A natural gas processing system and method for a gas storage facility

Abstract

This invention belongs to the field of natural gas processing technology and discloses a natural gas processing system and method for gas storage facilities. The natural gas processing system for gas storage facilities is used to remove oil from produced gas extracted from gas wells in a gas storage facility. It includes a production separator, a pipeline filter, a first cooler, a combined separator, a second cooler, a J-T valve, and a cryogenic separator connected in sequence. The inlet of the production separator is connected to the outlet of the gas well, and the outlet of the cryogenic separator is connected to a downstream gas pipeline. With this configuration, the produced gas undergoes two cooling processes via the first and second coolers, and then four separation processes via the production separator, pipeline filter, combined separator, and cryogenic separator. This significantly improves the oil-gas separation accuracy of the produced gas from the gas storage facility and reduces the impact on downstream equipment operation.

Description

Technical Field

[0001] This invention relates to the field of natural gas processing technology, and in particular to a natural gas processing system and method for a gas storage facility. Background Technology

[0002] Underground gas storage facilities utilize depleted oil and gas reservoirs. A key characteristic of these facilities is that the produced gas contains a large amount of condensate oil, and sometimes even crude oil. Processing the produced natural gas is crucial. If the upstream separation equipment lacks sufficient precision, the natural gas can carry a small amount of black oil into the downstream cryogenic section, causing the black oil components to solidify and precipitate. This can lead to equipment and pipeline blockages, affecting the safe operation of the unit and resulting in the exported dry gas failing to meet quality standards. To ensure the normal operation of subsequent pipelines, production equipment, and instruments, it is essential to remove impurities such as saturated water, condensate oil, and black oil from the produced gas.

[0003] In existing technologies, most gas storage facilities employ the following produced gas processing technology: Produced gas from a single well is gathered and transported via a production pipeline to a production separator at the gathering and injection station for processing. The separated condensate oil and water are metered separately and then fed into the condensate pipeline. The natural gas separated by the production separator is cooled to 15℃~35℃ by a precooler, injected with ethylene glycol, and then fed into a shell-and-tube heat exchanger to exchange cooling temperatures with the natural gas separated at low temperatures. The temperature is then throttled to -5℃~-15℃ before entering the low-temperature separator. The gas phase separated by the low-temperature separator is reheated in a shell-and-tube heat exchanger and, after pressure regulation, transported via a natural gas pipeline to the external transmission network.

[0004] However, it is often found in production operations that the oil removal of the produced gas after the above-mentioned treatment process is not thorough, resulting in oil in the produced gas. Formed black oil is found in parts such as the low-temperature separator, propane evaporator, and even downstream ethylene glycol regeneration unit, causing increased equipment pressure differential and poor ethylene glycol regeneration effect. Summary of the Invention

[0005] The purpose of this invention is to provide a natural gas processing system and method for gas storage facilities, which can improve the oil removal effect of produced gas extracted from gas storage facilities.

[0006] To achieve this objective, the present invention adopts the following technical solution: This invention provides a natural gas processing system for a gas storage facility, used to remove oil from produced gas extracted from gas wells in the gas storage facility. The system is characterized by comprising a production separator, a pipeline filter, a first cooler, a second cooler, a JT valve, a cryogenic separator, and a combined separator. The production separator, the pipeline filter, the first cooler, the combined separator, the second cooler, the JT valve, and the cryogenic separator are sequentially connected. The inlet of the production separator is connected to the outlet of the gas well, and the outlet of the cryogenic separator is connected to a downstream gas pipeline.

[0007] As an optional solution to the natural gas processing system for gas storage facilities provided by the present invention, the combined separator includes: The housing has a first cavity, a second cavity, and a third cavity that are connected in sequence. The first cavity has a first air inlet that is connected to the outlet of the first cooler. The third cavity has a first air outlet that is connected to the inlet of the second cooler. A cyclone separator is disposed inside the first cavity and is capable of separating the extracted gas that enters the first cavity from the first air inlet; A filter assembly, disposed inside the second cavity, is capable of separating the extracted gas entering the second cavity from the first cavity; A coalescing assembly, disposed inside the third cavity, is capable of separating the produced gas entering the third cavity from the second cavity; The liquid collection bag is connected to the first cavity, the second cavity, and the third cavity to collect the liquid separated by the cyclone separation component, the filtration component, and the coalescence component.

