Tracer injection system for carbon dioxide displacement production of coal bed methane

Abstract

The utility model relates to a tracer injection system for carbon dioxide displacement production coal bed gas relates to coal bed gas production equipment technical field, it includes storage tank, the input of injection pump communicates with storage tank for injecting liquid carbon dioxide into injection well, throttle valve one end communicates with main pipeline through branch pipeline, another end communicates with buffer tank, for making at least part liquid carbon dioxide that flows through branch pipeline into gaseous carbon dioxide and store in buffer tank, jet flow ware and buffer tank communicate, dosing device and jet flow ware communicate, gaseous carbon dioxide flows through jet flow ware and generates negative pressure in jet flow ware, and utilize negative pressure and draw reagent from dosing device, compressor input and the outflow hole of jet flow ware communicate, the output of compressor communicates with main pipeline, make after gaseous carbon dioxide mixed with reagent liquefied, and after mixing, the solution is injected into main pipeline.

Description

Technical Field

[0001] This invention relates to the field of coalbed methane production equipment technology, specifically to a tracer injection system for producing coalbed methane by carbon dioxide displacement. Background Technology

[0002] Carbon dioxide displacement process for coalbed methane production ( Its principle is to use stronger adsorption force. This process, which "displaces" methane from the micropores of coal, is the optimal solution for the efficient development of deep coalbed methane and is also the most mature and scalable technology direction for CCUS in the coal sector.

[0003] In some existing technologies, tracer powder is mixed with water to form a solution, which is then injected into injection wells used for carbon dioxide displacement to produce coalbed methane. For example, Chinese invention patent CN108905842B, authorized on August 27, 2021, discloses a fully automatic preparation and dispensing control device and operating method for Rhodamine B fluorescent tracer, including a water supply device, an integrated three-chamber combination box, a centralized control device, and an online real-time monitoring device; the integrated three-chamber combination box includes a premixing chamber, a mixing chamber, and a storage chamber connected in sequence; the premixing chamber is responsible for storing the dry powders of Rhodamine, sodium fluorescein, and fenestrate; the mixing chamber includes a temperature sensor, a stirring rod, and a cooling base, with the temperature sensor located at the bottom of the mixing chamber; the stirring rod is used to stir the solution to be mixed; the cooling base is located at the bottom of the premixing chamber, and the temperature sensor is connected to the centralized control device, which controls the cooling base to control the temperature inside the mixing chamber; the storage chamber is used to store the prepared solution. However, the mixture of water and carbon dioxide is acidic, which adversely affects the lifespan of wellhead equipment and components such as casing inside the well. Summary of the Invention

[0004] This invention addresses the aforementioned technical problems in the prior art by providing a tracer injection system for producing coalbed methane using carbon dioxide displacement. The system diverts a portion of the injected liquid carbon dioxide and vaporizes it, then utilizes the Venturi principle to achieve rapid mixing between the gaseous carbon dioxide and the tracer powder before injecting it into the well.

[0005] To achieve the above technical objectives, this invention provides a tracer injection system for producing coalbed methane using carbon dioxide displacement, comprising: a storage tank for storing liquid carbon dioxide; an injection pump, the input end of which is connected to the storage tank and the pump is connected to an injection well via a main pipeline for injecting liquid carbon dioxide into the injection well; a throttle valve, one end of which is connected to the main pipeline via a branch pipeline and the other end of which is connected to a buffer tank for converting at least a portion of the liquid carbon dioxide flowing through the branch pipeline into gaseous carbon dioxide and storing it in the buffer tank; an ejector connected to the buffer tank; a dosing device connected to the ejector, wherein a negative pressure is generated within the ejector when the gaseous carbon dioxide flows through it, and the negative pressure is used to draw the reagent from the dosing device; and a compressor, the input end of which is connected to the outlet of the ejector and the output end of which is connected to the main pipeline for liquefying the gaseous carbon dioxide mixed with the reagent and injecting the mixed solution into the main pipeline.

[0006] In one possible implementation, a shut-off valve is provided on the branch line between the throttle valve and the main line.

