Wellhead gas-to-lng system with power generation system

Abstract

The present disclosure relates to the technical field of natural gas liquefaction, and particularly relates to a wellhead gas-to-LNG system with a power generation system, which can comprise a sand removal system, a decarbonization system, a dehydration system, a liquefaction system, an LNG collection device, a flue gas waste heat recovery system and a power generation system. The sand removal system is used to obtain and remove solid particles in wellhead gas; the decarbonization system is used to obtain wellhead gas in the sand removal system and remove carbon-containing substances in the wellhead gas; the dehydration system is used to obtain wellhead gas in the decarbonization system for separating water in the wellhead gas; the liquefaction system is used to obtain and cool wellhead gas in the dehydration system; and the LNG collection device is connected with an outlet end of the liquefaction system for collecting liquefied wellhead gas. According to the present disclosure, the power generation system is connected with at least the sand removal system, and the flue gas waste heat recovery system is connected with the power generation system, so that self-sufficiency of power can be realized, and the flue gas waste heat generated by the power generation system can be used to supply heat for the decarbonization system and / or the dehydration system.

Description

Technical Field

[0001] This disclosure belongs to the field of natural gas liquefaction technology, specifically relating to a wellhead gas to LNG system with a power generation system. Background Technology

[0002] Existing wellhead gas-to-LNG (liquefied natural gas) processes typically require external power support. However, remote and scattered wells are often situated in isolated locations without available or reliable power supplies. Establishing a power grid to these wellheads would be not only cumbersome and costly, but also economically unsustainable, as these wellheads are mostly temporary production facilities with production periods typically ranging from 1 to 3 years, and in rare cases extending to 5 years. Furthermore, supplying power to wellhead gas-to-LNG systems with integrated power generation systems generates significant heat, which is not effectively utilized and requires additional cooling equipment, leading to substantial energy consumption in the LNG production process. Utility Model Content

[0003] The purpose of this application is to provide a wellhead gas to LNG system with a power generation system. By connecting the power generation system to at least the desanding system and the flue gas waste heat recovery system to the power generation system, the system can achieve self-sufficiency in electricity and reduce the overall energy consumption of the system.

[0004] This disclosure provides an embodiment of a wellhead gas-to-LNG system with a power generation system, comprising:

[0005] Desanding systems are used to capture and remove solid particles from wellhead gas.

[0006] A decarbonization system is used to obtain wellhead gas from the desanding system and remove carbon-containing substances from the wellhead gas.

[0007] A dehydration system is used to obtain wellhead gas from the decarbonization system for separating water from the wellhead gas;

[0008] A liquefaction system is used to acquire and cool the wellhead gas in the dehydration system for the purpose of liquefying the wellhead gas.

[0009] An LNG collection device is connected to the outlet of the liquefaction system to collect liquefied wellhead gas.

[0010] The power generation system is at least connected to the desanding system to receive wellhead gas supplied by the desanding system and to start up;

[0011] A flue gas waste heat recovery system, which is connected to the power generation system, is used to recover the waste heat from the flue gas generated by the power generation system and transfer the heat to the decarbonization system and / or the dehydration system.

[0012] In one exemplary embodiment of this disclosure, the flue gas waste heat recovery system includes:

[0013] A flue gas waste heat exchanger is connected to the power generation system to receive the waste heat from the flue gas generated by the power generation system.

[0014] An elevated oil tank is provided, which can hold heat transfer oil. The elevated oil tank is connected to the flue gas waste heat exchanger to transport the heat transfer oil to the flue gas waste heat exchanger and absorb the waste heat from the flue gas in the power generation system.

[0015] A hot oil circulation pump, one end of which is connected to the flue gas waste heat exchanger, and the other end of which can be connected to the decarbonization system and / or the dehydration system, for conveying the heated heat transfer oil to the decarbonization system and / or the dehydration system.

[0016] In one exemplary embodiment of this disclosure, the sand removal system includes:

[0017] A desander is used to obtain wellhead gas and remove solid particles from it.

[0018] A water jacket furnace is connected to the desander to obtain wellhead gas from the desander and to heat and depressurize the wellhead gas.

[0019] A pressure regulating valve is connected to the outlet end of the water jacket furnace to obtain wellhead gas and depressurize it to the target pressure.

[0020] In one exemplary embodiment of this disclosure, the decarbonization system includes:

[0021] The absorption tower is hollow inside, and its bottom is connected to the outlet end of the desanding system for obtaining wellhead gas; the top of the absorption tower can obtain amine liquid, which can be used to absorb carbon-containing substances in the wellhead gas inside the absorption tower.

[0022] The regeneration tower is hollow inside, and its top can receive the amine liquid in the absorption tower and separate carbon-containing substances from the amine liquid; wherein, the regeneration tower can transport the amine liquid obtained after separating the carbon-containing substances to the top of the absorption tower;

[0023] A reboiler is connected to the bottom of the regeneration tower to obtain amine liquid from the regeneration tower; the reboiler is also connected to the flue gas waste heat recovery system to achieve heat exchange between the flue gas waste heat and the amine liquid in the reboiler; the amine liquid heated in the reboiler can be returned to the regeneration tower to achieve separation of amine liquid from carbonaceous substances.

[0024] In one exemplary embodiment of this disclosure, the decarbonization system further includes:

[0025] A tower top cooler is provided at the top of the absorption tower to obtain and cool the gas at the top of the absorption tower;

[0026] A top separator, connected to the top cooler, is used to obtain the material cooled by the top cooler and separate amine liquid and wellhead gas. The amine liquid can be transported from the bottom of the top separator to the regeneration tower, and the wellhead gas can be transported to the dehydration system.

[0027] In one exemplary embodiment of this disclosure, the decarbonization system further includes:

[0028] A flash tank, connected to the top and / or bottom of the column top separator, for obtaining amine solution;

[0029] The lean and rich liquid heat exchangers are connected to the bottom of the flash tank and the regeneration tower respectively, so as to realize the heat exchange between the amine liquid at the bottom of the regeneration tower and the amine liquid in the flash tank; after the amine liquid in the flash tank is heated, it enters the top of the regeneration tower and separates out carbon-containing substances.