[0008] As an optional solution to the natural gas processing system for gas storage provided by the present invention, the cyclone separation component includes a cyclone separator and a corrugated plate separator. The extracted gas entering the first cavity from the first inlet is sequentially separated by the cyclone separator and the corrugated plate separator.

[0009] As an optional solution to the natural gas processing system for gas storage provided by the present invention, the filtration assembly includes a filter plate disposed inside the second cavity and dividing the second cavity into a first filtration cavity and a second filtration cavity along the direction of gravity. The first filtration cavity is connected to the first cavity, and the second filtration cavity is connected to the third cavity.

[0010] As an optional embodiment of the natural gas processing system for a gas storage facility provided by the present invention, the first cavity, the second cavity, and the third cavity are arranged side by side in a horizontal direction, and the liquid collection bag includes: The liquid collection chamber is connected to the first cavity, the second cavity and the third cavity and is located on the lower side of the first cavity, the second cavity and the third cavity along the direction of gravity; A heating assembly is used to heat the liquid collected in the collection chamber.

[0011] As an optional solution to the natural gas processing system of the gas storage facility provided by the present invention, the second cooler adopts an indirect heat exchanger. The second cooler is connected between the cryogenic separator and the downstream gas pipeline, so that the produced gas flowing out of the outlet of the cryogenic separator can serve as the cold source of the second cooler.

[0012] As an optional solution to the natural gas processing system for gas storage facilities provided by the present invention, the natural gas processing system for gas storage facilities further includes: A first atomizer, connected between the pipeline filter and the first cooler, is used to spray ethylene glycol onto the produced gas.

[0013] As an optional solution to the natural gas processing system for gas storage facilities provided by the present invention, the natural gas processing system for gas storage facilities further includes: A wellhead throttle valve is connected between the gas well and the production separator.

[0014] As an optional solution to the natural gas processing system for gas storage facilities provided by the present invention, the natural gas processing system for gas storage facilities further includes: A metering separator is connected in parallel with the production separator and is connected between the gas well and the pipeline filter.

[0015] The present invention also provides a method for processing natural gas in a gas storage facility, comprising the following steps: S1. The produced gas from the gas well undergoes a first separation in the production separator to obtain the first gas phase; S2. The first gas phase undergoes a second separation via a pipeline filter to obtain the second gas phase; S3. The second gas phase is cooled for the first time by the first cooler, and the cooled second gas phase is separated for the third time by the combined separator to obtain the third gas phase. S4. The third gas phase is cooled a second time by the second cooler, and the cooled third gas phase is separated a fourth time by the low temperature separator to obtain the fourth gas phase. S5. The fourth gas phase and the third gas phase exchange heat in the second cooler, and the fourth gas phase after heat exchange is output through the downstream gas pipeline.

[0016] The beneficial effects of this invention are: This invention provides a natural gas processing system for a gas storage facility, used to remove oil from produced gas extracted from gas wells in a gas storage facility. It includes a production separator, a pipeline filter, a first cooler, a combined separator, a second cooler, a JT valve, and a cryogenic separator connected in sequence. The inlet of the production separator is connected to the outlet of the gas well, and the outlet of the cryogenic separator is connected to a downstream gas pipeline. Produced gas from the gas well undergoes a first separation in the production separator to obtain a first gas phase. The first gas phase undergoes a second separation in the pipeline filter to obtain a second gas phase. The second gas phase undergoes a first cooling in the first cooler. The cooled second gas phase undergoes a third separation in the combined separator to obtain a third gas phase. The third gas phase undergoes throttling and a second cooling in the second cooler and JT valve. The cooled third gas phase undergoes a fourth separation in the cryogenic separator to obtain a fourth gas phase. With this configuration, the produced gas is cooled twice by the first and second coolers, and then separated four times by the production separator, pipeline filter, combined separator and cryogenic separator. This significantly improves the oil and gas separation accuracy of the produced gas from the gas storage facility and reduces the impact on the operation of downstream units. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the natural gas processing system for a gas storage facility according to an embodiment of the present invention; Figure 2 This is a structural diagram of the combined separator described in an embodiment of the present invention; Figure 3 This is a flowchart of the natural gas processing method for a gas storage facility according to an embodiment of the present invention.