[0007] In one possible implementation, the dosing device includes a drive element, a drive gear, a large gear, a storage tank, a transmission gear, and a gearbox; the drive element is fixedly installed, and its output end is connected to the drive gear; the large gear is horizontally placed and supported to rotate around a longitudinally positioned support shaft; the drive gear meshes with the large gear; the upper surface of the large gear has a storage groove circumferentially surrounding the support shaft; the gearbox is located below the storage tank, and a conveying gear is installed inside the gearbox; a discharge pipe is located below the gearbox, and the lower end of the discharge pipe is located above the storage groove; the transmission gear meshes with the large gear and is connected to the conveying gear, for driving the conveying gear to rotate to deliver the drug to the storage tank through the discharge pipe.

[0008] In one possible implementation, it further includes a first drive shaft, a first bevel gear, and a second bevel gear; the drive gear is drivenly connected to the lower end of the first drive shaft; the upper end of the first drive shaft is drivenly connected to the first bevel gear; the first bevel gear is drivenly connected to the second bevel gear; and the second bevel gear is drivenly connected to the material conveying gear via a second drive shaft.

[0009] In one possible implementation, the jet injector includes a suction tube with its free end extending to the upper side of the storage tank for drawing in the drug from the storage tank.

[0010] In one possible implementation, the jet ejector includes an outer jet tube and an inner jet tube; one end of the inner jet tube is an inlet hole, and the other end narrows to form a nozzle; the inner jet tube communicates with the outer jet tube, and the nozzle is located inside the outer jet tube; the outer jet tube has a constriction section, a throat, and a diffuser section arranged sequentially; the outlet hole is located on the diffuser section away from the throat; the nozzle opens towards the throat, and gaseous carbon dioxide is ejected from the nozzle and enters the throat from the constriction section; the outer jet tube is provided with a suction hole communicating with the inner cavity of the outer jet tube; the suction hole communicates with the suction pipe.

[0011] In one possible implementation, the suction tube is provided with a second one-way valve that allows the agent to flow unidirectionally from the free end of the suction tube toward the suction port.

[0012] In one possible implementation, a mixer is provided on the main pipeline; the discharge end of the injection pump is connected to the injection well through the main pipeline and the mixer; the compressor is connected to the mixer and injects the mixed agent into the mixer.

[0013] In one possible implementation, the mixer includes an outer tube section and an inner tube section located within the outer tube section; the inner bore of the outer tube section forms a main flow channel, and a second flow inlet communicating with the main flow channel is provided on the side wall of the outer tube section; the discharge end of the compressor is connected to the mixer through the second flow inlet; a first flow inlet is formed on one side of the main flow channel, and a flow outlet is formed on the other side; the main pipeline is connected to the first flow inlet; the flow outlet is connected to the injection well; a spiral blade is provided on the outer wall of the inner tube section; and the second flow inlet is located between the first flow inlet and the inner tube section.

[0014] In one possible implementation, the inner diameter of the main channel is larger than the outer diameter of the spiral blade, forming a gap between the inner tube and the outer tube.

[0015] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages: The tracer injection system used for carbon dioxide displacement in coalbed methane production diverts a portion of the injected liquid carbon dioxide and vaporizes it. It then utilizes the Venturi principle to achieve rapid mixing between the gaseous carbon dioxide and the tracer powder before injecting it into the well, replacing the previous method of mixing water with the tracer powder and then injecting it.

[0016] Furthermore, in the dosing device of the present invention, the driving element of the present invention can drive the large gear and the conveying gear to rotate synchronously and work together, so that the powdered tracer can fall into the storage tank and be evenly distributed in the circumferential direction of the storage tank, forming a loose powder form, which is beneficial for the ejector to draw in the powder and mix it with carbon dioxide.

[0017] Furthermore, in the mixer of the present invention, laminar flow is formed in the gap and the flow hole, while spiral flow is formed in the spiral groove between the spiral blades, thereby forming a "laminar flow-spiral flow-laminar flow" fluid flow characteristic from the inside to the outside in the radial direction of the main channel, which is beneficial to the rapid and uniform mixing of carbon dioxide fluid and carbon dioxide with solvent in the main channel. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a tracer injection system for producing coalbed methane using carbon dioxide displacement, according to an embodiment of the present invention.

[0019] Figure 2 This is a perspective view of a dosing device in a tracer injection system for producing coalbed methane using carbon dioxide displacement, according to an embodiment of the present invention.

[0020] Figure 3 This is a perspective view of the dosing device in a tracer injection system for producing coalbed methane using carbon dioxide displacement, according to an embodiment of the present invention.

