Carbon dioxide displacement block associated gas upgrading utilization system

Abstract

The utility model discloses a carbon dioxide displacement block associated gas upgrading utilization system, which comprises a first separation buffer tank, a second separation buffer tank, a gas inlet and a gas outlet, an inlet of the first filter is connected with an outlet of the first separation buffer tank; a tube pass inlet of the evaporator is connected with an outlet of the first filter; an inlet of the second separation buffer tank is connected with a tube pass outlet of the evaporator; an inlet of the second filter is connected with an outlet of the second separation buffer tank; an inlet of the third separation buffer tank is connected with an outlet of the second filter; an inlet of the compressor unit is connected with an outlet of the third separation buffer tank; the inlet of the fourth separation buffer tank is connected with the outlet of the compressor unit, and the outlet is connected with the reinjection gas pipeline. The cold source gas pipeline is connected with a tube pass inlet of the evaporator through the first pressure reduction buffer. The associated gas upgrading and utilizing system for the carbon dioxide displacement block can relieve the existing problems of associated gas treatment and utilization, so that the associated gas resources are effectively and comprehensively utilized.

Description

Technical Field

[0001] The utility model relates to the CCUS field of oil fields, and in particular to a carbon dioxide displacement block associated gas quality improvement and utilization system, which specifically belongs to the technical field of associated gas utilization, and is mainly used for the treatment, utilization and storage of non-combustible associated gas containing CO2 produced in the CO2 displacement block of the oil field. Background Art

[0002] Carbon dioxide storage and oil recovery (EOR) is a method currently being explored under the "dual carbon" goal that not only meets the needs of oilfield development but also partially solves the problem of carbon dioxide storage, thereby achieving a win-win situation in economic and social benefits.

[0003] Carbon dioxide flooding and enhanced oil recovery technology is a technology that injects carbon dioxide into oil layers and uses its miscibility, energy enhancement, gas drive, viscosity reduction, acidification and other mechanisms to improve the recovery rate of oil fields. It originated in the 1950s. In foreign oil fields, industrial applications have become mature in America, Europe and other countries. Data show that the United States is the country with the most carbon dioxide flooding projects in the world. The recovery rate of some oil fields is nearly 30.0%, which has become one of the important technologies for improving oil recovery in the United States. In domestic oil fields, such as Daqing, Shengli, Jilin, East China, Zhongyuan and other oil fields, relevant research and application have been carried out, and corresponding technical reserves have been obtained. In particular, Jilin, East China and other oil fields have made in-depth research and supporting work on ground processes.

[0004] However, about 40%-50% of the injected carbon dioxide returns to the ground. Considering the scale of oil injection wells of millions of tons, more than 400,000 tons of carbon dioxide need to be recycled for secondary use each year. On-site recycling of returned gas carbon dioxide can significantly reduce the cost of purchasing and transporting carbon dioxide for oil fields. The current carbon cost of oil fields is more than 300 yuan / ton. If the returned gas is treated and then reinjected, the use of purchased carbon dioxide for oil recovery can be reduced, and the treatment and emission problems of hydrocarbon-containing gases can be solved. It is the key to improving economic benefits and carbon reduction benefits.

[0005] However, in addition to carbon dioxide, the return gas from the wellhead also contains light hydrocarbons, water vapor, solid particles, etc., so it is impossible to directly inject carbon dioxide into the compressor. Directly discharging non-methane hydrocarbons into the atmosphere cannot meet environmental protection requirements and will generate a lot of noise, affecting the surrounding residents. At the same time, it will also emit a large amount of greenhouse gases, causing economic losses. The flow rate, pressure, and composition of this part of the wellhead gas fluctuate greatly and are difficult to handle, which has become a bottleneck restricting oilfield companies from carrying out carbon dioxide storage and oil recovery (EOR).

[0006] CN104403710B discloses a method for improving the separation efficiency of oilfield associated gas and recovering carbon dioxide, using a double membrane separator to purify natural gas, without describing the front-end gas source, pretreatment and back-end recovery methods, and focusing on the purity of natural gas.

