Gas lift valve reversing device

Abstract

The utility model discloses a gas lift valve reversing device, which relates to the technical field of gas production process, and comprises a working barrel connected in series on an oil pipe, two ends of the working barrel are opened, and both ends of the working barrel are communicated with the oil pipe; an airflow channel is formed in the side wall of the working barrel, and the two ends of the airflow channel penetrate through the inner wall and the outer wall of the working barrel respectively. And in the direction from the outer end to the inner end of the air flow channel, the air flow channel inclines towards the flowing direction of well fluid. By the adoption of the scheme, the inclined airflow channel is formed in the gas lift valve, the flowing direction of introduced high-pressure gas is almost consistent with the flowing direction of fluid in a shaft, the high-pressure gas transmits kinetic energy to liquid flowing along the pipe wall at a low speed, and therefore liquid slippage is reduced, and the gas lift efficiency is improved; the high-pressure air flow does not directly impact the inner wall of the oil pipe after coming out of the air flow channel, working barrel perforation caused by the fact that the high-pressure air flow directly impacts the inner wall of the oil pipe is effectively avoided, the gas lift valve working barrel can be effectively protected, and the production period of a gas lift well is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of gas production technology, and particularly relates to a gas lift valve commutation device. Background Art

[0002] The gas lift process is an artificial lift process that injects high-pressure gas into the tubing through a high-pressure gas source, reduces the flow pressure gradient above the gas injection point, reduces the slippage loss during the lifting process, discharges the bottom-hole liquid accumulation, increases the production pressure difference, and restores or improves the production capacity of the gas well. Compared with other processes, the gas lift process has great advantages, such as wide application range, low failure rate, and long maintenance-free period.

[0003] At present, there are dozens of various types of gas lift valves used abroad. The commonly used non-balanced bellows casing pressure-operated valve in China. At present, the mainly applied gas lift valve is the injection pressure-operated valve. The gas lift valve working barrel is the carrier of the valve. At present, there are different types of gas lift valve working barrels (ordinary material, stainless steel, 35CrMo, 718) suitable for various situations (conventional gas lift, high-pressure gas lift, acidification drainage process combined process, suitable for high-sulfur gas wells), suitable for various tubing sizes (1.5in, 2in, 2.5in, 3.0in), various thread types, and different corrosive media. The integral gas lift valve working barrel can be made with higher strength than the connected same-type tubing and longer service life than the tubing to ensure that the process will not fail due to the working barrel. At present, the integral working barrel completely replaces the welded working barrel.

[0004] The use of gas lift valves is currently the main process for drainage gas production in gas lift, but there are the following problems in the current process:

[0004]

[0005] 1) Natural gas and water flow upward from the bottom of the well to the wellhead. When the conventional gas lift injection gas enters the inside of the working barrel through the gas lift valve from the annulus, the injection direction of the injection gas is downward, as shown in Figure 3 Figure 3 the gas lift ejection direction in the working barrel. While causing a large amount of energy loss, the downward flowing injection gas will greatly reduce the gas lift efficiency and gas lift stability.

[0006] 2) The gas lift valve working barrel is a mixing channel for high-pressure gas and well fluid. When the gas lift is not implemented, the central flow velocity in the working barrel is the fastest and the flow velocity along the pipe wall is the lowest. Since the outlet of the gas lift valve working barrel forms a 90-degree angle with the flow direction of the fluid in the tubing, when the gas lift injection gas enters the inside of the working barrel from the annulus through the working barrel, it will successively pass through the low-speed area, the central high-speed area, and then to the low-speed area on the opposite pipe wall, and the high-pressure gas forms local turbulence, resulting in low gas lift efficiency.

