Wellhead treatment sledge for shale gas platform

Abstract

The utility model relates to a wellhead treatment sledge for a shale gas platform. The wellhead treatment sledge comprises an input pipeline, a gas-liquid separator and a liquid drainage pipeline. The gas-liquid separator is communicated with the input pipeline, and external water-containing shale natural gas enters the gas-liquid separator through the input pipeline for gas-liquid separation; a liquid level detection unit is arranged in the gas-liquid separator, and under the condition that the liquid level in the gas-liquid separator is higher than a first liquid level height, the liquid level detection unit sends a first trigger signal; the liquid discharge pipeline is communicated with a liquid outlet of the gas-liquid separator and the sewage discharge pipeline, so that liquid separated by the gas-liquid separator is discharged to the sewage discharge pipeline; the liquid discharging pipeline comprises a first liquid discharging branch line and a second liquid discharging branch line which are arranged in parallel; a drain valve is arranged on the first drainage branch line; under the condition that the liquid level in the drain valve reaches a preset liquid level, liquid is discharged through the drain valve; an electromagnetic valve is arranged on the second liquid discharge branch line, and the electromagnetic valve is started in response to the first trigger signal so as to open the second liquid discharge branch line.

Description

Technical Field

[0001] The present application relates to the technical field of shale gas extraction, and in particular to a wellhead processing skid for a shale gas platform. Background Art

[0002] Shale gas is a natural gas resource found in shale formations and can be mined. China has significant recoverable reserves of shale gas. Compared to conventional natural gas, shale gas development offers the advantages of a longer mining life and production cycle. Most shale gas-producing formations are widely distributed, thick, and generally contain gas. This allows shale gas wells to produce gas at a stable rate over the long term.

[0003] Shale gas often contains a high water content. This is because hydraulic fracturing, a method often used in shale gas extraction, often requires a slow, gradual release of the large amount of fracturing fluid that enters the formation. This fluid can fluctuate significantly during shale gas extraction, potentially producing a large amount of gas-liquid mixture in a short period of time. This can make wellhead gas processing equipment susceptible to failure and potentially lead to safety incidents. Utility Model Content

[0004] In order to solve the problems existing in the prior art, the present application provides a wellhead processing skid for a shale gas platform.

[0005] According to a first aspect of the present application, a wellhead processing skid for a shale gas platform is provided, comprising:

[0006] Input pipeline;

[0007] a gas-liquid separator, connected to the input pipeline, configured to allow external water-containing shale natural gas to enter the gas-liquid separator through the input pipeline for gas-liquid separation; a liquid level detection unit provided in the gas-liquid separator, configured to send a first trigger signal when the liquid level in the gas-liquid separator exceeds a first liquid level height;

[0008] a liquid discharge pipeline, configured to communicate with the liquid outlet of the gas-liquid separator and the sewage discharge pipeline, so as to discharge the liquid separated by the gas-liquid separator to the sewage discharge pipeline; the liquid discharge pipeline includes a first liquid discharge branch line and a second liquid discharge branch line arranged in parallel;

[0009] A steam trap is provided on the first liquid discharge branch line; when the liquid level in the steam trap reaches a predetermined level, the liquid is configured to be discharged through the steam trap;

[0010] The second liquid discharge branch line is provided with a solenoid valve, and the solenoid valve is configured to be turned on in response to the first trigger signal to open the second liquid discharge branch line.

[0011] In one embodiment of the present application, when the liquid level in the gas-liquid separator is lower than a second liquid level height, the liquid level detection unit sends a second trigger signal; the solenoid valve is configured to close in response to the second trigger signal to close the second liquid drainage branch line.

[0012] In one embodiment of the present application, the first liquid level height is configured to be higher than the second liquid level height; when the second drainage branch line is opened, the liquid is configured to be discharged through the first drainage branch line and the second drainage branch line at the same time.

[0013] In one embodiment of the present application, the gas-liquid separator includes a separation tank and a liquid collection bag arranged at the bottom of the separation tank; the liquid collection bag is constructed to temporarily store the liquid separated by the gas-liquid separator; the liquid outlet of the gas-liquid separator is constructed to be arranged at the lower position of the liquid collection bag.

[0014] In one embodiment of the present application, the liquid level detection unit includes a high level sensor and a low level sensor; the high level sensor is configured to be disposed in the separation tank, and the low level sensor is configured to be disposed in the liquid collection bag;

[0015] When the liquid level in the gas-liquid separator is higher than a first liquid level height, the high-level sensor sends a first trigger signal; when the liquid level in the gas-liquid separator is lower than a second liquid level height, the low-level sensor sends a second trigger signal.

