Scattered gas recovery system

Abstract

The invention relates to the technical field of petrochemical engineering, and discloses a scattered gas recovery system. The scattered gas recovery system comprises a movable scattered gas treatment module, according to the scattered gas treatment module, a gas inlet of a pretreatment unit is used for being communicated with a gas recovery well; the deacidification unit is used for deacidifying the first treatment gas; a gas inlet of the deacidification vehicle is communicated with a gas outlet of the pretreatment unit; a gas inlet of the dehydration and demercuration unit is communicated with a gas outlet of the deacidification unit; a gas inlet of the liquefaction unit is communicated with a gas outlet of the dehydration and demercuration unit, and a liquid outlet of the liquefaction unit is used for discharging liquefied gas; and a refrigerant circulation loop is formed between the refrigerant compression unit and the liquefaction unit, so that the second treatment gas entering the liquefaction unit is condensed and liquefied. According to the invention, the problems of large equipment size, high cost and low economic benefit in the aspect of scattered gas recycling in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical engineering, and particularly relates to a scattered gas recovery system. Background Art

[0002] For scattered gases such as associated gas, test production gas, casing gas, coalbed methane, shale gas, tight gas, and biogas in remote oilfields, due to their characteristics of small gas source flow rate, scattered gas sources, long distances, and instability, the traditional method of laying pipelines for recovery has high investment and high risks. If not recovered, it will cause environmental pollution and waste of resources; at the same time, a large amount of dry gas in some remote oilfields cannot be efficiently utilized. At present, in order to realize the recovery of such scattered gases, skid-mounted or fixed liquefaction devices have been developed. Most of these devices are large in volume, inconvenient to move, have high operating costs, and low economic benefits, which limit the development and utilization of the areas where they are located. Summary of the Invention

[0003] The present invention provides a scattered gas recovery system to solve the problems of large equipment volume, high cost, and low economic benefits in the recovery and utilization of scattered gases in the prior art.

[0004] The present invention provides a scattered gas recovery system, including a movable scattered gas treatment module, and the scattered gas treatment module includes: A pretreatment unit for pretreating the raw gas to discharge the first treated gas; the inlet of the pretreatment unit is used to communicate with a gas production well; An acid removal unit for removing acid from the first treated gas; the inlet of the acid removal unit is communicated with the outlet of the pretreatment unit; A dehydration and mercury removal unit for dehydrating and removing mercury from the first treated gas after acid removal treatment to form a second treated gas; the inlet of the dehydration and mercury removal unit is communicated with the outlet of the acid removal unit; A liquefaction unit, the inlet of the liquefaction unit is communicated with the outlet of the dehydration and mercury removal unit, and the liquid outlet of the liquefaction unit is used to discharge liquefied gas; A refrigerant compression unit, the refrigerant outlet of the refrigerant compression unit is communicated with the refrigerant inlet of the liquefaction unit, and the refrigerant inlet of the refrigerant compression unit is communicated with the refrigerant outlet of the liquefaction unit to form a refrigerant circulation loop, so that the second treated gas is condensed and liquefied in the liquefaction unit.

[0005] According to the scattered gas recovery system provided by the present invention, the pretreatment unit includes: A pretreatment box body; A pretreatment module, which is arranged in the pretreatment box body; the pretreatment module includes a gas-liquid separator; an air inlet of the gas-liquid separator is used to communicate with the gas production well, and an air outlet of the gas-liquid separator is communicated with an air inlet of the acid removal unit.

[0006] According to the scattered gas recovery system provided by the present invention, the acid removal unit includes: An acid removal box body; An acid removal module, which is arranged in the acid removal box body; the acid removal module includes an absorption tower; an air inlet of the absorption tower is communicated with an air outlet of the pretreatment unit, and an air outlet of the absorption tower is communicated with an air inlet of the dehydration and mercury removal unit, so that the first treated gas is mixed with an acid removal adsorbent in the absorption tower.

[0007] According to the scattered gas recovery system provided by the present invention, the acid removal adsorbent includes methyldiethanolamine.