[0018] In the picture: 1. Gas production well; 2. Wellhead throttle valve; 3. Production separator; 4. Metering separator; 5. Pipeline filter; 6. First atomizer; 7. First cooler; 8. Combined separator; 9. Second cooler; 10. JT valve; 11. Cryogenic separator; 12. Export regulating valve; 801. Housing; 802. First cavity; 803. Second cavity; 804. Third cavity; 805. First air inlet; 806. Filter assembly; 807. Coalescing assembly; 808. Cyclone separator; 809. Corrugated plate separator; 810. Liquid collection bag; 811. First air outlet; 812. Heating assembly; 813. Connecting pipe; 814. Water inlet; 815. First partition; 816. Quick-release blind flange; 817. Drain outlet; 818. Level gauge port; 819. Differential pressure gauge port; 820. Second partition. Detailed Implementation

[0019] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0020] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection or a detachable connection; a mechanical connection or an electrical connection; a direct connection or an indirect connection through an intermediate medium; or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0021] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] In existing technologies, most gas storage facilities employ the following produced gas treatment process: Produced gas from a single well is collected and transported via a production pipeline to a production separator at the gathering and injection station for processing. The separated condensate oil and water are metered and fed into the condensate pipeline. Natural gas separated by the production separator is pre-cooled to 15℃~35℃, injected with ethylene glycol, and then fed into a shell-and-tube heat exchanger to exchange cooling with the natural gas separated at low temperatures. The temperature is then throttled to -5℃~-15℃ before entering the low-temperature separator. The gas phase separated by the low-temperature separator is reheated in a shell-and-tube heat exchanger and, after pressure regulation, transported to the external transmission network via a natural gas pipeline. However, during production operation, it is frequently found that the produced gas treated by the above process is not thoroughly de-oiled, resulting in oil content in the produced gas. Formed black oil is found in parts such as the low-temperature separator, propane evaporator, and even downstream ethylene glycol regeneration units, causing increased equipment pressure differentials and poor ethylene glycol regeneration efficiency.

[0024] To solve the above problems, such as Figures 1 to 3As shown, this invention provides a natural gas processing system for a gas storage facility, used to remove oil from produced gas extracted from a gas production well 1 in a gas storage facility. It includes a production separator 3, a pipeline filter 5, a first cooler 7, a combined separator 8, a second cooler 9, a JT valve 10, and a cryogenic separator 11 connected in sequence. The inlet of the production separator 3 is connected to the outlet of the gas production well 1, and the outlet of the cryogenic separator 11 is connected to a downstream gas pipeline. The produced gas extracted from the gas production well 1 undergoes a first separation in the production separator 3 to obtain a first gas phase. The first gas phase undergoes a second separation in the pipeline filter 5 to obtain a second gas phase. The second gas phase undergoes a first cooling in the first cooler 7. The cooled second gas phase undergoes a third separation in the combined separator 8 to obtain a third gas phase. The third gas phase undergoes throttling and a second cooling in the second cooler 9 and the JT valve 10. The cooled third gas phase undergoes a fourth separation in the cryogenic separator 11 to obtain a fourth gas phase. With this configuration, the produced gas is cooled twice by the first cooler 7 and the second cooler 9, and then separated four times by the production separator 3, the pipeline filter 5, the combined separator 8 and the cryogenic separator 11. This can significantly improve the oil and gas separation accuracy of the produced gas from the gas storage facility and reduce the impact on the operation of downstream units.

[0025] Specifically, the second gas phase, after being cooled by the first cooler 7, reaches the first cooling temperature, which can be 15℃ to 35℃. The third gas phase, after being cooled by the second cooler 9 and the JT valve 10, reaches the second cooling temperature, which can be -5℃ to -15℃.

[0026] Optionally, an external gas regulating valve 12 is also installed on the downstream gas pipeline to control the flow rate and pressure of the fourth gas phase output.

[0027] As described above, the second gas phase, cooled by the first cooler 7, reaches a temperature of 15°C to 35°C. When the temperature of natural gas drops sharply, if it falls below the hydrate formation temperature, the water vapor in the natural gas will combine with components such as methane to form ice-like hydrates, clogging downstream equipment and pipelines. To address this issue, in this embodiment, the natural gas processing system further includes a first atomizer 6. The first atomizer 6 is connected between the pipeline filter 5 and the first cooler 7 and is used to spray ethylene glycol into the second gas phase. Ethylene glycol, as a thermodynamic inhibitor, lowers the freezing point of water, ensuring that even at low temperatures, water exists in liquid form and is removed by the subsequent separator, preventing hydrate formation and thus avoiding blockage of downstream equipment and pipelines.

