Natural gas reservoir CO2 injection gas driving and burying simulation experiment device and method

Abstract

The invention relates to the technical field of natural gas extraction, and discloses a natural gas reservoir CO2 injection gas driving and burying simulation experiment device and method. The natural gas reservoir CO2 injection gas driving and burying simulation experiment device comprises a bottom water natural gas reservoir physical simulation system, a production horizontal well system, a resistivity monitoring system, a metering analysis system and a CO2 injection system. According to the natural gas reservoir CO2 injection gas driving and burying simulation experiment device and method, the resistivity change of each point position of the gas reservoir can be monitored in real time, and the water invasion form and the dynamic change rule of the gas reservoir can be obtained through the resistivity change rule. Meanwhile, components of produced gas are measured and analyzed through a chromatographic instrument, real-time monitoring is combined with the gas production speed, CO2 injection is quantified, the recovery rate of natural gas is increased, and the storage amount after CO2 injection is quantified, well pattern arrangement can be optimized, the injection-production speed and the injection-production amount can be optimized through the experimental device, and therefore production guidance is provided for CO2 injection gas driving and storage of the natural gas reservoir.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas exploitation, and in particular to a natural gas reservoir CO2 injection, gas displacement and storage simulation experimental device and method. Background Art

[0002] For gas reservoirs in the middle and late stages of development, water production from gas reservoirs caused by edge water or bottom water is one of the important factors restricting gas reservoir development. With the continuous production of natural gas in the gas reservoir, the pressure of the gas reservoir gradually decreases. At this time, the edge and bottom water will gradually invade the gas reservoir under the action of the pressure difference, and gradually push to the bottom of the production well to cause liquid accumulation at the bottom of the well, seriously damaging the gas well production capacity. A large amount of natural gas is retained underground, which seriously threatens the recovery rate of the gas reservoir. At this time, injecting carbon dioxide into the gas reservoir can effectively supplement the formation energy, thereby effectively inhibiting water invasion. In addition, the injected carbon dioxide can displace and replace the remaining natural gas in the formation, thereby effectively increasing the production of the remaining gas and improving the overall recovery rate of the gas reservoir. After injecting carbon dioxide into the formation, most of the carbon dioxide will be retained in the gas reservoir, thereby effectively realizing the storage of carbon dioxide. The currently disclosed technology still lacks physical simulation characterization technology for carbon dioxide displacement and storage in gas reservoirs.

[0003] At present, most of the existing natural gas reservoir simulations are mainly carried out on cores, and there is no simulation device and method for CO2 injection. For example, the disclosed invention patent CN202210563763.1 discloses a simulation experimental device based on step-by-step pressure reduction exploitation of gas reservoirs, which can carry out multiple small core experiments; another example is the invention patent CN202410051231.9, which discloses a microscopic visualization experimental device and method for inhibiting water invasion by injecting CO2 into high-temperature and high-pressure water-containing gas reservoirs. The experiment is carried out by replicating the pore structure of the core casting thin slice to prepare an etching model, and the water invasion inhibition process is studied from a two-dimensional plane perspective.

[0004] The existing technology is unable to characterize the planar and vertical morphology of water invasion when CO2 is injected into gas reservoirs to drive gas, and is unable to simultaneously describe the drive gas process and the storage process in a coordinated manner. Summary of the invention

[0005] The present invention provides a CO2 injection and flooding and storage simulation experimental device and method for natural gas reservoirs, aiming to realize the physical simulation of rigid water drive or elastic water drive development of natural gas reservoirs with edge water or bottom water, and the CO2 injection and flooding and storage simulation experiment in the middle and late stages of gas reservoir development through this experimental device. The device can monitor the resistivity changes at various points in the gas reservoir in real time, and obtain the water invasion morphology and dynamic change law of the gas reservoir through the resistivity change law. At the same time, the output gas components are measured and analyzed by a chromatograph, and combined with the real-time monitoring of the gas production rate, the degree of CO2 injection on the improvement of natural gas recovery and the storage volume after CO2 injection are quantified. Furthermore, through this experimental device, the well network layout can be optimized, the injection and production speed can be optimized, and the injection and production volume can be optimized, thereby providing production guidance for CO2 injection and flooding and storage in natural gas reservoirs.

