A method for characterizing the degree of solid particle shedding and migration process in carbon dioxide sequestration.

Abstract

This invention belongs to the field of carbon dioxide geological storage and discloses a method for characterizing the degree of solid particle detachment and migration process during carbon dioxide storage. The method includes constructing a detachment-migration model based on the detachment of solid particles from the formation solid skeleton and the migration behavior of detached solid particles during carbon dioxide storage; constructing an initial reservoir model of the target carbon dioxide storage area based on the geological conditions of the carbon dioxide storage area and the field conditions, setting initial and boundary conditions, and performing mesh generation to obtain an initial reservoir mesh model; inputting the initial reservoir mesh model into the detachment-migration model to obtain the detachment amount and detachment rate of solid particles from the formation solid skeleton, and characterizing the degree of detachment and migration process of detached solid particles during carbon dioxide storage using the detachment amount and detachment rate. This invention enables effective analysis and prediction of the detachment and migration process of formation skeleton particles during injection.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide geological storage, and specifically discloses a method for characterizing the degree of solid particle detachment and migration process in carbon dioxide storage. Background Technology

[0002] Carbon sequestration (CFS) technology refers to the long-term storage of carbon dioxide in the biosphere, underground structures, or oceans to reduce the amount of carbon dioxide in the atmosphere. Storage in underground structures is also known as geological sequestration. Existing research has identified three main types of geological sequestration sites: saline aquifers, depleted oil and gas reservoirs, and coal seams. Among these three types, saline aquifers, due to their high water content, high permeability, and widespread distribution worldwide, have become the most promising sequestration sites. Currently, the United States, Japan, Norway, and other countries have conducted field sequestration tests, preliminarily confirming its feasibility.

[0003] To further explore the feasibility of carbon dioxide sequestration in saline aquifers, Australia also launched a CCS project in the Gorgon region on its west coast. However, during carbon dioxide injection, severe sand blockage in both pumping and injection wells rendered the entire underground rock storage system inoperable, leading to the project's premature termination. Currently, there is a lack of effective prediction and characterization methods for the particle detachment and migration processes within the formation framework during carbon dioxide sequestration, resulting in insufficient understanding of formation detachment and migration behavior and hindering the development of mitigation and monitoring strategies. Addressing these issues, this paper proposes effective methods for characterizing the degree of detachment and migration processes within the carbon dioxide sequestration framework, which is of great significance for long-term carbon dioxide sequestration efforts. Summary of the Invention

[0004] To address the lack of effective prediction methods and characterization techniques for particle shedding and migration processes in the formation framework during existing carbon dioxide sequestration processes, this invention proposes a characterization method for the degree of solid particle shedding and migration processes during carbon dioxide sequestration.

[0005] This invention provides a method for characterizing the degree of solid particle detachment and migration process during carbon dioxide sequestration, comprising the following steps:

[0006] S1. A shedding-transport model is constructed based on the shedding of solid particles in the formation solid skeleton and the migration behavior of the detached solid particles during carbon dioxide sequestration.

[0007] S2. Based on the geological conditions of the carbon dioxide storage area and the on-site conditions, an initial reservoir model of the carbon dioxide storage target area is constructed. The initial conditions and boundary conditions of the initial reservoir model are set, and the grid is divided to obtain the initial reservoir grid model.

[0008] S3. Input the initial reservoir grid model obtained in step S2 into the shedding-migration model obtained in step S1 to obtain the amount and rate of solid particles shedding from the formation solid skeleton during carbon dioxide storage. The amount and rate of shedding are used to characterize the degree of shedding of solid particles from the formation solid skeleton and the migration process of the shed solid particles during carbon dioxide storage.

[0009] According to a method for characterizing the degree of solid particle shedding and migration process in carbon dioxide sequestration according to some embodiments of this application, in step S1,

[0010] When the hydraulic gradient is greater than the critical value for the solid particles to detach, the solid particles begin to detach. The mass of the solid particles detached per unit volume and per unit time is shown in formula (1):

[0011]

[0012] Where ω1 represents the control parameter for the solid particle shedding rate, in units of seconds (s). -1 ), m ssi This indicates the mass of the solid skeleton of the formation after detachment, expressed in kg / m³; m ssi ε represents the mass of the initial formation solid skeleton, expressed in kg / m³. d ω represents the deviatoric strain; ω2 represents the model parameter indicating the increased potential for solid particle detachment due to shear deformation; and t represents time.

[0013] The hydraulic gradient is shown in equation (2):

[0014]

[0015] Where i represents the hydraulic gradient, i x Let i be the hydraulic gradient in the x-direction. y The hydraulic gradient is in the y-direction.

[0016] Hydraulic gradient i in the x direction x As shown in formula (3):

[0017]

[0018] Where H represents the total head, as shown in formula (4):

[0019]

[0020] Where h represents the position head, in meters (m), and P... w ρ represents pressure, with units of MPa. w The density of the aqueous phase is expressed in kg / m³. 3 ;uw This indicates the water flow velocity, with units of m / s.

[0021] Hydraulic gradient i in the y direction y As shown in formula (5):

[0022]

[0023] The migration process of the detached solid skeleton particles is shown in equation (6):

[0024]

[0025] Where, m fs This indicates the mass of solid particles undergoing transport, expressed in kg / m³. 3 ;u fs ρ represents the flow velocity of solid particles undergoing transport, expressed in m / s. s This indicates the density of the detached solid particles. Represents the gradient.

