A device and method for calculating the change of CO2 storage volume before and after reservoir drying

Abstract

The present invention discloses a device and method for calculating the change of CO2 storage volume before and after the reservoir is dried up, and the method comprises the following steps: S1: obtaining a target layer core, and preparing a formation water sample and a CO2 gas sample; S2: measuring the saturated condensate water content of the CO2 gas sample under the target formation condition; S3: saturating the target layer core with formation water; S4: performing a displacement experiment until the water saturation of the target layer core reaches the actual formation bound water saturation, and recording the core porosity #imgabs0# at this time; S5: continuing the displacement experiment until the formation water in the target layer core is completely evaporated, and recording the core porosity #imgabs1# at this time; S6: calculating the drying radius of the reservoir and the change of CO2 storage volume after the reservoir is dried up. The present invention can determine the drying radius of the reservoir and the change of CO2 storage volume after the reservoir is dried up, provide more accurate storage volume parameters for the geological storage of CO2, and utilize CO2 more efficiently.

Description

[0001] This application claims the priority of Chinese patent application No. 202310787606.3 filed on June 30, 2023, and entitled “A device and method for calculating the change in CO2 storage volume before and after reservoir drying”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present invention relates to the technical field of CO2 geological storage, and in particular to a device and method for calculating the change in CO2 storage amount before and after reservoir drying. Background Art

[0003] With the continuous progress of society, the level of energy consumption continues to increase. The consumption of fossil fuels such as coal, oil and natural gas is increasing, which increases carbon dioxide emissions and accelerates the global greenhouse effect. At present, my country's energy consumption structure is still dominated by coal. In order to cope with global warming, CO2 storage is one of the most direct and effective ways to promote the development of low-carbon emission reduction technology.

[0004] The main geological sites for storage include: depleted oil and gas reservoirs, deep saline water layers, and coal seams that are difficult to mine. Among them, the storage of depleted oil and gas reservoirs is widely used, and pilot tests have been carried out in mines. A large number of domestic and foreign literature also shows that injecting CO2 into the formation can not only improve the greenhouse effect through storage, but also improve the later recovery rate of oil and gas reservoirs and increase the economic benefits of oil fields. It has certain economic value and huge ecological and environmental benefits.

[0005] During the process of CO2 injection into the formation, the continuous evaporation of formation water by the injected dry CO2 will lead to an increase in the CO2 storage capacity, while the salt crystals left after the evaporation of formation water will reduce the CO2 storage capacity. Therefore, a method is urgently needed to comprehensively evaluate the impact of formation water evaporation and salt deposition on the CO2 storage capacity, so as to facilitate timely adjustment of parameters in the subsequent CO2 storage scheme design, which is conducive to efficient construction on site and effective storage of CO2. Summary of the invention

[0006] In view of the above problems, the present invention aims to provide a device and method for calculating the change in CO2 storage volume before and after reservoir drying.

[0007] The technical solution of the present invention is as follows:

[0008] In one aspect, a method for calculating the change in CO2 storage before and after reservoir drying is provided, comprising the following steps:

[0009] S1: Obtain the target layer core and prepare formation water samples and CO2 gas samples;

[0010] S2: under target formation conditions, mixing the formation water sample and the CO2 gas sample, and measuring the saturated condensate water content of the CO2 gas sample;

[0011] S3: placing the target layer core in a core holder, and saturating the core with formation water using the formation water sample;

[0012] S4: Under the target formation conditions, the CO2 gas sample is used to conduct a displacement experiment until the water saturation of the target layer core reaches the actual formation bound water saturation, the target layer core is taken out and the core porosity at this time is recorded. ;

[0013] S5: Place the target layer core in the core holder, continue to use the CO2 gas sample to perform displacement experiments until the formation water in the target layer core is completely evaporated, take out the target layer core and record the core porosity at this time ;

[0014] S6: Calculate the desiccation radius of the reservoir and the change in CO2 storage after the reservoir desiccates.

[0015] Preferably, when measuring the saturated condensate water content of the CO2 gas sample, the mixed sample is first passed into a condensation device, then the mass of condensate water in the condensation device and the volume of CO2 gas output from the condensation device are recorded, and finally the saturated condensate water content of the CO2 gas sample is calculated based on the obtained parameters.