[0008] According to the scattered gas recovery system provided by the present invention, the dehydration and mercury removal unit includes: A dehydration and mercury removal box body; A dehydration and mercury removal module, including: A drying adsorption tower, which is arranged in the dehydration and mercury removal box body; an air inlet of the drying adsorption tower is communicated with an air outlet of the acid removal unit; A mercury remover, which is arranged in the dehydration and mercury removal box body; an air outlet of the drying adsorption tower is communicated with an air inlet of the mercury remover, and an air outlet of the mercury remover is communicated with an air inlet of the liquefaction unit.

[0009] According to the scattered gas recovery system provided by the present invention, the liquefaction unit includes: A liquefaction box body; A liquefaction module, which is arranged in the liquefaction box body; the liquefaction module includes a liquefaction heat exchanger; the liquefaction heat exchanger has a liquefaction flow channel and a refrigerant flow channel; an air inlet of the liquefaction flow channel is communicated with an air outlet of the dehydration and mercury removal unit, and a liquid outlet of the liquefaction flow channel is used to discharge the liquefied gas; the refrigerant flow channel is communicated with the refrigerant compression unit to form the refrigerant circulation loop.

[0010] According to the scattered gas recovery system provided by the present invention, it further includes: An instrument control module, which is electrically connected to the scattered gas treatment module.

[0011] A power supply module, which is electrically connected to the scattered gas treatment module and the instrument control module.

[0012] According to the scattered gas recovery system provided by the present invention, the mobile module is connected to the scattered gas treatment module, the instrument control module, and the power module, and is used to enable the scattered gas treatment module, the instrument control module, and the power module to move.

[0013] According to the scattered gas recovery system provided by the present invention, the mobile module includes: The first mobile unit, and the pretreatment unit is arranged on the first mobile unit; The second mobile unit, and the deacidification unit is arranged on the second mobile unit; The third mobile unit, and the dehydration and mercury removal unit is arranged on the third mobile unit; The fourth mobile unit, and the liquefaction unit is arranged on the fourth mobile unit; The fifth mobile unit, and the refrigerant compression unit is arranged on the fifth mobile unit; The sixth mobile unit, and the instrument control module is arranged on the sixth mobile unit; The seventh mobile unit, and the power module is arranged on the seventh mobile unit.

[0014] According to the scattered gas recovery system provided by the present invention, the first mobile unit is a vehicle.

[0015] In the scattered gas recovery system provided by the present invention, by setting a movable scattered gas treatment module, and the scattered gas treatment module includes a pretreatment unit, a deacidification unit, a dehydration and mercury removal unit, a liquefaction unit, and a refrigerant compression unit, scattered gases such as associated gas in remote oilfields, gas from well testing, casing gas, coalbed methane, shale gas, tight gas, biogas, wellhead gas, etc. can be efficiently utilized, avoiding waste, and solving many problems that are not convenient for recovery due to small gas volume, low pressure, remote location, complex gas source components, short recoverable period, etc. of such gas sources; at the same time, it avoids the high cost and long cycle of building fixed facilities, and solves the problems of large equipment volume, high cost, and low economic benefits existing in the prior art in the recovery and utilization of scattered gases. It adapts to the characteristics of the variable position of scattered gas sources, realizes "where the gas source is, it is processed there", each unit can be independently loaded and unloaded, and the process combination can be flexibly adjusted according to the gas source composition. The refrigerant compression unit and the liquefaction unit form a closed loop to improve energy efficiency; the dehydration and mercury removal unit is placed in front to avoid freezing of heavy hydrocarbons and mercury at low temperatures. The scattered gas that was originally flared and burned is converted into high-value liquefied natural gas (LNG), reducing greenhouse gas emissions. The hydrogen sulfide recovered by the deacidification unit can be further used to produce sulfur to achieve resource utilization. Description of the Drawings

[0016] To more clearly illustrate the technical solutions in the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is one of the schematic structural diagrams of the scattered gas recovery system provided by the present invention.

[0018] Figure 2 It is another schematic structural diagram of the scattered gas recovery system provided by the present invention.

[0019] Figure 3 It is the schematic structural diagram of the pretreatment module of the scattered gas recovery system provided by the present invention.

[0020] Figure 4 It is the schematic structural diagram of the acid removal module of the scattered gas recovery system provided by the present invention.

[0021] Figure 5 It is the schematic structural diagram of the dehydration and mercury removal module, liquefaction module and refrigerant compression unit of the scattered gas recovery system provided by the present invention.

