A highly efficient decarbonization system for petroleum associated gas

Abstract

The present invention discloses a system for efficient decarbonization of associated petroleum gas, which belongs to the technical field of decarbonization of associated petroleum gas. The system comprises a main control module, a raw gas intake system, a cold dryer and an adsorption tower group, wherein the raw gas intake system is connected to the cold dryer in sequence; the adsorption tower group comprises a first adsorption tower and a second adsorption tower; the first adsorption tower is connected to a first inlet valve and a first pressure relief valve at the bottom; the second adsorption tower is connected to a second inlet valve and a second pressure relief valve at the bottom; the first inlet valve and the second inlet valve are both connected to the output end of the second filter; the first pressure relief valve and the second pressure relief valve are both connected to the same port of the first three-way valve, and the remaining two ends of the first three-way valve are respectively connected to an exhaust pipe and a vacuum pump. The system for efficient decarbonization of associated petroleum gas of the present invention, the adsorption tower group can realize continuous decarbonization, and online desorption of the adsorbent, which can ensure the decarbonization efficiency and decarbonization effect of associated petroleum gas.

Description

Technical Field

[0001] The present invention specifically relates to a highly efficient decarbonization system for petroleum associated gas, and belongs to the technical field of decarbonization of petroleum associated gas. Background Art

[0002] Oilfield associated gas is the gas that escapes from the oil layer along with the oil and the natural gas that is partially dissolved in the oil. It contains more hydrocarbons and has good utilization value. At present, the measures to solve this kind of problem at home and abroad are to adopt carbon monoxide injection oil recovery technology, which can greatly improve the crude oil recovery rate compared with water drive and other gas drives (such as nitrogen, air), and the oil recovery effect is remarkable. However, the associated gas that escapes after the carbon monoxide injection mixed phase oil recovery has the characteristics of high carbon monoxide content and large fluctuation range (5%~90%) in a short period of time. At present, there are low-temperature separation method, solution absorption method, membrane separation method and the like for the separation and recovery of hydrocarbons and carbon monoxide from oilfield associated gas. For example, the Chinese patent authorization announcement number: CN116510471B discloses an oilfield associated gas decarbonization system, which adopts membrane separation method for treatment, and the outlet of the membrane module is connected with the qualified associated gas and the inlet of the shale gas flowmeter. This structure has no chemical reaction in the process of shale gas separating carbon dioxide, but the decarbonization efficiency of this structure is general, and it is impossible to carry out decarbonization treatment continuously. Summary of the invention

[0003] To solve the above problems, the present invention proposes a highly efficient decarbonization system for associated petroleum gas. The adsorption tower group can realize continuous decarbonization and online desorption of the adsorbent, which can ensure both the decarbonization efficiency and the decarbonization effect of associated petroleum gas.

[0004] The petroleum associated gas efficient decarbonization system of the present invention comprises:

[0005] Main control module for whole machine control;

[0006] The raw gas intake system includes a gas supply pipe for the petroleum-associated gas, and the gas supply pipe is connected to a pressure reducing valve to reduce the pressure of the petroleum-associated gas to a set pressure value;

[0007] Cold dryer, the output end of the raw gas intake system is connected to the input end of the cold dryer through the first filter, and the output end of the cold dryer is connected to the second filter; the first filter and the second filter before and after the cold dryer are precision gas filters, and the cold dryer has an automatic drainage function;

[0008] An adsorption tower group, the adsorption tower group includes a first adsorption tower and a second adsorption tower; the first adsorption tower is connected to a first inlet valve and a first pressure relief valve at the bottom; the second adsorption tower is connected to a second inlet valve and a second pressure relief valve at the bottom; the first inlet valve and the second inlet valve are both connected to the output end of the second filter; the first pressure relief valve and the second pressure relief valve are both connected to the same port of the first three-way valve, and the remaining two ends of the first three-way valve are respectively connected to an exhaust pipe and a vacuum pump, and the other ends of the exhaust pipe and the vacuum pump are connected to an exhaust pipe; the top of the first adsorption tower and the top of the second adsorption tower are connected to an associated gas decarbonization pipe through a first outlet valve and a second outlet valve, respectively; the first outlet valve and the second outlet valve input ends are connected in parallel to an adsorption tower top balancing valve.