[0021] Figure 4 This is a perspective view of a storage tank and gearbox in a tracer injection system for carbon dioxide displacement in coalbed methane production, according to an embodiment of the present invention.

[0022] Figure 5 This is a cross-sectional view of a storage tank and gearbox in a tracer injection system for carbon dioxide displacement in coalbed methane production, according to an embodiment of the present invention.

[0023] Figure 6 This is a cross-sectional view of an ejector in a tracer injection system for carbon dioxide displacement in coalbed methane production according to an embodiment of the present invention.

[0024] Figure 7 This is a cross-sectional view of a mixer in a tracer injection system for carbon dioxide displacement in coalbed methane production according to an embodiment of the present invention.

[0025] Figure 8 This is a perspective view of the inner tube section of a tracer injection system for carbon dioxide displacement in coalbed methane production, according to an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures 1. Storage tank; 2. Injection pump; 3. Main pipeline; 4. Branch pipeline; 5. Throttling valve; 6. Buffer tank; 7. Ejector; 701. Inlet port; 702. Nozzle; 703. Contraction section; 704. Diffusion section; 705. Outlet port; 706. Suction port; 707. Throat; 708. Outer jet tube; 709. Inner jet tube; 710. Suction pipe; 8. Dosing device; 801. Drive element; 802. Drive gear; 803. Large gear; 804. Storage tank; 805. Support shaft; 806. Storage container; 807. Transmission gear; 808. First transmission shaft; 809. First bevel gear; 810. Second bevel gear; 811. Second transmission shaft; 812. Gearbox; 813. Discharge pipe; 814. Conveying gear; 9. Compressor; 10. First check valve; 11. Mixer; 111. Outer tube section; 1110. Main flow channel; 1111. First flow inlet; 1112. Second flow inlet; 1113. Flow outlet; 112. Inner tube section; 1120. Flow hole; 1121. Spiral blade; 1122. Spiral groove; 1123. Support plate; 113. Gap section; 12. Injection well; 13. Shut-off valve; 14. Refrigerator. Detailed Implementation

[0027] Other objects and advantages of the present invention will become clear by explaining the preferred embodiments of the present application below.

[0028] Figure 1 This is a schematic diagram of a tracer injection system for producing coalbed methane using carbon dioxide displacement, according to an embodiment of the present invention.

[0029] like Figure 1 As shown, a tracer injection system for producing coalbed methane by carbon dioxide displacement includes: a storage tank 1, an injection pump 2, a main pipeline 3, branch pipelines 4, a throttle valve 5, a buffer tank 6, an ejector 7, a dosing device 8, and a compressor 9.

[0030] Storage tank 1 is used to store liquid carbon dioxide. The input end of injection pump 2 is connected to storage tank 1, and injection pump 2 is connected to injection well 12 through main pipeline 3, and is used to inject liquid carbon dioxide into injection well 12 for coalbed methane displacement operation.

[0031] One end of the throttle valve 5 is connected to the main line 3 via a branch line 4, and the other end is connected to the buffer tank 6. The throttle valve is used to convert at least a portion of the liquid carbon dioxide flowing through the branch line 4 into gaseous carbon dioxide and store it in the buffer tank 6.

[0032] The ejector 7 is connected to the buffer tank 6, and the dosing device 8 is connected to the ejector 7. When gaseous carbon dioxide flows through the ejector 7, a negative pressure is generated inside the ejector 7, and the dosing device 8 is used to draw the agent from the ejector 7.

[0033] The input end of the compressor 9 is connected to the ejector 7, and the output end of the compressor 9 is connected to the main pipeline 3, so that the gaseous carbon dioxide mixed with the agent is liquefied and the mixed solution is injected into the main pipeline 3.

[0034] In some embodiments, a cooler 14 may be installed between the ejector 7 and the compressor 9, and the temperature of the mixture by the cooler 14 helps to liquefy the gaseous carbon dioxide in the mixture.

[0035] In some embodiments, a shut-off valve 13 is provided on the branch line 4 between the throttle valve 5 and the main line 3, which can be used to control whether tracer is injected by opening and closing the shut-off valve 13.