[0006] To achieve the above-mentioned purpose, the natural gas reservoir CO2 injection and storage simulation experimental device provided by the present invention includes a bottom water natural gas reservoir physical simulation system, a production horizontal well system, a resistivity monitoring system, a metering analysis system, and a CO2 injection system;

[0007] The bottom water natural gas reservoir simulation system includes an ISCO pump, an intermediate container for holding simulated formation water and bottom water, a six-way valve, a pressure gauge, a simulated gas cylinder, a gas flow meter, a six-way valve, a pressure gauge, and a gas reservoir simulation device;

[0008] The production horizontal well system includes several laid production horizontal wells;

[0009] The resistivity monitoring system includes a computer, a resistivity sensor, and several resistivity monitoring probes;

[0010] The metering and analysis system includes two gas flow meters, three six-way valves, a produced water metering bottle, a balance, and a gas collection bag, wherein the number of metering and analysis systems is consistent with the number of production horizontal wells;

[0011] The CO2 injection system includes two ISCO pumps, two intermediate containers, four six-way valves, three pressure gauges, three gas flow meters, and injection horizontal wells.

[0012] Preferably, both the upper and lower ends of the intermediate container 1 and the intermediate container 2 have at least three-way interfaces, and the ISCO pump 1 and the ISCO pump 2 are connected to one end of the intermediate container 1 and the intermediate container 2 respectively through threads.

[0013] Preferably, there is at least a three-way valve at the outer bottom of the gas reservoir simulation device, the bottom of the gas reservoir simulation device, pressure gauge one and the other end of intermediate container one are threadedly connected through a six-way valve one, the bottom of the gas reservoir simulation device and gas flow meter one are threadedly connected through a three-way valve, and gas flow meter one, pressure gauge two and the other end of intermediate container two are threadedly connected through a six-way valve two.

[0014] Preferably, the production horizontal wellhead is connected to a metering and analysis system; the resistivity sensor is connected to a plurality of resistivity monitoring probes via electric wires, and the resistivity monitoring probes are placed on the inner bottom of the gas reservoir simulation device by welding.

[0015] Preferably, the gas reservoir simulation device is made of stainless steel, has a water supply grid at the bottom, and an end cover at the top, which is sealed by threads.

[0016] Preferably, suitable threaded holes are reserved in the upper end cover of the gas reservoir simulation device for the wires of the production horizontal well system and the resistivity monitoring system, and each hole is sealed with the corresponding component through threaded connection and rubber ring.

[0017] Preferably, in the CO2 injection system, the intermediate container 2, the pressure gauge 3, and the gas flow meter 3 are threadedly connected together through the six-way valve 4, and the gas flow meter 3 is threadedly connected to the injection horizontal well.

[0018] Preferably, each hole in contact with the filling sand is paved with a wire filter, the mesh number of the filter is greater than the maximum mesh number of the filling sand, to prevent the filling sand from entering the holes, thereby ensuring the normal use of each component.

[0019] The present invention also proposes a method for a natural gas reservoir CO2 injection, flooding and storage simulation experiment, which is applied to the above-mentioned natural gas reservoir CO2 injection, flooding and storage simulation experiment device, and comprises the following steps:

[0020] S1. Gas reservoir simulation sand filling:

[0021] In the gas reservoir simulation device, according to the original formation pressure of the gas reservoir of 35 MPa, a rigid development model of the bottom water gas reservoir was constructed by layered sand filling. The porosity of the sand body from top to bottom is φ1, φ2, φ3, and the thickness is h1, h2, h3, respectively, to match the porosity and permeability of the gas reservoir;

[0022] S2, sand body saturated fluid:

[0023] Use an intermediate container—through an ISCO pump—to inject simulated formation water at a flow rate of 2 ml / min until it reaches a saturation of 3 PV, then use a gas cylinder to inject simulated gas CH4 at a constant pressure of 30 MPa, record the base resistivity value ρw, monitor the water saturation until the irreducible water saturation Swor is reached, and keep the model constant pressure at 35 MPa;

[0024] S3. Depletion development of rigid bottom water gas reservoirs:

[0025] Maintain a pressure of 35 MPa using an ISCO pump, record gas production and resistivity values, and calculate the gas reservoir recovery factor ERt;

[0026] S4, injection of CO2 to drive gas:

[0027] When the production well starts to produce water, the production horizontal well system is closed, and CO2 is injected at a rate of 1 ml / min through ISCO pump 2 and gas flow meter 3 to monitor the suppression of water invasion during the CO2 injection process;

[0028] S5. Continue to open the well for production after CO2 injection:

[0029] Continue to record gas production, resistivity values, measure produced gas components, and calculate gas reservoir recovery and CO2 storage conditions;

[0030] S6. Draw a graph showing the recovery factor and resistivity at different times versus the cumulative gas production time.

