatic gas-driven downhole tool for drainage, characterized in that, Comprising: A liquid accumulation collecting component (1), the liquid accumulation component includes a screen pipe (101), and a plurality of liquid guiding holes (103) are provided on the screen pipe (101); A liquid accumulation cylinder (2), the openings at both ends of the liquid accumulation cylinder (2) are in a converging shape, a liquid accumulation cavity (201) is provided inside the liquid accumulation cylinder (2), a gas source connector (202) is installed at one end of the liquid accumulation cylinder (2), the other end of the liquid accumulation cylinder (2) is communicated with the screen pipe (101), a first one-way valve (203) that only opens towards the liquid accumulation cavity (201) is installed at one end of the liquid accumulation cylinder (2) close to the gas source connector (202), a second one-way valve (204) that only opens towards the liquid accumulation cavity (201) is installed at the other end of the liquid accumulation cylinder (2) far from the first one-way valve (203), a liquid discharge channel (3) is provided on the liquid accumulation cylinder (2), and the liquid discharge channel (3) is used to communicate the liquid accumulation cavity (201) with the outside; An outer shell sleeve (4), the liquid accumulation cylinder (2) is located inside the outer shell sleeve (4) and is detachably connected to the outer shell sleeve (4), fixing heads (5) are installed at both ends of the outer shell sleeve (4), the fixing heads (5) are used to fix the position of the liquid accumulation cylinder (2), and the screen pipe (101) is connected to the outer shell sleeve (4) through the fixing heads (5).

2. The automatic gas-driven downhole tool according to claim 1, characterized in that, The liquid accumulation cylinder (2) is of a multi-section structure and is detachably connected by means of threads or buckles. When multiple sections of the liquid accumulation cylinder (2) are assembled and installed, the liquid accumulation cavity (201) is formed.

3. An automatic gas-driven downhole tool for drainage according to claim 1, wherein Further comprising: A plugging member (205), the plugging member (205) is located inside the liquid accumulation cavity (201), and the plugging member (205) is used to plug the openings at both ends of the liquid accumulation cylinder (2).

4. The automatic gas-driven downhole tool according to claim 3, wherein The plugging member (205) is of a spherical structure, the plugging member (205) moves freely inside the liquid accumulation cavity (201), and the gravity of the plugging member (205) is less than the buoyancy force, so that the plugging member (205) moves along with the liquid level inside the liquid accumulation cavity (201).

5. An automatic gas-driven downhole tool according to claim 4, characterized in that, Funnel-shaped grooves (206) are provided at both ends of the liquid accumulation cylinder (2), and the openings of the two grooves (206) face each other.

6. An automatic gas-driven downhole tool for drainage according to any one of claims 1-5, characterized in that, When the liquid accumulation cylinder (2) is installed inside the outer shell sleeve (4), a communication cavity (303) is formed between the outer shell sleeve (4) and the liquid accumulation cylinder (2). The liquid discharge channel (3) includes a first channel (302), a second channel (301) and a third channel (304). The first channel (302) is located on one side of the liquid accumulation cylinder (2) close to the gas source connector (202), and the first channel (302) is used to communicate the communication cavity (303) with the outside. The second channel (301) is located on the side of the liquid accumulation cylinder (2) far from the first channel (302), and the first channel (302) is used to communicate the liquid accumulation cavity (201) with the screen pipe (101). The third channel (304) is located on the liquid accumulation cylinder (2) and is used to communicate the first channel (302) with the communication cavity (303).

7. An automatic gas-driven downhole tool for draining water according to claim 6, characterized in that The second one-way valve (204) is installed in the second channel (301).

8. An automatic gas-driven downhole tool for drainage according to claim 6, characterized in that, The liquid collection component (1) further includes: A plug (102), which is installed at one end of the screen pipe (101) away from the outer shell sleeve (4).

9. The automatic gas-driven downhole tool according to claim 8, characterized in that, A plurality of the liquid guiding holes (103) are arranged on the side wall of the screen pipe (101).

10. The automatic gas-driven downhole tool according to claim 9, characterized in that, The plug (102) is of a hollow cylindrical structure, and the diameter of the plug (102) is larger than the diameter of the screen pipe (101).

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