[0028] Similarly, as mentioned above, the third gas phase, cooled by the second cooler 9 and JT valve 10, reaches -5℃ to -15℃, a temperature significantly lower than the first cooling temperature. Optionally, a second atomizer (not shown in the figure) is connected between the combined separator 8 and the second cooler 9. The first atomizer 6 is used to spray ethylene glycol into the third gas phase, further lowering the freezing point of water and ensuring that even at the second cooling temperature, water exists in liquid form and is removed by the subsequent separator, preventing the formation of hydrates and thus avoiding blockages in downstream equipment and pipelines.

[0029] It is understandable that the temperature of the fourth gas phase generated after separation by the cryogenic separator 11 is between -5°C and -15°C, the second cooling temperature. Typically, the fourth gas phase needs to be reheated before being introduced into the downstream gas pipeline to avoid low-temperature damage. Furthermore, to address the above problem and avoid energy waste, in this embodiment, the second cooler 9 is an indirect heat exchanger. The second cooler 9 is connected between the cryogenic separator 11 and the downstream gas pipeline, allowing the fourth gas phase flowing out of the outlet of the cryogenic separator 11 to serve as a cold source for the second cooler 9. The fourth gas phase is heated by the second cooler 9, and the third gas phase is cooled by the second cooler 9. This configuration, on the one hand, eliminates the need for compressors or other devices to provide a cold source for the second cooler 9 to lower the temperature of the third gas phase; on the other hand, it eliminates the need for heating devices to raise the temperature of the fourth gas phase, thus reducing the energy consumption of the gas storage natural gas processing system.

[0030] Furthermore, the gas storage facility's natural gas processing system also includes a wellhead throttle valve 2. The wellhead throttle valve 2 connects the gas production well 1 and the production separator 3. On one hand, it can shut down the gas production well 1 in case of an anomaly, improving the safety of the gas storage facility's natural gas processing system. On the other hand, it can regulate the pressure and temperature of the produced gas from the gas production well 1, preventing overpressure in downstream equipment and creating conditions for subsequent separation processes. Specifically, the wellhead throttle valve 2 must be able to withstand harsh operating conditions with high pressure and high impurity content.

[0031] Optionally, the metering separator 4 is connected in parallel with the production separator 3 and is connected between the gas production well 1 and the pipeline filter 5. The gas production well 1 can be selectively connected to either the metering separator 4 or the production separator 3. When the gas production well 1 is connected to the metering separator 4, the metering separator 4 separates the produced gas extracted from the gas production well 1 and separately meters the separated liquid and gas phases. Specifically, the metering separator 4 includes a separator, a gas mass flow meter, and a liquid mass flow meter.

[0032] Furthermore, the combined separator 8 includes a housing 801, a cyclone separation assembly, a filter assembly 806, a coalescing assembly 807, and a liquid collection bag 810. The housing 801 contains a first chamber 802, a second chamber 803, and a third chamber 804 connected in sequence. The first chamber 802 has a first air inlet 805 connected to the outlet of the first cooler 7. The third chamber 804 has a first air outlet 811 connected to the inlet of the second cooler 9. The cyclone separation assembly is located inside the first chamber 802 and can separate the collected gas entering the first chamber 802 from the air inlet. The filter assembly 806 is located inside the second chamber 803 and can separate the collected gas entering the second chamber 803 from the first chamber 802. The coalescing assembly 807, located inside the third chamber 804, separates the produced gas entering the third chamber 804 from the second chamber 803. The liquid collection bag 810 communicates with the first chamber 802, the second chamber 803, and the third chamber 804 to collect the liquid separated by the cyclone separator, the filter assembly 806, and the coalescing assembly 807. This arrangement, on the one hand, reduces the volume of the combined separator 8 by concentrating the cyclone separator, the filter assembly 806, and the coalescing assembly 807 inside the housing 801; on the other hand, by separating the produced gas first through the cyclone separator before entering the filter assembly 806, the possibility of clogging in the filter assembly 806 is reduced, and the replacement cycle of the filter assembly 806 is increased.

[0033] For example, the housing 801 is cylindrical, and two first partitions 815 are provided inside the housing 801. The two first partitions 815 are spaced apart along the axial direction of the housing 801 to divide the cavity inside the housing 801 into a first cavity 802, a second cavity 803 and a third cavity 804.