[0016] Preferably, the saturated condensate water content of the CO2 gas sample is calculated by the following formula:

[0017] (1)

[0018] Where: ω is the saturated condensate water content of the CO2 gas sample under the target formation conditions, kg / m 3 ; M1 is the mass of condensate water in the condensation device, kg; G1 is the volume of CO2 gas output from the condensation device, m 3 .

[0019] Preferably, in step S6, the desiccation radius of the reservoir is calculated by the following formula:

[0020] (2)

[0021] Where: R0 is the desiccation radius of the reservoir, m; Q is the volume of CO2 injected into the formation, m 3 ; ω is the saturated condensate water content of CO2 gas sample under target formation conditions, kg / m 3 ; It is dimensionless to consider the core porosity after CO2 drying under salt deposition conditions; is the core porosity under irreducible water saturation conditions, dimensionless; R1 is the wellbore radius, m; h is the effective thickness of the reservoir, m; ρ 纯水 is the density of pure water, kg / m 3 ; ρ0 is the density of the formation water sample, kg / m 3 .

[0022] Preferably, in step S6, the change in CO2 storage after the reservoir is dried is calculated by the following formula:

[0023] (3)

[0024] Where: V is the increase in CO2 storage after reservoir drying, m 3 ; Z1 is the deviation coefficient under ground conditions, dimensionless; T1 is the temperature under ground conditions, K; P2 is the pressure under target formation conditions, MPa; P1 is the pressure under ground conditions, MPa; Z2 is the deviation coefficient under target formation conditions, dimensionless; T2 is the temperature under target formation conditions, K.

[0025] As a preferred method, a new displacement device is used to determine the change in CO2 storage before and after reservoir drying;

[0026] The novel displacement device comprises a displacement pump 1, a displacement pump 2, an intermediate container 1, an intermediate container 2, a core holder, a confining pressure pump, a gas recovery device 1, a gas recovery device 2, a condensation device and a fluid sample preparation device;

[0027] The intermediate container 1 and the intermediate container 2 are arranged in parallel, and are used to store the formation water sample and the CO2 gas sample respectively; the input ends of the two intermediate containers are connected to the displacement pump 1, and the output ends of the two intermediate containers are connected to the inlet end of the core clamp through pipeline 1, and a valve 1 is provided between the intermediate container 1 and the pipeline 1, and a valve 2 is provided between the intermediate container 2 and the pipeline 1, and a valve 3 and a pressure sensor 1 are provided on the pipeline 1 in sequence; the output ends of the two intermediate containers are also connected to the fluid sampling device through pipeline 2, and a valve 4 and a pressure sensor 2 are provided on the pipeline 2 in sequence; the pipeline 2 between the valve 4 and the pressure sensor 2 is also connected to the condensing device, and a valve 5 is provided on the connected pipeline, and the output end of the condensing device is connected to the gas recovery device 1, and a gas flowmeter 1 is provided on the connected pipeline; the fluid sampling device is also connected to the displacement pump 2, and a valve 6 is provided on the connected pipeline;

[0028] The side of the core holder is connected to the confining pressure pump, and a valve 7 is provided on the connected pipeline;

[0029] The output end of the core clamp is connected to the second gas recovery device, and a third pressure sensor, a back pressure valve, and a second gas flow meter are sequentially arranged on the connected pipeline.

[0030] Preferably, a pressure reducing valve is provided between the second intermediate container and the second valve.

[0031] On the other hand, a device for calculating the change in CO2 storage before and after the reservoir is dried up is provided, which is used in any of the above methods for calculating the change in CO2 storage before and after the reservoir is dried up, and the device comprises a displacement pump 1, a displacement pump 2, an intermediate container 1, an intermediate container 2, a core holder, a confining pressure pump, a gas recovery device 1, a gas recovery device 2, a condensing device and a fluid sampling device;

[0032] The intermediate container 1 and the intermediate container 2 are arranged in parallel, and are used to store the formation water sample and the CO2 gas sample respectively; the input ends of the two intermediate containers are connected to the displacement pump 1, and the output ends of the two intermediate containers are connected to the inlet end of the core clamp through pipeline 1, and a valve 1 is provided between the intermediate container 1 and the pipeline 1, and a valve 2 is provided between the intermediate container 2 and the pipeline 1, and a valve 3 and a pressure sensor 1 are provided on the pipeline 1 in sequence; the output ends of the two intermediate containers are also connected to the fluid sampling device through pipeline 2, and a valve 4 and a pressure sensor 2 are provided on the pipeline 2 in sequence; the pipeline 2 between the valve 4 and the pressure sensor 2 is also connected to the condensing device, and a valve 5 is provided on the connected pipeline, and the output end of the condensing device is connected to the gas recovery device 1, and a gas flowmeter 1 is provided on the connected pipeline; the fluid sampling device is also connected to the displacement pump 2, and a valve 6 is provided on the connected pipeline;

[0033] The side of the core holder is connected to the confining pressure pump, and a valve 7 is provided on the connected pipeline;

[0034] The output end of the core clamp is connected to the second gas recovery device, and a third pressure sensor, a back pressure valve, and a second gas flow meter are sequentially arranged on the connected pipeline.