[0007] 3) In the design of process parameters for conventional gas lift devices, multi-point gas injection should be avoided as much as possible because it will reduce the gas lift efficiency. At the same time, the gas injection pressure, gas injection volume, and drainage volume fluctuate violently. Even when the formation pressure drops to a certain extent, a "short circuit" is formed, resulting in the injected gas circulating in the wellbore and rendering the gas lift ineffective. Summary of the Invention

[0008] The purpose of the present utility model is to provide a gas lift valve commutation device to solve the deficiencies of the prior art. By adopting this solution, an inclined gas flow channel is opened on the gas lift valve, making the flow direction of the introduced high-pressure gas nearly the same as the flow direction of the fluid in the wellbore. The high-pressure gas transfers kinetic energy to the liquid flowing slowly along the pipe wall, thereby reducing liquid slippage and improving the gas lift efficiency. Moreover, the high-pressure gas flow will not directly impact the inner wall of the tubing after coming out of the gas flow channel, effectively avoiding the perforation of the working barrel caused by the direct impact of the high-pressure gas flow on the inner wall of the tubing, protecting the working barrel of the gas lift valve, and extending the production cycle of the gas lift well.

[0009] The present utility model is realized through the following technical solutions:

[0010] A gas lift valve commutation device, comprising:

[0011] A working barrel connected in series on the tubing, with both ends of the working barrel open and both communicating with the tubing;

[0012] A gas flow channel is opened on the side wall of the working barrel, and both ends of the gas flow channel penetrate the inner wall and the outer wall of the working barrel respectively;

[0013] In the direction from the outer end to the inner end of the gas flow channel, the gas flow channel is inclined in the direction of the well fluid flow.

[0014] In the prior art, the gas lift process is an artificial lift process that injects high-pressure gas into the tubing through a high-pressure gas source, reduces the flow pressure gradient above the gas injection point, reduces the slippage loss during the lifting process, discharges the bottom-hole liquid accumulation, increases the production pressure difference, and restores or improves the production capacity of the gas well. Compared with other processes, the gas lift process has greater advantages, such as a wide application range, low failure rate, and long maintenance-free period. For example Figure 1 and Figure 2As shown in the figure, let A-A be the static liquid level position after the gas well is flooded. When high-pressure gas is injected from the casing, the high-pressure gas causes the liquid level in the casing to drop and the liquid level in the tubing to rise. When the liquid level in the casing drops to the inlet B-B of the first gas lift valve, the gas lift valve is opened by the pressure of the high-pressure gas. The high-pressure gas enters the tubing through the gas lift valve. Under the action of the gas expansion force, the liquid above the B-B interface is lifted to the ground. At the same time, due to a large amount of high-pressure gas entering the tubing, the casing pressure decreases. When the casing pressure drops to the closing pressure of the gas lift valve, the first gas lift valve closes. Then, the high-pressure gas forces the liquid level in the casing to drop again and the liquid level in the tubing to rise. When the liquid level in the casing drops to the inlet C-C of the second gas lift valve, the second gas lift valve is opened by the high-pressure gas, and the liquid above the C-C to B-B interface is lifted to the ground. In this way, the liquid level in the tubing is continuously lowered until the gas well resumes production. During the design of process parameters, the design depth, opening pressure and other parameters are designed starting from the first gas lift valve at the top, and then the second gas lift valve, and so on in sequence. Therefore, through the above gas lift valve gas production principle, the following problems will occur: 1) The downward flowing injection gas causes a large amount of energy loss, and at the same time, the gas lift efficiency and gas lift stability will be greatly reduced; 2) When the gas lift injection gas enters the inside of the working barrel from the annulus through the working barrel, it will successively pass through the low-speed area, the central high-speed area, and then to the low-speed area on the opposite pipe wall. The high-pressure gas forms turbulence locally, and the gas lift efficiency is low; 3) When the formation pressure drops to a certain extent, a "short circuit" is formed, resulting in the injection gas circulating in the wellbore, resulting in problems such as ineffective gas lift. Therefore, the present invention provides a gas lift valve commutation device. By adopting this solution, an inclined air flow channel is opened on the gas lift valve, so that the flowing direction of the introduced high-pressure gas is almost the same as the flowing direction of the fluid in the wellbore. The high-pressure gas transfers kinetic energy to the liquid flowing at a low speed along the pipe wall, thereby reducing liquid slippage and improving gas lift efficiency. Moreover, the high-pressure gas flow will not directly impact the inner wall of the tubing after coming out of the air flow channel, effectively avoiding the perforation of the working barrel caused by the direct impact of the high-pressure gas flow on the inner wall of the tubing, and can effectively protect the working barrel of the gas lift valve and extend the production cycle of the gas lift well.

