Liquid drainage and gas production device
By designing a floating body and sealing plug that automatically open and closes without external power supply, the problem of complex external power supply in existing technologies has been solved, realizing automated fluid channel control, improving natural gas recovery rate and reducing operational complexity and manufacturing costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHINA PETROLEUM & CHEMICAL CORP
- Filing Date
- 2025-05-08
- Publication Date
- 2026-05-05
AI Technical Summary
Existing downhole fluid drainage devices require external power supply and control, resulting in complex systems and cumbersome operations, which affects natural gas recovery rates.
A fluid drainage and gas production device without external functions was designed. It utilizes the reciprocating movement of a float and a sealing plug within the wellbore to automatically open and close the through hole through buoyancy and pressure difference. The structure is simple, including a sleeve, a sealing plug, and a float. Under the action of buoyancy, the float drives the sealing plug to rise or fall, thereby achieving the sealing and opening of the fluid channel.
It achieves automatic start-up and shutdown without external power supply, simplifies the device structure, improves natural gas recovery rate, and reduces operational complexity and manufacturing costs.
Smart Images
Figure CN224200617U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of natural gas extraction and development equipment, and in particular to a liquid drainage and gas extraction device. Background Technology
[0002] During natural gas extraction, formation water flows with the natural gas and accumulates in and near the wellbore. If this accumulated fluid is not drained in time, it will seriously affect the normal production of the gas well and reduce the natural gas recovery rate.
[0003] Currently, most existing downhole fluid drainage devices use plungers, which reciprocate within the wellbore to lift fluid accumulated at the bottom of the well. In these technologies, as the plunger descends along the wellbore, a through-hole opens, allowing fluid at the bottom of the well to flow through and above the plunger. Then, the through-hole closes, and the pressure of the gas at the bottom of the well pushes the plunger upwards along the wellbore, thus discharging the fluid above the plunger from the wellhead. However, this device uses electrically controlled equipment (such as a motor) to control the opening and closing of the plunger and wellbore, requiring external power, making the system complex, and necessitating periodic replenishment, such as battery replacement, which makes operation cumbersome. Utility Model Content
[0004] This application provides a liquid drainage and gas collection device that can be turned on and off without external functions, and has a simple structure, reducing manufacturing costs.
[0005] This application provides a drainage and gas production device for use in a wellbore, comprising: a sleeve having an axially extending cavity, an annular limiting boss extending radially inward on the inner wall of the sleeve, the inner wall of the annular limiting boss forming a first through hole; a sealing plug disposed within the cavity and clearance-fitted with the sleeve, the sealing plug being axially disposed on one side of the annular limiting boss, the sealing plug having a fluid channel for fluid in the wellbore to pass through the sleeve; and a float disposed on the side of the limiting boss away from the sealing plug, the float being connected to the sealing plug, and the float being movable relative to the sealing plug along the axial direction; wherein the device includes a first state and a second state, in the first state, the float moves upward in the wellbore to close the first through hole with the sealing plug, and the float blocks the fluid channel; in the second state, the float moves downward in the wellbore to open the fluid channel with the float, and the sealing plug opens the first through hole.
[0006] According to the aforementioned embodiments of this application, the sealing plug includes a sealing part and a connecting part. The connecting part is rod-shaped and passes through the first through hole and is clearance-fitted with the first through hole. The sealing part is disposed on the side of the limiting boss away from the float. The sealing part is fixedly connected to the connecting part. The float is slidably sleeved on the connecting part. The fluid channel includes a first opening and a second opening. The first opening is disposed on the side wall of the connecting part and is disposed on the side of the sealing part facing the limiting boss. The second opening is disposed on the side of the sealing part away from the limiting boss.
[0007] According to any of the foregoing embodiments of this application, the sealing plug further includes a limiting part, which is fixedly connected to the connecting part and is disposed on the side of the float away from the limiting boss. The limiting part is used to limit the float in the axial direction. In the first state, the float moves upward in the wellbore and abuts against the limiting part, so that the float closes the first opening to block the fluid passage and the sealing part closes the first through hole. In the second state, the float moves downward in the wellbore and disengages from the limiting part, so that the float opens the first opening to conduct the fluid passage and the sealing part opens the first through hole.
[0008] According to any of the foregoing embodiments of this application, a straightening component is further included. The straightening component is disposed in the cavity and connected to the sealing part so that the sealing plug reciprocates axially within the cavity of the sleeve.
[0009] According to any of the foregoing embodiments of this application, the straightening assembly includes a straightening rod and a straightening ring. The straightening ring is fixedly connected to a sleeve. The straightening rod passes through the straightening ring in the axial direction and is movably connected to the straightening ring. One end of the straightening rod is fixedly connected to a sealing part.
