Deep extremely-close coal seam group carbon dioxide collaborative storage integrated system and method

Abstract

The invention discloses a deep extremely close coal seam group carbon dioxide collaborative storage integrated system and method.The system comprises a carbon dioxide injection system, a rapid cementing material injection system and a multifunctional injection device, and a pipeline of the carbon dioxide injection system and a pipeline of the rapid cementing material injection system are both communicated to a target reservoir stratum below the earth surface; the target reservoir sequentially comprises an upper coal seam, a dirt band layer and a lower coal seam from top to bottom, and the multifunctional injection device is arranged in a pinniform distribution horizontal well of the dirt band layer. The multifunctional injection device comprises an inner pipe, an outer pipe and a branch pipe, the end of the outer pipe and the end of the branch pipe are each provided with an energy gathering cavity I, the end of the inner pipe is provided with an energy gathering cavity II, the lower portion of an injection pipeline of the carbon dioxide injection system is connected with the outer pipe, and the lower end of an injection pipeline of the rapid cementing material injection system is connected with the inner pipe. According to the method, the target reservoir is fractured through the carbon dioxide, then the carbon dioxide is injected, and the carbon dioxide is sealed and stored by injecting the rapid cementing material into the dirt band layer.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide storage, and in particular to an integrated system and method for coordinated storage of carbon dioxide in a deep and extremely close coal seam group. Background Art

[0002] Carbon capture and storage technology can achieve carbon dioxide emission reduction and has broad application prospects. Based on this, a large number of scholars have conducted research on geological storage of carbon dioxide. At present, there are three main geological structures that can be used for geological storage of carbon dioxide, including saline-alkali aquifers, oil and gas reservoirs, and unmineable coal seams. Among them, the storage of carbon dioxide in unmineable coal seams is often integrated with the enhanced mining of coalbed methane, taking advantage of the significant competitive adsorption advantage of carbon dioxide over CH4, and achieving the purpose of efficient development of CH4 while storing carbon dioxide.

[0003] For example, a Chinese patent with publication number CN115539130A discloses a method for enhanced coalbed methane extraction and carbon dioxide storage in unmineable coal seams. The unmineable coal seams are first fractured by carbon dioxide foam pulsating fracturing, thereby expanding the reservoir transformation range, improving the coal body cracking effect, and providing a broad adsorption space for carbon dioxide storage. Then, carbon dioxide injection and coalbed methane enhanced extraction process are started. Carbon dioxide injection and coalbed methane extraction are carried out simultaneously, and carbon dioxide gas forms a closed cycle between the extraction system, injection wells, unmineable coal seams and drainage wells, so that carbon dioxide gas is continuously injected into various cracks in the coal seam, continuously displacing the adsorbed methane for desorption and discharge, and adsorbing carbon dioxide gas in the coal seam until a large amount of coalbed methane has been extracted, and then the unmineable coal seam is sealed to achieve carbon dioxide storage. The shortcoming of this patent is that it only considers the situation of carbon dioxide storage in a single deep coal seam. If it is aimed at the situation of a group of deep and close coal seams, it is impossible to achieve the injection and storage of the coal seam group at the same time through this method, and the injected carbon dioxide has the risk of leakage to other formations through the interlayer of gangue. Summary of the invention

[0004] In order to overcome the defects in the prior art, the present invention provides an integrated system and method for the coordinated storage of carbon dioxide in a deep and extremely close coal seam group.

[0005] The technical solution adopted by the present invention is as follows: in the first aspect, the present invention proposes an integrated system for the coordinated storage of carbon dioxide in a deep and extremely close coal seam group, including a carbon dioxide injection system for fracturing a target reservoir and injecting carbon dioxide into the target reservoir; the target reservoirs are, from top to bottom, an upper coal seam, an interlayer of gangue and a lower coal seam; a fast gelling material injection system for injecting fast gelling material into the interlayer of gangue to store carbon dioxide; a multifunctional injection device, arranged in a feather-shaped branch horizontal well in the interlayer of gangue, for cooperating with the carbon dioxide injection system and the fast gelling material injection system to inject carbon dioxide and store it; the multifunctional injection device includes an outer pipe, an inner pipe and a branch pipe, the outer pipe is arranged along the feather-shaped branch The horizontal well is arranged in the horizontal direction, the inner pipe is located inside the outer pipe and is consistent with the extension direction of the outer pipe; the upper and lower branches of the feather-shaped branch horizontal well extend into the upper coal seam and the lower coal seam respectively; the branch pipe is located in the upper and lower branches of the feather-shaped branch horizontal well, and is integrally connected with the outer pipe; the outer pipe is connected to the carbon dioxide injection system, and the inner pipe is connected to the rapid gelling material injection system; the outer pipe and the branch pipe ends are provided with an energy-gathering cavity I, the energy-gathering cavity I is provided with a plurality of energy discharge ports along the circumferential direction, and the head is provided with a conveying port; the inner pipe end is provided with an energy-gathering cavity II, the energy-gathering cavity II is located inside the energy-gathering cavity I at the outer pipe end, and the outlet of the energy-gathering cavity II faces the conveying port.