[0035] The beneficial effects of the present invention are:

[0036] The present invention takes into account the impact of salt analysis during formation water evaporation on the CO2 storage capacity, and for the first time proposes to determine the increase in CO2 storage caused by formation water evaporation during CO2 geological storage based on the reservoir drying principle. It can provide more accurate storage capacity parameters for CO2 geological storage, so as to adjust the construction plan and utilize CO2 more efficiently.

[0037] In addition to being used to calculate the change in CO2 storage before and after reservoir drying, the present invention can also be extended to calculate the change in storage capacity caused by the drying effect of gas on reservoirs in underground natural gas storage, underground hydrogen storage, and gas reservoir development, and has wide application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0039] Figure 1 It is a structural schematic diagram of a novel displacement device according to a specific embodiment;

[0040] Figure 2 It is a schematic diagram of the calculation result of the desiccation radius of a reservoir in a specific embodiment;

[0041] Figure 3 This is a schematic diagram of the calculation results of the change in CO2 storage after reservoir drying out, according to a specific embodiment.

[0042] Numbers in the figure: 1-displacement pump 1, 2-displacement pump 2, 3-intermediate container 1, 4-intermediate container 2, 5-core clamp, 6-confining pressure pump, 7-gas recovery device 1, 8-gas recovery device 2, 9-condensation device, 10-fluid sampling device, 11-pressure sensor 1, 12-pressure sensor 2, 13-gas flow meter 1, 14-pressure sensor 3, 15-back pressure valve, 16-gas flow meter 2, 17-pressure reducing valve, A-valve 1, B-valve 2, C-valve 3, D-valve 4, E-valve 5, F-valve 6, G-valve 7. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with the accompanying drawings and embodiments. It should be noted that, in the absence of conflict, the embodiments in this application and the technical features in the embodiments can be combined with each other. It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as those generally understood by those of ordinary skill in the art to which this application belongs. The words "including" or "comprising" and the like used in the disclosure of the present invention mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0044] The present invention provides a method for calculating the change in CO2 storage before and after reservoir drying, comprising the following steps:

[0045] S1: Obtain the target layer core and prepare formation water samples and CO2 gas samples.

[0046] S2: Under target formation conditions, the formation water sample and the CO2 gas sample are mixed, and the saturated condensate water content of the CO2 gas sample is measured.

[0047] In a specific embodiment, when measuring the saturated condensate water content of the CO2 gas sample, the mixed sample is first passed into a condensation device, and then the mass of the condensate water in the condensation device and the volume of the CO2 gas output from the condensation device are recorded, and finally the saturated condensate water content of the CO2 gas sample is calculated based on the obtained parameters; the saturated condensate water content of the CO2 gas sample is calculated by the following formula:

[0048] (1)

[0049] Where: ω is the saturated condensate water content of the CO2 gas sample under the target formation conditions, kg / m 3 ; M1 is the mass of condensate water in the condensation device, kg; G1 is the volume of CO2 gas output from the condensation device, m 3 .

[0050] S3: placing the target layer core in a core holder, and saturating it with formation water using the formation water sample.

[0051] S4: Under the target formation conditions, the CO2 gas sample is used to conduct a displacement experiment until the water saturation of the target layer core reaches the actual formation bound water saturation, the target layer core is taken out and the core porosity at this time is recorded. .

[0052] S5: Place the target layer core in the core holder, continue to use the CO2 gas sample to perform displacement experiments until the formation water in the target layer core is completely evaporated, take out the target layer core and record the core porosity at this time .

[0053] S6: Calculate the desiccation radius of the reservoir and the change in CO2 storage after the reservoir desiccates.