[0022] Figure 6 It is the schematic structural diagram of the pretreatment unit and the first moving unit of the scattered gas recovery system provided by the present invention.

[0023] Figure 7 It is the schematic structural diagram of the acid removal unit and the second moving unit of the scattered gas recovery system provided by the present invention.

[0024] Figure 8 It is the schematic structural diagram of the dehydration and mercury removal unit and the third moving unit of the scattered gas recovery system provided by the present invention.

[0025] Figure 9 It is the schematic structural diagram of the liquefaction unit and the fourth moving unit of the scattered gas recovery system provided by the present invention.

[0026] Figure 10 It is the schematic structural diagram of the refrigerant compression unit and the fifth moving unit of the scattered gas recovery system provided by the present invention.

[0027] Figure 11 It is the schematic structural diagram of the instrument control module and the sixth moving unit of the scattered gas recovery system provided by the present invention.

[0028] Figure 12 It is the schematic structural diagram of the power supply module and the seventh moving unit of the scattered gas recovery system provided by the present invention.

[0029] Reference Signs: 10, gas production well; 110, pretreatment unit; 120, acid removal unit; 130, dehydration and mercury removal unit; 140, liquefaction unit; 150, refrigerant compression unit; 160, utility vehicle; 200, instrument control module; 300, power supply module; 410, first moving unit; 420, second moving unit; 430, third moving unit; 440, fourth moving unit; 450, fifth moving unit; 460, sixth moving unit; 470, seventh moving unit. Detailed Embodiments

[0030] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", and "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0032] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "connected" and "connected to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood in specific situations.

[0033] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "below" and "beneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0034] In the description of this specification, the description referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0035] The following combines Figures 1 to 12 to make a detailed description of the structure and working principle of the stray gas recovery system of the present invention.

[0036] As Figures 1 to 12 shown, a specific embodiment of the present invention provides a stray gas recovery system. The stray gas recovery system includes a movable stray gas treatment module; the stray gas treatment module includes a pretreatment unit 110, a deacidification unit 120, a dehydration and mercury removal unit 130, a liquefaction unit 140, and a refrigerant compression unit 150. The pretreatment unit 110 is used to pretreat the raw gas to discharge the first treated gas; the air inlet of the pretreatment unit 110 is used to communicate with the gas production well 10; the deacidification unit 120 is used to perform deacidification treatment on the first treated gas; the air inlet of the deacidification vehicle is communicated with the air outlet of the pretreatment unit 110; the dehydration and mercury removal unit 130 is used to perform dehydration and mercury removal on the first treated gas after deacidification treatment to form a second treated gas; the air inlet of the dehydration and mercury removal unit 130 is communicated with the air outlet of the deacidification unit 120; the air inlet of the liquefaction unit 140 is communicated with the air outlet of the dehydration and mercury removal unit 130, and the liquid outlet of the liquefaction unit 140 is used to discharge the liquefied gas; the refrigerant outlet of the refrigerant compression unit 150 is communicated with the refrigerant inlet of the liquefaction unit 140, and the refrigerant inlet of the refrigerant compression unit 150 is communicated with the refrigerant outlet of the liquefaction unit 140 to form a refrigerant circulation loop, so that the second treated gas is condensed and liquefied in the liquefaction unit 140.

[0037] In this embodiment, by setting up a movable scattered gas treatment module, and the scattered gas treatment module includes a pretreatment unit 110, a deacidification unit 120, a dehydration and mercury removal unit 130, a liquefaction unit 140 and a refrigerant compression unit 150, it is possible to efficiently utilize scattered gases such as associated gas from remote oilfields, trial production gas, casing gas, coalbed methane, shale gas, tight gas, biogas, wellhead gas, etc., avoid waste, and solve many problems that are not convenient for recovery of such gas sources due to small gas volume, low pressure, remote location, complex gas source components, short recoverable period, etc.; at the same time, it avoids the high cost and long cycle of building fixed facilities, and solves the problems of large equipment volume, high cost and low economic efficiency existing in the prior art in the recovery and utilization of scattered gases. It adapts to the characteristics of the variable position of scattered gas sources, realizes "where the gas source is, it is processed there", and each unit can be independently loaded and unloaded, and the process combination can be flexibly adjusted according to the gas source composition. The refrigerant compression unit 150 and the liquefaction unit 140 form a closed loop to improve energy efficiency; the dehydration and mercury removal unit 130 is placed in front to avoid freezing of heavy hydrocarbons and mercury at low temperatures. The scattered gas that was originally flared is converted into high-value liquefied natural gas, reducing greenhouse gas emissions. The hydrogen sulfide recovered by the deacidification unit 120 can be further used to produce sulfur to achieve resource utilization.