[0034] The coalescing module 807 includes a glass fiber coalescing filter element, through which the extracted gas flows from bottom to top. Because the glass fiber coalescing filter element contains glass fibers with a high density gradient, the pore size of the multi-layered filter media increases layer by layer. As the fluid flows through the filter media, small droplets compete to pass through the openings and gradually coalesce into larger droplets, which are more easily separated from the continuous phase fluid.

[0035] Optionally, the housing 801 includes a main housing and two quick-release blind flanges 816. The main housing and the two quick-release blind flanges 816 are joined to form a closed housing 801. The cavities inside the housing 801 can be easily opened or closed through the quick-release blind flanges 816, thereby allowing for maintenance and replacement of the cyclone separation assembly, filter assembly 806, and coalescing assembly 807 inside the housing 801. Specifically, one quick-release blind flange 816, the housing 801, and one first partition 815 are joined to form a first cavity 802; the two first partitions 815 and the housing 801 are joined to form a second cavity 803; and the other quick-release blind flange 816, the housing 801, and the other first partition 815 are joined to form a third cavity 804. A differential pressure gauge port 819 is provided on the wall of the third cavity 804. The differential pressure gauge extends into the third cavity 804 through the differential pressure gauge port 819 to detect the gas pressure inside the third cavity 804, thereby determining whether the coalescing assembly 807 is blocked or the blockage situation.

[0036] Furthermore, the cyclone separation assembly includes a cyclone separator 808 and a corrugated plate separator 809. The extracted gas entering the first chamber 802 from the inlet passes sequentially through the cyclone separator 808 and the corrugated plate separator 809 for separation. This configuration serves two purposes: firstly, the cyclone separator 808 utilizes centrifugal force to quickly separate larger droplets (such as free water and condensate oil) from the gas, achieving preliminary gas-liquid separation; the corrugated plate separator 809, by increasing the gas-liquid contact area and through collision and coalescence, effectively removes tiny droplets (diameter <10 micrometers) entrained in the gas, further purifying the gas. The combination of these two components significantly improves the efficiency of gas-liquid separation, ensuring cleaner gas exiting the first chamber 802. Secondly, the preliminary separation effect of the cyclone separator 808 reduces the number and size of droplets entering the corrugated plate separator 809, lowering the risk of corrugated plate blockage.

[0037] Furthermore, the filter assembly 806 includes a filter plate disposed inside the second cavity 803, dividing the second cavity 803 into a first filter cavity and a second filter cavity along the direction of gravity. The first filter cavity is connected to the first cavity 802, and the second filter cavity is connected to the third cavity 804. This arrangement not only provides a larger filtration area but also improves filtration efficiency. Specifically, the first filter cavity is connected to the first cavity 802 via a connecting pipe 813. A second air inlet is provided on the upper wall of the first filter cavity along the direction of gravity, and a second air outlet is provided on the wall of the first cavity 802. The connecting pipe 813 connects the second air inlet and the second air outlet. A differential pressure gauge port 819 is provided on the wall of the second filter cavity. The differential pressure gauge extends into the second filter cavity through this port 819 to detect the gas pressure inside the second filter cavity, thereby determining whether the filter plate is blocked or the blockage condition.

[0038] Optionally, the filter plate includes two spaced-apart mesh plates and ceramic packing material filling the space between them. The ceramic packing material (such as ceramic particles, honeycomb ceramics, or ceramic fibers) has a rich microporous structure and a large specific surface area, effectively intercepting and adsorbing tiny solid particles, droplets, and impurities in the produced gas, achieving a filtration accuracy far exceeding that of ordinary metal wire mesh. Ceramic materials are chemically stable, resistant to corrosion from common acidic gases in natural gas (such as H2S and CO2) and highly mineralized water, while maintaining structural stability at higher temperatures, extending the filter plate's service life. The mesh plates on both sides (usually stainless steel wire mesh or perforated plates) provide reliable mechanical support and protection for the ceramic packing material, preventing damage, loss, or blockage under high-speed airflow impact, ensuring the integrity of the filter layer structure. A well-designed ceramic packing porosity and mesh plate opening ratio can maintain filtration efficiency while keeping pressure loss during gas flow at a low level, thus maintaining the separator's processing capacity. When the filter plate becomes clogged, it can be regenerated through reverse purging (e.g., with clean natural gas or nitrogen) or by replacing the ceramic packing material, reducing operating costs.

