Pressurized gas lift drainage gas recovery device

Abstract

The utility model relates to the technical field of natural gas extraction, in particular to a pressurized gas lift drainage gas extraction device which comprises a natural gas well, a gas pump, a gravity gas-liquid separator, a sealing cover, a gas injection pipe and an extrusion pipe. The sealing cover is fixedly installed at the top end of the natural gas well, and the gas injection pipe is installed between the sealing cover and the gas pump; the extrusion pipe is mounted between the gravity gas-liquid separator and the sealing cover and extends into the natural gas well; a connecting pipe is fixedly mounted on the gravity gas-liquid separator, a flash tank is fixedly mounted at the tail end of the connecting pipe, a recovery pipe is fixedly mounted on the flash tank, a gas supply group is fixedly mounted at the tail end of the recovery pipe, and the gas supply group comprises a first nitrogen tank, a second nitrogen tank, a three-way pipe, a normally closed electromagnetic valve and a normally open electromagnetic valve; nitrogen supply is maintained through the gas supply set, so that a high-pressure environment is kept in the natural gas well, and the effect of continuous gas production operation is achieved.

Description

Technical Field

[0001] This utility model relates to the field of natural gas extraction technology, and in particular to a pressurized gas lift drainage gas extraction device. Background Technology

[0002] During gas field development, as production time increases and formation energy is continuously depleted, liquid accumulation at the bottom of gas wells is prone to occur. This severely affects normal gas production, leading to reduced output or even shutdown. Therefore, efficient pressurized gas lift drainage gas production equipment is crucial for the continuous and stable development of gas fields. In practical applications, pressurized gas lift drainage gas production equipment typically requires the following technologies:

[0003] 1. Pressurization mechanism: such as a compressor, which can pressurize the gas injected into the gas well, giving it sufficient pressure to lift the liquid accumulated at the bottom of the well to the surface;

[0004] 2. Gas-liquid separation mechanism: such as gravity separator or centrifugal separator, which effectively separates the gas-liquid mixture after it reaches the ground;

[0005] 3. Injection control mechanism: including various valves and control systems, which precisely control parameters such as the injection volume, injection pressure and injection time of the booster gas, and make flexible adjustments according to the actual production situation of the gas well to achieve the best drainage and gas production effect.

[0006] An existing Chinese patent, "A Drainage Gas Extraction Device," publication number CN207004489U, includes a natural gas compressor, a gas-liquid separator, and a sealing cover fixed to the top of a gas well. The sealing cover has a connector and a central hole connecting to the gas well at its top. A delivery pipe is fixed inside the central hole, with its lower end extending into the gas well and its upper end extending out of the gas well. The gas-liquid separator has an inlet and an outlet on its side wall. The inlet is connected to the upper end of the delivery pipe, and a shut-off valve is connected to the outlet. The top of the gas-liquid separator has a gas outlet connected to the inlet of the natural gas compressor. The natural gas compressor has an outlet A and an outlet B. The outlet B of the natural gas compressor is connected to a connector, and a delivery pipeline is connected to the outlet A of the natural gas compressor.

[0007] However, during the implementation of the above technical solution, at least the following technical problems were found: After the above-mentioned drainage gas extraction device pumps out natural gas and accumulated liquid, the gas pressure in the natural gas well will decrease, the pumped liquid will be discharged to the outside, and part of the extracted natural gas will be stored and part will be compressed and reinjected into the natural gas well. As the natural gas and accumulated liquid are discharged, the gas pressure in the natural gas well will decrease. After the compressed natural gas enters, it expands back to its original volume, but it is still impossible to maintain high pressure inside the natural gas well. Therefore, as the natural gas and accumulated liquid are discharged, the gas pressure inside the well decreases, and gas extraction operations cannot be carried out continuously. Utility Model Content

[0008] To address the shortcomings of existing technologies, this utility model provides a pressurized gas lift drainage gas extraction device, which solves the problem that in the aforementioned drainage gas extraction devices, after natural gas and accumulated liquid are pumped out, the gas pressure in the natural gas well will decrease, the pumped liquid will be discharged to the outside, and part of the extracted natural gas will be stored and part will be compressed and reinjected into the natural gas well. As natural gas and accumulated liquid are discharged, the gas pressure in the natural gas well will decrease, and the compressed natural gas will re-expand to its original volume after entering, still unable to maintain high pressure inside the natural gas well. Therefore, as natural gas and accumulated liquid are discharged, the gas pressure inside the well decreases, making it impossible to continue gas extraction operations.