[0038] Further, the intake port of the pretreatment unit 110 is used to communicate with the gas production well 10 through a quick-connect pipe; the deacidification unit 120 is used to perform deacidification treatment on the first treated gas; the intake port of the deacidification vehicle is communicated with the outlet of the pretreatment unit 110 through a quick-connect pipe; the dehydration and mercury removal unit 130 is used to perform dehydration and mercury removal on the first treated gas after deacidification treatment to form a second treated gas; the intake port of the dehydration and mercury removal unit 130 is communicated with the outlet of the deacidification unit 120 through a quick-connect pipe; the intake port of the liquefaction unit 140 is communicated with the outlet of the dehydration and mercury removal unit 130 through a quick-connect pipe, and the liquid outlet of the liquefaction unit 140 can be connected to a liquid storage tank truck through a quick-connect pipe for discharging the liquefied gas into the liquid storage tank truck. The refrigerant outlet of the refrigerant compression unit 150 is communicated with the refrigerant inlet of the liquefaction unit 140 through a quick-connect pipe, and the refrigerant inlet of the refrigerant compression unit 150 is communicated with the refrigerant outlet of the liquefaction unit 140 through a quick-connect pipe to form a refrigerant circulation loop, so that the second treated gas is condensed and liquefied in the liquefaction unit 140. In this embodiment, the quick connection of each unit is realized through the quick-connect pipe, which can improve the disassembly and assembly efficiency, thereby improving the operation efficiency.

[0039] Such as Figure 1 And Figure 2As shown, in some embodiments, the scattered gas recovery system includes an instrument control module 200 and a power module 300; the instrument control module 200 is electrically connected to the scattered gas processing module. The power module 300 is electrically connected to the scattered gas processing module and the instrument control module 200. Specifically, the instrument control module 200 is electrically connected to at least one of the pretreatment unit 110, the deacidification unit 120, the dehydration and demercuration unit 130, the liquefaction unit 140 and the refrigerant compression unit 150. The instrument control module 200 serves as the control center of the entire system, and is responsible for data collection and control of the entire device, and is used to monitor the operation of each unit, such as monitoring the pressure and temperature of the raw gas entering each unit, to ensure the smooth operation of the system. The power module 300 is electrically connected to the instrument control module 200, the pretreatment unit 110, the deacidification unit 120, the dehydration and demercuration unit 130, the liquefaction unit 140 and the refrigerant compression unit 150 through cables, and is used to supply power to the instrument control module 200, the pretreatment unit 110, the deacidification unit 120, the dehydration and demercuration unit 130, the liquefaction unit 140 and the refrigerant compression unit 150.

[0040] Optionally, the instrument control module 200 is connected to the pretreatment unit 110 , the deacidification unit 120 , the dehydration and demercuration unit 130 , the liquefaction unit 140 , and the refrigerant compression unit 150 through wireless communication.

[0041] Optionally, the control system of the instrument control module 200 may adopt the distributed control system of Zhejiang University Central Control Technology Co., Ltd., which is mature in the industry, referred to as the Zhejiang University Central Control DCS system.

[0042] Furthermore, the power module 300 includes a generator set. Preferably, the power module 300 includes at least two generator sets.

[0043] Specifically, the power module 300 includes five 250KW generator sets, with a continuous load of approximately 875KW / h, which can meet the power supply of the entire system.

[0044] like Figure 2 As shown, in some embodiments, the scattered gas recovery system further includes a public engineering vehicle 160; the public engineering vehicle 160 is electrically connected to the instrument control module 200, and the instrument control module 200 is used to undertake data collection and control of the public engineering vehicle 160. The public engineering vehicle 160 is also electrically connected to the power module 300, and the power module 300 is used to supply power to the public engineering vehicle 160.

[0045] It can be understood that the utility vehicle 160 is used to provide the required nitrogen, desalted water, cooling circulating water, etc. to the scattered gas processing module.