[0030] A buffer tank, with its opposite ends connected to the top of the lean and rich liquid heat exchanger and the top of the absorption tower respectively, is used to obtain the amine liquid cooled at the bottom of the regeneration tower and to transport the amine liquid to the absorption tower.

[0031] A lean solution cooler is located between the buffer tank and the absorption tower to cool the amine solution in the buffer tank.

[0032] In one exemplary embodiment of this disclosure, the decarbonization system further includes:

[0033] A carbon-containing material cooler is used to obtain and cool the gas at the top of the regeneration tower;

[0034] A carbon-containing material separator, one end of which is connected to the carbon-containing material cooler, is used to obtain the material cooled by the carbon-containing material cooler and separate the amine liquid from the carbon-containing material. The other end of the carbon-containing material separator is connected to the top of the absorption tower to transport the separated amine liquid to the absorption tower.

[0035] In one exemplary embodiment of this disclosure, the outlet of the dehydration system is connected to the power generation system to provide wellhead gas to the power generation system;

[0036] The dehydration system includes:

[0037] The first dehydration tower is used to obtain well gas from the outlet of the decarbonization system and, after adsorbing water from the well gas, transport the well gas to the liquefaction system.

[0038] The second dehydration tower is used to obtain and cool the wellhead gas at the outlet of the decarbonization system;

[0039] A regenerated gas heater is connected to the top of the second dehydration tower to obtain wellhead gas from the second dehydration tower; the regenerated gas heater is connected to the flue gas waste heat recovery system to utilize the flue gas waste heat in the power generation system to raise the temperature of the wellhead gas in the regenerated gas heater.

[0040] The third dehydration tower is connected to the regeneration gas heater to obtain wellhead gas; the third dehydration tower can use the heat of the wellhead gas to desorb water from the adsorbent; the wellhead gas in the third dehydration tower can be transported to the power generation system.

[0041] In one exemplary embodiment of this disclosure, the dehydration system includes:

[0042] The regenerated gas electric heater is capable of acquiring and heating the wellhead gas in the regenerated gas heater, and the heated wellhead gas can be delivered to the third dehydration tower; and / or,

[0043] A regenerated gas cooler is connected to the bottom of the third dehydration tower to obtain and cool the wellhead gas in the third dehydration tower;

[0044] A regenerated gas separator, connected to the regenerated gas cooler, is used to obtain the material cooled by the regenerated gas cooler and to separate wellhead gas from water; the separated water can be discharged from the bottom of the regenerated gas separator, and the separated wellhead gas can be transported from the top of the regenerated gas separator to the power generation system.

[0045] In one exemplary embodiment of this disclosure, the wellhead gas to LNG system with a power generation system includes a mercury removal system disposed between the decarbonization system and the dehydration system for acquiring and removing mercury from the wellhead gas in the decarbonization system and delivering the wellhead gas to the dehydration system; and / or,

[0046] The liquefaction system includes:

[0047] A plate-fin heat exchanger is used to receive wellhead gas in the dehydration system; the plate-fin heat exchanger includes a high-temperature section and a low-temperature section;

[0048] A high-temperature refrigerant compressor is used to compress and cool a high-temperature refrigerant and deliver the high-temperature refrigerant to the high-temperature section. After the high-temperature refrigerant initially cools the wellhead gas, it can return to the high-temperature refrigerant compressor to achieve refrigeration.

[0049] A cryogenic refrigerant compressor is used to compress and cool cryogenic refrigerant. After the wellhead gas is initially cooled, the cryogenic refrigerant compressor can sequentially deliver the cryogenic refrigerant to the high-temperature section and the low-temperature section. After the cryogenic refrigerant has cooled the wellhead gas to a certain depth, it can return to the cryogenic refrigerant compressor to achieve refrigeration.

[0050] The technical solutions provided in this disclosure have at least the following advantages:

[0051] This embodiment of the disclosure connects the power generation system to at least the desandering system in the wellhead gas-to-LNG system with the power generation system. This allows the system to receive and start the wellhead gas delivered after the desandering system has removed solid particles. Since the desandering system does not require electricity to remove solid particles from the wellhead gas, the power generation system can generate electricity after receiving the wellhead gas to power the normal operation of the entire wellhead gas-to-LNG system with the power generation system. In other words, the wellhead gas-to-LNG system with the power generation system in this embodiment of the disclosure can achieve self-sufficiency in electricity, thereby reducing the construction cost of the power grid.

[0052] Meanwhile, by connecting the flue gas waste heat recovery system to the power generation system, this embodiment of the present disclosure can recover the waste heat generated by the flue gas from the power generation system and transfer the heat to the decarbonization system and / or dehydration system, thereby achieving efficient utilization of the waste heat generated by the power generation system, significantly reducing the overall energy consumption of the wellhead gas to LNG system with the power generation system, and thus reducing the production cost of LNG.

[0053] Furthermore, the wellhead gas to LNG system with power generation system in this embodiment can save gas resources for the country by recovering wellhead gas, and can also bring good economic benefits to the gas well while avoiding environmental pollution.

[0054] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0055] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0056] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0057] Figure 1 A schematic diagram of a wellhead gas-to-LNG system with a power generation system is shown in an embodiment of this disclosure.

[0058] Explanation of reference numerals in the attached figures:

[0059] 1. High-level oil tank; 2. Hot oil circulation pump; 3. Flue gas waste heat exchanger; 4. Sand remover; 5. Water jacket furnace; 6. Power generation system; 7. Absorber; 8. Tower top cooler; 9. Tower top separator; 10. Flash tank; 11. Lean liquor cooler; 12. Lean and rich liquor heat exchanger; 13. Regeneration tower; 14. Carbonaceous material cooler; 15. Carbonaceous material separator; 16. Lean liquor pump; 17. Buffer tank; 18. Mercury removal tower; 19. Reboiler; 20. First dehydration tower; 21. Third dehydration tower; 22. Second dehydration tower; 23. Regeneration gas heater; 24. Regeneration gas electric heater; 25. Regeneration gas cooler; 26. Regeneration gas separator; 27. High-temperature refrigerant compressor; 28. Plate-fin heat exchanger; 29. ​​LNG collection device; 30. Heavy hydrocarbon separator; 31. Low-temperature refrigerant compressor. Detailed Implementation

[0060] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0061] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0062] The present application will now be described in further detail with reference to the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present application, and should not be construed as limiting the present application.