[0010] According to any of the foregoing embodiments of this application, the sleeve, the first through hole, and the straightening ring are all coaxially arranged.
[0011] According to any of the foregoing embodiments of this application, the straightening rod and the connecting part are coaxially arranged, and the second opening is provided on the end face of the straightening rod away from the sealing part.
[0012] According to any of the foregoing embodiments of this application, the radial dimension of the sealing portion is greater than the radial dimension of the first through hole.
[0013] According to any of the foregoing embodiments of this application, the limiting boss has a first wedge-shaped surface on the side facing the sealing part, and the sealing part has a second wedge-shaped surface on the side facing the limiting boss. The first wedge-shaped surface and the second wedge-shaped surface cooperate to seal the first through hole.
[0014] According to any of the foregoing embodiments of this application, the float is a hollow structure.
[0015] According to the embodiments of this application, the liquid drainage and gas production device is placed at the bottom of the wellbore during use. The sleeve and wellbore are fitted with a clearance fit, allowing the sleeve to reciprocate relative to the wellbore along its axial direction under external force. When liquid accumulates in the wellbore, it flows upward through a first through-hole formed on the inner wall of the limiting boss, while natural gas also moves upward along the first through-hole. As the liquid level in the wellbore rises, the float rises relative to the sealing plug within the wellbore under buoyancy. When the float reaches a certain position, it blocks the fluid passage. Under buoyancy, the float continues to drive the sealing plug to rise relative to the sleeve within the wellbore until the sealing plug engages with the limiting boss inside the sleeve. The sealing plug then blocks the first through-hole, preventing the fluid from flowing upward through it, and the liquid drainage and gas production device enters its first state. As gas accumulates in the well, the pressure difference between the upper and lower ends of the sealing plug increases until it can push the entire drainage and gas production device upwards along the wellbore, causing the accumulated liquid above the device to flow towards the wellhead. When the device reaches the vicinity of the wellhead, the accumulated liquid is continuously discharged, and the float descends in the wellbore along with it. When the float reaches a certain position, it releases the blockage of the fluid channel in the sealing plug, allowing the channel to open. Gas below the sealing plug flows upwards through the fluid channel, reducing the pressure difference between the upper and lower ends of the sealing plug and causing it to disengage from the limiting boss. The drainage and gas production device then enters its second state. Under gravity, the device moves downwards within the wellbore, returning to its initial state. When the accumulated liquid in the wellbore increases again, the device repeats the above process. This device requires no external function for opening and closing the first through-hole and has a simple structure. Attached Figure Description
[0016] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings.
[0017] Figure 1 This is a schematic diagram of the structure of the liquid drainage and gas collection device in the first state according to an embodiment of this application;
[0018] Figure 2 This is a schematic diagram of the structure of the liquid drainage and gas collection device in the second state in one embodiment of this application.
[0019] Figure label:
[0020] 1000-Drainage and gas extraction device; 100-Sleeve; 110-Limiting boss; 111-First through hole; 200-Sealing plug; 210-Fluid channel; 211-First opening; 212-Second opening; 220-Sealing part; 230-Connecting part; 240-Limiting part; 300-Float; 400-Centering assembly; 410-Centering rod; 420-Centering ring. Detailed Implementation
[0021] The present invention will be further described below with reference to the accompanying drawings.
[0022] This application provides a liquid drainage and gas collection device that can be turned on and off without external functions, and has a simple structure that is easy to process and manufacture.
[0023] Figure 1 This is a schematic diagram of the structure of the drainage and gas collection device 1000 in the first state in one embodiment of this application; Figure 2 This is a schematic diagram of the structure of the drainage and gas collection device 1000 in the second state according to an embodiment of this application. Figure 1-2 As shown, this application embodiment provides a drainage and gas production device 1000, which is used in a wellbore. The drainage and gas production device 1000 includes a sleeve 100, a sealing plug 200, and a float 300. The sleeve 100 has an axially extending cavity, and an annular limiting boss 110 extending radially inward is provided on the inner wall of the sleeve 100. The inner wall of the annular limiting boss 110 forms a first through hole 111. The sealing plug 200 is disposed within the cavity and has a clearance fit with the sleeve 100. The sealing plug 200 is axially disposed on one side of the annular limiting boss 110 and has a fluid channel 210 for fluid in the wellbore to pass through the sleeve 100. The float 300 is disposed on the side of the limiting boss 110 opposite to the sealing plug 200. The float 300 is connected to the sealing plug 200 and is axially movable relative to the sealing plug 200. The device includes a first state and a second state. In the first state, the float 300 moves upward in the wellbore to close the first through-hole 111 with the sealing plug 200, and the float 300 blocks the fluid passage 210. In the second state, the float 300 moves downward in the wellbore to open the fluid passage 210, and the sealing plug 200 opens the first through-hole 111.