[0031] Compared with the related art, the natural gas reservoir CO2 injection and storage simulation experimental device and method provided by the present invention has the following beneficial effects:

[0032] The present invention provides a natural gas reservoir CO2 injection, flooding and storage simulation experimental device and method:

[0033] 1. Water invasion law of bottom water gas reservoir development: This experimental device can realize the physical model simulation experiment of rigid water drive or elastic water drive development of bottom water natural gas reservoir. The device uses the resistivity monitoring device to monitor the resistivity changes of each point of the natural gas reservoir physical simulation device in real time, and the water invasion law of the gas reservoir is obtained through the resistivity change law;

[0034] 2. Effect of CO2 injection and CO2 burial: This experimental device simulates the exploitation for a period of time and then injects CO2 to continue the development. The chromatograph is used to measure and analyze the components of the produced gas to determine the effect of CO2 injection on the water flooding of the gas reservoir and the burial situation of the natural gas reservoir after CO2 injection.

[0035] 3. Optimization of horizontal well patterns: By arranging different horizontal well patterns, the corresponding water invasion law and recovery rate can be obtained. By comparing the experimental results, the best well pattern layout can be selected. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 A schematic diagram of a CO2 injection, flooding and storage simulation experimental device for a natural gas reservoir provided by the present invention;

[0037] Figure 2 This is a detailed diagram of the resistivity monitoring system;

[0038] Figure 3 This is a top view of the gas reservoir simulation system.

[0039] Numbers in the figure: 1. ISCO pump 1; 2. intermediate container 1; 3. six-way valve 1; 4. pressure gauge 1; 5. simulated gas cylinder; 6. gas flow meter 1; 7. six-way valve 2; 8. pressure gauge 2; 9. gas reservoir simulation device; 10. water supply grid; 11. end cover; 12. production horizontal well system; 13. computer; 14. resistivity sensor; 15. resistivity monitoring probe; 16. gas flow meter 2; 17. six-way valve 3; 18. produced water metering bottle; 19. balance; 20. gas collection bag; 21. ISCO pump 2; 22. intermediate container 2; 23. six-way valve 4; 24. pressure gauge 3; 25. gas flow meter 3; 26. injection horizontal well. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0041] Please refer to Figure 1-3 ,in, Figure 1 A schematic diagram of a CO2 injection, flooding and storage simulation experimental device for a natural gas reservoir provided by the present invention; Figure 2 This is a detailed diagram of the resistivity monitoring system; Figure 3 This is a top view of the gas reservoir simulation system.

[0042] The invention proposes a natural gas reservoir CO2 injection, gas displacement and storage simulation experimental device, comprising a bottom water natural gas reservoir physical simulation system, a production horizontal well system, a resistivity monitoring system, a metering and analysis system, and a CO2 injection system;

[0043] The bottom water natural gas reservoir simulation system includes an ISCO pump 1, an intermediate container for holding simulated formation water and bottom water 2, a six-way valve 3, a pressure gauge 4, a simulated gas cylinder 5, a gas flow meter 6, a six-way valve 7, a pressure gauge 8, and a gas reservoir simulation device 9;

[0044] The gas reservoir simulation device 9 is made of stainless steel, with a water supply grid 10 at the bottom and an end cover 11 at the top, which is sealed by threads;

[0045] The production horizontal well system 12 includes several laid production horizontal wells;

[0046] The resistivity monitoring system includes a computer 13, a resistivity sensor 14, and a plurality of resistivity monitoring probes 15;

[0047] The metering and analysis system includes a gas flow meter 2 16, a six-way valve 3 17, a produced water metering bottle 18, a balance 19, and a gas collection bag 20, wherein the number of the metering and analysis systems is consistent with the number of production horizontal wells;

[0048] The CO2 injection system includes an ISCO pump 21 , an intermediate container 22 , a six-way valve 4 23 , a pressure gauge 3 24 , a gas flow meter 3 25 , and an injection horizontal well 26 .