[0009] Furthermore, the raw gas intake system allows the associated petroleum gas to enter the first filter after decompression, and then enter the cold dryer after coarse filtration through the first filter. The associated petroleum gas is cooled, dehumidified and deoiled by the cold dryer. The treated associated petroleum gas is introduced into the first adsorption tower or the second adsorption tower through the first inlet valve or the second inlet valve. The first inlet valve and the second inlet valve are opened alternately, and the associated petroleum gas enters the first adsorption tower or the second adsorption tower. The carbon dioxide in the associated petroleum gas is adsorbed and removed by the molecular sieve in the first adsorption tower or the second adsorption tower. The associated petroleum gas after decarbonization is discharged from the first outlet valve or the second outlet valve into the associated gas decarbonization pipe; the adsorption regeneration process of the adsorption tower group adopts time sequence control, and the adsorption regeneration process of the first adsorption tower is first carried out, specifically: the first pressure relief valve, the first three-way valve and the vacuum pump are opened, and the vacuum pump performs vacuum desorption on the first adsorption tower. When the vacuum degree reaches the set value, the first pressure relief valve is closed, and then the top balance valve of the adsorption tower is opened to connect the associated gas decarbonization pipe with the first adsorption tower, and the associated gas decarbonization pipe and the adsorption tower are connected. The top balancing valve slowly pressurizes and balances the first adsorption tower to the operating pressure, and then closes the top balancing valve of the adsorption tower; then closes the second inlet valve and the second outlet valve, and opens the first inlet valve and the first outlet valve in sequence, the first adsorption tower enters the adsorption state, and adsorbs and removes the carbon dioxide in the associated gas of the petroleum; at the same time, the second adsorption tower is adsorbed and regenerated, and the adsorption and regeneration process of the second adsorption tower is consistent with that of the first adsorption tower; when the first adsorption tower is saturated with adsorption, close the first inlet valve and the first outlet valve of the first adsorption tower, open the first pressure relief valve, and switch the first three-way valve at the same time to connect the first pressure relief valve with the exhaust pipe, and the first adsorption tower is exhausted to the emptying pipe through the exhaust pipe. After the pressure in the first adsorption tower is continuously released to normal pressure, the first three-way valve is switched again to connect the first pressure relief valve with the vacuum pump. Under the suction action of the vacuum pump, the molecular sieve in the first adsorption tower is desorbed by negative pressure. After the desorption is completed, the first pressure relief valve is closed, the top balancing valve of the adsorption tower is opened again to balance the pressure, and the top balancing valve of the adsorption tower is closed. After the second adsorption tower is saturated with adsorption, the first adsorption tower enters the next adsorption process.

[0010] Furthermore, the associated gas decarbonization pipe is connected to the temporary storage pressure tank; the temporary storage pressure tank is connected to the first inlet valve output end and the second inlet valve output end through the first purification valve and the second purification valve respectively; the first outlet valve and the second outlet valve are both three-way valve groups; the third ends of the three-way valve groups are connected to the decarbonization output pipeline; the associated gas decarbonization pipe receives the decarbonized associated gas transmitted from the first adsorption tower, and the decarbonized associated gas is connected to the decarbonization output pipeline through the third end of the first outlet valve, and the decarbonized associated gas is sent to the lower-level processing process through the decarbonization output pipeline; when the decarbonization process of the first adsorption tower reaches the set time, the set time is 50~60% of the total decarbonization time of the first adsorption tower; switch the first outlet valve, and send the decarbonized associated gas into the temporary storage pressure tank through the associated gas decarbonization pipe; then, the temporary storage pressure tank sends the associated gas that has completed the first decarbonization to the second adsorption tower through the second purification valve, and the second adsorption tower performs a second decarbonization on the associated gas of the first decarbonization, and the decarbonized associated gas of the second decarbonization passes through the second The third end of the outlet valve is sent to the decarbonization output pipeline; when the first adsorption tower is saturated with adsorption, the first inlet valve and the first outlet valve of the first adsorption tower are closed, and the first adsorption tower is subjected to the adsorption regeneration process; at this time, the associated gas transmitted from the second filter directly enters the second adsorption tower, and after the associated gas is decarbonized once through the second adsorption tower, it is sent to the decarbonization output pipeline through the third end of the second outlet valve; when the decarbonization process of the second adsorption tower reaches the set time, the second outlet valve is switched, and the decarbonized associated gas is sent to the temporary storage pressure tank through the associated gas decarbonization pipe; until the first adsorption tower completes the adsorption regeneration process, the associated gas that has completed the first decarbonization in the temporary storage pressure tank is sent to the first adsorption tower through the first purification valve for secondary decarbonization, and the decarbonized associated gas of the secondary decarbonization is sent to the decarbonization output pipeline through the third end of the first outlet valve; when the second adsorption tower is saturated with adsorption, the second inlet valve and the second outlet valve of the second adsorption tower are closed, and the second adsorption tower adsorption regeneration process is carried out to complete the first decarbonization and desorption cycle of the adsorption tower group.