[0063] During the oilfield extraction process, a large amount of associated gas is generated at the wellhead, commonly known as wellhead gas. Natural gas wellhead gas (including associated gas from remote wells, scattered wells, and low-production wells) often faces the problem of venting and combustion or direct discharge due to its small and unstable gas volume, large differences in gas quality, dispersed location, difficulty in gas gathering and transportation, lack of local users, and distance from pipeline systems.

[0064] The technology of producing LNG (liquefied natural gas) from wellhead gas is gradually becoming an effective way to solve the problem of wellhead gas utilization. However, existing wellhead gas-to-LNG systems with integrated power generation systems usually require external power support. Due to the remote location of gas wells, there is often no available or reliable power supply, resulting in high costs and poor overall economic efficiency when setting up power grids. Moreover, there is currently a lack of technology to utilize the heat generated during the wellhead gas-to-LNG process, which usually requires additional cooling equipment, leading to high energy consumption in the LNG production process.

[0065] To solve the above technical problems, such as Figure 1 As shown, this disclosure provides a wellhead gas to LNG system with a power generation system, including: a desanding system, a decarbonization system, a dehydration system, a liquefaction system, an LNG collection device 29, a power generation system 6, and a flue gas waste heat recovery system.

[0066] The desanding system is used to acquire and remove solid particles from the wellhead gas. The decarbonization system is used to acquire the wellhead gas from the desanding system and remove carbonaceous substances from it. The dehydration system is used to acquire the wellhead gas from the decarbonization system to separate water from it. The liquefaction system is used to acquire and cool the wellhead gas from the dehydration system to liquefy it. LNG collection unit 29 is connected to the outlet of the liquefaction system to collect the liquefied wellhead gas.

[0067] In this embodiment, the power generation system 6 can be an internal combustion engine power generation component. The power generation system 6 can at least be connected to the desandering system to receive wellhead gas supplied by the desandering system and start up.

[0068] It should be noted that after obtaining wellhead gas in the gas production well, the wellhead gas can be transported from the gas production well to the desanding system under the action of pressure difference.

[0069] For example, when a wellhead gas-to-LNG system with a power generation system is started for the first time, the wellhead gas in the gas production well can be transported to the desanding system under the action of pressure difference. The desanding system can remove solid particles from the wellhead gas through structures such as filters.

[0070] In other words, this disclosure allows for the use of no electricity during the process of wellhead gas entering the wellhead gas-to-LNG system with a power generation system and during the process of removing solid particles by the desanding system. By connecting the power generation system 6 to the desanding system, this disclosure allows a portion of the wellhead gas after the solid particles have been removed by the desanding system to be transported to the power generation system 6 for power generation. The electricity generated by the power generation system 6 can supply power to the entire wellhead gas-to-LNG system with a power generation system, ensuring the smooth progress of the LNG preparation process. Another portion of the wellhead gas can be transported to subsequent process systems such as the decarbonization system for appropriate processing.

[0071] At the same time, by connecting the power generation system 6 to the desanding system, this disclosure can also improve the problem of high operating costs of wellhead gas-to-LNG systems with power generation systems, which require additional power grids to be erected at the gas production well to provide power for the operation of the wellhead gas-to-LNG system with power generation system. In this way, while ensuring the normal operation of the wellhead gas-to-LNG system with power generation system to achieve LNG production, the cost of LNG production can also be reduced, thereby improving the overall economic efficiency.

[0072] In this embodiment of the present disclosure, the power generation system 6 can be connected to the flue gas waste heat recovery system. The waste heat generated by the flue gas in the power generation system 6 can be recovered through the flue gas waste heat recovery system and the heat can be transferred to the decarbonization system and / or dehydration system. This enables the recovery and utilization of the waste heat of the flue gas in the power generation system 6, reduces the overall energy consumption of the wellhead gas to LNG system with the power generation system, and thus reduces the operating cost of the wellhead gas to LNG system with the power generation system.

[0073] Specifically, the flue gas waste heat recovery system may include: a flue gas waste heat exchanger 3, an elevated oil tank 1, and a hot oil circulation pump 2. The flue gas waste heat exchanger 3 is connected to the power generation system 6 to receive the waste heat from the flue gas generated by the power generation system 6. The elevated oil tank 1 can hold heat transfer oil. The elevated oil tank 1 is connected to the flue gas waste heat exchanger 3 to transport the heat transfer oil to the flue gas waste heat exchanger 3 and absorb the waste heat from the flue gas in the power generation system 6. One end of the hot oil circulation pump 2 is connected to the flue gas waste heat exchanger 3, and the other end can be connected to the decarbonization system and / or dehydration system to transport the heated heat transfer oil to the decarbonization system and / or dehydration system. This improves the recovery and utilization of waste heat from the flue gas in the power generation system 6, reduces the overall energy consumption of the wellhead gas-to-LNG system with the power generation system, and thus reduces the operating cost of the wellhead gas-to-LNG system with the power generation system.

[0074] In some embodiments, the desanding system may include a desander 4, which can be used to obtain wellhead gas and remove solid particles from the wellhead gas.

[0075] In this embodiment of the disclosure, the desander 4 may include a filter screen to remove solid particles from the wellhead gas. However, it is not limited to this; the desander 4 in this embodiment may also include other structures besides a filter screen that can remove solid particles from the wellhead gas, depending on the actual situation.

[0076] Furthermore, in some embodiments, the desanding system may include a water jacket furnace 5, which is connected to the desander 4 to obtain wellhead gas after solid particles have been removed from the desander 4, and to heat and depressurize the wellhead gas.

[0077] It should be noted that the pressure of the wellhead gas produced from the gas well is relatively high and unstable. This disclosure uses a water-jacketed furnace 5 to reduce the pressure of the wellhead gas, adjusting it to a stable pressure range suitable for subsequent processes and equipment operation, thus ensuring the safe and stable operation of the entire system. Since the temperature of the wellhead gas will decrease after pressure adjustment, to mitigate problems such as freezing and blockage due to excessively low temperatures during subsequent transportation and processing, this embodiment uses a water-jacketed furnace 5 to heat the wellhead gas, thereby ensuring its smooth flow.