[0046] In some embodiments, the scattered gas recovery system includes a mobile module; the mobile module is connected to the scattered gas treatment module, the instrument control module 200, and the power supply module 300, and is used to enable the scattered gas treatment module, the instrument control module 200, and the power supply module 300 to move.

[0047] In this embodiment, scattered gas (such as associated oilfield gas and remote wellhead gas) is usually widely distributed and has unstable production. The mobile module can be quickly transported to different gas wells or sites without fixed infrastructure. After arriving at the site, only simple connections (such as pipelines and electricity) are required, shortening the project cycle, which is especially suitable for temporary or short-term mining scenarios. It avoids building permanent treatment stations for each scattered gas point, saving land, civil engineering, and long-term maintenance costs. The same set of mobile modules can be recycled for multiple gas sources, improving the equipment utilization rate.

[0048] As Figures 6 to 12 shown, further, the mobile module includes a first mobile unit 410, a second mobile unit 420, a third mobile unit 430, a fourth mobile unit 440, a fifth mobile unit 450, a sixth mobile unit 460, and a seventh mobile unit 470. The pretreatment unit 110 is arranged on the first mobile unit 410; the deacidification unit 120 is arranged on the second mobile unit 420; the dehydration and mercury removal unit 130 is arranged on the third mobile unit 430; the liquefaction unit 140 is arranged on the fourth mobile unit 440; the refrigerant compression unit 150 is arranged on the fifth mobile unit 450; the instrument control module 200 is arranged on the sixth mobile unit 460; the power supply module 300 is arranged on the seventh mobile unit 470. Designed in this way, specific units can be flexibly selected and enabled according to the characteristics of the gas source (such as sulfur content and water content) (for example, the deacidification unit 120 needs to be enabled for high-sulfur gas sources, and the dehydration unit can be skipped for dry gas sources), avoiding waste of resources. When the production increases, the processing capacity can be improved by adding mobile units (such as increasing the number of liquefaction units 140) without rebuilding the entire system. The failure of a single unit does not affect the operation of other units (for example, when the deacidification unit 120 is under maintenance, the pretreatment unit 110 can still continue to work), and the system reliability is greatly improved. Compared with the segmented hoisting scheme of the overall system, each unit can be transported and installed simultaneously, shortening the on-site assembly time.

[0049] Further, the first mobile unit 410 is a vehicle.

[0050] Optionally, the first mobile unit 410, the second mobile unit 420, the third mobile unit 430, the fourth mobile unit 440, the fifth mobile unit 450, the sixth mobile unit 460, and the seventh mobile unit 470 are all vehicles.

[0051] As Figure 3 and Figure 6As shown, in some embodiments, the pretreatment unit 110 includes a pretreatment box body and a pretreatment module; the pretreatment module is disposed within the pretreatment box body; the pretreatment module includes a gas-liquid separator; the inlet of the gas-liquid separator is used to communicate with the gas production well 10, and the outlet of the gas-liquid separator is communicated with the inlet of the acid removal unit 120. Specifically, the inlet of the gas-liquid separator is used to communicate with the gas production well 10 through a quick-connect pipe, and the outlet of the gas-liquid separator can also be communicated with the inlet of the acid removal unit 120 through a quick-connect pipe. Specifically, the pretreatment box body is disposed on the first moving unit 410, and preferably, the pretreatment box body is disposed on the chassis of the vehicle; the pretreatment module is disposed within the pretreatment box body.

[0052] In this embodiment, by disposing the pretreatment module within the pretreatment box body, the number of external pipeline connection points can be reduced, and the risk of gas leakage can be lowered. The inlet is in standardized docking with the gas production well 10, and the outlet is directly connected to the acid removal unit 120. Only "quick pipe connection" is required on-site, shortening the commissioning time. By providing a gas-liquid separator, free liquid droplets, condensate, formation water, etc. in the raw material of the gas production well 10 can be quickly removed, preventing liquids from entering the subsequent acid removal unit 120 and causing solvent pollution (such as amine solution foaming). The separated dry gas can improve the acid removal reaction efficiency. By providing the pretreatment box body, it can also play a role in protecting the pretreatment module.