[0039] For example, a water inlet 814 is also provided on the wall of the first cavity 802, through which cleaning water can be sprayed onto the filter plate to prevent the filter plate from being blocked.

[0040] Furthermore, the first cavity 802, the second cavity 803, and the third cavity 804 are arranged side by side in a horizontal direction, and the liquid collection bag 810 includes a liquid collection chamber and a heating assembly 812. The liquid collection chamber communicates with the first cavity 802, the second cavity 803, and the third cavity 804 and is located on the lower side of the first cavity 802, the second cavity 803, and the third cavity 804 in the direction of gravity, so that the separated liquid can flow to the liquid collection chamber under the action of gravity, eliminating the need for an additional collection structure and simplifying the device structure of the liquid collection bag 810. The heating assembly 812 is used to heat the liquid collected in the liquid collection chamber. Since oil has a high freezing point, by setting the heating assembly 812, the liquid collected in the liquid collection chamber can be heated to ensure that the separated oil is in a flowing state, making it easy to flow out of the liquid collection chamber.

[0041] For example, the liquid collection bag 810 is fixedly connected to the housing 801. The liquid collection bag 810 is cylindrical in shape, and the cavity of the cylinder is the liquid collection cavity. Two heating components 812 are provided, which are located at both ends of the cylinder along the axis to heat the cylinder, thereby heating the liquid collected in the liquid collection cavity. A drain port 817 is also provided on the lower side of the cylinder along the direction of gravity, through which the collected liquid can flow out of the liquid collection cavity. A level gauge port 818 is also provided on the cylinder, through which the level gauge extends into the liquid collection cavity to measure the liquid in the liquid collection cavity. When the liquid in the liquid collection cavity reaches a preset value, the drain port 817 is opened to discharge the liquid.

[0042] Optionally, the liquid collection chamber is divided into multiple collection chambers by the second partition 820.

[0043] Optionally, the liquid collection tank 810 is made of metal. The heating component 812 is an electromagnetic induction heater. The electromagnetic induction heater uses the principle of electromagnetic induction (eddy current heating) to directly heat the metal pipe liquid collection tank 810. On the one hand, compared with traditional heating methods, it can reduce energy consumption by 30%-50%, which is especially suitable for liquid collection tanks 810 that require continuous heating; on the other hand, electromagnetic induction heating does not require fuel combustion, making it suitable for application in natural gas processing systems.

[0044] The present invention also provides a method for processing natural gas in a gas storage facility, characterized by comprising the following steps: S1. The produced gas from gas well 1 undergoes a first separation in production separator 3 to obtain the first gas phase; S2. The first gas phase undergoes a second separation via pipeline filter 5 to obtain the second gas phase; S3. The second gas phase is cooled for the first time by the first cooler 7, and the cooled second gas phase is separated for the third time by the combined separator 8 to obtain the third gas phase. S4. The third gas phase is cooled for the second time by the second cooler 9. The cooled third gas phase is then separated for the fourth time by the low temperature separator 11 to obtain the fourth gas phase. S5, the fourth gas phase and the third gas phase exchange heat in the second cooler 9, and the fourth gas phase after heat exchange is output through the downstream gas pipeline.

[0045] With this configuration, the produced gas is cooled twice by the first cooler 7 and the second cooler 9, and then separated four times by the production separator 3, the pipeline filter 5, the combined separator 8 and the cryogenic separator 11. This can significantly improve the oil and gas separation accuracy of the produced gas from the gas storage facility and reduce the impact on the operation of downstream units.

[0046] Optionally, in step S3 above, the second gas phase is mixed with ethylene glycol and then subjected to a first cooling process via the first cooler 7. In step S4 above, the third gas phase is mixed with ethylene glycol and then subjected to a second cooling process via the second cooler 9. Ethylene glycol, as a thermodynamic inhibitor, lowers the freezing point of water, ensuring that even at low temperatures, water exists in liquid form and is removed by the subsequent separator, preventing the formation of hydrates and thus avoiding blockages in downstream equipment and pipelines.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A natural gas processing system for a gas storage facility, used for removing oil from produced gas extracted from a gas production well (1) in a gas storage facility, characterized in that, The system includes a production separator (3), a pipeline filter (5), a first cooler (7), a second cooler (9), a JT valve (10), a cryogenic separator (11), and a combined separator (8). The production separator (3), the pipeline filter (5), the first cooler (7), the combined separator (8), the second cooler (9), the JT valve (10), and the cryogenic separator (11) are connected in sequence. The inlet of the production separator (3) is connected to the outlet of the gas well (1), and the outlet of the cryogenic separator (11) is connected to the downstream gas pipeline.