[0078] It should also be noted that the water jacket furnace 5 in this embodiment of the present disclosure does not require external power during the process of heating and depressurizing the wellhead gas.

[0079] For example, the water jacket furnace 5 can burn a portion of the wellhead gas to heat it. However, it is not limited to this; in this embodiment, the water jacket furnace 5 can also be connected to a power generation system 6 to start up using power from the power generation system 6. This embodiment avoids situations where the water jacket furnace 5 is unavailable or requires an additional power grid to power it due to the remote location of the gas well. Therefore, while ensuring the normal operation of the wellhead gas-to-LNG system with a power generation system to achieve LNG production, it can also reduce the cost of LNG production.

[0080] Among them, the wellhead gas entering the water jacket furnace 5 can be heated and depressurized to 8MPa.

[0081] In addition, in some embodiments, the desanding system may also include a pressure regulating valve that can be used to obtain wellhead gas and depressurize the wellhead gas to a target pressure.

[0082] For example, in this embodiment of the present disclosure, a pressure regulating valve can be installed between the desander 4 and the decarbonization system to obtain wellhead gas after solid particles have been removed and to reduce the pressure of the wellhead gas to a target pressure. The wellhead gas, after being pressure-regulated by the pressure regulating valve, is reduced to 5 MPa and then delivered to the decarbonization system.

[0083] It should be noted that the target pressure of the wellhead gas here refers to a stable pressure range suitable for subsequent processes and equipment operation, in order to ensure the safe and stable operation of the entire system.

[0084] The pressure regulating valve can be directly connected to the desander 4 to obtain wellhead gas and reduce its pressure to the target pressure.

[0085] However, this is not the only possibility. In this embodiment, the pressure regulating valve can also be located between the water jacket furnace 5 and the decarbonization system. Specifically, the pressure regulating valve can be connected to the outlet end of the water jacket furnace 5 to obtain wellhead gas. After preliminary heating and depressurization within the water jacket furnace 5, the wellhead gas is delivered to the pressure regulating valve, which can further depressurize the wellhead gas to the target pressure. By utilizing the water jacket furnace 5 and the pressure regulating valve to depressurize the wellhead gas twice, this embodiment reduces the risk of low temperature after the first throttling, and the pressure regulating valve enables precise pressure control, system safety redundancy, and flow adaptation, thereby facilitating the safe operation of the system.

[0086] In some embodiments, the decarbonization system may include an absorption tower 7, a regeneration tower 13, and a reboiler 19. The absorption tower 7 is hollow inside, and its bottom is connected to the outlet end of the desanding system for obtaining wellhead gas.

[0087] Specifically, the absorption tower 7 can be connected to the desander 4, the water jacket furnace 5, or a pressure regulating valve to obtain wellhead gas after solid particles have been removed. Amine liquid can be obtained at the top of the absorption tower 7, which can be used to absorb carbonaceous substances in the wellhead gas within the absorption tower 7, thus achieving decarbonization of the wellhead gas. The regeneration tower 13 is hollow inside, and its top can obtain the amine liquid from the absorption tower 7 and separate carbonaceous substances from the amine liquid. The regeneration tower 13 can transport the amine liquid obtained after separating the carbonaceous substances to the top of the absorption tower 7.

[0088] It should be noted that the carbon-containing substances in this embodiment refer to impurities such as carbon dioxide. The amine solution refers to N-methyldiethanolamine (MDEA). The amine solution can undergo an acid-base neutralization reaction with the carbon-containing substances in the wellhead gas, thereby effectively removing the carbon-containing substances from the wellhead gas and achieving wellhead gas purification. Specifically, the amine solution entering the top of the absorption tower 7 is a regenerated amine solution that has had most or all of the acidic gases removed, also known as lean solution; the amine solution obtained after undergoing an acid-base neutralization reaction with the carbon-containing substances in the wellhead gas is a rich solution.

[0089] In this embodiment, lean liquid can be added from the top of the absorption tower 7, and well gas can be added from the bottom. As the well gas moves upwards, it comes into full contact with the lean liquid moving downwards in the absorption tower 7. Carbonaceous substances in the well gas are absorbed by the lean liquid and enter the liquid phase. The lean liquid, after undergoing an acid-base neutralization reaction with the carbonaceous substances, is converted into a rich liquid and flows to the bottom of the absorption tower 7. The well gas and any carbonaceous substances not absorbed by the lean liquid move to the top of the tower. The bottom of the absorption tower 7 can be connected to the top of the regeneration tower 13 to transport the rich liquid from its bottom to the regeneration tower 13 and regenerate lean liquid by separating the carbonaceous substances.

[0090] It should be noted that some of the amine liquid in the absorption tower 7 may be carried to the top of the absorption tower 7 by the wellhead gas. In order to improve the recycling rate of the amine liquid, the top of the absorption tower 7 can also be connected to the top of the regeneration tower 13, so that the amine liquid flowing out from the top of the absorption tower 7 can be transported to the top of the regeneration tower 13 and regenerated to obtain lean liquid by separating carbonaceous substances.

[0091] The bottom of the regeneration tower 13 is connected to a reboiler 19, which is used to obtain and heat the amine solution inside the regeneration tower 13. The heated amine solution is then returned to the regeneration tower 13 and decomposes carbonaceous substances, thereby regenerating lean solution. The bottom of the regeneration tower 13 is connected to the top of the absorption tower 7, so that the regenerated lean solution can be transported to the absorption tower 7 to continue absorbing carbonaceous substances in the wellhead gas.

[0092] This embodiment utilizes carbon-containing substances within the amine absorption tower 7 to achieve decarbonization of wellhead gas. The amine solution, after absorbing a large amount of carbon-containing substances, is then transported to the regeneration tower 13 for regeneration to obtain lean solution. The regenerated lean solution can be transported back to the absorption tower 7 to absorb carbon-containing substances, thereby achieving the recycling of amine solution and reducing the cost of decarbonization.

[0093] In some embodiments, the reboiler 19 may be connected to a flue gas waste heat recovery system to enable heat exchange between the flue gas waste heat and the amine liquid in the reboiler 19.