[0006] As a further improvement of the present invention, the carbon dioxide injection system includes a carbon dioxide storage and transportation tank, a carbon dioxide injection pump, a carbon dioxide injection valve and a flow meter I, the carbon dioxide storage and transportation tank is connected to the carbon dioxide injection pump, and the carbon dioxide injection valve and the flow meter I are located on the pipeline connecting the carbon dioxide injection pump and the outer tube of the multifunctional injection device.

[0007] As a further improvement of the present invention, the rapid gelling material injection system includes a gelling material storage tank, a gelling material injection pump, a gelling material injection valve and a flow meter II, the gelling material storage tank is connected to the gelling material injection pump, and the gelling material injection valve and the flow meter II are located on the pipeline between the gelling material injection pump and the inner tube of the multifunctional injection device.

[0008] As a further improvement of the present invention, a branch magnetically controlled valve is arranged at the position where the outer tube is connected to the inner tube, and a main magnetically controlled valve is arranged between the outer tube and the energy focusing cavity I at its end; the main magnetically controlled valve and the branch magnetically controlled valve are used for opening and closing the injection of carbon dioxide; and flow meters III are arranged in the energy focusing cavity I of the outer tube and the inner tube.

[0009] As a further improvement of the present invention, the system further includes a control terminal, and the flowmeter I, the flowmeter II, the flowmeter III, the main magnetic control valve and the branch magnetic control valve are all connected to the control terminal.

[0010] As a further improvement of the present invention, the system further comprises a packer, which is installed at the air inlet end of the multifunctional injection device to prevent carbon dioxide from rising.

[0011] In a second aspect, the present invention also proposes a method for synergistic storage of carbon dioxide in a deep and extremely close coal seam group, comprising the following steps: S1. Select the target reservoir for feather-shaped branch horizontal well construction, including: Step S11, determining the accurate positions of the upper coal seam, the interbedded gangue layer and the lower coal seam in the deep and close coal seam group in the stratum; Step S12, constructing a feather-shaped branch horizontal well from the ground to the coal seam group through the near-surface rock layer, aquifer, dense rock layer and upper coal seam in sequence, the main branch of the horizontal well is located in the center of the interlayer and constructed along the interlayer, the upper branch of the horizontal well is constructed to the upper coal seam roof at an inclination angle of no more than 45°, and the lower branch of the horizontal well is constructed to the lower coal seam floor at an inclination angle of no more than 45°, and the drilling work is stopped after completion; S2. Arrangement of carbon dioxide injection system and rapid gelling material injection system, including: Step S21, extending the multifunctional injection device from the surface horizontal wellhead, placing the outer pipe and the inner pipe of the multifunctional injection device into the designed position in the main branch of the horizontal well according to the actual construction position of the main branch and the branch of the feather-shaped branch horizontal well, and placing the branch pipe into the branch of the horizontal well; Step S22, connecting the lower end of the injection pipeline of the carbon dioxide injection system to the outer pipe, and connecting the lower end of the injection pipeline of the rapid gelling material injection system to the inner pipe; S3. Carry out carbon dioxide fracturing and injection into the target reservoir, including: Step S31, the carbon dioxide in the carbon dioxide storage tank is heated and pressurized by the carbon dioxide injection pump to be converted into supercritical carbon dioxide, and injected into the outer tube at a pressure greater than the target reservoir, and the carbon dioxide energy release port on the side wall of the energy-gathering chamber I is opened by the control terminal, and the supercritical carbon dioxide undergoes a phase change due to the change in pressure and temperature, thereby fracturing the upper coal seam, the lower coal seam and the interbedded gangue layer; Step S32: After fracturing, the delivery port at the front end of the energy-gathering chamber 1 is controlled to open, and carbon dioxide is continuously injected into the reservoir through the energy-release port and the delivery port at a constant pressure. The injection rate threshold is set, and the carbon dioxide injection amount and injection rate are monitored. When the injection rate continues to decrease below the threshold, the carbon dioxide injection into the target reservoir is completed; S4. Rapidly inject gelling materials into the target reservoir, specifically including: Step S41, after the rapid gelling material in the gelling material storage tank is increased in delivery pressure by the gelling material injection pump, it enters the energy-gathering chamber II along the inner tube at a pressure greater than the reservoir pressure, and the gelling material is rapidly ejected into the interlayer through the energy discharge port and the delivery port of the energy-gathering chamber I at the end of the outer tube. After entering the interlayer, the gelling material is mixed with the carbon dioxide and the interlayer rock to form a negative carbon high-porosity filling material structure, so as to solidify the carbon dioxide flowing in the interlayer and the carbon dioxide escaping from the upper coal seam and the lower coal seam into the interlayer; Step S42, continuously injecting fast gelling material into the reservoir at a constant pressure, setting an injection rate threshold, monitoring the injection amount and injection rate of the gelling material, and when the injection rate continues to decrease below the threshold, removing the multifunctional injection device from the horizontal well to complete the coordinated storage of carbon dioxide in the target reservoir.