[0016] In one embodiment of the present application, the drainage pipeline also includes a drainage bus connected to the downstream position of the first drainage branch line and the second drainage branch line; a liquid flow meter is provided on the drainage bus, and the liquid flow meter is configured to detect the liquid flow in the drainage bus.

[0017] In one embodiment of the present application, it also includes an air supply pipeline, which is constructed to connect the air outlet of the gas-liquid separator and the gathering pipeline to transport the natural gas separated by the gas-liquid separator to the gathering pipeline; a gas flow meter is provided on the air supply pipeline, and the gas flow meter is configured to detect the natural gas flow in the air supply pipeline.

[0018] In one embodiment of the present application, a filtering device is further provided on the gas supply pipeline, and the filtering device is configured to filter impurities in natural gas; a sewage outlet is provided at the bottom of the filtering device, and the sewage outlet is configured to be connected to the liquid drainage pipeline to discharge the impurities obtained by filtration to the sewage pipeline.

[0019] In one embodiment of the present application, the filtering device is configured to be disposed upstream of the gas flow meter.

[0020] In one embodiment of the present application, an emergency shut-off valve and a throttle valve are sequentially provided on the input pipeline along the fluid flow direction; the processing skid includes a high-pressure portion located upstream of the throttle valve and a low-pressure portion located downstream of the throttle valve;

[0021] A pressure detection unit is also provided on the input pipeline; when the input pipeline pressure of the high-pressure part is greater than the first predetermined pressure and / or less than the second predetermined pressure, the pressure detection unit sends a third trigger signal; when the input pipeline pressure of the low-pressure part is greater than the third predetermined pressure, the pressure detection unit sends a fourth trigger signal; the emergency shut-off valve is configured to close in response to the third trigger signal and / or the fourth trigger signal to cut off the input pipeline.

[0022] One beneficial effect of the present application is that the drainage pipeline includes two parallel drainage branches, wherein the steam trap on the first drainage branch acts as a throttling valve, thereby ensuring that the gas-liquid mixture can be fully separated, thereby improving the natural gas yield. The solenoid valve installed on the second drainage branch is interlocked with the liquid level detection unit. When the liquid level in the gas-liquid separator is higher than the first liquid level, it indicates that the current shale gas production is too large. At this time, the solenoid valve will open, thereby opening the second drainage branch for rapid discharge. The liquid level in the gas-liquid separator drops rapidly, effectively preventing the processing skid from malfunctioning and improving the safety of the processing skid. In addition, the present application integrates the pipeline and various processing equipment into a compact processing skid, realizing the integration of parts into a whole, improving the integrity of the wellhead processing system for shale gas platforms, and facilitating installation and relocation.

[0023] Other features and advantages of the present application will become apparent from the following detailed description of exemplary embodiments of the present application with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the application and, together with the description, serve to explain the principles of the application.

[0025] Figure 1 This is a schematic diagram of the structure of a wellhead processing skid for a shale gas platform provided in this application;

[0026] Figure 2 It is a structural schematic diagram of the gas-liquid separator and liquid level detection unit provided in this application.

[0027] Figures 1 to 2 The one-to-one correspondence between the component names and the reference numerals is as follows:

[0028] 101. Christmas tree; 102. Gathering and transportation pipeline; 103. Drain line; 104. Vent line; 1040. Safety valve assembly; 2. Gas-liquid separator; 21. Separation tank; 22. Liquid collecting bag; 23. Liquid outlet; 24. Gas outlet; 25. Inlet; 31. Liquid level display and control alarm; 32. Liquid level interlock alarm; 33. High-level sensor; 34. Low-level sensor; 41. Steam trap; 42. Solenoid valve; 51. First bypass valve; 52. Second bypass valve; 53. Third bypass valve; 61. Liquid flow meter; 62. Gas flow meter; 7. Filter device; 71. Drain outlet; 81. Emergency shut-off valve; 811. High-pressure detector; 812. Low-pressure detector; 82. Throttle valve; 83. First service valve; 84. Second service valve. DETAILED DESCRIPTION

[0029] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present application.

[0030] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0031] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0032] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0033] In this document, “upper”, “lower”, “front”, “back”, “left”, “right”, etc. are only used to indicate the relative position relationship between related parts, rather than to limit the absolute positions of these related parts.

[0034] In this article, "first", "second", etc. are only used to distinguish each other, and do not indicate the importance and order, or the prerequisite for each other's existence.

[0035] In this document, “equal”, “same”, etc. are not strictly limited in a mathematical and / or geometric sense, but also include errors that can be understood by those skilled in the art and are allowed in manufacturing or use.