2. The natural gas processing system for a gas storage facility according to claim 1, characterized in that, The combined separator (8) includes: The housing (801) has a first cavity (802), a second cavity (803) and a third cavity (804) connected in sequence. The first cavity (802) has a first air inlet (805) connected to the outlet of the first cooler (7). The third cavity (804) has a first air outlet (811) connected to the inlet of the second cooler (9). A cyclone separator is disposed inside the first cavity (802) and is capable of separating the extracted gas that enters the first cavity (802) from the first air inlet (805); A filter assembly (806) is disposed inside the second cavity (803) and is capable of separating the extracted gas entering the second cavity (803) from the first cavity (802); A coalescing assembly (807), disposed inside the third cavity (804), is capable of separating the produced gas entering the third cavity (804) from the second cavity (803); The liquid collection bag (810) is connected to the first cavity (802), the second cavity (803) and the third cavity (804) to collect the liquid separated by the cyclone separation assembly, the filtration assembly (806) and the coalescence assembly (807).

3. The natural gas processing system for a gas storage facility according to claim 2, characterized in that, The cyclone separation assembly includes a cyclone separator (808) and a corrugated plate separator (809). The extracted gas entering the first cavity (802) from the first air inlet (805) is separated by the cyclone separator (808) and the corrugated plate separator (809).

4. The natural gas processing system for a gas storage facility according to claim 2, characterized in that, The filter assembly (806) includes a filter plate disposed inside the second cavity (803) and divides the second cavity (803) into a first filter cavity and a second filter cavity along the direction of gravity. The first filter cavity is connected to the first cavity (802), and the second filter cavity is connected to the third cavity (804).

5. The natural gas processing system for a gas storage facility according to claim 2, characterized in that, The first cavity (802), the second cavity (803), and the third cavity (804) are arranged side by side in a horizontal direction, and the liquid collection bag (810) includes: The liquid collection chamber is connected to the first chamber (802), the second chamber (803) and the third chamber (804) and is disposed on the lower side of the first chamber (802), the second chamber (803) and the third chamber (804) along the direction of gravity; Heating assembly (812) is used to heat the liquid collected in the liquid collection chamber.

6. The natural gas processing system for a gas storage facility according to claim 5, characterized in that, The second cooler (9) is an indirect heat exchanger. The second cooler (9) is connected between the cryogenic separator (11) and the downstream gas pipeline, so that the extracted gas flowing out from the outlet of the cryogenic separator (11) can serve as the cold source of the second cooler (9).

7. The natural gas processing system for a gas storage facility according to claim 5, characterized in that, The gas storage facility's natural gas processing system also includes: The first atomizer (6), connected between the pipeline filter (5) and the first cooler (7), is used to spray ethylene glycol onto the extracted gas.

8. The natural gas processing system for a gas storage facility according to claim 1, characterized in that, The gas storage facility's natural gas processing system also includes: The wellhead throttle valve (2) is connected between the gas well (1) and the production separator (3).

9. The natural gas processing system for a gas storage facility according to any one of claims 1-8, characterized in that, The gas storage facility's natural gas processing system also includes: The metering separator (4) is connected in parallel with the production separator (3) and is connected between the gas well (1) and the pipeline filter (5).

10. A method for processing natural gas in a gas storage facility, characterized in that, Includes the following steps: S1. The produced gas from the gas well (1) is separated for the first time by the production separator (3) to obtain the first gas phase; S2, the first gas phase is separated a second time through the pipeline filter (5) to obtain the second gas phase; S3. The second gas phase is cooled for the first time by the first cooler (7), and the cooled second gas phase is separated for the third time by the combined separator (8) to obtain the third gas phase; S4. The third gas phase is cooled for the second time by the second cooler (9), and the cooled third gas phase is separated for the fourth time by the low temperature separator (11) to obtain the fourth gas phase. S5. The fourth gas phase and the third gas phase exchange heat in the second cooler (9), and the fourth gas phase after heat exchange is output through the downstream gas pipeline.

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