[0094] Specifically, in this embodiment, the reboiler 19 can be connected to the hot oil circulation pump 2 in the flue gas waste heat recovery system. The heat transfer oil, after heat exchange with the flue gas waste heat in the power generation system 6, is transported to the reboiler 19 to heat the amine solution within it. The heated amine solution in the reboiler 19 can be returned to the regeneration tower 13 to separate the amine solution from carbonaceous substances and obtain lean liquor. The heat transfer oil after heat exchange with the amine solution in the reboiler 19 can be returned to the flue gas waste heat exchanger 3 to continue utilizing the flue gas waste heat generated by the power generation system 6 for further heating.

[0095] That is, by connecting the reboiler 19 to the hot oil circulation pump 2 in the flue gas waste heat recovery system, the waste heat of the flue gas from the power generation system 6 can be used to heat the rich liquid in the regeneration tower 13, thereby regenerating lean liquid to achieve the recycling of amine liquid. At the same time, it can also improve the utilization of the waste heat of the flue gas generated by the power generation system 6 to reduce the energy consumption for LNG production.

[0096] In some embodiments, the decarbonization system may further include: a top cooler 8 and a top separator 9. The top separator 9 is located at the top of the absorption tower 7 to obtain and cool the gas at the top of the absorption tower 7, thereby facilitating the separation of wellhead gas and amine liquid. The top separator 9 is connected to the top cooler 8 to obtain the material cooled by the top cooler 8 and to separate the amine liquid and wellhead gas.

[0097] The top of the top separator 9 can be connected to the subsequent process system of the decarbonization system. When the carbon content in the well gas separated by the top separator 9 is less than 50 ppm, the well gas can be transported to the subsequent process system of the decarbonization system. For example, the well gas separated by the top separator 9 can be transported to the dehydration system. At the same time, the bottom of the top separator 9 can be connected to the top of the regeneration tower 13 to transport the rich liquid obtained from the separation to the regeneration tower 13 for regeneration treatment.

[0098] In some embodiments, the decarbonization system may further include a flash tank 10, one end of which may be connected to the top and / or bottom of the top separator 9 for obtaining amine liquid. A small amount of hydrocarbons and carbon-containing substances in the amine liquid can be flashed out in the flash tank 10, reducing the load on the subsequent regeneration tower 13 when heating and desorbing carbon-containing substances, and improving the efficiency of the subsequent regeneration tower 13 in decomposing carbon-containing substances from the amine liquid.

[0099] A level control valve can be installed between the top separator 9 and the flash tank 10. The level control valve can be used to measure the level of amine liquid in the top separator 9 to improve the problem of well gas entering the flash tank 10 due to the low level of amine liquid.

[0100] For example, after the amine liquid in the top separator 9 enters the level control valve, the level control valve can first reduce the pressure of the amine liquid to 0.6 MPa before sending the amine liquid to the flash tank 10.

[0101] The other end of the flash tank 10 can be connected to the regeneration tower 13 for conveying the flashed amine liquid into the regeneration tower 13.

[0102] In some embodiments, the decarbonization system may further include a lean-rich liquid heat exchanger 12, which can be connected to the bottom of the flash tank 10 and the regeneration tower 13 respectively, to achieve heat exchange between the amine liquid at the bottom of the regeneration tower 13 and the amine liquid in the flash tank 10. After the amine liquid in the flash tank 10 is heated, it can enter the top of the regeneration tower 13 to separate carbon-containing substances and obtain lean liquid.

[0103] Specifically, the temperature of the amine solution in flash tank 10 is relatively low, while the temperature of the lean solution obtained from regeneration in regeneration tower 13 is relatively high. By setting up a lean-rich solution heat exchanger 12, heat exchange can be achieved between the rich solution in flash tank 10 and the lean solution in regeneration tower 13. After heat exchange, the rich solution in flash tank 10 is heated and transported to the top of regeneration tower 13. For example, the rich solution after heat exchange can be heated to 90°C-100°C. This embodiment of the present disclosure utilizes the residual heat of the regenerated lean solution to heat the rich solution, which can reduce the energy consumption required for heating the rich solution after it enters regeneration tower 13, thereby reducing the overall cost of LNG production. The lean solution after heat exchange and cooling can be transported to the top of absorption tower 7 for absorbing carbonaceous substances in the wellhead gas.

[0104] In some embodiments, the decarbonization system may further include a buffer tank 17, whose opposite ends are respectively connected to the top of the lean and rich liquid heat exchanger 12 and the absorption tower 7, for receiving the amine liquid cooled at the bottom of the regeneration tower 13. The amine liquid can flow slowly in the buffer tank 17, thereby reducing the impact of the amine liquid on subsequent process equipment. When the buffer tank 17 has buffered a sufficient liquid level of amine liquid, the amine liquid can be transported to the absorption tower 7, thereby ensuring that the amine liquid can be stably transported to the absorption tower 7.

[0105] In some embodiments, the decarbonization system may further include a lean liquor cooler 11, located between the buffer tank 17 and the absorption tower 7, for obtaining the amine solution in the buffer tank 17 and cooling the amine solution. The lean liquor can be cooled to below 45°C by the lean liquor cooler 11 before entering the absorption tower 7.

[0106] A lean liquid pump 16 can also be installed between the buffer tank 17 and the absorption tower 7. The lean liquid pump 16 can be used to pressurize the lean liquid, and then send the lean liquid in the buffer tank 17 to the absorption tower 7.

[0107] For example, the lean solution pump 16 can be located between the buffer tank 17 and the lean solution cooler 11. The lean solution pump 16 can pressurize the lean solution to 6.0 MPa.

[0108] It should be noted that when the carbonaceous material decomposed in the rich liquor in the regeneration tower 13 exits through the top of the regeneration tower 13, some of the amine liquor may leave the regeneration tower 13 along with the carbonaceous material. To utilize the amine liquor leaving the top of the regeneration tower 13, in some embodiments, the decarbonization system may further include: a carbonaceous material cooler 14 and a carbonaceous material separator 15.

[0109] Specifically, the carbonaceous material cooler 14 can be used to obtain and cool the gas at the top of the regeneration tower 13, thereby facilitating gas-liquid separation.

[0110] For example, carbon-containing material cooler 14 can cool carbon-containing materials to below 45°C.