[0036] This application provides a wellhead processing skid for shale gas platforms, including an input pipeline, a gas-liquid separator, and a liquid discharge pipeline. Natural gas extracted from shale has a higher-than-standard water content and cannot be used directly, so the incoming gas needs to be dehydrated. Various shale gas processing equipment and pipelines can be integrated into the skid base, forming a compact wellhead processing skid for shale gas platforms. This achieves a comprehensive design, improves the integrity of the shale gas platform wellhead processing system, and facilitates installation and relocation.

[0037] The gas-liquid separator is connected to the input pipeline, through which external water-bearing shale gas is configured to enter the gas-liquid separator for gas-liquid separation. The water in the water-bearing shale gas is largely removed in the gas-liquid separator, and the resulting gas phase is the dehydrated natural gas. Understandably, the gas-liquid mixture requires a considerable time in the gas-liquid separator to fully separate, and the gas-liquid separator has a limited capacity. If the production volume is too high in a short period of time, the volume of shale gas from the input pipeline may exceed the gas-liquid separator's processing capacity, potentially causing the processing skid to malfunction and potentially leading to safety accidents.

[0038] In order to solve the above technical problems, the present application designs a drainage pipeline so that it can cope with situations where the shale gas flow rate is too large or too small. Specifically, the drainage pipeline is constructed to connect the liquid outlet of the gas-liquid separator and the sewage pipeline to discharge the liquid separated by the gas-liquid separator to the sewage pipeline. The sewage discharged into the sewage pipeline will be further sealed to prevent pollution to the environment. The drainage pipeline includes a first drainage branch line and a second drainage branch line arranged in parallel, wherein a steam trap is provided on the first drainage branch line. When the liquid level in the steam trap reaches a predetermined level, the liquid is configured to be discharged through the steam trap.

[0039] A steam trap is an automatic drainage device that blocks steam and drains away water. When production is low, the trap drains liquid at a relatively slow rate, allowing the gas-liquid mixture to remain in the gas-liquid separator long enough to ensure adequate separation. Furthermore, the liquid entering the trap will still contain a small amount of unseparated natural gas, which can be separated in the trap, thereby increasing natural gas yield.

[0040] The gas-liquid separator is equipped with a liquid level detection unit. When the liquid level in the gas-liquid separator rises above a first liquid level, the liquid level detection unit sends a first trigger signal. A solenoid valve is installed on the second drainage branch line. The solenoid valve is configured to activate in response to the first trigger signal, thereby opening the second drainage branch line. The solenoid valve on the second drainage branch line is interlocked with the liquid level detection unit. When the liquid level in the gas-liquid separator rises above the first liquid level, indicating that the current shale gas production volume is excessive, the solenoid valve activates, thereby opening the second drainage branch line for rapid discharge. This rapidly reduces the liquid level in the gas-liquid separator, effectively preventing malfunctions of the processing skid and improving its safety.

[0041] The specific implementation of this application is described below with reference to the accompanying drawings.

[0042] like Figure 1 As shown, the present application provides a wellhead processing skid for a shale gas platform, comprising an input pipeline, a gas-liquid separator 2, and a liquid discharge pipeline. The input end of the input pipeline is connected to a Christmas tree 101, which delivers the gas-liquid mixture extracted from the shale into the processing skid. Natural gas extracted from shale has a higher water content than the standard and cannot be used directly, so the incoming gas needs to be dehydrated.

[0043] The gas-liquid separator 2 is connected to the input pipeline, and the external water-containing shale natural gas is configured to enter the gas-liquid separator 2 through the input pipeline for gas-liquid separation. The water in the water-containing shale natural gas will be basically removed in the gas-liquid separator 2, and the separated gas phase is the dehydrated natural gas. Specifically, Figure 2 As shown, the gas-liquid separator 2 is provided with a liquid outlet 23 , a gas outlet 24 and an input port 25 , and the output end of the input pipeline is connected to the input port 25 , so that the water-containing shale natural gas is fed into the gas-liquid separator 2 .

[0044] The gas phase obtained by separation has a relatively low density and can therefore flow out of the gas outlet 24 located at the top of the gas-liquid separator 2. The processing skid also includes a gas supply pipeline, which is constructed to connect the gas outlet 24 of the gas-liquid separator 2 and the gathering pipeline 102 to transport the natural gas separated by the gas-liquid separator 2 to the gathering pipeline 102. The liquid phase obtained by separation has a relatively high density and can therefore flow out of the liquid outlet 23 located at the bottom of the gas-liquid separator 2.