[0054] In a specific embodiment, the desiccation radius of the reservoir is calculated by the following formula:

[0055] (2)

[0056] Where: R0 is the desiccation radius of the reservoir, m; Q is the volume of CO2 injected into the formation, m 3 ; ω is the saturated condensate water content of CO2 gas sample under target formation conditions, kg / m3 ; It is dimensionless to consider the core porosity after CO2 drying under salt deposition conditions; is the core porosity under irreducible water saturation conditions, dimensionless; R1 is the wellbore radius, m; h is the effective thickness of the reservoir, m; ρ 纯水 is the density of pure water, kg / m 3 ; ρ0 is the density of the formation water sample, kg / m 3 .

[0057] The change in CO2 storage after the reservoir is dried is calculated by the following formula:

[0058] (3)

[0059] Where: V is the increase in CO2 storage after reservoir drying, m 3 ; Z1 is the deviation coefficient under ground conditions, dimensionless; T1 is the temperature under ground conditions, K; P2 is the pressure under target formation conditions, MPa; P1 is the pressure under ground conditions, MPa; Z2 is the deviation coefficient under target formation conditions, dimensionless; T2 is the temperature under target formation conditions, K.

[0060] In a specific embodiment, a new displacement device is used to determine the change in CO2 storage before and after the reservoir is dried; the new displacement device includes a displacement pump 1, a displacement pump 2, an intermediate container 3, an intermediate container 4, a core holder 5, a confining pressure pump 6, a gas recovery device 1 7, a gas recovery device 2 8, a condensation device 9 and a fluid sampling device 10;

[0061] The intermediate container 1 3 and the intermediate container 2 4 are arranged in parallel, and are used to store the formation water sample and the CO2 gas sample respectively; the input ends of the two intermediate containers are connected to the displacement pump 1, and the output ends of the two intermediate containers are connected to the inlet end of the core clamp 5 through pipeline 1, and a valve 1 A is provided between the intermediate container 1 3 and the pipeline 1, and a valve 2 B is provided between the intermediate container 2 4 and the pipeline 1, and a valve 3 C and a pressure sensor 1 11 are provided on the pipeline 1 in sequence; the output ends of the two intermediate containers are also connected to the fluid sample preparation device 10 through pipeline 2, and a valve 4 D and a pressure sensor 2 12 are provided on the pipeline 2 in sequence; the pipeline 2 between the valve 4 D and the pressure sensor 2 12 is also connected to the condensation device 9, and a valve 5 E is provided on the connected pipeline, and the output end of the condensation device 9 is connected to the gas recovery device 1 7, and a gas flowmeter 13 is provided on the connected pipeline; the fluid sample preparation device 10 is also connected to the displacement pump 2 2, and a valve 6 F is provided on the connected pipeline;

[0062] The side of the core holder 5 is connected to the confining pressure pump 6, and a valve 7G is provided on the connected pipeline;

[0063] The output end of the core holder 5 is connected to the second gas recovery device 8, and a pressure sensor 3 14, a back pressure valve 15, and a second gas flow meter 16 are sequentially arranged on the connected pipeline.

[0064] Optionally, a pressure reducing valve 17 is further provided between the intermediate container 2 4 and the valve 2 B.

[0065] In the above embodiment, the device required for measuring the saturated condensate water content of the CO2 gas sample in step S2 and the device required for the subsequent displacement experiment are combined together, so that only one device is needed to complete the experiment, and the operation is more convenient. It should be noted that the saturated condensate water content of the CO2 gas sample can also be measured separately, and then other displacement devices in the prior art are used to perform the displacement experiment.

[0066] Taking the W gas field as an example, the method for calculating the change in CO2 storage before and after reservoir drying of the present invention is used to determine the change in CO2 storage before and after the reservoir drying of the target reservoir of the gas field, which specifically includes the following steps:

[0067] (1) Obtain the target layer core and prepare formation water samples and CO2 gas samples; in this embodiment, the basic parameters of the target layer core are shown in Table 1:

[0068] Table 1 Basic parameters of target layer cores

[0069]

[0070] (2) Place the formation water sample into the intermediate container 1, place the CO2 gas sample into the intermediate container 2, and place the target layer core into the core holder;

[0071] (3) Measuring the saturated condensate content in CO2 under target formation conditions;