[0024] The buoyancy of the float 300 in the accumulated fluid is greater than the sum of the weights of the sealing plug 200 and the sleeve 100, causing the float 300 to lift the sealing plug 200 and the sleeve 100 together within the wellbore under the action of buoyancy. The float 300 can be made of a material with low density, or the interior of the float 300 can be made into a hollow structure, etc.
[0025] The float 300 is connected to the sealing plug 200, and the float 300 can move relative to the sealing plug 200 along the axial direction of the sleeve 100. It can be understood that the float 300 and the sealing plug 200 can be slidably connected, specifically, the float 300 is slidably sleeved on the sealing plug 200; the float 300 and the sealing plug 200 can also be indirectly movably connected through a connecting assembly, specifically, the float 300 is connected to a sliding collar sleeved on the sealing plug 200 through a flexible element. Under the action of buoyancy, the float 300 can cause the flexible element to pull the sliding collar to move circumferentially relative to the sealing plug 200. During the axial reciprocating movement of the sealing plug 200, the sliding collar can open or block the fluid channel 210.
[0026] It should be noted that, in the initial position, the fluid below the sealing plug 200 can flow upward through the first through hole 111 of the limiting boss 110. The fluid can be liquid or natural gas. At this time, the connection between the float 300 and the fluid channel 210 is not restricted. As the liquid level in the wellbore rises, the buoyancy of the float 300 in the liquid causes it to rise in the wellbore. When the float 300 rises to its limit position relative to the sealing plug 200, it blocks the fluid channel 210 and causes the sealing plug 200 to rise relative to the sleeve 100 in the wellbore until the sealing plug 200 closes the first through hole 111. Then, the entire liquid drainage and gas production device 1000, consisting of the float 300, the sealing plug 200, and the sleeve 100, rises in the wellbore.
[0027] According to the embodiment of this application, the liquid drainage and gas production device 1000 is placed at the bottom of the wellbore during use. The sleeve 100 is clearance-fitted with the wellbore, allowing the sleeve 100 to reciprocate relative to the wellbore along its axial direction under external force. When liquid accumulates in the wellbore, it can flow upward through the first through hole 111 formed on the inner wall of the limiting boss 110, and natural gas can also move upward along the first through hole 111. As the liquid level in the wellbore rises, the float 300 rises relative to the sealing plug 200 within the wellbore under buoyancy. When the float 300 reaches a certain position, it blocks the fluid passage 210. Under buoyancy, the float 300 continues to drive the sealing plug 200 to rise relative to the sleeve 100 within the wellbore until the sealing plug 200 engages with the limiting protrusion inside the sleeve 100. The sealing plug 200 then blocks the first through hole 111, preventing the fluid from flowing upward through the first through hole 111, and the liquid drainage and gas production device 1000 enters its first state. As gas continuously accumulates in the gas well, the pressure difference between the upper and lower ends of the sealing plug 200 increases until the pressure difference is sufficient to push the entire liquid drainage and gas production device 1000 upward along the wellbore, causing the accumulated liquid at the top of the device to flow towards the wellhead. When the drainage and gas production device 1000 reaches the vicinity of the wellhead, the accumulated liquid will continuously be discharged from the wellhead. The float 300 will descend in the wellbore along with the discharged liquid. When the float 300 descends to a certain position, it releases the blockage of the fluid channel 210 of the sealing plug 200, allowing the fluid channel 210 to be opened. The gas below the sealing plug 200 flows upward through the fluid channel 210, thereby reducing the pressure difference between the upper and lower ends of the sealing plug 200, causing the sealing plug 200 to disengage from the limiting boss 110, and the drainage and gas production device 1000 enters the second state. Then, under the action of gravity, the drainage and gas production device 1000 moves downward in the wellbore, returning to the initial state. When the accumulated liquid in the wellbore increases again, the drainage and gas production device 1000 repeats the above working process. This drainage and gas production device 1000 does not require external functions when opening and closing the first through hole 111 and has a simple structure.