[0045] In one embodiment of the present application, Figure 2As shown, the gas-liquid separator 2 includes a separation tank 21 and a liquid collecting bag 22 arranged at the bottom of the separation tank 21. The liquid collecting bag 22 is constructed to temporarily store the liquid separated by the gas-liquid separator 2, and the liquid outlet 23 of the gas-liquid separator 2 is constructed to be arranged at the lower position of the liquid collecting bag 22. The separation tank 21 is the main place for gas-liquid separation, and the liquid collecting bag 22 is a container connected to the bottom of the separation tank 21. The liquid phase obtained by separation can first flow into the liquid collecting bag 22 for temporary storage, and then flow out of the gas-liquid separator 2 from the liquid outlet 23 arranged at the lower position of the liquid collecting bag 22. The present application provides the liquid collecting bag 22 so that the liquid in the separation tank 21 can be drained, and the liquid collecting bag 22 also allows the liquid phase obtained by separation to stay in the gas-liquid separator 2 for a longer time, thereby making the gas-liquid separation more sufficient.

[0046] It is understandable that the gas-liquid mixture needs to stay in the gas-liquid separator 2 for a long time to be fully separated, and the capacity of the gas-liquid separator 2 is limited; when the production volume in a short period of time is too large, the amount of shale gas from the input pipeline may exceed the processing capacity of the gas-liquid separator 2, which may cause the processing skid to malfunction and easily lead to safety accidents.

[0047] In order to solve the above technical problems, the present application designs a drainage pipeline so as to cope with situations where the shale gas flow rate is too large or too small. Specifically, the drainage pipeline is constructed to connect the liquid outlet 23 of the gas-liquid separator 2 and the sewage pipeline 103, so as to discharge the liquid separated by the gas-liquid separator 2 to the sewage pipeline 103. The sewage discharged to the sewage pipeline 103 will be further sealed to prevent pollution to the environment. Figure 1 As shown, the drainage pipeline includes a first drainage branch line and a second drainage branch line arranged in parallel, wherein a steam trap 41 is provided on the first drainage branch line. When the liquid level in the steam trap 41 reaches a predetermined liquid level, the liquid is configured to be discharged through the steam trap 41.

[0048] Steam trap 41 is an automatic drainage device capable of blocking steam and draining water. Steam trap 41 has an inner cavity in which a float is movably mounted via a connecting rod. When the liquid level in the cavity is low, the float cannot rise, blocking the drain port of steam trap 41, thereby trapping the liquid in steam trap 41. When the liquid level in the cavity reaches a predetermined level, the float rises under the action of buoyancy, opening the drain port of steam trap 41 and allowing the liquid to flow from the first drainage branch line to the sewage pipeline 103. When the production volume is low, the drainage rate is relatively slow, allowing the gas-liquid mixture to remain in gas-liquid separator 2 for a sufficient period of time to ensure adequate separation.

[0049] In addition, a small amount of unseparated natural gas will still be mixed in the liquid entering the steam trap 41. This part of natural gas can be separated in the steam trap 41, thereby further improving the yield of natural gas. Figure 1 As shown, the upper end of the steam trap 41 is connected to the gas supply pipeline, so that a small amount of natural gas separated in the steam trap 41 can be transported to the gathering pipeline 102 through the gas supply pipeline.

[0050] Gas-liquid separator 2 is equipped with a liquid level detection unit. When the liquid level in gas-liquid separator 2 exceeds a first liquid level, the liquid level detection unit sends a first trigger signal. A solenoid valve 42 is provided on the second drainage branch line. Solenoid valve 42 is configured to activate in response to the first trigger signal, thereby opening the second drainage branch line. Solenoid valve 42 on the second drainage branch line is interlocked with the liquid level detection unit. When the liquid level in gas-liquid separator 2 exceeds the first liquid level, indicating that the current shale gas production volume is excessive, solenoid valve 42 opens, thereby opening the second drainage branch line for rapid discharge. This rapidly reduces the liquid level in gas-liquid separator 2, effectively preventing malfunctions of the processing skid and improving its safety.

[0051] In one embodiment of the present application, when the liquid level in gas-liquid separator 2 falls below a second liquid level, the liquid level detection unit transmits a second trigger signal, and solenoid valve 42 is configured to close in response to the second trigger signal, thereby closing the second drainage branch line. It will be appreciated that the second drainage branch line is only opened in emergency situations involving excessive flow. In such situations, the gas-liquid mixture entering the processing skid is discharged from gas-liquid separator 2 without undergoing sufficient separation. To minimize natural gas waste, the second drainage branch line should be closed promptly after the emergency situation has passed.