[0036] Figure 2 This is a perspective view of a dosing device 8 in a tracer injection system for producing coalbed methane using carbon dioxide displacement, according to an embodiment of the present invention. Figure 3 This is a perspective view of the dosing device 8 in a tracer injection system for producing coalbed methane using carbon dioxide displacement, according to an embodiment of the present invention. Figure 4 This is a perspective view of a tracer injection system for producing coalbed methane using carbon dioxide displacement, according to an embodiment of the present invention, comprising a storage tank 806 and a gearbox 812. Figure 5 This is a cross-sectional view of a storage tank 806 and a gearbox 812 in a tracer injection system for carbon dioxide displacement in coalbed methane production according to an embodiment of the present invention.

[0037] like Figures 2 to 5 As shown, the dosing device 8 includes a drive element 801, a drive gear 802, a large gear 803, a storage tank 806, a transmission gear 807, and a gearbox 812.

[0038] The drive element 801 is fixedly installed, and the output end of the drive element 801 is connected to the drive gear 802 for transmission; the drive element 801 can be, for example, an electric motor or other components.

[0039] The large gear 803 is placed horizontally and supported so that it can rotate around a longitudinally arranged support shaft 805. The support shaft 805 is fixedly installed, for example, it can be fixedly connected to the frame (not shown in the figure). The driving gear 802 meshes with the large gear 803; the upper surface of the large gear 803 is provided with a storage groove 804 that surrounds the support shaft 805 circumferentially.

[0040] Gearbox 812 is located below storage tank 806, and a conveying gear 814 is provided inside gearbox 812. A discharge pipe 813 is provided below gearbox 812, and the lower end of discharge pipe 813 is located above storage trough 804. There is a channel for the downward flow of the medicine between storage tank 806 and the lower end of discharge pipe 813. When the conveying gear 814 rotates, the groove formed between two adjacent teeth of the conveying gear 814 can receive the medicine from the bottom of storage tank 806. When it rotates to the lower side, the medicine falls from the groove into discharge pipe 813 and then into storage trough 804.

[0041] The transmission gear 807 meshes with the large gear 803 and is connected to the conveying gear 814 for driving the conveying gear 814 to rotate and convey the reagent to the storage tank 804 through the discharge pipe 813. This invention enables the large gear 803 and the conveying gear 814 to rotate synchronously and work together, thereby allowing the powdered tracer (hereinafter referred to as the reagent) to fall into the storage tank 804 and be evenly distributed in the circumferential direction of the storage tank 804.

[0042] In one possible implementation, it further includes a first drive shaft 808, a first bevel gear 809, and a second bevel gear 810; a drive gear 807 is drivenly connected to the lower end of the first drive shaft 808; the upper end of the first drive shaft 808 is drivenly connected to the first bevel gear 809; the first bevel gear 809 is drivenly connected to the second bevel gear 810; and the second bevel gear 810 is drivenly connected to the conveying gear 814 via a second drive shaft 811.

[0043] Figure 6 This is a cross-sectional view of an ejector in a tracer injection system for carbon dioxide displacement in coalbed methane production according to an embodiment of the present invention.

[0044] like Figure 6 As shown, in one possible embodiment, the ejector 7 includes a suction pipe 710, the free end of which extends to the upper side of the storage tank 804 for drawing the agent from the storage tank 804. In one possible embodiment, the suction pipe 710 is provided with a second one-way valve (not shown) that allows the agent to flow unidirectionally from the free end of the suction pipe 710 toward the suction port 706, thereby preventing carbon dioxide from flowing back from the ejector 7 into the dosing device 8.

[0045] In one possible implementation, the jet ejector 7 includes an outer jet tube 708 and an inner jet tube 709; one end of the inner jet tube 709 is an inlet hole 701, and the other end is narrowed to form a nozzle 702; the inner jet tube 709 is connected to the outer jet tube 708, and the nozzle 702 is located inside the outer jet tube 708; the outer jet tube 708 has a converging section 703, a throat 707, and a diffuser section 704 arranged in sequence; the outlet hole 705 is located on the side of the diffuser section 704 away from the throat 707; the opening direction of the nozzle 702 is towards the throat 707, and gaseous carbon dioxide is ejected from the nozzle 702 and enters the throat 707 from the converging section 703; the outer jet tube 708 is provided with a suction hole 706 that communicates with the inner cavity of the outer jet tube 708; the suction hole 706 is connected to the suction pipe 710. When gaseous carbon dioxide flows through the ejector 7, a negative pressure is generated in the suction port 706, and the agent in the storage tank 804 is sucked into the ejector 7 through the suction pipe 710.