[0049] The connection method of the above-mentioned components is as follows: the upper and lower ends of the intermediate container 2 and the intermediate container 22 are both provided with at least three-way interfaces, and the ISCO pump 1 and the ISCO pump 21 are respectively connected to one end of the intermediate container 2 and the intermediate container 22 through threads; the outer bottom of the gas reservoir simulation device 9 is provided with at least a three-way valve, the bottom of the gas reservoir simulation device 9, the pressure gauge 4 and the other end of the intermediate container 2 are threadedly connected through a six-way valve 3, the bottom of the gas reservoir simulation device 9 and the gas flow meter 6 are threadedly connected through a three-way valve, and the gas flow meter 1 is connected to the gas reservoir simulation device 9 through a three-way valve. 6. The other end of the pressure gauge 28 and the intermediate container 22 are threadedly connected through a six-way valve 27; the production horizontal wellhead is connected to the metering and analysis system; the resistivity sensor 14 is connected to several resistivity monitoring probes 15 through wires, and the resistivity monitoring probes 15 are placed on the inner bottom of the gas reservoir simulation device 9 by welding; suitable threaded holes are reserved in the upper end cover 11 of the gas reservoir simulation device 9 for the wires of the production horizontal well system 12 and the resistivity monitoring system, and each hole is sealed with the corresponding components through threaded connections and rubber rings.

[0050] In the CO2 injection system, the intermediate container 22, the pressure gauge 3 24, and the gas flow meter 3 25 are threadedly connected together through the six-way valve 4 23, and the gas flow meter 3 25 is threadedly connected to the injection horizontal well 26.

[0051] One point that needs to be particularly emphasized is that a wire filter is laid on each hole that comes into contact with the filling sand. The mesh number of the filter is larger than the maximum mesh number of the filling sand to prevent the filling sand particles from entering the holes and ensure the normal use of each component.

[0052] In addition, the present invention also proposes a method for a natural gas reservoir CO2 injection and storage simulation experiment, comprising the following steps: (This embodiment takes a dry gas reservoir with rigid bottom water drive as an example, and the porosity and permeability of the model and the gas reservoir are kept consistent by filling sand, CH4 is used as the simulated gas, and formation water is used as the simulated water.)

[0053] 1) Gas reservoir simulation sand filling

[0054] Taking the rigid development of bottom water gas reservoir with original gas reservoir formation pressure of 35MPa as an example, the gas reservoir reservoir simulation device 9 is filled with sand in three layers, and the production horizontal well system 12 is laid at the designated position. Taking the five-point well pattern as an example (the middle is the injection horizontal well), the gas reservoir model is a rectangular parallelepiped with a cross-sectional area of ​​A (m). The porosity of the three layers of sand filling from top to bottom are The thickness from top to bottom are: h1, h2, h3 (m), and the pore volume is

[0055] 2) Sand body saturated fluid

[0056] ① Saturation of simulated formation water. Open the intermediate container 2, and use ISCO pump 1 to inject simulated formation water into the gas reservoir simulation device 9 through the bottom inlet of the gas reservoir simulation device 9 at a rate of 2 ml / min to saturate the gas reservoir simulation device 9. When the injection volume reaches 3 PV, stop the injection and close the bottom inlet of the gas reservoir simulation device 9;

[0057] ② Saturated simulated gas. Turn on the resistivity measurement system and measure a basic resistivity value ρ at each point before starting gas drive. w Open the production well system, gas flow meter 6, with a simulated gas cylinder 5 at a constant pressure of 30MP through the bottom inlet of the gas reservoir simulation device 9 to inject simulated gas into the gas reservoir simulation device 9, through the metering analysis system to record the production of the horizontal well system 12 of the liquid V iwt (i=1,2,3,4) and gas production V igt (i=1,2,3,4) until no water is produced, stop injection and close the outlet of the production horizontal well system. During the whole recording process, measure a group of resistivity values ​​ρ every 1 minute. wt , and calculate the corresponding water saturation S wt =(V p -ΣV iwt ) / V p *100, we can get the water saturation S wt The corresponding relationship with the resistivity profile. Finally, the bound water saturation S wor A set of resistance values ​​ρ is also measured wor Serves as the basic comparison profile for subsequent water invasion.

[0058] ③ The model maintains a constant pressure of 35 MPa. Use the simulated gas cylinder 5 to inject simulated gas into the gas reservoir simulation device 9 through the bottom inlet of the gas reservoir simulation device 9 at a constant pressure of 35 MPa, so that the model pressure is maintained at 35 MPa. The original formation pressure p i =35MPa.