[0052] Furthermore, the first liquid level is configured to be higher than the second liquid level. When the liquid level exceeds the higher first liquid level, the solenoid valve 42 needs to be opened promptly. It is understood that when the second drainage branch line is opened, the liquid is configured to be discharged through both the first and second drainage branches, thereby accelerating the drainage rate and rapidly reducing the liquid level in the gas-liquid separator 2.

[0053] When the liquid level drops below the second liquid level, it indicates that the liquid level in gas-liquid separator 2 is safe. Therefore, it is necessary to promptly close the second drainage branch line to reaccumulate the gas-liquid mixture in separation tank 21 for gas-liquid separation. After closing the solenoid valve 42, drainage continues only through the first drainage branch line. The steam trap 41 on the first drainage branch line can slow the drainage rate, thereby ensuring that the gas-liquid mixture can be fully separated.

[0054] In one embodiment of the present application, Figure 2As shown, the liquid level detection unit includes a high-level sensor 33 and a low-level sensor 34. The high-level sensor 33 is configured to be disposed within the separator tank 21, and the low-level sensor 34 is configured to be disposed within the liquid collection bag 22. When the liquid level within the gas-liquid separator 2 exceeds a first liquid level, the high-level sensor 33 transmits a first trigger signal. The high-level sensor 33 can be disposed at a position corresponding to the first liquid level. When the liquid level within the separator tank 21 exceeds the position of the high-level sensor 33, the high-level sensor 33 is triggered, thereby transmitting the first trigger signal to promptly open the solenoid valve 42.

[0055] When the liquid level in the gas-liquid separator 2 is lower than the second liquid level height, the low-level sensor 34 sends a second trigger signal. The low-level sensor 34 can be set at a position corresponding to the second liquid level height. When the liquid level in the liquid collecting bag 22 is lower than the second liquid level height, the low-level sensor 34 can be triggered, thereby sending a second trigger signal to close the solenoid valve 42 in time. Setting the low-level sensor 34 in the liquid collecting bag 22 means that when the liquid level is lower than the second liquid level height, the separation tank 21 has been completely emptied. The separation tank 21 has a large capacity and can accumulate a large amount of gas-liquid mixture. Therefore, after the separation tank 21 is emptied, the solenoid valve 42 can be closed to slow down the drainage speed. Even if the current input flow is still large, it still takes a period of accumulation for the liquid level to reach the first liquid level again, thereby ensuring the safety of the processing skid and avoiding the waste of too much natural gas.

[0056] In one embodiment of the present application, the liquid level detection unit includes a liquid level display control alarm 31 and a liquid level interlock alarm 32. The liquid level display control alarm 31 is communicatively connected to a high level sensor 33 and a low level sensor 34. Thus, when the high level sensor 33 or the low level sensor 34 is triggered, an alarm is promptly issued, allowing staff to promptly understand the liquid level within the gas-liquid separator 2. The liquid level interlock alarm 32 is also communicatively connected to the liquid level display control alarm 31 and the solenoid valve 42. When the liquid level display control alarm 31 issues an alarm signal, the liquid level interlock alarm 32 can control the solenoid valve 42 to open or close in a timely manner, ensuring the safe operation of the processing skid.

[0057] In one embodiment of the present application, in addition to the water inlet and outlet for connecting to the first drainage branch line, the steam trap 41 is also provided with a bypass port. This bypass port directly communicates with the inner cavity of the steam trap 41 and is not blocked by the float. The drainage pipeline also includes a first bypass line, which connects the bypass port and the second drainage branch line. A first bypass valve 51 is provided on the first bypass line. When the first bypass valve 51 is opened, liquid in the steam trap 41 can flow through the first bypass line into the second drainage branch line. When the first and second drainage branches are opened simultaneously for drainage, the first bypass valve 51 can be opened to further increase the drainage speed, allowing accumulated liquid in the steam trap 41 to be quickly discharged through the second drainage branch line. Furthermore, if the steam trap 41 or other valves on the first drainage branch line need to be repaired, the first bypass valve 51 can be opened to drain the liquid in the steam trap 41.

[0058] In one embodiment of the present application, the drainage pipeline further includes a drainage bus connected to the first drainage branch line and the second drainage branch line at a downstream position. A liquid flowmeter 61 is provided on the drainage bus. The liquid flowmeter 61 is configured to detect the liquid flow in the drainage bus. The liquid flowmeter 61 may be an electromagnetic flowmeter that can at least have flow recording and remote transmission functions, allowing personnel to monitor the amount of liquid discharged per unit time.

[0059] Furthermore, the liquid discharge line may include a second bypass line, the two ends of which are respectively connected to the liquid discharge bus located upstream and downstream of the liquid flow meter 61. A second bypass valve 52 is provided on the second bypass line. When the liquid flow meter 61 needs to be repaired, the second bypass valve 52 can be opened to allow the liquid to bypass the liquid flow meter 61 through the second bypass line.