[0009] To achieve the above objectives, this utility model provides the following technical solution:

[0010] A pressurized gas lift drainage gas extraction device includes a natural gas well, a gas pump, a gravity gas-liquid separator, a sealing cap, an injection pipe, and an extrusion pipe. The sealing cap is fixedly installed at the top of the natural gas well. The injection pipe is installed between the sealing cap and the gas pump. The extrusion pipe is installed between the gravity gas-liquid separator and the sealing cap, and extends into the interior of the natural gas well. A connecting pipe is fixedly installed on the gravity gas-liquid separator. A flash tank is fixedly installed at the end of the connecting pipe. A recovery pipe is fixedly installed on the flash tank. A gas supply group is fixedly installed at the end of the recovery pipe. The gas supply group includes a first nitrogen tank, a second nitrogen tank, a three-way pipe, a normally closed solenoid valve, and a normally open solenoid valve.

[0011] Preferably, the first nitrogen cylinder and the second nitrogen cylinder are connected to the gas pump via a three-way pipe.

[0012] Preferably, the first nitrogen tank and the second nitrogen tank are connected to the flash tank via a recovery pipe.

[0013] Preferably, a solenoid valve assembly is installed between the first nitrogen tank and the second nitrogen tank and the recovery pipe and the tee pipe.

[0014] Preferably, the solenoid valve assembly includes a normally closed solenoid valve and a normally open solenoid valve.

[0015] Preferably, the normally closed solenoid valve and the normally open solenoid valve are connected in series via wires.

[0016] Preferably, a liquid level sensor is fixedly installed inside the gravity gas-liquid separator.

[0017] Preferably, the height of the liquid level sensor is lower than that of the extrusion tube.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. During operation, the gas supply unit will supply nitrogen to the gas pump. The gas pump will send the nitrogen into the natural gas well along the injection pipe, increasing the gas pressure inside the natural gas well. This will then force the gas-liquid mixture of nitrogen, natural gas, and sludge through the extrusion pipe into the gravity gas-liquid separator. After entering the gravity gas-liquid separator, the sludge will fall to the bottom of the separator and be discharged under the influence of gravity, while the mixture of nitrogen and natural gas will enter the flash tank along the connecting pipe. The flash tank will separate the nitrogen and natural gas, and the natural gas will be sent to the storage device. The gas supply unit will supply nitrogen to maintain a high-pressure environment inside the natural gas well, thus achieving the effect of continuous gas production operations.

[0020] 2. The separated nitrogen gas will be sent to the first nitrogen tank and the second nitrogen tank through the recovery pipe. During this process, if the normally closed solenoid valve at the outlet of the first nitrogen tank is in the open state, the normally open solenoid valve at the outlet of the second nitrogen tank will be in the closed state. At this time, the normally closed solenoid valve at the inlet of the second nitrogen tank will be in the open state, and the normally open solenoid valve at the inlet of the first nitrogen tank will be in the closed state. The first nitrogen tank will supply gas to the gas pump, while the nitrogen gas separated by the flash tank will be discharged to the second nitrogen tank for storage. Similarly, when the second nitrogen tank supplies gas, the first nitrogen tank stores gas, which can reduce the consumption of nitrogen gas and improve the utilization rate of nitrogen gas in the gas supply group. Attached Figure Description

[0021] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model and to implement it in accordance with the contents of the specification, the preferred embodiments of this utility model are described in detail below with reference to the accompanying drawings.

[0022] Figure 1 This is an overall structural diagram of the present invention;

[0023] Figure 2 This is a connection structure diagram of the present invention;

[0024] Figure 3 This is a structural diagram of the gas supply unit of this utility model;

[0025] Figure 4This is a cross-sectional structural diagram of the gravity gas-liquid separator of this utility model.