[0028] like Figure 1-2 As shown, in some embodiments, the sealing plug 200 includes a sealing portion 220 and a connecting portion 230. The connecting portion 230 is rod-shaped, passes through the first through hole 111 and is clearance-fitted with the first through hole 111. The sealing portion 220 is disposed on the side of the limiting boss 110 away from the float 300. The sealing portion 220 is fixedly connected to the connecting portion 230. The float 300 is slidably sleeved on the connecting portion 230. The fluid channel 210 includes a first opening 211 and a second opening 212. The first opening 211 is disposed on the side wall of the connecting portion 230 and is disposed on the side of the sealing portion 220 facing the limiting boss 110. The second opening 212 is disposed on the side of the sealing portion 220 away from the limiting boss 110.
[0029] In this embodiment, the float 300 is directly sleeved on the connecting part 230. When the float 300 is buoyed by the fluid in the wellbore, it can rise relative to the connecting part 230 inside the wellbore. When the float 300 rises to its limit position relative to the connecting part 230, it can block the first opening 211 of the fluid channel 210. This allows the float 300 to drive the connecting part 230 and the sealing part 220 to rise together under the action of buoyancy, until the sealing part 220 engages with the limiting boss 110 and blocks the first through hole 111. This allows the float 300 to drive the connecting part 230, the sealing part 220, and the sleeve 100 to rise inside the wellbore, thereby discharging the fluid from the wellhead. After the accumulated fluid is discharged, the float 300 moves downward relative to the connecting part 230 inside the wellbore. When it reaches a certain position, the float 300 opens the first opening 211, allowing the fluid channel 210 to be open. Gas in the lower part of the sealing part 220 can enter the upper part of the sealing part 220 through the fluid channel 210, thereby reducing the pressure difference between the upper and lower parts of the sealing part 220. The sealing plug 200 moves under its own gravity. When the sealing part 220 separates from the limiting boss 110, the entire fluid drainage and gas extraction device 1000 moves downward under gravity until it returns to its initial position.
[0030] like Figure 1-2 As shown, in some embodiments, the sealing plug 200 further includes a limiting portion 240. The limiting portion 240 is fixedly connected to the connecting portion 230, and the limiting portion 240 is disposed on the side of the float 300 opposite to the limiting boss 110. The limiting portion 240 is used to limit the float 300 in the axial direction. In a first state, the float 300 moves upward in the wellbore and abuts against the limiting portion 240, so that the float 300 closes the first opening 211 to block the fluid passage 210, and the sealing portion 220 closes the first through hole 111. In a second state, the float 300 moves downward in the wellbore and disengages from the limiting portion 240, so that the float 300 opens the first opening 211 to conduct the fluid passage 210, and the sealing portion 220 opens the first through hole 111.
[0031] In this embodiment, when the float 300 rises relative to the sealing plug 200 under the buoyancy of the accumulated liquid, when it rises to abut against the limiting part 240, the float 300 can block the first opening 211. Then the float 300 drives the sealing plug 200 to rise together with it relative to the sleeve 100 in the wellbore until the sealing plug 200 engages with the limiting boss 110.
[0032] like Figure 1-2As shown, in some embodiments, the drainage and gas sampling device 1000 further includes a centralizing component 400. The centralizing component 400 is disposed within the cavity and connected to the sealing portion 220, allowing the sealing plug 200 to reciprocate axially within the cavity of the sleeve 100. In this embodiment, the centralizing component 400 guides the sealing portion 220 of the sealing plug 200 to reciprocate axially along the sleeve 100, ensuring the effectiveness of the sealing plug 200 in sealing the first through hole 111 of the limiting boss 110.
[0033] like Figure 1-2 As shown, in some embodiments, the straightening assembly 400 includes a straightening rod 410 and a straightening ring 420. The straightening ring 420 is fixedly connected to the sleeve 100, and the straightening rod 410 passes through the straightening ring 420 and is movably connected to the straightening ring 420 in the axial direction. One end of the straightening rod 410 is fixedly connected to the sealing part 220.
[0034] The straightening rod 410 moves back and forth axially relative to the straightening ring 420, thereby driving the sealing part 220 connected to the straightening rod 410 to move back and forth axially, so as to ensure that the movement trajectory of the sealing plug 200 in the axial direction of the sleeve 100 is a straight line, so that the sealing part 220 can effectively seal the first through hole 111.
[0035] like Figure 1-2 As shown, in some embodiments, the sleeve 100, the first through hole 111, and the straightening ring 420 are all coaxially arranged to reduce the large offset and vibration generated when the sealing plug 200 moves axially, thereby improving the stability and accuracy of the device.
[0036] like Figure 1-2 As shown, in some embodiments, the straightening rod 410 and the connecting portion 230 are coaxially arranged, and the second opening 212 is provided on the end face of the straightening rod 410 away from the sealing portion 220, so that fluid can easily enter the fluid channel 210 from the second opening 212, avoiding the straightening rod 410 or the straightening ring 420 from blocking the second opening 212 when they move relative to each other. At the same time, providing the second opening 212 on the end face of the straightening rod 410 away from the sealing portion 220 facilitates the processing and manufacturing of the fluid channel 210.