[0012] The beneficial effects of the present invention are as follows: the present invention introduces negative carbon filling technology for extremely close coal seam groups, realizes the coordinated storage of deep unmineable extremely close coal seam groups and interlayer gangue layers, uses the deep unmineable coal seams in coal mines as carbon dioxide storage space, and utilizes coal-based solid waste to prepare carbon dioxide adsorption and storage materials to achieve safe storage of carbon dioxide, and can also utilize interlayer gangue layers for large-scale disposal of solid waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1 It is a layout diagram of the integrated system for the coordinated storage of carbon dioxide in deep and extremely close coal seams of the present invention; Figure 2 It is a structural schematic diagram of a multifunctional injection device.

[0015] In the figure, 1, control terminal; 2, flow meter I; 3, carbon dioxide injection valve; 4, carbon dioxide injection pump; 5, carbon dioxide storage tank; 6, flow meter II; 7, cementitious material injection valve; 8, cementitious material injection pump; 9, cementitious material storage tank; 10, near-surface rock layer; 11, aquifer; 12, dense rock layer; 13, upper coal seam; 14, interbedded gangue layer; 15, lower coal seam; 16, packer; 17, multi-functional injection device; 17-1, outer pipe; 17-2, inner pipe; 17-3, branch pipe; 17-4, energy-gathering chamber I; 17-5, energy discharge port; 17-6, conveying port; 17-7, energy-gathering chamber II; 17-8, main magnetic-controlled valve; 17-9, branch magnetic-controlled valve; 17-10, energy-gathering chamber outlet valve; 17-11, flow meter III. DETAILED DESCRIPTION

[0016] Figure 1The figure shows an integrated system for the coordinated storage of carbon dioxide in a group of deep and extremely close coal seams. The so-called deep refers to coal seams with a burial depth greater than 1,500 meters. These coal seams are difficult to mine with existing technical means and are suitable for carbon dioxide storage. The group of extremely close coal seams is a group of coal seams with very close interlayer spacing (within 5 meters above and below). If one coal seam is mined, it will have a significant impact on another coal seam, or a coal seam will bifurcate into two coal seams in some areas. In the above case, the thin rock layer between the two coal seams can often be regarded as an interlayer of gangue.

[0017] The integrated system for coordinated storage of the present invention includes a carbon dioxide injection system, a rapid gelling material injection system and a multifunctional injection device 17, wherein the carbon dioxide injection system includes a carbon dioxide injection pump 4, a carbon dioxide storage tank 5 and an injection pipeline, a flow meter I2 and a carbon dioxide injection valve 3 are provided on the injection pipeline, and the flow meter I2 and the carbon dioxide injection valve 3 are both connected to the control terminal 1. The rapid gelling material injection system includes a gelling material injection pump 8, a gelling material storage tank 9 and an injection pipeline, a flow meter II6 and a gelling material injection valve 7 are provided on the injection pipeline, and the flow meter II6 and the gelling material injection valve 7 are connected to the control terminal 1.