[0059] 3) Depletion development of rigid bottom water gas reservoirs

[0060] ① Maintain the rigid bottom water gas reservoir depletion development at 35 MPa pressure through ISCO pump-1, open the outlet of the production horizontal well system 12, record the cumulative production time t, gas production VJCH4t (j = 1, 2, 3, 4), and the resistivity value ρt of each resistivity monitoring point;

[0061] ② Calculate the gas reservoir recovery rate at different times t

[0062] Original geological reserves:

[0063] Among them, S gi =1-S wor , Bgi =3.447*10 -4 *(Z*T) / p i , T = 273.15 + 25 = 298.15K, Z is the natural gas deviation factor.

[0064] Recovery rate:

[0065] 4) CO2 injection

[0066] ① When the balance shows a digital display, it means that the production well starts to produce water, and CO2 injection starts at this time. Close the production horizontal well system 12, turn on the gas flow meter 3 25 and ISCO pump 2 21 to inject a volume of V through the injection horizontal well 26 at 1 ml / min. CO2in After the CO2 gas is injected, all the above devices are closed. During the injection process, a group of resistivity values ​​are measured every 1 minute to obtain the three-dimensional resistivity profile at the corresponding moment to observe the suppression of water invasion during the CO2 injection process.

[0067] 5) Continue to open the well for production after CO2 injection

[0068] ①Open the outlet of the production horizontal well system 12 and continue to record the cumulative production time t and gas production V jg1t , Resistivity monitoring resistivity value ρ at each point it ;

[0069] ② The gas production of the four production wells at different times was obtained through the gas collection bag every 5 minutes, and the gas production components were measured using a chromatograph. The CO2 component values ​​at different times were recorded as H CO2jt , the CH4 component value at different times is recorded as H CH4jt , we can get the coordinate point set of the CO2 and CH4 component values ​​of the four production wells at different times. Through interpolation processing, we can get the smooth curve of the two components changing with time, and get the component values ​​of the two gases at any time. Through integration, we can get the cumulative CO2 volume V of the four production wells at different times after CO2 injection. CO2jt , cumulative CH4 output volume V 1CH4jt .

[0070] ③ Calculate the gas reservoir recovery rate at different times t

[0071]

[0072] ④Stop production until gas stops being produced.

[0073] ⑤ Calculate the storage of CO2

[0074] The final cumulative CO2 volume V produced by the four production wells is obtained by integration CO2j

[0075] The storage volume of CO2 is:

[0076] 6) Draw the recovery rate and resistivity at different times versus cumulative gas production time

[0077] Draw the full life cycle production dynamic curve of the rigid bottom water gas reservoir simulation device 9, draw the water invasion profile, analyze the changing law of water invasion in the rigid development of bottom water gas reservoirs, and clarify the inhibitory effect of CO2 injection on water invasion and the CO2 storage situation.

[0078] Immune water saturation S wor The resistance value ρ measured at wor As the basic comparison profile for subsequent water invasion, when water invasion begins to occur in a certain part, the resistivity value measured at the resistivity measurement point will increase significantly, so as to judge the occurrence of water invasion. If the resistivity value of the water invaded part becomes significantly lower before, during and after the subsequent CO2 injection, the effect of CO2 injection on water invasion suppression can be known.

[0079] The resistivity points can be changed according to the experimental needs. The resistivity changes are reflected by the values ​​measured at each resistivity point at different times in the horizontal and vertical directions to obtain a three-dimensional resistivity profile.

[0080] ISCO pump 21 can inject CO2 of different pressures and volumes into injection well 26 through intermediate container 1 to carry out control experiments.

[0081] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A simulation experimental device for injecting CO2 into a natural gas reservoir and storing it, characterized in that: Including bottom water natural gas reservoir physical simulation system, production horizontal well system, resistivity monitoring system, measurement and analysis system, CO2 injection system; The bottom water natural gas reservoir simulation system includes an ISCO pump (1), an intermediate container (2) for containing simulated formation water and bottom water, a six-way valve (3), a pressure gauge (4), a simulated gas cylinder (5), a gas flow meter (6), a six-way valve (7), a pressure gauge (8), and a gas reservoir simulation device (9); The production horizontal well system (12) includes a plurality of laid production horizontal wells; The resistivity monitoring system includes a computer (13), a resistivity sensor (14), and a plurality of resistivity monitoring probes (15); The metering and analysis system includes two gas flow meters (16), three six-way valves (17), a produced water metering bottle (18), a balance (19), and a gas collection bag (20), wherein the number of the metering and analysis systems is consistent with the number of production horizontal wells; The CO2 injection system includes two ISCO pumps (21), two intermediate containers (22), four six-way valves (23), three pressure gauges (24), three gas flow meters (25), and injection horizontal wells (2)(6).