[0111] One end of the carbonaceous material separator 15 is connected to the carbonaceous material cooler 14 to obtain the material cooled by the carbonaceous material cooler 14 and separate the amine liquid from the carbonaceous material. The carbonaceous material can be discharged to the atmosphere through the top of the carbonaceous material separator 15, and the other end of the carbonaceous material separator 15 can be connected to the top of the absorption tower 7 to transport the separated amine liquid to the absorption tower 7, thereby improving the recycling rate of the amine liquid and improving the decarbonization efficiency of the absorption tower 7.

[0112] In some embodiments, the power generation system 6 can also be connected to the outlet of the dehydration system to provide the power generation system 6 with wellhead gas that has been dehydrated by the dehydration system.

[0113] It should be noted that the power generation system 6 in this embodiment can be connected to both the desanding system and the dehydration system to obtain sufficient wellhead gas, thereby ensuring that sufficient power can be provided to the wellhead gas to LNG system with power generation system to maintain the normal operation of the system.

[0114] However, this is not the only option. In this embodiment, the desanding system can also be connected to the power generation system 6 during the initial startup of the wellhead gas-to-LNG system with the power generation system. This allows for desanding of the wellhead gas and supply of wellhead gas to the power generation system 6 without the need for electricity, thereby using the power from the power generation system 6 to power the entire wellhead gas-to-LNG system with the power generation system. Once the dehydration system obtains dehydrated wellhead gas for the first time, it can directly supply wellhead gas to the power generation system 6. Compared to wellhead gas directly using the desanding system to remove solid particles before power generation, the non-flammable components in the wellhead gas after desanding, decarbonization, and dehydration are significantly reduced. This improves the power generation efficiency of the power generation system 6 and reduces wear and tear, thus extending its service life.

[0115] In this embodiment, the dehydration system may include three dehydration towers and at least one regeneration gas heater 23. All three dehydration towers are capable of adsorbing water from the wellhead gas. Specifically, the dehydration system in this embodiment employs a three-tower isobaric regeneration scheme. Within one adsorption cycle, the three dehydration towers can be in adsorption, cold blowing, and heating states, respectively. In the next adsorption cycle, the dehydration tower previously in the adsorption state can be switched to the heating state, thereby utilizing high temperature to regenerate the adsorbent within the tower, facilitating the adsorption of water from the wellhead gas in the next adsorption cycle. Simultaneously, the dehydration tower previously in the heating state can be switched to the cooling state, and the dehydration tower previously in the cooling state can be switched back to the adsorption state. The three dehydration towers in the dehydration system can be used in a cyclical manner, changing their specific states (i.e., adsorption, heating, and cold blowing states) according to actual conditions. In other words, the three dehydration towers in this embodiment can be used alternately by switching states to achieve continuous dehydration treatment of the wellhead gas.

[0116] Specifically, the dehydration system may include a first dehydration tower 20, a second dehydration tower 22, a third dehydration tower 21, and a regeneration gas heater 23. The first dehydration tower 20 is used to obtain wellhead gas from the outlet of the decarbonization system and, after adsorbing water from the wellhead gas, delivers it to the liquefaction system. The second dehydration tower 22 is used to obtain and cool the wellhead gas from the outlet of the decarbonization system. The regeneration gas heater 23 can be connected to the top of the second dehydration tower 22 to obtain and heat the wellhead gas. The third dehydration tower 21 can be connected to the regeneration gas heater 23 to obtain the heated wellhead gas. The third dehydration tower 21 can utilize the heat of the wellhead gas to desorb water from the adsorbent within the tower, thereby regenerating the adsorbent in the third dehydration tower 21 for use in subsequent adsorption cycles to adsorb water from the wellhead gas.

[0117] Furthermore, the heated wellhead gas can be cooled after entering the third dehydration tower 21. The cooled wellhead gas in the third dehydration tower 21 can then be delivered to the power generation system 6.

[0118] In some embodiments, the dehydration system may further include a regenerated gas electric heater 24, which can acquire and heat the wellhead gas in the regenerated gas heater 23, and the wellhead gas heated by the regenerated gas electric heater 24 can be delivered to the third dehydration tower 21.

[0119] It should be noted that, in order to facilitate the alternating use of the three dehydration towers, the first dehydration tower 20, the second dehydration tower 22, and the third dehydration tower 21 in this embodiment can all be connected to the previous process system (e.g., the decarbonization system), the regenerated gas heater 23, and the power generation system 6.

[0120] In this embodiment of the disclosure, the regenerated gas heater 23 can be connected to the flue gas waste heat recovery system to utilize the flue gas waste heat in the power generation system 6 to raise the temperature of the wellhead gas in the regenerated gas heater 23, thereby improving the utilization of flue gas waste heat and reducing the energy consumption for LNG production.

[0121] Specifically, the regenerated gas heater 23 can be connected to the flue gas waste heat exchanger 3 in the flue gas waste heat recovery system to utilize the heat transfer oil heated by the flue gas waste heat in the power generation system 6 to raise the temperature of the wellhead gas in the regenerated gas heater 23. The heat transfer oil after heat exchange can be returned to the flue gas waste heat exchanger 3.

[0122] In some embodiments, the wellhead gas after being dehydrated by the dehydration tower in the adsorption state can be filtered for dust by a purified gas filter and then transported to the liquefaction system, wherein the filtration accuracy of the purified gas filter can be 5μm-10μm.

[0123] In some embodiments, the wellhead gas passes from bottom to top through a dehydration tower in a cold-blowing state, and then enters the regeneration gas heater 23 and / or the regeneration gas electric heater 24. The wellhead gas can be heated to 220°C before entering the heated dehydration tower. The high temperature of the wellhead gas can desorb water from the adsorbent in the tower, facilitating subsequent adsorption of water from the wellhead gas. After exiting the bottom of the heated dehydration tower, the wellhead gas can be transported to the power generation system 6.

[0124] In some embodiments, the dehydration system may further include a regenerated gas cooler 25 and a regenerated gas separator 26.

[0125] The regenerated gas cooler 25 can be connected to the bottom of a dehydration tower (e.g., a third dehydration tower 21) under heating conditions to obtain and cool the wellhead gas in the dehydration tower under heating conditions.

[0126] For example, in this embodiment of the present disclosure, the wellhead gas can be cooled to below 45°C by the regenerated gas cooler 25 before being delivered to the regenerated gas separator 26.