[0018] from Figure 1 It can be seen that the geological layers from the surface downward are the near-surface rock layer 10, the aquifer 11, the dense rock layer 12, the upper coal seam 13, the interlayer 14 and the lower coal seam 15, among which the upper coal seam 13, the interlayer 14 and the lower coal seam 15 are set as the target reservoirs.

[0019] like Figure 2 As shown, the main body of the multifunctional injection device 17 is arranged in the interlayer 14 in the target reservoir, and a feather-shaped horizontal well is constructed in the interlayer 14. The main branch of the horizontal well extends in the horizontal direction of the interlayer 14, and the upper and lower branches extend into the upper coal seam 13 and the lower coal seam 15 at an inclined angle. The multifunctional injection device 17 is arranged in the feather-shaped branch horizontal well. The multifunctional injection device 17 includes an outer pipe 17-1, an inner pipe 17-2 and a branch pipe 17-3. The outer pipe 17-1 is arranged in the horizontal direction, the inner pipe 17-2 is located inside the outer pipe 17-1 and arranged in the horizontal direction, and the branch pipe 17-3 is a telescopic pipe folded on both sides of the outer pipe 17-1. Each branch pipe 17-3 is connected to the outer pipe 17-1 and arranged in each branch of the feather-shaped branch horizontal well. Energy-gathering chambers I17-4 are provided at the ends of the branch pipe 17-3 and the ends of the outer pipe 17-1. Energy-discharging ports 17-5 are provided circumferentially on the shell wall of the energy-gathering chamber I17-4, and a delivery port 17-6 is provided at the front end thereof. Energy-gathering chambers II17-7 are provided inside the energy-gathering chamber I17-4 at the end of the outer pipe 17-1. The energy-gathering chambers II17-7 are connected to the ends of the inner pipe 17-2. Energy-gathering chamber outlets are provided at the front end of the energy-gathering chambers II17-7, facing the delivery port 17-6. Energy-gathering chamber outlet valves 17-10 are provided at the outlets of the energy-gathering chambers II17-7.

[0020] A branch magnetic control valve 17-9 is provided at the connection between the outer tube 17-1 and the branch tube 17-3, and a main magnetic control valve 17-8 is provided between the end of the outer tube 17-1 and the energy focusing chamber I17-4. A flow meter III17-11 is also provided inside the energy focusing chamber I17-4. The branch magnetic control valve 17-9, the main magnetic control valve 17-8, the flow meter III17-11, and the energy focusing chamber outlet valve 17-10 are all connected to the control terminal 1.

[0021] The lower end of the pipeline of the carbon dioxide injection system is connected to the outer pipe 17 - 1 of the multifunctional injection device 17 , and the lower end of the pipeline of the rapid gelling material injection system is connected to the inner pipe 17 - 2 of the multifunctional injection device 17 .

[0022] The present invention also discloses a method for synergistically storing carbon dioxide in a deep and extremely close coal seam group, comprising the following steps: S1. Select the target reservoir for feather-shaped branch horizontal well construction. The specific process is as follows: Firstly, determine the exact positions of the upper coal seam 13, interlayer 14 and lower coal seam 15 in the deep and near coal seam group in the stratum, and construct a feather-shaped branch horizontal well from the ground through the near-surface rock layer 10, aquifer 11, dense rock layer 12 and upper coal seam 13 to the coal seam group. The main branch of the horizontal well is located in the center of the interlayer 14 and constructed at the designed position along the direction of the interlayer 14. The upper branch of the horizontal well is constructed to the roof of the upper coal seam with an inclination of no more than 45°, and the lower branch of the horizontal well is also constructed to the bottom of the lower coal seam with an inclination of no more than 45°. After completion, stop drilling.