[0011] Furthermore, a carbon dioxide concentration monitor is provided on the temporary storage pressure tank; the temporary storage pressure tank is connected to the decarbonization output pipeline through an external discharge valve; the carbon dioxide concentration monitor is connected to an online time adjustment unit, and the online time adjustment unit is connected to a comparison table of concentration threshold segments and switching times; the online time adjustment unit is connected to a main control module; the external discharge valve is connected to the online time adjustment unit; when the carbon dioxide concentration monitor detects carbon dioxide in the decarbonization associated gas When the concentration is lower than 5 vol%, the time online adjustment unit gives a signal to the external discharge valve, so that the external discharge valve is opened. Even if the temporary storage pressure tank discharges the decarbonization associated gas into the decarbonization output pipeline, when the pressure is lower than the set pressure value, the external discharge valve is closed.

[0012] Furthermore, the carbon dioxide concentration monitor monitors the carbon dioxide concentration value of the petroleum associated gas in the temporary storage pressure tank in real time, and sends the carbon dioxide concentration value to the time online adjustment unit. The online adjustment unit determines whether the carbon dioxide concentration value falls into a certain concentration threshold segment of the comparison table, and obtains the switching time according to the concentration threshold segment. Then the time online adjustment unit sends the switching time to the main control module; the main control module updates the setting time of the first outlet valve and the second outlet valve online; the time online adjustment unit first obtains the switching time and sends it to the main control module. When the carbon dioxide in the decarbonized associated gas is When the concentration is below 5 vol%, the gas can be directly exhausted to the decarbonization output pipeline.

[0013] Compared with the prior art, the petroleum associated gas efficient decarbonization system of the present invention has the following advantages:

[0014] The system converts carbon dioxide from associated gas into The concentration is removed from 9.05 vol% to below 5 vol%, providing a low-carbon environment for the subsequent associated gas distillation process; the cold dryer pre-treats the associated gas to achieve cold drying and dehydration, the inlet temperature of the adsorption tower group is controlled below 5°C, the petroleum associated gas is adsorbed at low temperature, and before the first adsorption tower and the second adsorption tower are saturated with adsorption, the decarbonized associated gas is directly used as the output gas for treatment by the adsorption tower group. When the adsorption tower is close to saturation, the petroleum associated gas that has completed the first decarbonization will be decarbonized for the second time, and the adsorbent for the secondary decarbonization is the adsorbent that has completed desorption, thereby ensuring the decarbonization effect of the petroleum associated gas, and by setting up a temporary storage pressure tank and its ancillary components, the qualified petroleum associated gas can be directly output to avoid secondary decarbonization and improve the decarbonization efficiency, and the switching time point between the primary decarbonization discharge and the secondary decarbonization discharge of the associated gas can be monitored and adjusted online; both the decarbonization efficiency and the decarbonization effect of the petroleum associated gas can be guaranteed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the overall structure of the petroleum associated gas efficient decarbonization system of the present invention.

[0016] Figure 2 It is a schematic diagram of the overall structure of the cold dryer of the present invention.

[0017] Figure 3 This is a schematic diagram of the working process of the petroleum associated gas efficient decarbonization system of the present invention.

[0018] Figure 4 It is a schematic diagram of the connection structure of the petroleum associated gas efficient decarbonization system and the secondary decarbonization module of the present invention.

[0019] Figure 5 It is a schematic diagram of the working process of the petroleum associated gas efficient decarbonization system and the secondary decarbonization module of the present invention.

[0020] Figure 6 It is a schematic diagram of the connection of the decarbonization system, temporary storage pressure tank, carbon dioxide concentration monitor, external discharge valve and decarbonization output pipeline of the present invention.