[0072] Open valve 1A, valve 2B, and valve 4D, and inject excess formation water sample and CO2 gas sample into the fluid sample preparation device 10. The temperature and pressure of the fluid sample preparation device 10 are set to the target formation conditions (128°C, 30MPa). After stirring for 2 hours, the part where the CO2 gas is located is facing upward, and valve 5E is opened to allow the gas to pass through the condensation device 9 at a speed of 50mL / min. The condensate water content in the condensation device 9 is recorded as 8.9g, and the volume of CO2 passing through the gas flow meter 13 is 1.33m 3 The saturated condensate water content of CO2 under formation temperature and pressure conditions is calculated by formula (1) to be 6.7 g / m 3 ;

[0073] (4) Measure the impact of formation water evaporation on reservoir properties under the consideration of salt deposition;

[0074] Open valve 1A, valve 3C, and back pressure valve 15, and use the formation water in the intermediate container 1 to saturate the core; close valve 1A, open valve 2B, and use the CO2 gas sample in the intermediate container 2 to displace the core at a rate of 5mL / min until the water saturation reaches the actual formation bound water saturation, and take out the core to measure its porosity under the condition of bound water saturation. 0.0931; then the core was continuously displaced with CO2 gas sample for 4 hours until all the formation water in the core evaporated. The core was taken out and the porosity of the core after CO2 drying under salt deposition conditions was measured. is 0.1476;

[0075] (5) Calculate the desiccation radius of the reservoir and the change in CO2 storage after the reservoir desiccates;

[0076] In this example, the wellbore radius is 10 cm, the effective thickness of the reservoir is 1350 cm, the ground temperature is 20 ° C, the ground pressure is 0.1 MPa, the deviation coefficient under ground conditions is 0.9964, the deviation coefficient under formation conditions is 0.7055, and the formation water density is 1.18 g / cm 3 The desiccation radius of the reservoir and the change in CO2 storage after desiccation are calculated by equations (2) and (3) as shown in Table 2. Figure 2 and Figure 3 shown.

[0077] Table 2 Reservoir desiccation radius and CO2 storage capacity changes after reservoir desiccation

[0078]

[0079] In summary, the present invention takes into account the influence of formation water evaporation and salt formation on CO2 storage capacity, and can more accurately calculate CO2 storage capacity. Compared with the prior art, the present invention has significant progress.

[0080] The above description is only a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A method for calculating the change in CO2 storage before and after reservoir drying, characterized in that: The following steps are involved: S1: Obtain the target layer core and prepare formation water samples and CO2 gas samples; S2: under target formation conditions, mixing the formation water sample and the CO2 gas sample, and measuring the saturated condensate water content of the CO2 gas sample; S3: placing the target layer core in a core holder, and saturating the core with formation water using the formation water sample; S4: Under the target formation conditions, the CO2 gas sample is used to conduct a displacement experiment until the water saturation of the target layer core reaches the actual formation bound water saturation, the target layer core is taken out and the core porosity at this time is recorded. ; S5: Place the target layer core in the core holder, continue to use the CO2 gas sample to perform displacement experiments until the formation water in the target layer core is completely evaporated, take out the target layer core and record the core porosity at this time ; S6: Calculate the desiccation radius of the reservoir and the change in CO2 storage after the reservoir desiccation; The desiccation radius of the reservoir is calculated by the following formula: （2） Where: R0 is the desiccation radius of the reservoir, m; Q is the volume of CO2 injected into the formation, m 3 ; ω is the saturated condensate water content of CO2 gas sample under target formation conditions, kg / m 3 ; It is dimensionless to consider the core porosity after CO2 drying under salt deposition conditions; is the core porosity under irreducible water saturation conditions, dimensionless; R1 is the wellbore radius, m; h is the effective thickness of the reservoir, m; ρ 纯水 is the density of pure water, kg / m 3 ; ρ0 is the density of the formation water sample, kg / m 3 ; The change in CO2 storage after the reservoir is dried is calculated by the following formula: （3） Where: V is the increase in CO2 storage after reservoir drying, m 3 ; Z1 is the deviation coefficient under ground conditions, dimensionless; T1 is the temperature under surface conditions, K; P2 is the pressure under target formation conditions, MPa; P1 is the pressure under surface conditions, MPa; Z2 is the deviation coefficient under target formation conditions, dimensionless; T2 is the temperature under target formation conditions, K.

2. The method for calculating the change in CO2 storage before and after reservoir drying according to claim 1 is characterized in that: In step S2, when measuring the saturated condensate water content of the CO2 gas sample, the mixed sample is first passed into a condensation device, and then the mass of the condensate water in the condensation device and the volume of CO2 gas output from the condensation device are recorded, and finally the saturated condensate water content of the CO2 gas sample is calculated based on the obtained parameters.