[0023] S2. Arrange the carbon dioxide and rapid gelling material injection system. The specific process is as follows: The multifunctional injection device 17 is extended from the ground horizontal wellhead. According to the actual construction orientation of the main branch and branches of the feather-shaped branch horizontal well, the main branch of the multifunctional injection device 17 is placed in the designed position in the main branch of the horizontal well. The branch pipe 17-3 on the multifunctional injection device 17 is extended into the upper branch to the interior of the upper coal seam 13 when it reaches the upper branch position of the horizontal well. The lower branch of the multifunctional injection device 17 is extended into the lower branch to the interior of the lower coal seam 15 when it reaches the lower branch position of the horizontal well. The packer 16 is placed between the upper coal seam 13 and the dense rock formation 12. The lower end of the pipeline of the carbon dioxide injection system is connected to the outer pipe 17-1 of the multifunctional injection device 17, and the lower end of the pipeline of the rapid gelling system is connected to the inner pipe 17-2 of the multifunctional injection device 17, thereby completing the pipeline connection between the carbon dioxide injection system and the rapid gelling material injection system and the multifunctional injection system.

[0024] S3. Carry out carbon dioxide fracturing and injection into the target reservoir. The specific process is as follows: After confirming that the main magnetic control valve 17-8 and the energy-gathering chamber outlet valve 17-10 are in the closed state, open the carbon dioxide injection valve 3, and control the opening of all branch magnetic control valves 17-9 and the main magnetic control valve 17-8 through the control terminal 1. The carbon dioxide in the carbon dioxide storage tank 5 is heated and pressurized by the carbon dioxide injection pump 4, and is converted into supercritical carbon dioxide. It enters the energy-gathering chamber I17-4 of the multifunctional injection device 17 along the outer tube 17-1 with a pressure greater than the reservoir, so that carbon dioxide accumulates in the shell and forms a large pressure. Then, the energy release port 17-5 is controlled to open through the control terminal 1, and the supercritical carbon dioxide undergoes a phase change due to the change in pressure and temperature, and quickly fractures the upper coal seam 13, the lower coal seam 15 and the interlayer 14.

[0025] After fracturing, the delivery port 17-6 is opened through the control terminal 1, and carbon dioxide is continuously injected into the reservoir through the energy release port 17-5 and the delivery port 17-6 at a constant pressure. The injection rate threshold is set, and the carbon dioxide injection amount and injection rate are monitored by the flow meter I2. When the injection rate of the outer pipe 17-1 or different branch pipes 17-3 continues to decrease below the threshold, the main magnetic control valve 17-8 and the branch magnetic control valve 17-9 are closed until all the magnetic control valves are closed and then the carbon dioxide injection valve 3 is closed. The carbon dioxide injection steps of the upper coal seam 13, the interlayer 14 and the lower coal seam 15 are completed.

[0026] S4. Rapidly inject gelling material into the target reservoir. The specific process is as follows: The main magnetic control valve 17-8 is opened, and the rapid gelling material in the rapid gelling material storage tank 9 increases the delivery pressure through the gelling material injection pump 8, and then enters the energy-gathering chamber II17-7 of the multifunctional injection device 17 body along the inner tube 17-2 at a pressure greater than the reservoir pressure, so that the delivered rapid gelling material is gathered to increase the fluid pressure in the chamber, and then the energy-gathering chamber outlet valve 17-10 is opened through the control terminal 1, and the rapid gelling material is rapidly ejected into the interlayer 14 through the energy discharge port 17-5 and the delivery port 17-6. After entering the interlayer 14, the rapid gelling material is mixed with carbon dioxide and the rock of the interlayer 14 to form a negative carbon high-porosity filling material structure (CGIF). After the rapid gelling material is mixed with carbon dioxide and the rock of the interlayer 14 to form CGIF, it can further solidify the carbon dioxide flowing in the interlayer 14 and the carbon dioxide escaping from the upper coal seam 13 and the lower coal seam 15 into the interlayer.

[0027] Then, the fast gelling material is continuously injected into the reservoir at a constant pressure, and an injection rate threshold is set. The injection amount and injection rate of the fast gelling material are monitored by the flow meter III17-11. When the injection rate continues to drop below the threshold, the main magnetic control valve 17-8 and the energy-gathering cavity outlet valve 17-10 are closed, and the multifunctional injection device 17 is removed from the horizontal well to complete the coordinated storage of carbon dioxide in the target reservoir.

[0028] The present invention provides an energy release port 17-5 to release the pressure and energy of the accumulated high-pressure carbon dioxide or fast-setting material, which can fracture the coal seam and interlayer of gangue on the one hand, and increase the injection distance of the carbon dioxide or fast-setting material by utilizing the kinetic energy after pressure relief on the other hand, thereby accelerating the plume speed toward the coal seam and interlayer of gangue.