[0007] CN201910989521.7 discloses a method for recovering and utilizing carbon dioxide from associated gas in carbon dioxide drive of low-yield oil fields. After the associated gas produced from the wellhead of the oil well is pressurized and separated by a membrane, the carbon dioxide is pressurized and reinjected. However, it is not processed on site, the transportation distance is long and the cost is high, and the utilization of the trapped gas is not described.

[0008] CN111004657B discloses a method for comprehensive utilization of oilfield associated gas, which uses step-by-step pressurization to separate hydrocarbons, separate carbon dioxide and methane, and liquefy methane to produce LNG, but does not describe the reinjection of carbon dioxide.

[0009] CN114702992A discloses a system and method for separating and purifying produced gas containing carbon dioxide from an oil field, which adopts multi-stage distillation and pressure swing adsorption to purify carbon dioxide drive, and is not suitable for small and scattered oil wells.

[0010] CN114774157A discloses a method for recovering shale oil associated gas rich in carbon dioxide, which does not involve wellhead carbon dioxide reinjection.

[0011] CN215209273U discloses a carbon dioxide recovery device in wellhead gas, which includes an oil-gas separator, a heat exchanger, an amine absorption tower, a copper-ammonia solution absorber, a drying bed, a liquefier, a gas-liquid separation tank, a combustion furnace, etc., and does not involve the separation of carbon dioxide and methane.

[0012] CN216273977U discloses a device for comprehensive utilization of associated gas for carbon dioxide oil recovery, including adsorption, membrane separation, pressure swing adsorption, cryogenic distillation and other units. The process is complicated and not suitable for small and scattered wellhead gas sources.

[0013] The East China Oilfield built one fixed and one skid-mounted processing system in 2012 and 2018 respectively. It mainly uses the cryogenic method to separate the carbon dioxide from the associated gas and process it into liquid phase for reinjection. The initial application effect was good.

[0014] Jilin Oilfield started the research work on CO2 flooding surface engineering technology in 2012, among which the produced gas circulation injection technology was one of the key research topics. The produced gas treatment process adopts the pressure swing adsorption method. The whole device consists of 12 adsorption towers, and each tower undergoes adsorption, pressure drop, reverse placement, vacuum, pressure increase, and final filling in one cycle.

[0015] Although the deep freezing method and adsorption method used in East China and Jilin Oilfields have good treatment and purification effects, the carbon dioxide content of the mixed gas after treatment in East China is >98.0%, and the carbon dioxide content of the mixed gas in Jilin is >95.0%. However, in order to purify the liquefied carbon dioxide, the process is complicated, the volume is large, and the cost is high.

[0016] With the in-depth development of CO2 flooding and enhanced oil recovery technology, many problems have gradually emerged on site. For example, due to the re-extraction of injected CO2, the CO2 content of associated gas in the block has become higher and higher, and the heating furnace used on site has experienced flameout and unstable combustion. Previously, this part of the associated gas could not be effectively utilized, causing HSE problems and affecting on-site production. For complex fault block reservoirs such as the Jiangsu Oilfield, which are "small, fragmented, poor, and scattered", the displacement blocks are scattered and the amount of associated gas is small, so there is a particular need for supporting facilities for processing processes with good on-site effects, low investment, high utilization rate, and easy transportation. Utility Model Content

[0017] The purpose of the utility model is to overcome the problems existing in the prior art and provide a carbon dioxide displacement block associated gas quality improvement and utilization system, which can alleviate the current difficulties in associated gas treatment and utilization and enable this part of gas resources to be effectively and comprehensively utilized.

[0018] In order to solve the above technical problems, the utility model of the carbon dioxide displacement block associated gas quality improvement and utilization system comprises:

[0019] A first separation buffer tank, the inlet of which is connected to the associated gas pipeline;

[0020] a first filter, an inlet of which is connected to the outlet of the first separation buffer tank;

[0021] An evaporator, wherein a tube-side inlet is connected to an outlet of the first filter;

[0022] a second separation buffer tank, the inlet of which is connected to the tube-side outlet of the evaporator;

[0023] a second filter, the inlet of which is connected to the outlet of the second separation buffer tank;

[0024] a third separation buffer tank, the inlet of which is connected to the outlet of the second filter;

[0025] A compressor unit, an inlet of which is connected to the outlet of the third separation buffer tank;

[0026] The fourth separation buffer tank has an inlet connected to the outlet of the compressor unit, and an outlet connected to the reinjection gas pipeline.