[0127] The regenerated gas separator 26 can be connected to the regenerated gas cooler 25 to obtain the material cooled by the regenerated gas cooler 25 and to separate the wellhead gas from the water. The separated water can be discharged from the bottom of the regenerated gas separator 26, and the separated wellhead gas can be transported from the top of the regenerated gas separator 26 to the power generation system 6.

[0128] In this embodiment of the disclosure, the entire dehydration and purification process of the dehydration system can be implemented by multiple programmable valves switching automatically according to a program, and the operator can adjust the program time to control the entire purification process.

[0129] In some embodiments, the wellhead gas to LNG system with a power generation system may further include a mercury removal system, which may be located between the decarbonization system and the dehydration system. This mercury removal system is used to acquire and remove mercury from the wellhead gas in the decarbonization system, and then deliver the mercury-removed wellhead gas to the dehydration system. Specifically, the mercury in the wellhead gas can be removed to a concentration of 0.001 μg / m³ by the mercury removal system before entering the dehydration system.

[0130] In some embodiments, the liquefaction system may include: a plate-fin heat exchanger 28, a high-temperature refrigerant compressor 27, and a low-temperature refrigerant compressor 31.

[0131] The plate-fin heat exchanger 28 can be used to receive wellhead gas in the dehydration system. The plate-fin heat exchanger 28 includes a high-temperature section and a low-temperature section.

[0132] The high-temperature refrigerant compressor 27 can be used to compress and cool the high-temperature refrigerant. The high-temperature refrigerant compressor 27 can deliver the compressed and cooled high-temperature refrigerant to the high-temperature section. After cooling, condensation, and throttling and depressurization, the high-temperature refrigerant returns to the high-temperature section of the plate-fin heat exchanger 28 to provide cooling capacity to achieve initial cooling of the wellhead gas. After being reheated by the plate-fin heat exchanger 28, the high-temperature refrigerant can return to the inlet of the high-temperature refrigerant compressor 27 and be compressed again to achieve cyclic refrigeration.

[0133] The cryogenic refrigerant compressor 31 can be used to compress and cool cryogenic refrigerant. After the wellhead gas is initially cooled, the cryogenic refrigerant compressor 31 can sequentially deliver the cryogenic refrigerant to the high-temperature section and the low-temperature section. After being cooled, condensed, and throttled, the cryogenic refrigerant returns to the high-temperature section and the low-temperature section of the plate-fin heat exchanger 28 to provide cooling capacity to achieve deep cooling of the wellhead gas. After being reheated by the plate-fin heat exchanger 28, the cryogenic refrigerant can return to the inlet of the cryogenic refrigerant compressor 31 and undergo compression again to achieve cyclic refrigeration.

[0134] In this embodiment, both the high-temperature refrigerant compressor 27 and the low-temperature refrigerant compressor 31 can be composed of screw compressors.

[0135] After being treated by the desanding system, decarbonization system, and dehydration system, the wellhead gas enters the liquefaction system for liquefaction. After liquefaction (i.e., after deep cooling), the wellhead gas can be throttled and depressurized by the throttle valve and then sent to the LNG collection unit 29.

[0136] For example, the LNG collection device 29 may be an LNG tanker truck.

[0137] In this embodiment of the disclosure, the wellhead gas is throttled to within 25 MPa after passing through the gas production tree in the first stage. The temperature of the raw material wellhead gas is 20°C and the gas volume is 60,000 cubic meters / day. The composition of the raw material wellhead gas can be seen in Table 1 below.

[0138] Table 1. Composition of raw material wellhead gas

[0139]

[0140] The volume of LNG formed after liquefaction of wellhead gas can be 94.20 cubic meters. The physical parameters of the LNG collected by LNG collection unit 29 are shown in Table 2 below, and the composition of the collected LNG is shown in Table 3 below.

[0141] Table 2 Physical parameters of LNG product

[0142]

[0143] Table 3 Composition of LNG Product

[0144]

[0145] In some embodiments, the wellhead gas can be transported to the heavy hydrocarbon separator 30 after preliminary cooling. The heavy hydrocarbon separator 30 can separate the heavy hydrocarbon substances in the wellhead gas, thereby improving the problem of pipelines, valves and equipment in the wellhead gas to LNG system with power generation system freezing and blockage caused by the heavy hydrocarbon substances in the wellhead gas, which may lead to economic losses or even safety accidents.

[0146] In the description of this specification, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0147] Furthermore, it should be noted that terms such as "upper," "lower," "left," and "right" are used only for distinction and convenience of description, and do not impose any positional limitations on the embodiments of the present invention. For example, "upper" in practice can refer to "lower," "left," or "right." In this disclosure, unless otherwise explicitly specified and limited, terms such as "assembly" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in this disclosure can be understood according to the specific circumstances.

[0148] In the description of this specification, references to terms such as "some embodiments," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. The illustrative expressions of the above terms in this specification do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0149] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application. Therefore, any changes or modifications made in accordance with the claims and description of this application should fall within the scope of this patent application.

Claims

1. A wellhead gas-to-LNG system with a power generation system, characterized in that, include: Desanding systems are used to capture and remove solid particles from wellhead gas. A decarbonization system is used to obtain wellhead gas from the desanding system and remove carbon-containing substances from the wellhead gas. A dehydration system is used to obtain wellhead gas from the decarbonization system for separating water from the wellhead gas; A liquefaction system is used to acquire and cool the wellhead gas in the dehydration system for the purpose of liquefying the wellhead gas. An LNG collection device is connected to the outlet of the liquefaction system to collect liquefied wellhead gas. The power generation system is at least connected to the desanding system to receive wellhead gas supplied by the desanding system and to start up; A flue gas waste heat recovery system, which is connected to the power generation system, is used to recover the waste heat from the flue gas generated by the power generation system and transfer the heat to the decarbonization system and / or the dehydration system.

2. The wellhead gas to LNG system with a power generation system according to claim 1, characterized in that, The flue gas waste heat recovery system includes: A flue gas waste heat exchanger is connected to the power generation system to receive the waste heat from the flue gas generated by the power generation system. An elevated oil tank is provided, which can hold heat transfer oil. The elevated oil tank is connected to the flue gas waste heat exchanger to transport the heat transfer oil to the flue gas waste heat exchanger and absorb the waste heat from the flue gas in the power generation system. A hot oil circulation pump, one end of which is connected to the flue gas waste heat exchanger, and the other end of which can be connected to the decarbonization system and / or the dehydration system, for conveying the heated heat transfer oil to the decarbonization system and / or the dehydration system.