[0015] In a specific solution, it includes a working barrel connected in series in the middle of the tubing. The working barrel is coaxially arranged with the tubing and is communicated with the tubing at both ends. An inclined air flow channel is arranged on the side wall of the working barrel. The air flow channel is inclined in the direction of the well fluid flow. In this way, the external high-pressure gas source can inject high-pressure gas into the inside through the air flow channel, and the injection direction of the high-pressure gas is basically the same as the well fluid flow direction. In this way, the high-pressure gas can transfer kinetic energy to the liquid flowing slowly along the pipe wall, thereby reducing liquid slippage and improving the gas lift efficiency. In addition, the present invention has also made improvements in erosion resistance. During the conventional gas lift process, the flow velocity in the center of the flow is usually fast, and the flow velocity along the pipe wall is low. In the present invention, the high-pressure gas can transfer kinetic energy to the liquid flowing slowly along the pipe wall, making the flow velocity along the pipe wall high. For wells with high temperature and easy scaling, it can significantly reduce the deposition of scale substances. At the same time, the fast flow velocity can also make some scale substances break away from the pipe wall. The design of the Laval nozzle can significantly improve the flow pattern, make the gas-liquid mixture more uniform, and the drainage efficiency higher. And the high-pressure air flow will not directly impact the inner wall of the tubing after coming out of the air flow channel, effectively avoiding the perforation of the working barrel caused by the direct impact of the high-pressure air flow on the inner wall of the tubing, and can effectively protect the gas lift valve working barrel and extend the production cycle of the gas lift well. Before the working barrel enters the well, the debugged gas lift valve is first passed through the protective sleeve on the ground, and then the end of the gas lift valve is fixed to the valve sleeve by threads. Finally, the plug and the compression spring are screwed into the tail end of the protective sleeve to fix the gas lift valve.

[0016] To facilitate the connection of the gas supply equipment to the working barrel, a valve sleeve is coaxially sleeved on the working barrel. The valve sleeve is sleeved at the position of the air flow channel, and a hole communicating with the air flow channel is opened on the valve sleeve. In this solution, a valve sleeve is arranged at the position of the air flow channel. Through the arrangement of the valve sleeve and the hole on it, the air flow channel can be extended and it is convenient for the output end of the gas supply equipment to be connected.

[0017] As a detachable connection method, the valve sleeve is threadedly connected to the working barrel.

[0018] As a setting method of the valve sleeve, the valve sleeve is located at the upper end position of the working barrel; the direction of the hole in the valve sleeve is set in the direction of the well fluid flow. In this solution, when the valve sleeve is set above, in order to leave the installation space for the output end of the gas supply equipment, the ventilation direction of the hole in the valve sleeve is set in the direction of the well fluid flow. In this way, the output end of the gas supply equipment can be located below the hole, that is, in the middle position of the working barrel.

[0019] As another setting method of the valve sleeve, the valve sleeve is located at the lower end position of the working barrel; the direction of the hole in the valve sleeve is opposite to the direction of the well fluid flow. In this solution, when the valve sleeve is set below, in order to leave the installation space for the output end of the gas supply equipment, the ventilation direction of the hole in the valve sleeve is opposite to the direction of the well fluid flow. In this way, the output end of the gas supply equipment can be located above the hole, that is, also in the middle position of the working barrel.

[0020] To protect the gas lift valve, a protective sleeve is also sleeved on the working barrel, and the protective sleeve and the valve sleeve are respectively arranged at both ends of the working barrel. In this solution, a protective sleeve is added to the working barrel, which can reduce the possibility of damaging the gas lift valve when it is put in, and also reduce the erosion of the downhole environment on the gas lift valve.

[0021] As a detachable connection method, the protective sleeve and the working barrel are threadedly connected. In addition, a plug is configured on the protective sleeve. There is a circumferential groove at one end of the protective sleeve closest to the end of the working barrel. The plug is used to be screwed into the circumferential groove and abutted tightly. After the configured plug is screwed into the internal thread of the protective sleeve, it can clamp the gas lift valve, effectively preventing the radial vibration of the gas lift valve and improving the reliability of the fixation of the gas lift valve.

[0022] As a series connection method of the gas lift valve, the upper and lower ends of the working barrel are respectively provided with upper threads and lower threads.