[0021] Figure numerals: 1, raw gas intake system, 2, cold dryer, 3, first filter, 4, second filter, 5, first adsorption tower, 6, second adsorption tower, 7, first inlet valve, 8, first pressure relief valve, 9, second inlet valve, 10, second pressure relief valve, 11, first three-way valve, 12, exhaust pipe, 13, vacuum pump, 14, exhaust pipe, 15, first outlet valve, 16, second outlet valve, 17, associated gas decarbonization pipe, 18, adsorption tower top balance valve, 19, refrigerant Compressor, 20. Condenser, 21. Dry filter, 22. Sight glass, 23. Expansion valve, 24. Gas mixing head, 25. Dispensing head, 26. Evaporator, 27. Gas-liquid separator, 28. Intake filter, 29. Sealed container, 30. Associated gas inlet, 31. Associated gas outlet, 32. Gas-water separator, 33. Exhaust port, 34. Automatic drainer, 35. Temporary storage pressure tank, 36. First purification valve, 37. Second purification valve, 38. Decarbonization output pipeline, 39. Carbon dioxide concentration monitor, 40. External exhaust valve. DETAILED DESCRIPTION

[0022] Example:

[0023] like Figures 1 to 6 The high-efficiency decarbonization system for associated petroleum gas shown includes:

[0024] Main control module for whole machine control;

[0025] The raw gas intake system 1 includes a gas supply pipe for the petroleum associated gas, and the gas supply pipe is connected to a pressure reducing valve to reduce the pressure of the petroleum associated gas to a set pressure value;

[0026] Cold dryer 2, the output end of the raw gas intake system 1 is connected to the input end of the cold dryer 2 through the first filter 3, and the output end of the cold dryer 2 is connected to the second filter 4; the first filter 3 and the second filter 4 before and after the cold dryer 2 are precision gas filters, and the cold dryer 2 has an automatic drainage function; the cold dryer 2 adopts a refrigerated biogas dryer, and the cold dryer 2 includes a refrigerant compressor 19, and the refrigerant compressor 19 passes through a condenser 20, a drying filter 21, a sight glass 22, an expansion valve 23, a gas mixing head 24, a liquid separation head 25, an evaporator 26, a gas-liquid separator 27 and an air intake filter 28 in sequence, and is connected to the other end of the refrigerant compressor 19; thereby forming a cooling system, the evaporator 26 is installed in a sealed container 29, and an associated gas inlet 30 and an associated gas outlet 31 are respectively arranged at the top and bottom of the sealed container 29, and the associated gas outlet 31 is connected to a gas-water separator 32, An exhaust port 33 is provided at the top of the gas-water separator 32; an automatic drainer 34 is provided at the bottom of the gas-water separator 32; according to the freezing and dehumidification principle, a fully enclosed compression refrigeration system is used to cool the low-temperature gas, so that a large amount of saturated water vapor and oil mist contained therein are condensed into liquid droplets, which are discharged by the automatic drainer 34 after gas-water separation; the saturated gas with a higher temperature enters the evaporator 26 of the cold dryer 2, exchanges heat with the refrigerant gas, and reduces the temperature to a temperature close to the evaporation temperature of the refrigerant. During the cooling process, the associated gas condenses into liquid water droplets and enters the gas-water separator 32 with the air flow. The liquid water separated from the gas-water separator 32 is discharged to the outside of the cold dryer 2 through the automatic drainer, so that dry gas with a low water content (i.e., a low dew point) and a low relative humidity is obtained at the exhaust port 33 of the gas-water separator 32; the working parameters of the cold dryer 2, the first filter 3 and the second filter 4 are as follows:

[0027] Parameter table of cold dryer 2, first filter 3 and second filter 4:

[0028]

[0029] An adsorption tower group, the adsorption tower group includes a first adsorption tower 5 and a second adsorption tower 6; the inlet temperature of the first adsorption tower 5 and the second adsorption tower 6 is controlled below 5°C, the associated gas is adsorbed under low temperature, and as the adsorption process proceeds, the temperature in the adsorption tower will show a peak-to-valley curve change, the adsorption saturation state can be intuitively judged by the temperature change, and the operation is convenient and reliable; the first adsorption tower 5 is connected to the bottom with a first inlet valve 7 and a first pressure relief valve 8; the second adsorption tower 6 is connected to the bottom with a second inlet valve 9 and a second pressure relief valve 10; the first inlet valve 7 and the second inlet valve 9 are both connected to the output end of the second filter 4; the first pressure relief valve 8 and the second pressure relief valve 10 are both connected to the same port of the first three-way valve 11, and the remaining two ends of the first three-way valve 11 are respectively connected to an exhaust pipe 12 and a vacuum pump 13, and the other ends of the exhaust pipe 12 and the vacuum pump 13 are connected to an exhaust pipe 14; the top of the first adsorption tower 5 and the top of the second adsorption tower 6 are respectively connected to the associated gas decarbonization pipe 17 through the first outlet valve 15 and the second outlet valve 16; the first outlet valve 15 and the second outlet valve 16 input ends are connected to the adsorption tower top balance valve 18.