[0026] Legend: 1. Natural gas well; 2. Gas pump; 3. Gravity gas-liquid separator; 4. Sealing cap; 5. Gas injection pipe; 6. Extrusion pipe; 7. Connecting pipe; 8. Flash tank; 9. Recovery pipe; 11. First nitrogen tank; 12. Second nitrogen tank; 13. T-connector; 14. Normally closed solenoid valve; 15. Normally open solenoid valve; 16. Liquid level sensor. Detailed Implementation

[0027] This application provides a pressurized gas lift drainage gas extraction device, effectively solving the problem of reduced gas pressure in the natural gas well after the aforementioned drainage gas extraction devices discharge natural gas and sludge. The discharged sludge is released to the outside, and some of the extracted natural gas is stored while the rest is compressed and reinjected into the well. As the natural gas and sludge are discharged, the gas pressure in the well decreases, and the compressed natural gas expands back to its original volume, failing to maintain high pressure inside the well. Therefore, the reduced well pressure due to the discharge of natural gas and sludge makes continuous gas extraction impossible. In operation, the gas supply unit provides nitrogen to the gas pump, which then delivers the nitrogen along the injection pipe into the natural gas well, increasing the internal pressure. This causes the gas-liquid mixture of nitrogen, natural gas, and sludge to be extruded through the extrusion pipe into a gravity gas-liquid separator. After entering the gravity gas-liquid separator, the sludge falls into the separator under gravity. The nitrogen and natural gas mixture discharged from the bottom of the gas-liquid separator will enter the flash tank along the connecting pipe. The flash tank will separate the nitrogen and natural gas. The natural gas will be sent to the storage device, and nitrogen will be supplied through the gas supply group to maintain a high-pressure environment inside the natural gas well, achieving the effect of continuous gas production. The separated nitrogen will be sent to the first nitrogen tank and the second nitrogen tank along the recovery pipe. During this process, if the normally closed solenoid valve at the outlet of the first nitrogen tank is in the open state, the normally open solenoid valve at the outlet of the second nitrogen tank will be in the closed state. At this time, the normally closed solenoid valve at the inlet of the second nitrogen tank will be in the open state, and the normally open solenoid valve at the inlet of the first nitrogen tank will be in the closed state. The first nitrogen tank will supply gas to the gas pump, and the nitrogen separated by the flash tank will be discharged to the second nitrogen tank for storage. Similarly, when the second nitrogen tank supplies gas, the first nitrogen tank stores gas, which can reduce nitrogen consumption and improve the utilization rate of nitrogen in the gas supply group.

[0028] Example

[0029] like Figure 1 , Figure 2 , Figure 3 and Figure 4As shown, the technical solution in this application embodiment effectively solves the problem of the aforementioned drainage gas extraction device. After the natural gas and accumulated liquid are discharged, the gas pressure in the natural gas well will decrease. The discharged accumulated liquid will be discharged to the outside. Part of the extracted natural gas will be stored, and part will be compressed and reinjected into the natural gas well. As the natural gas and accumulated liquid are discharged, the gas pressure in the natural gas well will decrease. The compressed natural gas will re-expand to its original volume after entering, but it is still impossible to maintain high pressure inside the natural gas well. Therefore, as the natural gas and accumulated liquid are discharged, the gas pressure inside the well decreases, making it impossible to continuously carry out gas extraction operations. The overall idea is as follows:

[0030] To address the problems existing in the prior art, this utility model provides a pressurized gas lift drainage gas extraction device, including a natural gas well 1, a gas pump 2, a gravity gas-liquid separator 3, a sealing cover 4, an injection pipe 5, and an extrusion pipe 6. The sealing cover 4 is fixedly installed at the top of the natural gas well 1, the injection pipe 5 is installed between the sealing cover 4 and the gas pump 2, and the extrusion pipe 6 is installed between the gravity gas-liquid separator 3 and the sealing cover 4, extending into the interior of the natural gas well 1.

[0031] A connecting pipe 7 is fixedly installed on the gravity gas-liquid separator 3. A flash tank 8 is fixedly installed at the end of the connecting pipe 7. A recovery pipe 9 is fixedly installed on the flash tank 8. A gas supply group is fixedly installed at the end of the recovery pipe 9. The gas supply group includes a first nitrogen tank 11, a second nitrogen tank 12, a three-way pipe 13, a normally closed solenoid valve 14, and a normally open solenoid valve 15. The first nitrogen tank 11 and the second nitrogen tank 12 are connected to the gas pump 2 through the three-way pipe 13.

[0032] The first nitrogen tank 11 and the second nitrogen tank 12 are connected to the flash tank 8 through the recovery pipe 9. A solenoid valve assembly is installed between the first nitrogen tank 11 and the second nitrogen tank 12 and the recovery pipe 9 and the three-way pipe 13. The solenoid valve assembly includes a normally closed solenoid valve 14 and a normally open solenoid valve 15. The normally closed solenoid valve 14 and the normally open solenoid valve 15 are connected in series by a wire. A liquid level sensor 16 is fixedly installed inside the gravity gas-liquid separator 3. The height of the liquid level sensor 16 is lower than that of the extrusion pipe 6.