[0029] Compared with the prior art, the present invention can, on the one hand, use carbon dioxide to fractur the upper coal seam 13, the lower coal seam 15 and the interlayer 14. After fracturing, carbon dioxide can be injected into the upper coal seam 13, the lower coal seam 15 and the interlayer 14. Then, a fast-setting material is injected into the interlayer 14 to seal the carbon dioxide. At the same time, the fast-setting material can be consumed. The fast-setting material is made of coal-based solid waste (fly ash, etc.), and the solid waste can be recycled so that it does not pollute the environment.

[0030] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Various changes that can be made within the knowledge scope of technicians in the relevant technical field without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. An integrated system for the coordinated storage of carbon dioxide in deep and close coal seams, characterized in that: include A carbon dioxide injection system is used for fracturing a target reservoir and injecting carbon dioxide into the target reservoir; the target reservoirs are, from top to bottom, an upper coal seam (13), an interlayer of gangue (14), and a lower coal seam (15); A fast-setting material injection system, used for injecting fast-setting material into the interlayer (14) to seal carbon dioxide; A multifunctional injection device (17) is arranged in a feather-shaped branch horizontal well in the interbedded coal layer (14), and is used to cooperate with the carbon dioxide injection system and the rapid gelling material injection system to inject carbon dioxide and seal it; the multifunctional injection device (17) comprises an outer pipe (17-1), an inner pipe (17-2) and a branch pipe (17-3); the outer pipe (17-1) is arranged in the horizontal direction of the feather-shaped branch horizontal well, the inner pipe (17-2) is located inside the outer pipe (17-1) and is consistent with the extension direction of the outer pipe (17-1); the upper and lower branches of the feather-shaped branch horizontal well extend into the upper coal seam (13) and the lower coal seam (15) respectively; the branch pipe (17-3) is located at the upper and lower branches of the feather-shaped branch horizontal well. The outer tube (17-1) is connected to a carbon dioxide injection system, and the inner tube (17-2) is connected to a rapid gelling material injection system; the ends of the outer tube (17-1) and the branch tube (17-3) are both provided with an energy-gathering chamber I (17-4); the energy-gathering chamber I (17-4) is provided with a plurality of energy-discharging ports (17-5) along the circumferential direction, and a delivery port (17-6) is provided at the head; the end of the inner tube (17-2) is provided with an energy-gathering chamber II (17-7); the energy-gathering chamber II (17-7) is located inside the energy-gathering chamber I (17-4) at the end of the outer tube (17-1), and the outlet of the energy-gathering chamber II (17-7) faces the delivery port (17-6).

2. The integrated system for the coordinated storage of carbon dioxide in deep and close coal seams according to claim 1 is characterized in that: The carbon dioxide injection system comprises a carbon dioxide storage tank (5), a carbon dioxide injection pump (4), a carbon dioxide injection valve (3) and a flow meter I (2); the carbon dioxide storage tank (5) is connected to the carbon dioxide injection pump (4); the carbon dioxide injection valve (3) and the flow meter I (2) are located on a pipeline connecting the carbon dioxide injection pump (4) and the outer tube (17-1) of the multifunctional injection device (17).

3. The integrated system for the coordinated storage of carbon dioxide in deep and near coal seams according to claim 2 is characterized in that: The rapid gelling material injection system comprises a gelling material storage tank (9), a gelling material injection pump (8), a gelling material injection valve (7) and a flow meter II (6); the gelling material storage tank (9) is connected to the gelling material injection pump (8); the gelling material injection valve (7) and the flow meter II (6) are located on the pipeline between the gelling material injection pump (8) and the inner tube (17-2) of the multifunctional injection device (17).

4. The integrated system for the coordinated storage of carbon dioxide in deep and close coal seams according to claim 3 is characterized in that: A branch magnetic control valve (17-9) is arranged at a position where the outer tube (17-1) is connected to the inner tube (17-2), and a main magnetic control valve (17-8) is arranged between the outer tube (17-1) and the energy-gathering cavity I (17-4) at its end; the main magnetic control valve (17-8) and the branch magnetic control valve (17-9) are used to open and close the injection of carbon dioxide; and flow meters III (17-11) are arranged in the energy-gathering cavity I (17-4) of the outer tube (17-1) and the inner tube (17-2).