[0023] Compared with the prior art, the present utility model has the following advantages and beneficial effects:

[0024] A gas lift valve commutation device provided by the present utility model adopts this solution. By providing an inclined gas flow channel on the gas lift valve, the flowing direction of the introduced high-pressure gas is nearly the same as the flowing direction of the fluid in the wellbore. The high-pressure gas transfers kinetic energy to the liquid flowing slowly along the pipe wall, thereby reducing liquid slippage and improving the gas lift efficiency. Moreover, after the high-pressure gas flow comes out of the gas flow channel, it will not directly impact the inner wall of the oil pipe, effectively avoiding the perforation of the working barrel caused by the direct impact of the high-pressure gas flow on the inner wall of the oil pipe, effectively protecting the working barrel of the gas lift valve and extending the production cycle of the gas lift well. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings described herein are used to provide a further understanding of the embodiments of the present utility model, form a part of this application, and do not limit the embodiments of the present utility model. In the drawings:

[0026] Figure 1 is a schematic diagram of the gas lift drainage gas production process in the prior art;

[0027] Figure 2 is a schematic diagram of the downhole pipe string of the gas lift drainage gas production process in the prior art;

[0028] Figure 3 is a cross-sectional view of the working barrel of the gas lift valve in the prior art;

[0029] Figure 4 is a schematic structural diagram of a gas lift valve commutation device provided by the present invention;

[0030] Figure 5 is another schematic structural diagram of a gas lift valve commutation device provided by the present invention.

[0031] Marks in the drawings and corresponding component names:

[0032] 1 - Lower thread, 2 - Plug, 3 - Protective sleeve, 4 - Working cylinder, 5 - Valve sleeve, 6 - Air flow channel, 7 - Upper thread. Detailed implementation manners

[0033] In order to make the purpose, technical solutions and advantages of the present utility model clearer and more understandable, the present utility model will be further described in detail below in conjunction with embodiments and drawings. The illustrative implementation manners of the present utility model and their descriptions are only used to explain the present utility model and do not limit the present utility model.

[0034] Embodiment:

[0035] This embodiment provides a gas lift valve commutation device, as Figures 1 - 5 shown, including:

[0036] A working cylinder 4 connected in series on the oil pipe, both ends of the working cylinder 4 are open and communicate with the oil pipe;

[0037] An air flow channel 6 is opened on the side wall of the working cylinder 4, and both ends of the air flow channel 6 penetrate the inner wall and the outer wall of the working cylinder 4 respectively;

[0038] In the direction from the outer end to the inner end of the air flow channel 6, the air flow channel 6 is inclined in the direction of the well fluid flow.