[0053] As Figure 3 As shown, further, the pretreatment module further includes a sand remover, a water jacket heater, and a first filter; the inlet of the sand remover is communicated with the gas production well 10 through a quick-connect pipe, the outlet of the sand remover is communicated with the inlet of the water jacket heater, the outlet of the water jacket heater is communicated with the inlet of the gas-liquid separator, the outlet of the gas-liquid separator is communicated with the inlet of the first filter, and the outlet of the first filter is communicated with the inlet of the acid removal unit 120 through a quick-connect pipe. The raw material gas discharged from the gas production well 10 is sand-removed by the sand remover and then enters the water jacket heater for heating to reduce the viscosity of the gas; subsequently, the heated gas enters the gas-liquid separator for gas-liquid separation, and finally, the gas discharged from the gas-liquid separator enters the acid removal unit 120 for acid removal treatment after being filtered by the first filter.

[0054] In this embodiment, by providing a sand remover to remove solid particles in the raw material gas, abrasion of the heating furnace tube wall by sand and gravel can be avoided. By providing a heating furnace, heating of the raw material gas is realized, preventing hydrate formation, reducing the gas viscosity, and improving the subsequent gas-liquid separation efficiency. By providing the first filter to intercept remaining particles and mist-like droplets with a particle size greater than a preset threshold (such as 1 micron), it is ensured that the desulfurization solvent is not polluted. Proceeding layer by layer in this way, equipment blockage or chemical pollution can be avoided. Double solid protection by the sand remover and the first filter prolongs the service life of the core equipment.

[0055] Further, a pressure reducing valve is provided at the inlet of the sand remover.

[0056] Optionally, the pretreatment box can be a mobile cabin or a container.

[0057] As Figure 4 and Figure 7 shown, in some embodiments, the acid removal unit 120 includes an acid removal box body and an acid removal module; the acid removal module is arranged in the acid removal box body; the acid removal module includes an absorption tower; the air inlet of the absorption tower is communicated with the air outlet of the pretreatment unit 110, and the air outlet of the absorption tower is communicated with the air inlet of the dehydration and mercury removal unit 130, so that the first treated gas is mixed with the acid removal adsorbent in the absorption tower. Specifically, the air inlet of the absorption tower is communicated with the air outlet of the first filter through a quick-connect pipe, and the air outlet of the absorption tower is communicated with the air inlet of the dehydration and mercury removal unit 130 through a quick-connect pipe. The acid removal box body is arranged on the second moving unit 420. Preferably, the acid removal box body is arranged on the carrying chassis of the vehicle, and the vehicle carries the acid removal unit to move.

[0058] Further, the acid removal module further includes a rich amine liquid pump, a flash tank, an amine liquid filter, a rich and lean amine liquid heat exchanger, a regeneration tower and a lean amine liquid pump. The rich amine liquid outlet of the absorption tower is communicated with the liquid inlet of the rich amine liquid pump, and the lean amine liquid inlet of the absorption tower is communicated with the liquid outlet of the lean amine liquid pump. The liquid outlet of the rich amine liquid pump is communicated with the liquid inlet of the flash tank, the liquid outlet of the flash tank is communicated with the rich amine liquid inlet of the rich and lean amine liquid heat exchanger through the amine liquid filter, the rich amine liquid outlet of the rich and lean amine liquid heat exchanger is communicated with the rich amine liquid inlet of the regeneration tower, the gas phase outlet of the regeneration tower is used for discharging acid gas (such as hydrogen sulfide or / and carbon dioxide), and the liquid phase outlet of the regeneration tower is communicated with the lean amine liquid inlet of the rich and lean amine liquid heat exchanger; the lean amine liquid outlet of the rich and lean amine liquid heat exchanger is communicated with the liquid inlet of the lean amine liquid pump, and the liquid outlet of the lean amine liquid pump is communicated with the lean amine liquid inlet of the absorption tower.

[0059] Further, the acid removal module further includes a lean amine liquid storage tank; the lean amine liquid outlet of the rich and lean amine liquid heat exchanger is communicated with the liquid inlet of the lean amine liquid pump through the lean amine liquid storage tank.

[0060] Further, the acid removal module further includes a regeneration tower reboiler; the regeneration tower reboiler is arranged at the bottom of the regeneration tower for heating the amine liquid.

[0061] Further, the acid removal adsorbent includes methyldiethanolamine, which can improve the acid removal effect.