[0046] Figure 7 This is a cross-sectional view of a mixer 11 in a tracer injection system for carbon dioxide displacement in coalbed methane production according to an embodiment of the present invention. Figure 8 This is a perspective view of the inner tube 112 in a tracer injection system for carbon dioxide displacement in coalbed methane production according to an embodiment of the present invention.

[0047] like Figure 7 and Figure 8 As shown, in one possible implementation, a mixer 11 is provided on the main pipeline 3; the discharge end of the injection pump 2 is connected to the injection well 12 via the main pipeline 3 and the mixer 11; the compressor 9 is connected to the mixer 11 and injects the mixed agent into the mixer 11. In some embodiments, a first check valve 10 is provided between the compressor 9 and the mixer 11. The first check valve 10 is used to limit the flow of fluid from the compressor 9 into the mixer 11 in one direction only, effectively preventing the accidental outflow of carbon dioxide.

[0048] In one possible implementation, the mixer 11 includes an outer tube 111 and an inner tube 112 located within the outer tube 111. The inner bore of the outer tube 111 forms a main flow channel 1110, and a second inlet 1112 communicating with the main flow channel 1110 is provided on the side wall of the outer tube 111. The discharge end of the compressor 9 is connected to the mixer 11 through the second inlet 1112. A first inlet 1111 is formed on one side of the main flow channel 1110, and an outlet 1113 is formed on the other side. The main pipeline 3 is connected to the first inlet 1111; the outlet 1113 is connected to the injection well 12; a spiral blade 1121 is provided on the outer wall of the inner tube 112; and the second inlet 1112 is located between the first inlet 1111 and the inner tube 112. Carbon dioxide flowing in from the first inlet 1111 and the mixture flowing in from the second inlet 1112 are mixed within the mixer 11.

[0049] In some embodiments, a plurality of radially extending support pieces 1123 may be provided on the inner tube portion 112, and a fixed connection between the two may be achieved by welding the support pieces 1123 to the outer tube portion 111.

[0050] In one possible implementation, the inner diameter ΦD of the main channel 1110 is larger than the outer diameter Φd of the spiral blade 1121, forming a gap 113 between the inner tube portion 112 and the outer tube portion 111.

[0051] Laminar flow is formed in the gap 113 and the flow hole 1120, while spiral flow is formed in the spiral groove 1122 between the spiral blades 1121. Thus, the present invention utilizes the above structure to form a "laminar flow-spiral flow-laminar flow" fluid flow characteristic from the inside to the outside in the radial direction of the main channel 1110, which is beneficial to the rapid and uniform mixing of carbon dioxide fluid and carbon dioxide with solvent in the main channel 1110.

[0052] The apparatus of this application has been described in detail with reference to the preferred technical solutions. However, it should be noted that, without departing from the spirit of this application, those skilled in the art can make any modifications, alterations, and variations based on the above disclosure. This application includes the above-described specific embodiments and any equivalent forms thereof.

Claims

1. A tracer injection system for producing coalbed methane using carbon dioxide displacement, characterized in that, include: Storage tank (1) is used to store liquid carbon dioxide; An injection pump (2) is connected to a storage tank (1) at its input end and to an injection well (12) via a main pipeline (3) for injecting liquid carbon dioxide into the injection well (12); A throttle valve (5), one end of which is connected to the main pipeline (3) via a branch pipeline (4) and the other end of which is connected to a buffer tank (6), is used to convert at least a portion of the liquid carbon dioxide flowing through the branch pipeline (4) into gaseous carbon dioxide and store it in the buffer tank (6). The jet injector (7) is connected to the buffer tank (6); The dosing device (8) is connected to the ejector (7). When gaseous carbon dioxide flows through the ejector (7), a negative pressure is generated in the ejector (7), and the agent is drawn from the dosing device (8) using the negative pressure. The compressor (9) has its input end connected to the outlet hole (705) of the ejector (7) and its output end connected to the main pipeline (3) to liquefy the gaseous carbon dioxide mixed with the agent and inject the mixed solution into the main pipeline (3).

2. The tracer injection system for producing coalbed methane via carbon dioxide displacement as described in claim 1, characterized in that, A shut-off valve (13) is provided on the branch line (4) between the throttle valve (5) and the main line (3).