5. The integrated system for the coordinated storage of carbon dioxide in deep and near coal seams according to claim 4 is characterized in that: The system also includes a control terminal (1), and the flow meter I (2), the flow meter II (6), the flow meter III (17-11), the main magnetic control valve (17-8) and the branch magnetic control valve (17-9) are all connected to the control terminal (1).

6. The integrated system for the coordinated storage of carbon dioxide in deep and near coal seams according to claim 1 is characterized in that: It also includes a packer (16), which is installed at the air inlet end of the multifunctional injection device (17) to prevent carbon dioxide from rising.

7. A method for the coordinated storage of carbon dioxide in a deep and close coal seam group, based on the coordinated storage integrated system according to any one of claims 1 to 6, characterized in that: The following steps are involved: S1. Select the target reservoir for feather-shaped branch horizontal well construction, including: Step S11, determining the accurate positions of the upper coal seam (13), the interlayer (14) and the lower coal seam (15) in the deep and near coal seam group in the stratum; Step S12, constructing a feather-shaped branch horizontal well from the ground to the coal seam group through the near-surface rock layer (10), the aquifer (11), the dense rock layer (12) and the upper coal seam (13) in sequence, wherein the main branch of the horizontal well is located at the center of the interlayer (14) and constructed along the direction of the interlayer (14), the upper branch of the horizontal well is constructed to the top plate of the upper coal seam (13) at an inclination angle of no more than 45°, and the lower branch of the horizontal well is constructed to the bottom plate of the lower coal seam (15) at an inclination angle of no more than 45°, and the drilling work is stopped after completion; S2. Arrangement of carbon dioxide injection system and rapid gelling material injection system, including: Step S21, extending the multifunctional injection device (17) from the surface horizontal wellhead, placing the outer pipe (17-1) and the inner pipe (17-2) of the multifunctional injection device (17) into the designed position in the main branch of the horizontal well according to the actual construction position of the main branch and the branch of the feather-shaped branch horizontal well, and placing the branch pipe (17-3) into the branch of the horizontal well; Step S22, connecting the lower end of the injection pipeline of the carbon dioxide injection system to the outer tube (17-1), and connecting the lower end of the injection pipeline of the rapid gelling material injection system to the inner tube (17-2); S3. Carry out carbon dioxide fracturing and injection into the target reservoir, including: Step S31, the carbon dioxide in the carbon dioxide storage tank (5) is heated and pressurized by the carbon dioxide injection pump (4) to be converted into supercritical carbon dioxide, and injected into the outer tube (17-1) at a pressure greater than the target reservoir, and the carbon dioxide energy release port (17-5) on the side wall of the energy collection chamber I (17-4) is opened by the control terminal (1), and the supercritical carbon dioxide undergoes a phase change due to the change in pressure and temperature, thereby fracturing the upper coal seam (13), the lower coal seam (15) and the interlayer (14); Step S32: after fracturing, control the opening of the delivery port (17-6) at the front end of the energy-gathering chamber I (17-4), continuously inject carbon dioxide into the reservoir through the energy-release port (17-5) and the delivery port (17-6) at a constant pressure, set an injection rate threshold, and monitor the carbon dioxide injection amount and injection rate. When the injection rate continues to decrease below the threshold, the carbon dioxide injection into the target reservoir is completed; S4. Rapidly inject gelling materials into the target reservoir, specifically including: Step S41, the rapid gelling material in the gelling material storage tank (9) increases the delivery pressure through the gelling material injection pump (8), and then enters the energy-gathering chamber II (17-7) along the inner tube (17-2) at a pressure greater than the reservoir pressure, and the gelling material is rapidly ejected into the interlayer (14) through the energy discharge port (17-5) and the delivery port (17-6) of the energy-gathering chamber I (17-4) at the end of the outer tube (17-1). After entering the interlayer (14), the gelling material is mixed with carbon dioxide and rocks in the interlayer (14) to form a negative carbon high-porosity filling material structure, so as to solidify the carbon dioxide flowing in the interlayer (14) and the carbon dioxide escaping from the upper coal seam (13) and the lower coal seam (15) into the interlayer (14); Step S42, continuously injecting fast gelling material into the reservoir at a constant pressure, setting an injection rate threshold, monitoring the injection amount and injection rate of the gelling material, and when the injection rate continues to decrease below the threshold, removing the multifunctional injection device (17) from the horizontal well to complete the carbon dioxide coordinated storage work in the target reservoir.

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