[0030] The first adsorption tower 5 and the second adsorption tower 6 are vertical pressure vessels filled with adsorbents. The first adsorption tower 5 and the second adsorption tower 6 have the same structure and adsorbents. The design parameters of the first adsorption tower 5 and the second adsorption tower 6 are as follows: the design pressure is 1.0Mpa, the container category is Class II, the working pressure is 0.6Mpa, and the design temperature is 50°C.

[0031] The parameters of the vertical pressure vessels of the first adsorption tower 5 and the second adsorption tower 6 are as follows:

[0032]

[0033] The vacuum pump 13 adopts a single-stage rotary vane oil-sealed vacuum pump 13, which has a rotor eccentrically installed with the pump body and tangent to the fixed straight line of the inner surface of the pump body, and there are three radially slidable rotary vanes in the rotor groove; when the rotor rotates, the centrifugal force makes the rotary vanes always contact with the inner wall of the pump body; the rotary vanes divide the pump into three periodically changeable working chambers; the periodic change of the working chamber enables the pump to complete the suction and exhaust; with each rotation, the pump extracts a part of the gas in the container until the limit pressure of the vacuum pump 13 is reached.

[0034] The parameters of vacuum pump 13 are as follows:

[0035]

[0036] The petroleum associated gas efficient decarbonization system of the present invention is an integral skid-mounted structure with an integral base. Before the system is used, the entire system needs to be replaced with nitrogen. After the replacement is completed, subsequent operations can be carried out.

[0037] The working steps of the petroleum associated gas efficient decarbonization system of the present invention are as follows:

[0038]

[0039] The raw gas intake system 1 allows the associated petroleum gas to enter the first filter 3 after decompression, and enter the cold dryer 2 after coarse filtration through the first filter 3. The associated petroleum gas is cooled, dehumidified and deoiled by the cold dryer 2. The associated petroleum gas after treatment is introduced into the first adsorption tower 5 or the second adsorption tower 6 through the first inlet valve 7 or the second inlet valve 9. The first inlet valve 7 and the second inlet valve 9 are opened alternately, and the associated petroleum gas enters the first adsorption tower 5 or the second adsorption tower 6. The carbon dioxide in the associated petroleum gas is adsorbed and removed by the molecular sieve in the first adsorption tower 5 or the second adsorption tower 6. The associated petroleum gas is discharged from the first outlet valve 15 or the second outlet valve 16 into the associated gas decarbonization pipe 17; the adsorption regeneration process of the adsorption tower group adopts time sequence control, and the adsorption regeneration process of the first adsorption tower 5 is firstly carried out, specifically: the first pressure relief valve 8, the first three-way valve 11 and the vacuum pump 13 are opened, and the vacuum pump 13 performs vacuum desorption on the first adsorption tower 5. When the vacuum degree reaches the set value, the first pressure relief valve 8 is closed, and then the adsorption tower top balance valve 18 is opened to connect the associated gas decarbonization pipe 17 with the first adsorption tower 5, and the associated gas decarbonization pipe 17 and the adsorption tower top balance valve 18 are connected to the associated gas decarbonization pipe 17 and the adsorption tower top balance valve 18. The first adsorption tower 5 is slowly pressurized to balance to the operating pressure, and then the top balance valve 18 of the adsorption tower is closed; then the second inlet valve 9 and the second outlet valve 16 are closed, and the first inlet valve 7 and the first outlet valve 15 are opened in sequence, and the first adsorption tower 5 enters the adsorption state to adsorb and remove the carbon dioxide in the associated gas of the petroleum; at the same time, the second adsorption tower 6 is adsorbed and regenerated, and the adsorption and regeneration process of the second adsorption tower 6 is consistent with the adsorption and regeneration process of the first adsorption tower 5; when the first adsorption tower 5 is saturated with adsorption, the first inlet valve 7 and the first outlet valve 15 of the first adsorption tower 5 are closed, and the first pressure relief valve 8 is opened, and at the same time Switch the first three-way valve 11 to connect the first pressure relief valve 8 with the exhaust pipe 12, and exhaust the first adsorption tower 5 to the emptying pipe 14 through the exhaust pipe 12. After the pressure in the first adsorption tower 5 is continuously released to normal pressure, the first three-way valve 11 is switched again to connect the first pressure relief valve 8 with the vacuum pump 13. Under the suction action of the vacuum pump 13, the molecular sieve in the first adsorption tower 5 is desorbed by negative pressure. After desorption is completed, the first pressure relief valve 8 is closed, and the balancing valve 18 on the top of the adsorption tower is opened again for pressure balance. The balancing valve 18 on the top of the adsorption tower is closed, and after waiting for the second adsorption tower 6 to be saturated with adsorption, the first adsorption tower 5 enters the next adsorption process.