3. The method for calculating the change in CO2 storage before and after reservoir drying according to claim 2, characterized in that: The saturated condensate water content of the CO2 gas sample is calculated by the following formula: （1） Where: ω is the saturated condensate water content of the CO2 gas sample under the target formation conditions, kg / m 3 ; M1 is the mass of condensate water in the condensation device, kg; G1 is the volume of CO2 gas output from the condensation device, m 3 .

4. The method for calculating the change in CO2 storage before and after reservoir drying according to any one of claims 1 to 3, characterized in that: A new displacement device was used to determine the change in CO2 storage before and after reservoir drying; The novel displacement device comprises a displacement pump 1, a displacement pump 2, an intermediate container 1, an intermediate container 2, a core holder, a confining pressure pump, a gas recovery device 1, a gas recovery device 2, a condensation device and a fluid sample preparation device; The intermediate container 1 and the intermediate container 2 are arranged in parallel, and are used to store the formation water sample and the CO2 gas sample respectively; the input ends of the two intermediate containers are connected to the displacement pump 1, and the output ends of the two intermediate containers are connected to the inlet end of the core clamp through pipeline 1, and a valve 1 is provided between the intermediate container 1 and the pipeline 1, and a valve 2 is provided between the intermediate container 2 and the pipeline 1, and a valve 3 and a pressure sensor 1 are provided on the pipeline 1 in sequence; the output ends of the two intermediate containers are also connected to the fluid sampling device through pipeline 2, and a valve 4 and a pressure sensor 2 are provided on the pipeline 2 in sequence; the pipeline 2 between the valve 4 and the pressure sensor 2 is also connected to the condensing device, and a valve 5 is provided on the connected pipeline, and the output end of the condensing device is connected to the gas recovery device 1, and a gas flowmeter 1 is provided on the connected pipeline; the fluid sampling device is also connected to the displacement pump 2, and a valve 6 is provided on the connected pipeline; The side of the core holder is connected to the confining pressure pump, and a valve 7 is provided on the connected pipeline; The output end of the core clamp is connected to the second gas recovery device, and a third pressure sensor, a back pressure valve, and a second gas flow meter are sequentially arranged on the connected pipeline.

5. The method for calculating the change in CO2 storage before and after reservoir drying according to claim 4 is characterized in that: A pressure reducing valve is also provided between the second intermediate container and the second valve.

6. A device for calculating the change in CO2 storage before and after reservoir drying, characterized in that: A method for calculating the change in CO2 storage before and after reservoir drying as described in any one of claims 1 to 5, wherein the device comprises a displacement pump 1, a displacement pump 2, an intermediate container 1, an intermediate container 2, a core holder, a confining pressure pump, a gas recovery device 1, a gas recovery device 2, a condensing device and a fluid sampling device; The intermediate container 1 and the intermediate container 2 are arranged in parallel, and are used to store the formation water sample and the CO2 gas sample respectively; the input ends of the two intermediate containers are connected to the displacement pump 1, and the output ends of the two intermediate containers are connected to the inlet end of the core clamp through pipeline 1, and a valve 1 is provided between the intermediate container 1 and the pipeline 1, and a valve 2 is provided between the intermediate container 2 and the pipeline 1, and a valve 3 and a pressure sensor 1 are provided on the pipeline 1 in sequence; the output ends of the two intermediate containers are also connected to the fluid sampling device through pipeline 2, and a valve 4 and a pressure sensor 2 are provided on the pipeline 2 in sequence; the pipeline 2 between the valve 4 and the pressure sensor 2 is also connected to the condensing device, and a valve 5 is provided on the connected pipeline, and the output end of the condensing device is connected to the gas recovery device 1, and a gas flowmeter 1 is provided on the connected pipeline; the fluid sampling device is also connected to the displacement pump 2, and a valve 6 is provided on the connected pipeline; The side of the core holder is connected to the confining pressure pump, and a valve 7 is provided on the connected pipeline; The output end of the core clamp is connected to the second gas recovery device, and a third pressure sensor, a back pressure valve, and a second gas flow meter are sequentially arranged on the connected pipeline.

7. The device for calculating the change in CO2 storage before and after reservoir drying according to claim 6, characterized in that: A pressure reducing valve is also provided between the second intermediate container and the second valve.

Images