[0062] Optionally, the acid removal box body is a mobile cabin or a container.

[0063] As Figure 5 and Figure 8As shown, in some embodiments, the dehydration and mercury removal unit 130 includes a dehydration and mercury removal box body and a dehydration and mercury removal module disposed within the dehydration and mercury removal box body; the dehydration and mercury removal module includes a drying adsorption tower and a mercury removal device. The drying adsorption tower is disposed within the dehydration and mercury removal box body; the inlet of the drying adsorption tower is in communication with the outlet of the acid removal unit 120; the mercury removal device is disposed within the dehydration and mercury removal box body; the outlet of the drying adsorption tower is in communication with the inlet of the mercury removal device, and the outlet of the mercury removal device is in communication with the inlet of the liquefaction unit 140. Specifically, the dehydration and mercury removal box body is disposed on the third moving unit 430, for example, the dehydration and mercury removal box body is disposed on the chassis of a vehicle. The dehydration and mercury removal module is disposed within the dehydration and mercury removal box body.

[0064] In this embodiment, the first treated gas after acid removal first passes through the drying adsorption tower to remove moisture to below the dew point, and then enters the mercury removal device to avoid moisture interfering with the mercury removal efficiency.

[0065] Optionally, the dehydration and mercury removal box body can be a shelter or a container.

[0066] Further, molecular sieve dehydration is used for dehydration, and a sulfur-impregnated activated carbon adsorption process is used for mercury removal.

[0067] Such as Figure 5 and Figure 9 As shown, in some embodiments, the liquefaction unit 140 includes a liquefaction box body and a liquefaction module; the liquefaction module is disposed within the liquefaction box body; the liquefaction module includes a liquefaction heat exchanger; the liquefaction heat exchanger has a liquefaction flow channel and a refrigerant flow channel; the inlet of the liquefaction flow channel is in communication with the outlet of the dehydration and mercury removal unit 130, and the liquid outlet of the liquefaction flow channel is used for discharging liquefied gas; the refrigerant flow channel is in communication with the refrigerant compression unit 150 to form a refrigerant circulation loop. Specifically, the liquefaction box body is disposed on the fourth moving unit 440, for example, the liquefaction box body is disposed on the carrying chassis of a vehicle, and the vehicle moves with the liquefaction box body and the liquefaction module. The liquefaction module is disposed within the liquefaction box body.

[0068] Optionally, the liquefaction heat exchanger can be a plate heat exchanger or a spiral wound heat exchanger.

[0069] Such as Figure 5 As shown, further, the liquefaction module further includes a heavy hydrocarbon separator; the inlet of the heavy hydrocarbon separator is in communication with the outlet of the dehydration and mercury removal unit 130, the outlet of the heavy hydrocarbon separator is in communication with the inlet of the liquefaction flow channel of the liquefaction heat exchanger, and the liquid outlet of the liquefaction flow channel is used for discharging liquefied gas.

[0070] In some embodiments, the refrigerant compression unit 150 includes a refrigerant compression box body and a refrigerant compression module; the refrigerant compression module is disposed within the refrigerant compression box body. The refrigerant compression module includes a compressor, an evaporator, and a throttle valve; the exhaust port of the compressor is in communication with the intake port of the evaporator, the outlet port of the evaporator is in communication with the liquid inlet of the refrigerant flow passage of the liquefaction heat exchanger through the throttle valve, and the liquid outlet of the refrigerant flow passage is in communication with the suction port of the compressor, thereby realizing a refrigerant circulation loop.

[0071] As Figure 10 shown, further, the refrigerant compression box body is disposed on the fifth moving unit 450.

[0072] Optionally, the refrigerant compression box body can be a mobile cabin or a container.