[0040] The associated gas decarbonization pipe 17 is connected to the temporary storage pressure tank 35; the temporary storage pressure tank 35 is connected to the output end of the first inlet valve 7 and the output end of the second inlet valve 9 through the first purification valve 36 and the second purification valve 37 respectively; the first outlet valve 15 and the second outlet valve 16 are both three-way valve groups; the third ends of the three-way valve groups are connected to the decarbonization output pipeline 38; the associated gas decarbonization pipe 17 receives the decarbonized associated gas transmitted from the first adsorption tower 5, and the decarbonized associated gas is connected to the decarbonization output pipeline 38 through the third end of the first outlet valve 15. The decarbonized associated gas is sent to the next processing step through the decarbonization output pipeline 38; when the decarbonization process of the first adsorption tower 5 reaches the set time, the set time is 50-60% of the total decarbonization time of the first adsorption tower 5; the first outlet valve 15 is switched to send the decarbonized associated gas to the temporary storage pressure tank 35 through the associated gas decarbonization pipe 17; then, the temporary storage pressure tank 35 sends the associated gas that has completed the first decarbonization to the second adsorption tower 6 through the second purification valve 37, and the second adsorption tower 6 performs a second decarbonization on the associated gas of the first decarbonization, and the decarbonized associated gas of the second decarbonization passes through the second outlet valve 17. The third end of the inlet valve 16 is sent to the decarbonization output pipeline 38; when the first adsorption tower 5 is saturated with adsorption, the first inlet valve 7 and the first outlet valve 15 of the first adsorption tower 5 are closed to perform the adsorption regeneration process of the first adsorption tower 5; at this time, the associated gas transmitted from the second filter 4 directly enters the second adsorption tower 6, and completes a decarbonization through the second adsorption tower 6. The associated gas is sent to the decarbonization output pipeline 38 through the third end of the second outlet valve 16; when the decarbonization process of the second adsorption tower 6 reaches the set time, the second outlet valve 16 is switched to pass the decarbonization associated gas through the associated gas. The gas decarbonization pipe 17 is sent to the temporary storage pressure tank 35; until the first adsorption tower 5 completes the adsorption regeneration process, the associated gas that has completed the primary decarbonization in the temporary storage pressure tank 35 is sent to the first adsorption tower 5 through the first purification valve 36 for secondary decarbonization, and the decarbonized associated gas of the secondary decarbonization is sent to the decarbonization output pipeline 38 through the third end of the first outlet valve 15; when the second adsorption tower 6 is saturated with adsorption, the second inlet valve 9 and the second outlet valve 16 of the second adsorption tower 6 are closed, and the second adsorption tower 6 adsorption regeneration process is carried out to complete the primary decarbonization and desorption cycle of the adsorption tower group.

[0041] The temporary storage pressure tank 35 is provided with a carbon dioxide concentration monitor 39; the temporary storage pressure tank 35 is connected to the decarbonization output pipeline 38 through an external discharge valve 40; the carbon dioxide concentration monitor 39 is connected to a time online adjustment unit, and the time online adjustment unit is connected to a comparison table of concentration threshold segments and switching times; the time online adjustment unit is connected to the main control module; the external discharge valve 40 is connected to the time online adjustment unit; when the carbon dioxide concentration monitor 39 detects carbon dioxide in the decarbonization associated gas When the concentration is lower than 5 vol%, the time online regulating unit sends a signal to the external discharge valve 40, so that the external discharge valve 40 is opened, and the temporary storage pressure tank 35 discharges the decarbonization associated gas into the decarbonization output pipeline 38. When the pressure is lower than the set pressure value, the external discharge valve 40 is closed.