[0033] Gas pump 2: It plays the role of transmitting nitrogen, receiving nitrogen from the gas supply group and sending it into the natural gas well 1 along the gas injection pipe 5, so as to provide the gas required for pressurization inside the natural gas well 1;

[0034] Gravity gas-liquid separator 3: used to receive the gas-liquid mixture pressed out from the natural gas well 1 and perform preliminary gas-liquid separation on it. After the gas-liquid mixture enters, the liquid falls into the gravity gas-liquid separator 3 under the action of gravity and is discharged, while the mixed gas enters the flash tank 8 along the connecting pipe 7.

[0035] Sealing cap 4: Fixedly installed at the top of natural gas well 1 to seal natural gas well 1;

[0036] Gas injection pipe 5: Installed between the sealing cover 4 and the gas pump 2, as part of the nitrogen transmission channel, connecting the gas pump 2 and the natural gas well 1, so that the nitrogen in the gas pump 2 can be smoothly delivered to the interior of the natural gas well 1.

[0037] Extrusion pipe 6: Installed between gravity gas-liquid separator 3 and sealing cover 4 and extending into the natural gas well 1, it is the channel for the gas-liquid mixture inside the natural gas well 1 to be discharged to gravity gas-liquid separator 3, and the gas-liquid mixture generated in the natural gas well 1 due to the increase in gas pressure is discharged to gravity gas-liquid separator 3 for subsequent processing.

[0038] Connecting pipe 7: It is fixedly installed on the gravity gas-liquid separator 3, and its end is connected to the flash tank 8. Its function is to guide the nitrogen and natural gas mixture separated from the gravity gas-liquid separator 3 into the flash tank 8. It is part of the gas transmission path.

[0039] Flash tank 8: Fixed at the end of connecting pipe 7, it separates the incoming nitrogen and natural gas mixture and sends the separated natural gas to the storage device, realizing the processing and storage of natural gas after gas-liquid separation. At the same time, it also participates in the nitrogen recycling process, sending the separated nitrogen along the recovery pipe 9 into the first nitrogen tank 11 and the second nitrogen tank 12.

[0040] Recovery pipe 9: Fixedly installed on flash tank 8, with its end connected to the gas supply group, serving as a transmission channel for nitrogen separated from flash tank 8, and transporting nitrogen to the first nitrogen tank 11 and the second nitrogen tank 12 of the gas supply group;

[0041] First nitrogen tank 11 and second nitrogen tank 12: As components of the gas supply group, they play a key role in the nitrogen recycling process. They alternately perform gas supply and storage operations. When one of them supplies gas to the gas pump 2, the other stores the nitrogen separated from the flash tank 8, thereby reducing nitrogen consumption and improving nitrogen utilization.

[0042] Three-way pipe 13: connects the first nitrogen tank 11, the second nitrogen tank 12 and the air pump 2, so that the nitrogen in the first nitrogen tank 11 and the second nitrogen tank 12 can be connected to the air pump 2 through the three-way pipe 13, so as to realize the function of supplying gas to the air pump 2. It is an important connecting component of the nitrogen transmission path.

[0043] Normally closed solenoid valve 14 and normally open solenoid valve 15: As solenoid valve components, they are connected in series by wires to form an interlock. They are installed between the first nitrogen tank 11, the second nitrogen tank 12 and the recovery pipe 9 and the three-way pipe 13 to control the gas inlet and outlet states of the first nitrogen tank 11 and the second nitrogen tank 12. Their on and off states cooperate with each other to realize the function of alternating gas supply and storage of the first nitrogen tank 11 and the second nitrogen tank 12, ensuring the orderly progress of the nitrogen recycling process.

[0044] Liquid level sensor 16: Fixedly installed inside the gravity gas-liquid separator 3, its height is lower than that of the extrusion tube 6. It is used to detect the liquid level inside the gravity gas-liquid separator 3. When the liquid level is higher than that of the gravity gas-liquid separator 3, the air pump 2 is turned off to allow the accumulated liquid in the gravity gas-liquid separator 3 to have time to drain, thus preventing the accumulated liquid from accumulating and causing backflow or entering the flash tank 8.