[0027] Furthermore, the carbon dioxide displacement block associated gas quality improvement and utilization system also includes:

[0028] an adsorption tower, the inlet of which is connected to the outlet of the second filter through an adsorption inlet valve, and the outlet of which is provided with an adsorption outlet valve;

[0029] A dust filter, the inlet of which is connected to the outlet of the adsorption outlet valve;

[0030] The first compressor has an inlet connected to the outlet of the dust filter, and an outlet connected to the inlet of the third separation buffer tank.

[0031] Furthermore, the outlet of the first compressor is also connected to the inlet of the heater, and the outlet of the heater is connected to the outlet of the adsorption tower through a regeneration inlet valve.

[0032] Furthermore, the inlet of the adsorption tower is connected to the inlet of the air cooler through a regeneration outlet valve, the outlet of the air cooler is connected to the inlet of the fifth separation buffer tank, and the outlet of the fifth separation buffer tank is connected to the tube side inlet of the evaporator.

[0033] Furthermore, the cold source gas pipeline is connected to the tube side inlet of the evaporator through a first pressure reducing buffer.

[0034] Furthermore, the interstage outlet of the compressor unit is connected to the inlet of the membrane separation component through the second pressure reducing buffer, the permeate outlet of the membrane separation component is connected to the inlet of the second compressor, and the outlet of the second compressor is also connected to the inlet of the third separation buffer tank.

[0035] Furthermore, the retentate gas outlet of the membrane separation assembly is connected to a fuel gas pipeline.

[0036] Furthermore, the bottom drain ports of the first separation buffer tank, the first filter and the second separation buffer tank are respectively connected to the liquid collecting tank.

[0037] Furthermore, the shell side of the evaporator is connected to the refrigerant circulation pipe of the refrigeration unit.

[0038] Furthermore, each level of the liquid discharge port of the compressor unit is respectively connected to the inlet of the liquid collecting cylinder, and the outlet of the liquid collecting cylinder is connected to the liquid collecting tank.

[0039] Furthermore, a buffer tank safety valve is installed on the top of the third separation buffer tank, and the outlet of the buffer tank safety valve is connected to the safety valve pressure relief storage tank.

[0040] Furthermore, each stage of the compressor unit is provided with a compressor safety valve, and the outlet of the safety valve is connected to the safety valve pressure relief tank.

[0041] Compared with the prior art, the utility model has achieved the following beneficial effects: 1. In view of the fact that the return wellhead gas generated in the tertiary oil recovery process is small and scattered and located in a remote area, it is specifically proposed to filter, separate, pre-cool, dehydrate, purify, and membrane separate the wellhead gas, use the separated carbon dioxide for oil well reinjection, and use the hydrocarbon-rich gas as fuel gas to supply hot water boilers, making full use of the cold released by the decompression of the reinjected carbon dioxide to realize the pre-cooling and dehydration of the wellhead gas. The return wellhead gas from tertiary oil recovery is used at a high value, which reduces the cost of purchasing carbon dioxide and fuel gas, is conducive to the continuous operation of tertiary oil recovery, and reduces carbon dioxide and VOCs emissions.

[0042] 2. The product of this system meets the gas intake standard of the reinjection unit, ensuring the stable operation of the reinjection unit. It can be applied in the displacement block of carbon dioxide flooding to achieve stable and effective treatment of associated gas. After treatment, the mixed gas rich in carbon dioxide flooding is reinjected into the oil layer, and the hydrocarbon-rich gas is used on site.

[0043] 3. The research and support of associated gas treatment in displacement blocks has formed an important part of the on-site "zero emission" system, which can make full use of carbon resources and alleviate the storage, safety and environmental protection issues of carbon dioxide displacement blocks, forming relevant technologies for the "closed loop" of carbon dioxide displacement blocks that are suitable for "small, fragmented, poor and scattered" complex fault block reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. The accompanying drawings are only provided for reference and explanation and are not intended to limit the present invention.