[0073] In summary, the scattered gas recovery system provided by the specific embodiments of the present invention can efficiently utilize associated gas, trial production gas, casing gas, coalbed methane, shale gas, tight gas, biogas, wellhead gas, etc. in remote oilfields, and solves many problems that are not convenient for recovery due to small gas volume, low pressure, remote location, complex gas source components, short recoverable period, etc. The scattered gas recovery system provided by the specific embodiments of the present invention has the advantages of fast connection, intelligence, digitization, convenient movement, high-efficiency operation, and good economic benefits.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A scattered gas recovery system, characterized in that, Comprising movable discrete gas treatment modules, the discrete gas treatment modules including: A pretreatment unit for pretreating raw gas to discharge a first treated gas; the inlet of the pretreatment unit is used to communicate with a gas production well; An acid removal unit for performing acid removal treatment on the first treated gas; the inlet of the acid removal unit is communicated with the outlet of the pretreatment unit; A dehydration and mercury removal unit for dehydrating and removing mercury from the first treated gas after acid removal treatment to form a second treated gas; the inlet of the dehydration and mercury removal unit is communicated with the outlet of the acid removal unit; A liquefaction unit, the inlet of the liquefaction unit is communicated with the outlet of the dehydration and mercury removal unit, and the liquid outlet of the liquefaction unit is used to discharge liquefied gas; A refrigerant compression unit, the refrigerant outlet of the refrigerant compression unit is communicated with the refrigerant inlet of the liquefaction unit, and the refrigerant inlet of the refrigerant compression unit is communicated with the refrigerant outlet of the liquefaction unit to form a refrigerant circulation loop, so that the second treated gas is condensed and liquefied in the liquefaction unit.

2. The scattered gas recovery system according to claim 1, characterized in that, The pretreatment unit includes: A pretreatment box body; A pretreatment module disposed in the pretreatment box body; the pretreatment module includes a gas-liquid separator; the inlet of the gas-liquid separator is used to communicate with the gas production well, and the outlet of the gas-liquid separator is communicated with the inlet of the acid removal unit.

3. The scattered gas recovery system according to claim 1, characterized in that, The acid removal unit includes: An acid removal box body; An acid removal module disposed in the acid removal box body; the acid removal module includes an absorption tower; the inlet of the absorption tower is communicated with the outlet of the pretreatment unit, and the outlet of the absorption tower is communicated with the inlet of the dehydration and mercury removal unit, so that the first treated gas is mixed with an acid removal adsorbent in the absorption tower.

4. The scattered gas recovery system according to claim 3, wherein, The acid removal adsorbent includes methyldiethanolamine.

5. The scattered gas recovery system according to claim 1, characterized in that, The dehydration and mercury removal unit includes: A dehydration and mercury removal box body; A dehydration and mercury removal module, including: A drying adsorption tower disposed in the dehydration and mercury removal box body; the inlet of the drying adsorption tower is communicated with the outlet of the acid removal unit; A mercury remover disposed in the dehydration and mercury removal box body; the outlet of the drying adsorption tower is communicated with the inlet of the mercury remover, and the outlet of the mercury remover is communicated with the inlet of the liquefaction unit.

6. The scattered gas recovery system according to claim 1, characterized in that, The liquefaction unit includes: A liquefaction box body; A liquefaction module disposed in the liquefaction box body; the liquefaction module includes a liquefaction heat exchanger; the liquefaction heat exchanger has a liquefaction flow channel and a refrigerant flow channel; the inlet of the liquefaction flow channel is communicated with the outlet of the dehydration and mercury removal unit, and the liquid outlet of the liquefaction flow channel is used to discharge the liquefied gas; the refrigerant flow channel is communicated with the refrigerant compression unit to form the refrigerant circulation loop.

7. The scavenging gas recovery system according to any one of claims 1 to 6, characterized in that, It further includes: An instrument control module electrically connected to the discrete gas treatment module; A power supply module electrically connected to the discrete gas treatment module and the instrument control module.

8. The scattered gas recovery system according to claim 7, wherein It further includes: A moving module connected to the discrete gas treatment module, the instrument control module and the power supply module, for enabling the discrete gas treatment module, the instrument control module and the power supply module to move.

9. The scattered gas recovery system according to claim 8, wherein, The moving module includes: The first moving unit, with the preprocessing unit disposed on the first moving unit; The second moving unit, with the deacidification unit disposed on the second moving unit; The third moving unit, with the dehydration and mercury removal unit disposed on the third moving unit; The fourth moving unit, with the liquefaction unit disposed on the fourth moving unit; The fifth moving unit, with the refrigerant compression unit disposed on the fifth moving unit; The sixth moving unit, with the instrument control module disposed on the sixth moving unit; The seventh moving unit, with the power supply module disposed on the seventh moving unit.

10. The scattered gas recovery system according to claim 9, characterized in that, The first moving unit is a vehicle.

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