3. The tracer injection system for carbon dioxide displacement in coalbed methane production as described in claim 2, characterized in that, The dosing device (8) includes a drive element (801), a drive gear (802), a large gear (803), a storage tank (806), a transmission gear (807), and a gearbox (812). The drive element (801) is fixedly installed, and the output end of the drive element (801) is connected to the drive gear (802) for transmission. The large gear (803) is placed horizontally and is supported so that it can rotate about a longitudinally arranged support shaft (805); the driving gear (802) meshes with the large gear (803); The upper surface of the large gear (803) is provided with a storage groove (804) that surrounds the support shaft (805) circumferentially. The gearbox (812) is located below the storage tank (806), and a conveying gear (814) is provided inside the gearbox (812); a discharge pipe (813) is provided below the gearbox (812), and the lower end of the discharge pipe (813) is located above the storage trough (804). The transmission gear (807) meshes with the large gear (803), and the transmission gear (807) is connected to the conveying gear (814) for driving the conveying gear (814) to rotate so as to convey the medicine to the storage tank (804) through the unloading pipe (813).

4. The tracer injection system for carbon dioxide displacement in coalbed methane production as described in claim 3, characterized in that, It also includes a first drive shaft (808), a first bevel gear (809), and a second bevel gear (810); The transmission gear (807) is connected to the lower end of the first transmission shaft (808); the upper end of the first transmission shaft (808) is connected to the first bevel gear (809); the first bevel gear (809) is connected to the second bevel gear (810); the second bevel gear (810) is connected to the conveying gear (814) via the second transmission shaft (811).

5. The tracer injection system for carbon dioxide displacement in coalbed methane production as described in claim 4, characterized in that, The jet injector (7) includes a suction pipe (710), the free end of which extends to the upper side of the storage tank (804) for the storage tank (804) to absorb the medicine.

6. The tracer injection system for carbon dioxide displacement in coalbed methane production as described in claim 5, characterized in that, The jet ejector (7) includes an outer jet tube (708) and an inner jet tube (709). One end of the jet inner tube (709) is an inlet hole (701), and the other end is narrowed to form a nozzle (702). The inner jet tube (709) is connected to the outer jet tube (708), and the nozzle (702) is located inside the outer jet tube (708); The jet outer tube (708) has a constriction section (703), a throat (707) and a diffuser section (704) arranged in sequence. The outflow hole (705) is located on the side of the diffuser section (704) away from the throat (707); The nozzle (702) has its opening facing the throat (707). After gaseous carbon dioxide is ejected from the nozzle (702), it enters the throat (707) from the constriction section (703). The jet outer tube (708) is provided with a suction hole (706) that communicates with the inner cavity of the jet outer tube (708); the suction hole (706) is connected to the suction tube (710).

7. The tracer injection system for carbon dioxide displacement in coalbed methane production as described in claim 6, characterized in that, The suction pipe (710) is provided with a second one-way valve that allows the agent to flow unidirectionally from the free end of the suction pipe (710) toward the suction hole (706).

8. The tracer injection system for carbon dioxide displacement in coalbed methane production as described in claim 7, characterized in that, A mixer (11) is provided on the main pipeline (3); the discharge end of the injection pump (2) is connected to the injection well (12) through the main pipeline (3) and the mixer (11); The compressor (9) is connected to the mixer (11) and injects the mixed agent into the mixer (11).

9. The tracer injection system for producing coalbed methane via carbon dioxide displacement as described in claim 8, characterized in that, The mixer (11) includes an outer tube section (111) and an inner tube section (112) located within the outer tube section (111). The inner hole of the outer tube (111) forms a main flow channel (1110), and the side wall of the outer tube (111) is provided with a second flow inlet (1112) that communicates with the main flow channel (1110). The discharge end of the compressor (9) is connected to the mixer (11) through the second flow inlet (1112). The main channel (1110) forms a first inlet (1111) on one side and an outlet (1113) on the other side. The main pipeline (3) is connected to the first inlet (1111); the outlet (1113) is connected to the injection well (12); The outer wall of the inner tube (112) is provided with spiral blades (1121). The second inlet (1112) is located between the first inlet (1111) and the inner tube (112).

10. The tracer injection system for carbon dioxide displacement production of coalbed methane as described in claim 9, characterized in that, The inner diameter of the main channel (1110) is larger than the outer diameter of the spiral blade (1121), forming a gap (113) between the inner tube (112) and the outer tube (111).

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