[0045] Figure 1 This is a flow chart of the utility model of the system for improving the quality of associated gas in the carbon dioxide displacement block;

[0046] In the figure: 1. associated gas; 2. first separation buffer tank; 3. first filter; 4. evaporator; 5. refrigeration unit; 6. second separation buffer tank; 7. second filter; 8. adsorption tower; 9. dust filter; 10. heater; 11. first compressor; 12. second compressor; 13. membrane separation assembly; 14. third separation buffer tank; 15. compressor unit; 16. fourth separation buffer tank; 17. liquid collecting cylinder; 18. reinjection gas; 19. fuel gas; 20. cold source gas; 21. first pressure reducing buffer; 22. second pressure reducing buffer; 23. safety valve pressure relief storage tank; 24. air cooler; 25. fifth separation buffer tank; 26. liquid collecting tank. DETAILED DESCRIPTION

[0047] In the following description of the utility model, the terms "upper", "lower", "front", "back", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the utility model and simplifying the description, and do not mean that the device must have a specific direction.

[0048] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below with reference to specific illustrations.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0050] like Figure 1 As shown, the carbon dioxide displacement block associated gas quality improvement and utilization system of the utility model includes a first separation buffer tank 2, a first filter 3, an evaporator 4, a refrigeration unit 5, a second separation buffer tank 6, a second filter 7, an adsorption tower 8, a dust filter 9, a heater 10, a first compressor 11, a second compressor 12, a membrane separation component 13, a third separation buffer tank 14, a compressor unit 15, a fourth separation buffer tank 16, a liquid collecting cylinder 17, a first pressure reducing buffer 21, a second pressure reducing buffer 22, a safety valve pressure relief storage tank 23, an air cooler 24, a fifth separation buffer tank 25 and a liquid collecting tank 26.

[0051] The pipeline outlet of the associated gas 1 is connected to the inlet of the first separation buffer tank 2. Two first separation buffer tanks 2 are arranged in parallel. The gas phase outlet of the first separation buffer tank 2 is connected to the inlet of the first filter 3. The gas phase outlet of the first filter 3 is connected to the tube side inlet of the evaporator 4. The shell side of the evaporator 4 is provided with indirect refrigerant by the refrigeration unit 5. The tube side outlet of the evaporator 4 is connected to the inlet of the second separation buffer tank 6. The gas phase outlet of the second separation buffer tank 6 is connected to the inlet of the second filter 7. The bottom drainage ports of the first separation buffer tank 2, the first filter 3, the second separation buffer tank 6 and the second filter 7 are respectively connected to the liquid collecting tank 26.

[0052] The gas phase outlet of the second filter 7 is connected to the inlet of the third separation buffer tank 14, the exhaust port on the upper part of the side wall of the third separation buffer tank 14 is connected to the inlet of the compressor unit 15, the outlet of the compressor unit 15 is connected to the inlet of the fourth separation buffer tank 16, and the gas phase outlet of the fourth separation buffer tank 16 is connected to the pipeline of the reinjection gas 18 through a one-way valve.

[0053] The gas phase outlet of the second filter 7 is also connected to the inlet of the adsorption tower 8 via the adsorption inlet valve, the outlet of the adsorption tower 8 is connected to the inlet of the dust filter 9 via the adsorption outlet valve, the outlet of the dust filter 9 is connected to the inlet of the first compressor 11, the outlet of the first compressor 11 is connected to the inlet of the third separation buffer tank 14 via the pressure regulating valve in one way, and is connected to the inlet of the heater 10 in the other way, the outlet of the heater 10 is connected to the outlet of the adsorption tower 8 via the regeneration inlet valve, the inlet of the adsorption tower 8 is connected to the inlet of the air cooler 24 via the regeneration outlet valve, the outlet of the air cooler 24 is connected to the inlet of the fifth separation buffer tank 25, and the gas phase outlet of the fifth separation buffer tank 25 is connected to the pipe side inlet of the evaporator 4.