[0042] The carbon dioxide concentration monitor 39 monitors the carbon dioxide concentration value of the petroleum associated gas in the temporary storage pressure tank 35 in real time, and sends the carbon dioxide concentration value to the time online adjustment unit. The online adjustment unit determines whether the carbon dioxide concentration value falls into a certain concentration threshold segment of the comparison table, and obtains the switching time according to the concentration threshold segment. Then the time online adjustment unit sends the switching time to the main control module; the main control module updates the setting time of the first outlet valve 15 and the second outlet valve 16 online; the time online adjustment unit first obtains the switching time and sends it to the main control module. When the carbon dioxide in the decarbonized associated gas When the concentration is below 5 vol%, the gas can be directly exhausted to the decarbonization output pipeline 38 .

[0043] The high-efficiency decarbonization system for associated petroleum gas of the present invention adopts air-cooled low-temperature cold-dry adsorption. The first adsorption tower 5 and the second adsorption tower 6 adopt highly selective molecular sieves and have a high vacuum regeneration function. The system is a modular device with an overall skid-mounted structure. It only needs one 380VAC power supply to be connected and operated. The system is simple to operate and has a high degree of automation. The first adsorption tower 5 and the second adsorption tower 6 are equipped with high-efficiency and large-capacity adsorbents to separate the associated gas carbon. The switching time of the adsorption towers is ≥30min. The system is suitable for application scenarios in harsh environments with water shortage and steam absence in the field.

[0044] The above embodiments are only preferred implementations of the present invention, so any equivalent changes or modifications made according to the structures, features and principles described in the scope of application of the present invention are included in the scope of application of the present invention.

Claims

1. A highly efficient decarbonization system for associated petroleum gas, characterized by: include: The main control module of the whole machine control, Raw gas intake system, A cold dryer, wherein the output end of the raw gas intake system is connected to the input end of the cold dryer through a first filter, and the output end of the cold dryer is connected to a second filter; An adsorption tower group, the adsorption tower group includes a first adsorption tower and a second adsorption tower; the first adsorption tower is connected to a first inlet valve and a first pressure relief valve at the bottom; the second adsorption tower is connected to a second inlet valve and a second pressure relief valve at the bottom; the first inlet valve and the second inlet valve are both connected to the output end of the second filter; the first pressure relief valve and the second pressure relief valve are both connected to the same port of the first three-way valve, the remaining two ends of the first three-way valve are respectively connected to an exhaust pipe and a vacuum pump, and the other ends of the exhaust pipe and the vacuum pump are connected to an exhaust pipe; the top of the first adsorption tower and the top of the second adsorption tower are connected to an associated gas decarbonization pipe through a first outlet valve and a second outlet valve, respectively; the first outlet valve and the second outlet valve input ends are connected to an adsorption tower top balancing valve; The associated gas decarbonization pipe is connected to the temporary storage pressure tank; the temporary storage pressure tank is connected to the first inlet valve output end and the second inlet valve output end through the first purification valve and the second purification valve respectively; the first outlet valve and the second outlet valve are both three-way valve groups; the third ends of the three-way valve groups are connected to the decarbonization output pipeline; the associated gas decarbonization pipe receives the decarbonized associated gas transmitted from the first adsorption tower, and the decarbonized associated gas is connected to the decarbonization output pipeline through the third end of the first outlet valve, and the decarbonized associated gas is sent to the lower-level processing process through the decarbonization output pipeline; when the decarbonization process of the first adsorption tower reaches the set time, the set time is 50~60% of the total decarbonization time of the first adsorption tower; switch the first outlet valve, and send the decarbonized associated gas into the temporary storage pressure tank through the associated gas decarbonization pipe; then, the temporary storage pressure tank sends the associated gas that has completed the first decarbonization to the second adsorption tower through the second purification valve, and the second adsorption tower performs a second decarbonization on the associated gas of the first decarbonization, and the decarbonized associated gas of the second decarbonization passes through the second outlet valve The third end of the door is sent into the decarbonization output pipeline; when the first adsorption tower is saturated with adsorption, the first inlet valve and the first outlet valve of the first adsorption tower are closed, and the first adsorption tower is subjected to the adsorption regeneration process; at this time, the associated gas transmitted from the second filter directly enters the second adsorption tower, and after the associated gas completes the first decarbonization through the second adsorption tower, it is sent into the decarbonization output pipeline through the third end of the second outlet valve; when the decarbonization process of the second adsorption tower reaches the set time, the second outlet valve is switched, and the decarbonized associated gas is sent into the temporary storage pressure tank through the associated gas decarbonization pipe; until the first adsorption tower completes the adsorption regeneration process, the associated gas that has completed the first decarbonization in the temporary storage pressure tank is sent to the first adsorption tower through the first purification valve for secondary decarbonization, and the decarbonized associated gas of the secondary decarbonization is sent into the decarbonization output pipeline through the third end of the first outlet valve; when the second adsorption tower is saturated with adsorption, the second inlet valve and the second outlet valve of the second adsorption tower are closed, and the second adsorption tower adsorption regeneration process is carried out to complete the first decarbonization and desorption cycle of the adsorption tower group.