[0039] In the prior art, the gas lift process is an artificial lift process that injects high-pressure gas into the oil pipe through a high-pressure gas source, reduces the flow pressure gradient above the gas injection point, reduces the slippage loss during the lifting process, discharges the bottom-hole liquid accumulation, increases the production pressure difference, and restores or improves the production capacity of the gas well. Compared with other processes, the gas lift process has greater advantages. It has a wide application range, low failure rate, and long maintenance-free period. As Figure 1 and Figure 2As shown in the figure, let A-A be the static liquid level position after the gas well is flooded. When high-pressure gas is injected from the casing, the high-pressure gas causes the liquid level in the casing to drop and the liquid level in the tubing to rise. When the liquid level in the casing drops to the inlet B-B of the first gas lift valve, the gas lift valve is opened by the pressure of the high-pressure gas. The high-pressure gas enters the tubing through the gas lift valve. Under the action of the gas expansion force, the liquid above the B-B interface is lifted to the ground. At the same time, due to a large amount of high-pressure gas entering the tubing, the casing pressure decreases. When the casing pressure drops to the closing pressure of the gas lift valve, the first gas lift valve closes. Then, the high-pressure gas forces the liquid level in the casing to drop again and the liquid level in the tubing to rise. When the liquid level in the casing drops to the inlet C-C of the second gas lift valve, the second gas lift valve is opened by the high-pressure gas, and the liquid above the C-C to B-B interface is lifted to the ground. In this way, the liquid level in the tubing is continuously reduced until the gas well resumes production. During the design process of process parameters, the design depth, opening pressure and other parameters are designed starting from the first gas lift valve at the top, and then the second gas lift valve, and so on in sequence. Therefore, through the above gas lift valve gas production principle, the following problems will occur: 1) The downward flowing injection gas causes a large amount of energy loss, and at the same time, the gas lift efficiency and gas lift stability will be greatly reduced; 2) When the gas lift injection gas enters the inside of the working barrel 4 from the annulus through the working barrel 4, it will successively pass through the low-speed area, the central high-speed area, and then to the low-speed area on the opposite pipe wall. The high-pressure gas forms turbulence locally, and the gas lift efficiency is low; 3) When the formation pressure drops to a certain extent, a "short circuit" is formed, resulting in the injection gas circulating in the wellbore and causing the gas lift to be ineffective. Therefore, the present invention provides a gas lift valve commutation device. Adopting this solution, by opening an inclined gas flow channel 6 on the gas lift valve, the flowing direction of the introduced high-pressure gas is nearly the same as the flowing direction of the fluid in the wellbore. The high-pressure gas transfers kinetic energy to the liquid flowing at a low speed along the pipe wall, thereby reducing liquid slippage and improving the gas lift efficiency. Moreover, after the high-pressure gas flow comes out of the gas flow channel 6, it will not directly impact the inner wall of the tubing, effectively avoiding the perforation of the working barrel 4 caused by the direct impact of the high-pressure gas flow on the inner wall of the tubing, and can effectively protect the gas lift valve working barrel 4 and extend the production cycle of the gas lift well.

[0040] In a specific solution, it includes a working cylinder 4 connected in series in the middle of the tubing. The working cylinder 4 is coaxially arranged with the tubing and is communicated with the tubing at both ends. An inclined air flow channel 6 is arranged on the side wall of the working cylinder 4. The air flow channel 6 is inclined in the direction of well fluid flow. In this way, the external high-pressure gas source can inject high-pressure gas into the inside through the air flow channel 6, and the injection direction of the high-pressure gas is basically the same as the well fluid flow direction. In this way, the high-pressure gas can transfer kinetic energy to the liquid flowing at a low speed along the pipe wall, thereby reducing liquid slippage and improving the gas lift efficiency. In addition, the present invention has also made improvements in erosion resistance. During the conventional gas lift process, usually the flow velocity in the center is fast and the flow velocity along the pipe wall is low. However, in the present invention, the high-pressure gas can transfer kinetic energy to the liquid flowing at a low speed along the pipe wall, making the flow velocity along the pipe wall high. For wells with high temperature and easy to scale, it can significantly reduce the deposition of scale substances. At the same time, the fast flow velocity can also make some scale substances break away from the pipe wall. The design of the Laval nozzle can significantly improve the flow pattern, make the gas-liquid mixture more uniform, and the drainage efficiency higher. And the high-pressure air flow will not directly impact the inner wall of the tubing after coming out of the air flow channel 6, effectively avoiding the perforation of the working cylinder 4 caused by the direct impact of the high-pressure air flow on the inner wall of the tubing, and can effectively protect the working cylinder 4 of the gas lift valve and extend the production cycle of the gas lift well. Before the working cylinder 4 is lowered into the well, on the ground, first pass the adjusted gas lift valve through the protective sleeve 3, then fix the end of the gas lift valve to the valve sleeve 5 by threads, and finally screw the plug 2 and the compression spring into the end of the protective sleeve 3 to fix the gas lift valve.

[0041] To facilitate the connection of the gas supply device to the working cylinder 4, a valve sleeve 5 is also coaxially sleeved on the working cylinder 4. The valve sleeve 5 is sleeved at the position of the air flow channel 6, and a hole communicating with the air flow channel 6 is opened on the valve sleeve 5. In this solution, a valve sleeve 5 is arranged at the position of the air flow channel 6. Through the setting of the valve sleeve 5 and the hole on it, the air flow channel 6 can be extended and it is convenient for the output end of the gas supply device to be connected.

[0042] As a detachable connection method, the valve sleeve 5 is threadedly connected to the working cylinder 4.