[0054] In addition, the pipeline outlet of the cold source gas 20 is connected to the pipe side inlet of the evaporator 4 through the first pressure reducing buffer 21 .

[0055] The interstage gas outlet of the compressor unit 15 is connected to the inlet of the membrane separation component 13 through the second pressure reducing buffer 22, and the outlet of the membrane separation component 13 is connected to the output pipeline of the fuel gas 19.

[0056] The second outlet of the membrane separation component 13 is connected to the inlet of the second compressor 12 , and the outlet of the second compressor 12 is also connected to the inlet of the third separation buffer tank 14 .

[0057] The liquid discharge ports of the compressor unit 15 are respectively connected to the inlet of the liquid collecting cylinder 17 , and the outlet of the liquid collecting cylinder 17 is connected to the liquid collecting tank 26 .

[0058] The top safety valve outlet of the third separation buffer tank 14 and the safety valve outlets of each level of the compressor unit 15 are connected to the safety valve pressure relief storage tank 23 respectively.

[0059] The associated gas 1 has a gas phase liquid content of about 2.0 g / Nm³, a pressure of ≤0.3 MPa, and a temperature of 25.0°C. After the associated gas 1 enters the first separation buffer tank 2 for separation, it is filtered through the first filter 3 to remove part of the free liquid and most of the solid particles. The gas phase contains about 800.0 mg / Nm³ of liquid, has a pressure of ≤0.3 MPa, and a temperature of 25.0°C. The liquid phase separated during this period is discharged into the liquid collecting tank 26.

[0060] The refrigeration system 5 cools the associated gas entering the evaporator 4 by heat exchange, and controls the temperature of the associated gas to ≤15.0℃. After removing all free liquid and part of the saturated liquid, the gas phase contains about 200.0mg / Nm³ of liquid, the pressure is ≤0.3MPa, and the temperature is ≤15.0℃, so as to achieve the purpose of preliminary removal of saturated liquid. The cold source gas can also be used to cool the associated gas directly after passing through the first pressure reducing buffer 21, without activating the refrigeration unit. The generated liquid phase is separated by the second separation buffer tank 6, enters the second filter 7 for filtration, and then discharged to the liquid collecting tank 26. The treated gas phase can be directly separated by the third separation buffer tank 14, enters the compressor unit 15 to increase the pressure to ≤25.0MPa, and then enters the fourth separation buffer tank 16 for separation and then is injected back into the formation as the reinjection gas 18. The generated liquid phase enters the liquid collecting cylinder 17 for collection and is concentrated and discharged to the liquid collecting tank 26.

[0061] The associated gas at the outlet of the second filter 7 can continue to enter the adsorption tower 8 for further drying and dehydration. After removing most of the saturated liquid, the gas phase contains about 15.0 mg / Nm³ of liquid, the pressure is less than 0.2 MPa, and the temperature is 40.0°C. After being filtered by the dust filter 9, it enters the first compressor 11 for pressure increase. The pressure of part of the dry gas after pressure increase is adjusted to ≤0.3 MPa and enters the heater 10 to be heated to about 200.0°C to regenerate the adsorption tower 8. After regeneration, the wet gas leaving the adsorption tower 8 is cooled by the cooler 24 and then separated by the fifth separation buffer tank 25. The gas phase part returns to the front end of the evaporator 4 and the liquid phase part is discharged to the liquid collecting tank 26. It can also be adjusted to ≤0.3 MPa and then directly pressurized to ≤25.0 MPa by the third separation buffer tank 14 and the compressor unit 15, and then separated by the fourth separation buffer tank 16 and injected back into the formation. The generated liquid phase is collected by the liquid collecting cylinder 17 and discharged to the liquid collecting tank 26.

[0062] After being moderately pressurized by the compressor 11, the associated gas also enters the membrane separation component 13 for decarbonization treatment. The gas source can also be extracted from the interstage of the compressor unit 15 and led to the front end of the membrane separation component 13 after passing through the second pressure reducing buffer 22 to meet the pressure requirement for entering the membrane separation component 13. After membrane separation, the residual gas can be used as fuel gas 19 to enter the gathering and transportation system for effective utilization. The permeated gas, that is, the part rich in carbon dioxide, is pressurized to ≤0.3MPa by the second compressor 12, and then pressurized to ≤25.0MPa by the third separation buffer tank 14 and the compressor unit 15. After separation in the fourth separation buffer tank 16, it is injected into the formation as the reinjection gas 18. The generated liquid phase is collected by the liquid collecting cylinder 17 and discharged to the liquid collecting tank 26.