3. The wellhead gas to LNG system with a power generation system according to claim 1, characterized in that, The sand removal system includes: A desander is used to obtain wellhead gas and remove solid particles from it. A water jacket furnace is connected to the desander to obtain wellhead gas from the desander and to heat and depressurize the wellhead gas. A pressure regulating valve is connected to the outlet end of the water jacket furnace to obtain wellhead gas and depressurize it to the target pressure.

4. The wellhead gas to LNG system with a power generation system according to claim 1, characterized in that, The decarbonization system includes: The absorption tower is hollow inside, and its bottom is connected to the outlet end of the desanding system for obtaining wellhead gas; the top of the absorption tower can obtain amine liquid, which can be used to absorb carbon-containing substances in the wellhead gas inside the absorption tower. The regeneration tower is hollow inside, and its top can receive the amine liquid in the absorption tower and separate carbon-containing substances from the amine liquid; wherein, the regeneration tower can transport the amine liquid obtained after separating the carbon-containing substances to the top of the absorption tower; A reboiler is connected to the bottom of the regeneration tower to obtain amine liquid from the regeneration tower; the reboiler is also connected to the flue gas waste heat recovery system to achieve heat exchange between the flue gas waste heat and the amine liquid in the reboiler; the amine liquid heated in the reboiler can be returned to the regeneration tower to achieve separation of amine liquid from carbonaceous substances.

5. The wellhead gas to LNG system with a power generation system according to claim 4, characterized in that, The decarbonization system also includes: A tower top cooler is provided at the top of the absorption tower to obtain and cool the gas at the top of the absorption tower; A top separator, connected to the top cooler, is used to obtain the material cooled by the top cooler and separate amine liquid and wellhead gas. The amine liquid can be transported from the bottom of the top separator to the regeneration tower, and the wellhead gas can be transported to the dehydration system.

6. The wellhead gas to LNG system with a power generation system according to claim 5, characterized in that, The decarbonization system also includes: A flash tank, connected to the top and / or bottom of the column top separator, for obtaining amine solution; The lean and rich liquid heat exchangers are connected to the bottom of the flash tank and the regeneration tower respectively, so as to realize the heat exchange between the amine liquid at the bottom of the regeneration tower and the amine liquid in the flash tank; after the amine liquid in the flash tank is heated, it enters the top of the regeneration tower and separates out carbon-containing substances. A buffer tank, with its opposite ends connected to the top of the lean and rich liquid heat exchanger and the top of the absorption tower respectively, is used to obtain the amine liquid cooled at the bottom of the regeneration tower and to transport the amine liquid to the absorption tower. A lean solution cooler is located between the buffer tank and the absorption tower to cool the amine solution in the buffer tank.

7. The wellhead gas to LNG system with a power generation system according to claim 4, characterized in that, The decarbonization system also includes: A carbon-containing material cooler is used to obtain and cool the gas at the top of the regeneration tower; A carbon-containing material separator, one end of which is connected to the carbon-containing material cooler, is used to obtain the material cooled by the carbon-containing material cooler and separate the amine liquid from the carbon-containing material. The other end of the carbon-containing material separator is connected to the top of the absorption tower to transport the separated amine liquid to the absorption tower.

8. The wellhead gas to LNG system with a power generation system according to claim 1, characterized in that, The outlet of the dehydration system is connected to the power generation system to provide wellhead gas to the power generation system; The dehydration system includes: The first dehydration tower is used to obtain well gas from the outlet of the decarbonization system and, after adsorbing water from the well gas, transport the well gas to the liquefaction system. The second dehydration tower is used to obtain and cool the wellhead gas at the outlet of the decarbonization system; A regenerated gas heater is connected to the top of the second dehydration tower to obtain wellhead gas from the second dehydration tower; the regenerated gas heater is connected to the flue gas waste heat recovery system to utilize the flue gas waste heat in the power generation system to raise the temperature of the wellhead gas in the regenerated gas heater. The third dehydration tower is connected to the regeneration gas heater to obtain wellhead gas; the third dehydration tower can use the heat of the wellhead gas to desorb water from the adsorbent; the wellhead gas in the third dehydration tower can be transported to the power generation system.

9. The wellhead gas to LNG system with a power generation system according to claim 8, characterized in that, The dehydration system includes: The regenerated gas electric heater is capable of acquiring and heating the wellhead gas in the regenerated gas heater, and the heated wellhead gas can be delivered to the third dehydration tower; and / or, A regenerated gas cooler is connected to the bottom of the third dehydration tower to obtain and cool the wellhead gas in the third dehydration tower; A regenerated gas separator, connected to the regenerated gas cooler, is used to obtain the material cooled by the regenerated gas cooler and to separate wellhead gas from water; the separated water can be discharged from the bottom of the regenerated gas separator, and the separated wellhead gas can be transported from the top of the regenerated gas separator to the power generation system.

10. The wellhead gas to LNG system with a power generation system according to claim 1, characterized in that, The wellhead gas to LNG system with power generation system includes a mercury removal system, which is located between the decarbonization system and the dehydration system to obtain and remove mercury from the wellhead gas in the decarbonization system and to transport the wellhead gas to the dehydration system. And / or, The liquefaction system includes: A plate-fin heat exchanger is used to receive wellhead gas in the dehydration system; the plate-fin heat exchanger includes a high-temperature section and a low-temperature section; A high-temperature refrigerant compressor is used to compress and cool a high-temperature refrigerant and deliver the high-temperature refrigerant to the high-temperature section. After the high-temperature refrigerant initially cools the wellhead gas, it can return to the high-temperature refrigerant compressor to achieve refrigeration. A cryogenic refrigerant compressor is used to compress and cool cryogenic refrigerant. After the wellhead gas is initially cooled, the cryogenic refrigerant compressor can sequentially deliver the cryogenic refrigerant to the high-temperature section and the low-temperature section. After the cryogenic refrigerant has cooled the wellhead gas to a certain depth, it can return to the cryogenic refrigerant compressor to achieve refrigeration.

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