[0043] As a setting method of the valve sleeve 5, the valve sleeve 5 is located at the upper end of the working cylinder 4; the direction of the hole in the valve sleeve 5 is set in the direction of the well fluid flow. In this solution, when the valve sleeve 5 is arranged above, in order to leave an installation space for the output end of the gas supply device, the ventilation direction of the hole in the valve sleeve 5 is set in the direction of the well fluid flow. In this way, the output end of the gas supply device can be located below the hole, that is, in the middle position of the working cylinder 4.

[0044] As another setting method of the valve sleeve 5, the valve sleeve 5 is located at the lower end of the working cylinder 4; the direction of the passage in the valve sleeve 5 is opposite to the direction of the well fluid flow. In this solution, when the valve sleeve 5 is arranged below, in order to leave an installation space for the output end of the gas supply device, the air passage direction in the valve sleeve 5 is opposite to the direction of the well fluid flow. In this way, the output end of the gas supply device can be located above the passage, that is, at the middle position of the working cylinder 4.

[0045] To protect the gas lift valve, a protective sleeve 3 is also sleeved on the working cylinder 4, and the protective sleeve 3 and the valve sleeve 5 are respectively arranged at both ends of the working cylinder 4. In this solution, adding the protective sleeve 3 on the working cylinder 4 can reduce the possibility of damaging the gas lift valve when the gas lift valve is put in, and at the same time, it also reduces the erosion of the downhole environment on the gas lift valve.

[0046] As a detachable connection method, the protective sleeve 3 and the working cylinder 4 are threadedly connected. In addition, a plug 2 is also configured on the protective sleeve 3. There is a circumferential groove at one end of the protective sleeve 3 closest to the end of the working cylinder 4. The plug 2 is used to be screwed into the circumferential groove and tightened. After the configured plug 2 is screwed into the internal thread of the protective sleeve 3, it can clamp the gas lift valve, effectively preventing the radial vibration of the gas lift valve and improving the reliability of the fixation of the gas lift valve.

[0047] As a series connection method of the gas lift valves, the upper and lower ends of the working cylinder 4 are respectively provided with an upper thread 7 and a lower thread 1.

[0048] The specific embodiments described above have further elaborated on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above description is only the specific embodiments of the present invention and is not used to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A gas lift valve reversing device, characterized in that: include: A working cylinder (4) connected in series to the oil pipe, wherein both ends of the working cylinder (4) are open and both are connected to the oil pipe; An air flow channel (6) is provided on the side wall of the working cylinder (4), and two ends of the air flow channel (6) respectively penetrate the inner wall and the outer wall of the working cylinder (4); From the outer end to the inner end of the air flow channel (6), the air flow channel (6) is inclined in the direction of well fluid flow.

2. A gas lift valve reversing device according to claim 1, characterized in that: The working cylinder (4) is also coaxially sleeved with a valve sleeve (5), the valve sleeve (5) being sleeved at the position of the air flow channel (6), and the valve sleeve (5) is provided with a hole communicating with the air flow channel (6).

3. A gas lift valve reversing device according to claim 2, characterized in that: The valve sleeve (5) and the working cylinder (4) are threadedly connected.

4. A gas lift valve reversing device according to claim 2, characterized in that: The valve sleeve (5) is located at the upper end of the working cylinder (4).

5. A gas lift valve reversing device according to claim 4, characterized in that: The direction of the hole in the valve sleeve (5) is arranged towards the direction of flow of the well fluid.

6. A gas lift valve reversing device according to claim 2, characterized in that: The valve sleeve (5) is located at the lower end of the working cylinder (4).

7. A gas lift valve reversing device according to claim 6, characterized in that: The direction of the channel in the valve sleeve (5) is opposite to the direction in which the well fluid flows.

8. A gas lift valve reversing device according to claim 2, characterized in that: The working cylinder (4) is also sleeved with a protective sleeve (3), and the protective sleeve (3) and the valve sleeve (5) are respectively arranged at two ends of the working cylinder (4).

9. A gas lift valve reversing device according to claim 8, characterized in that: The protective sleeve (3) and the working cylinder (4) are threadedly connected.

10. The gas lift valve reversing device according to claim 1, characterized in that: The upper and lower ends of the working cylinder (4) are respectively provided with an upper thread (7) and a lower thread (1).

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