[0063] This system uses separation, filtration, cold drying, adsorption, membrane separation and other technologies to remove moisture, liquid hydrocarbons and solid particles in the associated gas, and then reinjects the separated carbon dioxide. The hydrocarbon-rich gas is used on-site or sold as fuel gas, achieving effective utilization of the associated gas and reducing emissions to the atmosphere.

[0064] The carbon-containing associated gas produced by the gathering and transportation system is processed by the filtration and separation unit to remove most of the free liquid and solid particles; then it is processed by the pre-cooling unit through the principle of cooling and condensation to further remove the liquid phase; then it is processed by the drying and purification unit through the principle of temperature swing adsorption: molecular sieve adsorption and dehydration, and then desorption and regeneration by heating with dry gas, and deep drying treatment; finally it enters the membrane separation unit, and uses the selective permeable membrane as the separation medium to perform gas-gas separation. The separated carbon dioxide is reinjected into the well, and the separated hydrocarbon-rich gas is used as fuel gas for on-site hot water boilers, heating furnaces and other equipment fuel.

[0065] Part of the cold source gas is quoted from the site and moderately reduced in pressure as the refrigeration gas source for the pre-cooling unit, saving the energy consumption of the unit; a part of the gas source is extracted from the first-level outlet of the reinjection compressor unit and moderately reduced in pressure, and returned to the inlet of the membrane separation unit, moderately increasing the pressure difference at both ends of the membrane, improving the separation effect, and saving the energy consumption of the unit.

[0066] This system dries and purifies the associated gas in the carbon dioxide displacement block to reduce the burden on the back-end functional units. The byproducts in the process: hydrocarbon-rich gas and light hydrocarbons can be effectively utilized. It organically combines pre-cooling, dehydration purification, membrane separation and other processes. The final reinjection medium is gas phase, which is a mixed gas rich in carbon dioxide. No purification and liquefaction are performed, which simplifies the process, improves efficiency, saves costs and reduces energy consumption.

[0067] The filtration separation unit achieves the purpose of reducing droplets and solid particles in the associated gas through the principles of gravity, cyclone, physical shielding, etc. The pre-cooling unit achieves the purpose of preliminary removal of saturated liquid phase through the principle of cooling and condensation. The drying purification achieves further removal of saturated liquid phase through the principle of temperature swing adsorption. The membrane separation unit achieves gas-gas separation through the principle of selective permeation. The reinjection unit adopts a multi-stage compression design with a maximum reinjection pressure of ≤25.0MPa, which meets the on-site reinjection requirements.

[0068] In Block Lian 38, the associated gas carbon dioxide flooding content in the southern block is about 50.0%, and the gas volume is about 2000.0-3000.0m³ / d. Previously, this part of the associated gas could not be effectively utilized, which had an impact on the production, construction, HSE (health, safety and environmental management system) and other aspects of the site, restricting the advancement of the on-site carbon dioxide flooding work.

[0069] This part of associated gas is introduced into the associated gas upgrading and utilization system through the manifold, and its composition is about 40.0 mol% methane, 50.0 mol% carbon dioxide, 10.0 mol% hydrocarbons above C2, with a temperature of about 30.0°C, a relative density of about 1.13, and a pressure of 0.1-0.3 MPa.

[0070] After passing through the filtration separation unit, precooling unit and dehydration purification unit, the liquid content of the treated mixed gas is reduced to about 10.0ppm, which meets the requirements of the reinjection unit and can be directly injected into the formation by the reinjection unit; it can also enter the membrane separation unit to be separated into carbon dioxide-rich gas and hydrocarbon-rich gas. The carbon dioxide-rich gas enters the reinjection unit to be injected into the formation, and the hydrocarbon-rich gas is used on-site.