[0060] In one embodiment of the present application, a gas flow meter 62 is installed on the gas supply pipeline. The gas flow meter 62 is configured to detect the natural gas flow in the gas supply pipeline. The gas flow meter 62 may be an orifice plate flow meter that measures both instantaneous and cumulative natural gas flow. The gas flow meter 62 may have at least flow recording and remote transmission functions, allowing personnel to monitor the gas flow rate per unit time.

[0061] Furthermore, the gas supply pipeline may include a third bypass line, the ends of which are respectively connected to the gas supply pipeline located upstream and downstream of the gas flow meter 62. A third bypass valve 53 is provided on the third bypass line. When the gas flow meter 62 needs to be repaired, the third bypass valve 53 can be opened, allowing natural gas to bypass the gas flow meter 62 through the third bypass line.

[0062] In one embodiment of the present application, the natural gas entering the gas pipeline through the gas outlet 24 of the gas-liquid separator 2 may still contain a small amount of liquid and may also contain solid impurities such as fine rock fragments and silt. To further purify the natural gas, a filter device 7 is provided on the gas pipeline. The filter device 7 is configured to filter impurities from the natural gas. A drain port 71 is provided at the bottom of the filter device 7. The drain port 71 is configured to communicate with the liquid drainage pipeline to discharge the filtered liquid or solid impurities to the drain line 103.

[0063] In one embodiment of the present application, two filter devices 7 are provided, and the two filter devices 7 are configured to be connected in parallel via an air supply line. The two parallel filter devices 7 can be used in a backup mode, meaning that only one filter device 7 can be used for filtering, while the other is kept as a backup. When one filter device 7 needs to be repaired or its filter element replaced, the other filter device 7 can be activated, enabling online repair and replacement without interrupting production.

[0064] Furthermore, the two filters 7 arranged in parallel can be activated simultaneously. For example, if the air flow in the air supply line is high, the processing efficiency of a single filter 7 is low, and airflow will accumulate in the connecting line upstream of the filter 7. In this case, both filters 7 can be activated simultaneously to double the filtration speed and relieve pressure on the air supply line.

[0065] In one embodiment of the present application, the filter device 7 is configured to be positioned upstream of the gas flow meter 62. This allows the natural gas to be filtered and purified before the purified natural gas flow rate is recorded by the gas flow meter 62, thereby improving the measurement accuracy of the gas flow meter 62. Furthermore, impurities in unfiltered natural gas may clog the gas flow meter 62. As previously mentioned, the gas flow meter 62 of the present application is an orifice plate flow meter, and small amounts of impurities mixed in the natural gas may clog the small pores. Therefore, positioning the filter device 7 upstream of the gas flow meter 62 can reduce the failure rate of the gas flow meter 62 and extend its service life.

[0066] In another embodiment of the present application, the filter device 7 may also be disposed downstream of the gas flow meter 62. In actual production scenarios, trace impurities in natural gas will not have much impact on the measurement of the gas flow meter 62, so the gas flow meter 62 may also be disposed upstream of the filter device 7.

[0067] In one embodiment of the present application, Figure 1As shown, an emergency shut-off valve 81 and a throttle valve 82 are sequentially arranged along the fluid flow direction of the input pipeline. The emergency shut-off valve 81 can cut off the input pipeline in an emergency, thereby improving the safety of the treatment skid; the throttle valve 82 can reduce the pressure in the input pipeline. Specifically, the treatment skid includes a high-pressure section located upstream of the throttle valve 82 and a low-pressure section located downstream of the throttle valve 82. Figure 1 As shown by the dotted line in the figure, with the throttle valve 82 as the boundary, the input pipeline at the front end of the processing skid has a higher pressure. The gas-liquid mixture can be depressurized after flowing through the throttle valve 82, so that the fluid pressure entering the gas-liquid separator 2 and other equipment meets the standard.

[0068] The input pipeline is also equipped with a pressure detection unit. If the pressure in the high-pressure portion of the input pipeline exceeds a first predetermined pressure and / or falls below a second predetermined pressure, the pressure detection unit sends a third trigger signal. If the pressure in the low-pressure portion of the input pipeline exceeds the third predetermined pressure, the pressure detection unit sends a fourth trigger signal. Emergency shutoff valve 81 is configured to close in response to the third and / or fourth trigger signals, thereby shutting off the input pipeline.