2. The CO2 injection and storage simulation experimental device for natural gas reservoirs according to claim 1 is characterized in that: The intermediate container 1 (2) and the intermediate container 2 (22) have at least three-way interfaces at both upper and lower ends, and the ISCO pump 1 (1) and the ISCO pump 2 (21) are connected to one end of the intermediate container 1 (2) and the intermediate container 2 (22) respectively through threads.

3. The CO2 injection and storage simulation experimental device for natural gas reservoirs according to claim 1 is characterized in that: The outer bottom of the gas reservoir simulation device (9) is provided with at least a three-way valve, the bottom of the gas reservoir simulation device (9), the pressure gauge 1 (4) and the other end of the intermediate container 1 (2) are threadedly connected via a six-way valve 1 (3), the bottom of the gas reservoir simulation device (9) and the gas flow meter 1 (6) are threadedly connected via a three-way valve, and the gas flow meter 1 (6), the pressure gauge 2 (8) and the other end of the intermediate container 2 (22) are threadedly connected via a six-way valve 2 (7).

4. The CO2 injection and storage simulation experimental device for natural gas reservoirs according to claim 1 is characterized in that: The production horizontal wellhead is connected to a metering and analysis system; the resistivity sensor (14) is connected to a plurality of resistivity monitoring probes (15) via electric wires, and the resistivity monitoring probes (15) are placed on the inner bottom of the gas reservoir simulation device (9) by welding.

5. The CO2 injection and storage simulation experimental device for natural gas reservoirs according to claim 1 is characterized in that: The gas reservoir simulation device (9) is made of stainless steel, has a water supply grid (10) at the bottom, and an end cover (11) at the top, which is sealed by threads.

6. The CO2 injection and storage simulation experimental device for natural gas reservoirs according to claim 1 is characterized in that: The upper end cover (11) of the gas reservoir simulation device (9) has suitable threaded holes for the wires of the production horizontal well system (12) and the resistivity monitoring system, and each hole is sealed with the corresponding component through threaded connection and rubber ring.

7. The CO2 injection and storage simulation experimental device for natural gas reservoirs according to claim 1 is characterized in that: In the CO2 injection system, the intermediate container 2 (22), the pressure gauge 3 (24), and the gas flow meter 3 (25) are threadedly connected together via the six-way valve 4 (23), and the gas flow meter 3 (25) is threadedly connected to the injection horizontal well (26).

8. The CO2 injection and storage simulation experimental device for natural gas reservoirs according to claim 1 is characterized in that: A wire filter is laid on each hole in contact with the filling sand. The mesh number of the filter is larger than the maximum mesh number of the filling sand to prevent the filling sand from entering the holes and ensure the normal use of each component.

9. A method for a simulation experiment of CO2 injection, flooding and storage in a natural gas reservoir, characterized in that: The method is applied to the natural gas reservoir CO2 injection, flooding and storage simulation experimental device described in claims 1 to 8, and the method comprises the following steps: S1. Gas reservoir simulation sand filling: In the gas reservoir simulation device, according to the original formation pressure of the gas reservoir of 35 MPa, a rigid development model of the bottom water gas reservoir was constructed by layered sand filling. The porosity of the sand body from top to bottom is φ1, φ2, φ3, and the thickness is h1, h2, h3, respectively, to match the porosity and permeability of the gas reservoir; S2, sand body saturated fluid: Use intermediate container 1 to inject simulated formation water at a flow rate of 2 ml / min through an ISCO pump until the saturation reaches 3PV, then use a gas cylinder to inject simulated gas CH4 at a constant pressure of 30 MPa, record the basic resistivity value ρw, monitor the water saturation until the irreducible water saturation Swor is reached, and keep the model constant pressure at 35 MPa; S3. Depletion development of rigid bottom water gas reservoirs: Maintain a pressure of 35 MPa using an ISCO pump, record gas production and resistivity values, and calculate the gas reservoir recovery factor ERt; S4, injection of CO2 to drive gas: When the production wells start to produce water, the production horizontal well system is closed, and CO2 is injected at a rate of 1 ml / min through the ISCO pump and gas flow meter 3 to monitor the suppression of water invasion during the CO2 injection process; S5. Continue to open the well for production after CO2 injection: Continue to record gas production, resistivity values, measure produced gas components, and calculate gas reservoir recovery and CO2 storage conditions; S6. Draw a graph showing the recovery factor and resistivity at different times versus the cumulative gas production time.

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