[0071] After field application, the entire system operated stably, and the liquid content in the treated gas phase was controlled within the design indicators, achieving good results.

[0072] The above description is only the preferred feasible embodiment of the utility model, which shows and describes the basic principle, main features and advantages of the utility model, but does not limit the scope of patent protection of the utility model. The technicians in this industry should understand that the utility model is not limited by the above embodiments. In addition to the above embodiments, the utility model can also have other implementation modes without departing from the spirit and scope of the utility model. The utility model will also have various changes and improvements. All technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the utility model. The scope of protection required by the utility model is defined by the attached claims and their equivalents. The technical features not described in the utility model can be achieved by or using existing technologies, which will not be repeated here.

Claims

1. A carbon dioxide displacement block associated gas quality improvement and utilization system, characterized in that: include: A first separation buffer tank (2), the inlet of which is connected to the associated gas pipeline; A first filter (3), an inlet of which is connected to the outlet of the first separation buffer tank (2); An evaporator (4), the tube side inlet of which is connected to the outlet of the first filter (3); A second separation buffer tank (6), the inlet of which is connected to the tube-side outlet of the evaporator (4); A second filter (7), an inlet of which is connected to the outlet of the second separation buffer tank (6); a third separation buffer tank (14), the inlet of which is connected to the outlet of the second filter (7); A compressor unit (15), the inlet of which is connected to the outlet of the third separation buffer tank (14); The fourth separation buffer tank (16) has an inlet connected to the outlet of the compressor unit (15), and an outlet connected to the reinjection gas pipeline.

2. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 1, characterized in that: Also includes: An adsorption tower (8), the inlet of which is connected to the outlet of the second filter (7) via an adsorption inlet valve, and the outlet is provided with an adsorption outlet valve; a dust filter (9), the inlet of which is connected to the outlet of the adsorption outlet valve; The first compressor (11) has an inlet connected to the outlet of the dust filter (9), and an outlet connected to the inlet of the third separation buffer tank (14).

3. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 2, characterized in that: The outlet of the first compressor (11) is also connected to the inlet of the heater (10), and the outlet of the heater (10) is connected to the outlet of the adsorption tower (8) via a regeneration inlet valve.

4. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 3, characterized in that: The inlet of the adsorption tower (8) is connected to the inlet of the air cooler (24) through a regeneration outlet valve, the outlet of the air cooler (24) is connected to the inlet of the fifth separation buffer tank (25), and the outlet of the fifth separation buffer tank (25) is connected to the tube side inlet of the evaporator (4).

5. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 1, characterized in that: The cold source gas pipeline is connected to the pipe side inlet of the evaporator (4) through a first pressure reducing buffer (21).

6. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 3, characterized in that: The interstage outlet of the compressor unit (15) is connected to the inlet of the membrane separation component (13) through the second pressure reducing buffer (22), the permeate gas outlet of the membrane separation component (13) is connected to the inlet of the second compressor (12), and the outlet of the second compressor (12) is also connected to the inlet of the third separation buffer tank (14).

7. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 6, characterized in that: The retentate gas outlet of the membrane separation component (13) is connected to the fuel gas pipeline.

8. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 1, characterized in that: The bottom liquid discharge ports of the first separation buffer tank (2), the first filter (3) and the second separation buffer tank (6) are respectively connected to the liquid collecting tank (26).

9. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 1, characterized in that: The shell side of the evaporator (4) is connected to the refrigerant circulation pipe of the refrigeration unit (5).

10. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 8, characterized in that: The liquid discharge ports of each stage of the compressor unit (15) are respectively connected to the inlet of the liquid collecting cylinder (17), and the outlet of the liquid collecting cylinder (17) is connected to the liquid collecting tank (26).

11. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 1, characterized in that: A buffer tank safety valve is installed on the top of the third separation buffer tank (14), and the outlet of the buffer tank safety valve is connected to the safety valve pressure relief tank.

12. The carbon dioxide displacement block associated gas quality improvement and utilization system according to claim 11, characterized in that: Each stage of the compressor unit (15) is provided with a compressor safety valve, and the outlet of the safety valve is connected to a safety valve pressure relief storage tank.

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