2. The system for efficiently decarbonizing associated petroleum gas according to claim 1, characterized in that: The raw gas intake system allows the associated petroleum gas to enter the first filter after decompression, and then enter the cold dryer after coarse filtration through the first filter. The associated petroleum gas is cooled, dehumidified and deoiled by the cold dryer. The treated associated petroleum gas is introduced into the first adsorption tower or the second adsorption tower through the first inlet valve or the second inlet valve. The first inlet valve and the second inlet valve are opened alternately, and the associated petroleum gas enters the first adsorption tower or the second adsorption tower. The CO2 in the associated petroleum gas is adsorbed and removed by the molecular sieve in the first adsorption tower or the second adsorption tower. The associated petroleum gas after decarbonization is discharged from the first outlet valve or the second outlet valve into the associated gas decarbonization pipe; the adsorption regeneration process of the adsorption tower group adopts time sequence control, and the adsorption regeneration process of the first adsorption tower is first carried out, specifically: the first pressure relief valve, the first three-way valve and the vacuum pump are opened, and the vacuum pump performs vacuum desorption on the first adsorption tower. When the vacuum degree reaches the set value, the first pressure relief valve is closed, and then the top balance valve of the adsorption tower is opened to connect the associated gas decarbonization pipe with the first adsorption tower. The valve slowly pressurizes and balances the first adsorption tower to the operating pressure, and then closes the balancing valve on the top of the adsorption tower; then closes the second inlet valve and the second outlet valve, and opens the first inlet valve and the first outlet valve in sequence, the first adsorption tower enters the adsorption state, and adsorbs and removes CO2 from the associated gas of the petroleum; at the same time, the second adsorption tower is adsorbed and regenerated, and the adsorption and regeneration process of the second adsorption tower is consistent with that of the first adsorption tower; when the first adsorption tower is saturated with adsorption, close the first inlet valve and the first outlet valve of the first adsorption tower, open the first pressure relief valve, and switch the first three-way valve at the same time to connect the first pressure relief valve with the exhaust pipe, and the first adsorption tower is exhausted to the emptying pipe through the exhaust pipe. After the pressure in the first adsorption tower is continuously released to normal pressure, the first three-way valve is switched again to connect the first pressure relief valve with the vacuum pump. Under the suction action of the vacuum pump, the molecular sieve in the first adsorption tower is desorbed by negative pressure. After the desorption is completed, the first pressure relief valve is closed, the balancing valve on the top of the adsorption tower is opened again to charge and balance, and the balancing valve on the top of the adsorption tower is closed. After the second adsorption tower is saturated with adsorption, the first adsorption tower enters the next adsorption process.

3. The system for efficiently decarbonizing associated petroleum gas according to claim 1, characterized in that: The temporary storage pressure tank is provided with a CO2 concentration monitor; the temporary storage pressure tank is connected to the decarbonization output pipeline through an external exhaust valve; the CO2 concentration monitor is connected to an online time adjustment unit, and the online time adjustment unit is connected to a comparison table of concentration threshold segments and switching times; the online time adjustment unit is connected to a main control module; the external exhaust valve is connected to the online time adjustment unit.

4. The system for efficiently decarbonizing associated petroleum gas according to claim 3 is characterized in that: The CO2 concentration monitor monitors the CO2 concentration value of the associated petroleum gas in the temporary storage pressure tank in real time, and sends the CO2 concentration value to the time online adjustment unit. The online adjustment unit determines whether the CO2 concentration value falls into a certain concentration threshold segment in the comparison table, and obtains the switching time according to the concentration threshold segment. Then the time online adjustment unit sends the switching time to the main control module; the main control module updates the setting time of the first outlet valve and the second outlet valve online.

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