[0037] like Figure 1-2 As shown, in some embodiments, the radial dimension of the sealing part 220 is larger than the radial dimension of the first through hole 111, so as to ensure that the sealing part 220 can effectively block the first through hole 111 when it rises to abut against the limiting boss 110.
[0038] like Figure 1-2As shown, in some embodiments, the limiting boss 110 has a first wedge-shaped surface on the side facing the sealing part 220, and the sealing part 220 has a second wedge-shaped surface on the side facing the limiting boss 110. The first wedge-shaped surface and the second wedge-shaped surface cooperate to seal the sealing part 220 against the first through hole 111. The wedge-shaped cooperation provides mechanical self-locking to prevent the sealing part 220 from loosening under pressure or vibration, improve the sealing effect, and adapt to high pressure or dynamic working conditions.
[0039] like Figure 2 As shown, in some embodiments, the float 300 is a hollow structure to increase its own buoyancy.
[0040] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A drainage and gas production device for use in a wellbore, characterized in that, include: A sleeve is provided with a cavity extending along the axial direction. An annular limiting boss extending radially inward is provided on the inner wall of the sleeve, and the inner wall of the annular limiting boss forms a first through hole. A sealing plug, disposed within the cavity and clearance-fitted with the sleeve, is axially positioned on one side of the annular limiting boss and has a fluid channel for fluid in the wellbore to pass through the sleeve; and A float is disposed on the side of the limiting boss away from the sealing plug. The float is connected to the sealing plug and can move relative to the sealing plug along the axial direction. The device includes a first state and a second state. In the first state, the float moves upward in the wellbore to close the first through hole with the sealing plug, and the float blocks the fluid passage. In the second state, the float moves downward in the wellbore to open the fluid passage, and the sealing plug opens the first through hole.
2. The drainage and gas extraction device as described in claim 1, characterized in that, The sealing plug includes a sealing part and a connecting part. The connecting part is rod-shaped and passes through the first through hole, fitting with it with a clearance. The sealing part is located on the side of the limiting boss facing away from the float. The sealing part is fixedly connected to the connecting part, and the float is slidably sleeved on the connecting part. The fluid channel includes a first opening and a second opening. The first opening is disposed on the side wall of the connecting part and is disposed on the side of the sealing part facing the limiting boss. The second opening is disposed on the side of the sealing part away from the limiting boss.
3. The drainage and gas extraction device as described in claim 2, characterized in that, The sealing plug also includes a limiting part, which is fixedly connected to the connecting part, and the limiting part is disposed on the side of the float away from the limiting boss. The limiting part is used to limit the float in the axial direction. In the first state, the float moves upward in the wellbore and abuts against the limiting part, so that the float closes the first opening to block the fluid passage, and the sealing part closes the first through hole; in the second state, the float moves downward in the wellbore and disengages from the limiting part, so that the float opens the first opening to conduct the fluid passage, and the sealing part opens the first through hole.
4. The drainage and gas extraction device as described in claim 2, characterized in that, It also includes a straightening component, which is disposed in the cavity and connected to the sealing part, so that the sealing plug reciprocates within the cavity of the sleeve along the axial direction.
5. The drainage and gas extraction device as described in claim 4, characterized in that, The straightening assembly includes a straightening rod and a straightening ring. The straightening ring is fixedly connected to the sleeve. The straightening rod passes through the straightening ring in the axial direction and is movably connected to the straightening ring. One end of the straightening rod is fixedly connected to the sealing part.
6. The drainage and gas extraction device as described in claim 5, characterized in that, The sleeve, the first through hole, and the straightening ring are all coaxially arranged.
7. The drainage and gas extraction device as described in claim 5, characterized in that, The straightening rod is coaxially arranged with the connecting part, and the second opening is provided on the end face of the straightening rod away from the sealing part.
8. The drainage and gas extraction device as described in claim 2, characterized in that, The radial dimension of the sealing part is greater than the radial dimension of the first through hole.
9. The drainage and gas extraction device as described in claim 7, characterized in that, The limiting boss has a first wedge-shaped surface on the side facing the sealing part, and the sealing part has a second wedge-shaped surface on the side facing the limiting boss. The first wedge-shaped surface and the second wedge-shaped surface cooperate to seal the first through hole.
10. The drainage and gas extraction device as described in any one of claims 1-9, characterized in that, The float is a hollow structure.