[0069] Specifically, the pressure detection unit may include a high-pressure detector 811 and a low-pressure detector 812. The high-pressure detector 811 may be disposed on the input pipeline upstream of the emergency shut-off valve 81 to detect the pressure value of the high-pressure portion. When the measured pressure value is greater than a first predetermined pressure and / or less than a second predetermined pressure, the high-pressure detector 811 may transmit a third trigger signal. The low-pressure detector 812 may be disposed on the input pipeline downstream of the throttle valve 82 to detect the pressure value of the low-pressure portion. When the measured pressure value is greater than a third predetermined pressure, the low-pressure detector 812 may transmit a fourth trigger signal.

[0070] In a specific embodiment, the first predetermined pressure may be 10.0 MPa, the second predetermined pressure may be 1.0 MPa, and the third predetermined pressure may be 4.5 MPa. When the high-pressure portion pressure value measured by the high-pressure detector 811 is within the range of 1.0-10.0 MPa, and the low-pressure portion pressure value measured by the low-pressure detector 812 is no greater than 4.5 MPa, it indicates that the current system pressure is normal. The emergency shut-off valve 81 can remain open, and the gas-liquid mixture from the Christmas tree 101 can flow into the gas-liquid separator 2 through the input pipeline. If the high-pressure portion pressure value measured by the high-pressure detector 811 is greater than 10.0 MPa or less than 1.0 MPa, and / or the low-pressure portion pressure value measured by the low-pressure detector 812 is greater than 4.5 MPa, it indicates that the current system pressure is abnormal and the processing skid may malfunction. The emergency shut-off valve 81 can close in response to the signals sent by the high-pressure detector 811 and / or the low-pressure detector 812, thereby promptly shutting off the input pipeline and preventing an accident.

[0071] In one embodiment of the present application, Figure 1 As shown, the input pipeline is also equipped with a first service valve 83 and a second service valve 84. The first service valve 83 can be located between the emergency shutoff valve 81 and the throttle valve 82, and the second service valve 84 can be located downstream of the throttle valve 82. Both the first service valve 83 and the second service valve 84 are constructed to be manually opened and closed. If the power system of the treatment skid fails, the electronic control of the emergency shutoff valve 81 fails and cannot be closed in time. In this case, the first service valve 83 and the second service valve 84 need to be manually closed to shut off the flow.

[0072] When the throttle valve 82 fails and cannot reduce the pressure, or when the throttle valve 82 needs to be repaired, the first and second service valves 83 and 84 need to be manually closed to prevent the high-pressure gas-liquid mixture from continuously flowing into the gas-liquid separator 2. Although the second service valve 84 is provided in the low-pressure portion, a high-pressure gas-liquid mixture will flow through the second service valve 84 in the event of a throttle valve 82 failure. Therefore, the second service valve 84 should be constructed as a high-pressure-resistant valve. For example, the second service valve 84 can be a high-pressure valve capable of withstanding a pressure of 21 MPa.

[0073] In one embodiment of the present application, the processing skid further includes an exhaust line that can vent gas based on the pressure in the equipment or the connecting pipeline, thereby ensuring normal pressure in the system. The exhaust line can connect the pressure vessel in the processing skid to the vent line 104, thereby regulating the air pressure in the pressure vessel to prevent malfunction caused by excessive air pressure. The gas discharged to the vent line 104 will be further sealed to prevent environmental pollution. Specifically, Figure 1 As shown, the exhaust line can connect the gas-liquid separator 2 with the vent line 104. It is understood that the gas pressure in the gas-liquid separator 2 needs to be maintained at a certain level for normal operation. If too much gas is introduced into the gas-liquid separator 2 per unit time, the internal pressure of the gas-liquid separator 2 will be too high. A safety valve assembly 1040 can be provided on the exhaust line. When the pressure in the gas-liquid separator 2 is too high, the safety valve assembly 1040 can be opened, thereby opening the exhaust line to reduce the internal pressure of the gas-liquid separator 2.

[0074] The various equipment and pipelines for shale gas processing mentioned in the above embodiments can all be integrated on the skid. Other equipment and pipelines not mentioned in this application and applicable in the art can also be integrated on the skid. This creates a compact wellhead treatment skid for shale gas platforms, integrating various components into a complete system, improving the integrity of the shale gas platform wellhead treatment system and facilitating installation and relocation.

[0075] The embodiments of the present application have been described above. The above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, their practical applications, or technical improvements in the marketplace, or to enable other persons skilled in the art to understand the embodiments disclosed herein. The scope of this application is defined by the appended claims.