[0045] Working principle:

[0046] In the first step, during operation, the gas supply unit supplies nitrogen to the gas pump 2. The gas pump 2 delivers the nitrogen into the natural gas well 1 through the gas injection pipe 5, increasing the gas pressure inside the natural gas well 1. This causes the gas-liquid mixture of nitrogen, natural gas, and accumulated liquid to be extruded through the extrusion pipe 6 into the gravity gas-liquid separator 3. After entering the gravity gas-liquid separator 3, the accumulated liquid will fall below the gravity gas-liquid separator 3 and be discharged under the influence of gravity, while the mixture of nitrogen and natural gas will enter the flash tank 8 through the connecting pipe 7. The flash tank 8 will separate the nitrogen and natural gas, and the natural gas will be sent to the storage device. The gas supply unit supplies nitrogen to maintain a high-pressure environment inside the natural gas well 1, achieving the effect of continuous gas extraction operations.

[0047] In the second step, the separated nitrogen gas will be sent to the first nitrogen tank 11 and the second nitrogen tank 12 along the recovery pipe 9. During this process, if the normally closed solenoid valve 14 at the outlet of the first nitrogen tank 11 is in the conducting state, the normally open solenoid valve 15 at the outlet of the second nitrogen tank 12 will be in the closed state. At this time, the normally closed solenoid valve 14 at the inlet of the second nitrogen tank 12 will be in the conducting state, and the normally open solenoid valve 15 at the inlet of the first nitrogen tank 11 will be in the closed state. The first nitrogen tank 11 will supply gas to the gas pump 2, while the nitrogen gas separated by the flash tank 8 will be discharged to the second nitrogen tank 12 for storage. Similarly, when the second nitrogen tank 12 supplies gas, the first nitrogen tank 11 stores gas, which can reduce the consumption of nitrogen gas and achieve the effect of improving the utilization rate of nitrogen gas in the gas supply group.

[0048] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A pressurized gas lift drainage gas extraction device, comprising a natural gas well (1), a gas pump (2), a gravity gas-liquid separator (3), a sealing cap (4), an injection pipe (5), and an extrusion pipe (6), characterized in that, The sealing cap (4) is fixedly installed at the top of the natural gas well (1), the gas injection pipe (5) is installed between the sealing cap (4) and the gas pump (2), the extrusion pipe (6) is installed between the gravity gas-liquid separator (3) and the sealing cap (4), and the extrusion pipe (6) extends into the interior of the natural gas well (1); A connecting pipe (7) is fixedly installed on the gravity gas-liquid separator (3). A flash tank (8) is fixedly installed at the end of the connecting pipe (7). A recovery pipe (9) is fixedly installed on the flash tank (8). A gas supply group is fixedly installed at the end of the recovery pipe (9). The gas supply group includes a first nitrogen tank (11), a second nitrogen tank (12), a three-way pipe (13), a normally closed solenoid valve (14), and a normally open solenoid valve (15).

2. The pressurized gas lift drainage gas extraction device as described in claim 1, characterized in that, The first nitrogen tank (11) and the second nitrogen tank (12) are connected to the air pump (2) through a three-way pipe (13).

3. The pressurized gas lift drainage gas extraction device as described in claim 1, characterized in that, The first nitrogen tank (11) and the second nitrogen tank (12) are connected to the flash tank (8) through the recovery pipe (9).

4. The pressurized gas lift drainage gas extraction device as described in claim 1, characterized in that, A solenoid valve assembly is installed between the first nitrogen tank (11) and the second nitrogen tank (12) and the recovery pipe (9) and the three-way pipe (13).

5. The pressurized gas lift drainage gas extraction device as described in claim 4, characterized in that, The solenoid valve assembly includes a normally closed solenoid valve (14) and a normally open solenoid valve (15).

6. The pressurized gas lift drainage gas extraction device as described in claim 5, characterized in that, The normally closed solenoid valve (14) and the normally open solenoid valve (15) are connected in series by a wire.

7. The pressurized gas lift drainage gas extraction device as described in claim 1, characterized in that, A liquid level sensor (16) is fixedly installed inside the gravity gas-liquid separator (3).

8. The pressurized gas lift drainage gas extraction device as described in claim 7, characterized in that, The liquid level sensor (16) is lower than the extrusion tube (6).

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