Claims

1. A wellhead processing skid for a shale gas platform, characterized in that: include: Input pipeline; A gas-liquid separator (2) is connected to the input pipeline, and external water-containing shale natural gas is configured to enter the gas-liquid separator (2) through the input pipeline for gas-liquid separation; a liquid level detection unit is provided in the gas-liquid separator (2), and when the liquid level in the gas-liquid separator (2) is higher than a first liquid level height, the liquid level detection unit sends a first trigger signal; a liquid discharge pipeline, configured to communicate with the liquid outlet (23) of the gas-liquid separator (2) and the sewage discharge pipeline (103), so as to discharge the liquid separated by the gas-liquid separator (2) to the sewage discharge pipeline (103); the liquid discharge pipeline comprises a first liquid discharge branch line and a second liquid discharge branch line arranged in parallel; A drain valve (41) is provided on the first liquid discharge branch line; when the liquid level in the drain valve (41) reaches a predetermined level, the liquid is configured to be discharged through the drain valve (41); A solenoid valve (42) is provided on the second liquid discharge branch line, and the solenoid valve (42) is configured to open in response to the first trigger signal to open the second liquid discharge branch line.

2. The wellhead treatment skid for shale gas platform according to claim 1, characterized in that: When the liquid level in the gas-liquid separator (2) is lower than a second liquid level height, the liquid level detection unit sends a second trigger signal; and the solenoid valve (42) is configured to close in response to the second trigger signal to close the second liquid drainage branch line.

3. The wellhead treatment skid for shale gas platform according to claim 2, characterized in that: The first liquid level is configured to be higher than the second liquid level; when the second drainage branch line is opened, the liquid is configured to be discharged through the first drainage branch line and the second drainage branch line at the same time.

4. The wellhead treatment skid for shale gas platform according to claim 2, characterized in that: The gas-liquid separator (2) comprises a separation tank (21) and a liquid collection bag (22) arranged at the bottom of the separation tank (21); the liquid collection bag (22) is configured to temporarily store the liquid separated by the gas-liquid separator (2); and the liquid outlet (23) of the gas-liquid separator (2) is configured to be arranged at a lower position of the liquid collection bag (22).

5. The wellhead treatment skid for shale gas platform according to claim 4, characterized in that: The liquid level detection unit comprises a high-level sensor (33) and a low-level sensor (34); the high-level sensor (33) is configured to be disposed in the separation tank (21), and the low-level sensor (34) is configured to be disposed in the liquid collection bag (22); When the liquid level in the gas-liquid separator (2) is higher than a first liquid level height, the high-level sensor (33) sends a first trigger signal; when the liquid level in the gas-liquid separator (2) is lower than a second liquid level height, the low-level sensor (34) sends a second trigger signal.

6. The wellhead treatment skid for a shale gas platform according to claim 1, characterized in that: The drainage pipeline further comprises a drainage bus connected to the first drainage branch line and the second drainage branch line at a downstream position; a liquid flow meter (61) is provided on the drainage bus, and the liquid flow meter (61) is configured to detect the liquid flow in the drainage bus.

7. The wellhead treatment skid for a shale gas platform according to claim 1, characterized in that: The invention also includes an air supply pipeline, which is constructed to connect the air outlet (24) of the gas-liquid separator (2) and the gathering pipeline (102) so as to transport the natural gas separated by the gas-liquid separator (2) to the gathering pipeline (102); a gas flow meter (62) is provided on the air supply pipeline, and the gas flow meter (62) is configured to detect the flow of natural gas in the air supply pipeline.

8. The wellhead treatment skid for a shale gas platform according to claim 7, characterized in that: The air supply pipeline is further provided with a filter device (7), which is configured to filter impurities in natural gas; a sewage outlet (71) is provided at the bottom of the filter device (7), which is configured to communicate with the liquid drainage pipeline to discharge the filtered impurities to the sewage drainage pipeline (103).

9. The wellhead treatment skid for a shale gas platform according to claim 8, characterized in that: The filtering device (7) is configured to be disposed upstream of the gas flow meter (62).

10. The wellhead treatment skid for a shale gas platform according to claim 1, characterized in that: An emergency shut-off valve (81) and a throttle valve (82) are sequentially arranged on the input pipeline along the fluid flow direction; the processing skid includes a high-pressure part located upstream of the throttle valve (82) and a low-pressure part located downstream of the throttle valve (82); A pressure detection unit is further provided on the input pipeline; when the pressure of the input pipeline of the high-pressure part is greater than the first predetermined pressure and / or less than the second predetermined pressure, the pressure detection unit sends a third trigger signal; When the input pipeline pressure of the low-pressure part is greater than a third predetermined pressure, the pressure detection unit sends a fourth trigger signal; the emergency shut-off valve (81) is configured to close in response to the third trigger signal and / or the fourth trigger signal to shut off the input pipeline.

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