[0026] Solid particles undergoing transport have the same apparent flow velocity as the aqueous phase, as shown in equation (7):

[0027]

[0028] Among them, V fs V represents the volume of a solid particle undergoing transport. w Indicates the volume of the aqueous phase.

[0029] Porosity The dynamic change is shown in formula (8):

[0030]

[0031] in, The change in porosity caused by the change in effective stress, m s The total mass of the solid skeleton of the strata after detachment and the solid particles in the process of migration is represented by formula (9):

[0032]

[0033] The bulk modulus, shear modulus, and cohesion of a formation are all proportional to the volume of the solid skeleton of the formation, as shown in formulas (10)-(12):

[0034]

[0035]

[0036]

[0037] Where K represents the bulk modulus of the formation, in MPa; K′ represents the bulk modulus of the solid skeleton of the formation after detachment, in MPa; V ssi V represents the volume of the solid skeleton of the formation after detachment. ssi0 G represents the initial volume of the solid skeleton of the formation; G represents the shear modulus of the formation, in MPa; G′ represents the shear modulus of the solid skeleton of the formation after detachment, in MPa; c represents the cohesion of the formation, in MPa; c′ represents the cohesion of the solid skeleton of the formation after detachment, in MPa.

[0038] According to some embodiments of this application, a method for characterizing the degree of solid particle detachment and migration process in carbon dioxide sequestration, in step S2, the geological conditions of the carbon dioxide sequestration area include reservoir type and thickness value of each reservoir. The height of the reservoir model is set according to the reservoir type and thickness value of each reservoir, and an initial reservoir model is drawn and established.

[0039] According to some embodiments of this application, a method for characterizing the degree of solid particle shedding and migration process in carbon dioxide sequestration is provided, wherein the reservoir type includes a caprock, a brine layer, and a basement.

[0040] According to a method for characterizing the degree of solid particle detachment and migration process in carbon dioxide sequestration according to some embodiments of this application, the initial reservoir model further includes a horizontal well located at the saline aquifer.

[0041] According to a method for characterizing the degree of solid particle detachment and migration process in carbon dioxide sequestration according to some embodiments of this application, in step S2, setting the initial conditions of the initial reservoir model includes: setting the initial temperature distribution, initial pressure distribution, water saturation, gas saturation and formation prestress distribution of the initial reservoir model;

[0042] Setting the boundary conditions of the initial reservoir model includes: setting the temperatures of the upper, lower, left, and right boundaries of the initial reservoir model; setting the pressures of the upper, lower, left, and right boundaries of the initial reservoir model; setting the pressure gradients of the upper, lower, left, and right boundaries of the initial reservoir model; setting the gas saturation of the upper, lower, left, and right boundaries of the initial reservoir model; setting the liquid saturation of the upper, lower, left, and right boundaries of the initial reservoir model; and setting the injection rate at the horizontal well boundaries in the initial reservoir model.

[0043] According to a method for characterizing the degree of solid particle detachment and migration process in carbon dioxide sequestration according to some embodiments of this application, in step S2, when performing the grid division, the smallest grid is less than 1m and located near the horizontal well.

[0044] This invention proposes a method for characterizing the degree of solid particle detachment and migration process in carbon dioxide sequestration. It considers the combined effects of fluid erosion and formation deformation on the solid particle detachment process in the formation solid skeleton and proposes a detachment-migration model for solid particles in carbon dioxide sequestration. Because it simultaneously considers fluid flow and formation deformation and their influence on the detachment of solid particles in the formation solid skeleton, the prediction results of this invention can better reflect the actual CO2 saline aquifer sequestration process. By solving the initial reservoir grid model, it is possible to effectively analyze and predict the detachment and migration process of solid particles in the formation solid skeleton during carbon dioxide injection. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the characterization method for the degree of detachment and migration process of the carbon dioxide sequestration framework of the present invention;

[0046] Figure 2 This is a schematic diagram of the initial reservoir model selected in Embodiment 2 of the present invention;

[0047] Figure 3 This is a schematic diagram of the evolution of CO2 saturation in Embodiment 2 of the present invention;

[0048] Figure 4 This is a schematic diagram illustrating the volume fraction evolution of the solid skeleton of the formation after detachment in Embodiment 2 of the present invention;

[0049] Figure 5 This is a schematic diagram illustrating the evolution of the volume fraction of solid particles during the transport process in Embodiment 2 of the present invention;

[0050] Figure 6 The amount and rate of shedding are calculated in Embodiment 2 of the present invention. Detailed Implementation

[0051] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0052] Example 1

[0053] This embodiment provides a method for characterizing the degree of solid particle shedding and migration process during carbon dioxide sequestration, such as... Figure 1 As shown, it includes the following steps:

[0054] S1. A shedding-transport model is constructed based on the shedding of solid particles in the formation solid skeleton and the migration behavior of the detached solid particles during carbon dioxide sequestration.

[0055] When the hydraulic gradient exceeds the critical value for solid particle detachment, the solid particles begin to detach. The mass of solid particles detached per unit volume per unit time is shown in formula (1):

[0056]

[0057] Wherein, ψ1 represents the control parameter for the solid particle shedding rate, with units of seconds (s). -1 ), m ssi This indicates the mass of the solid skeleton of the formation after detachment, expressed in kg / m³; m ssi0 ε represents the mass of the initial formation solid skeleton, expressed in kg / m³. d ω represents the deviatoric strain; ω2 represents the model parameter indicating the increased potential for solid particle detachment due to shear deformation; and t represents time.

[0058] The hydraulic gradient is shown in equation (2):

[0059]

[0060] Where i represents the hydraulic gradient, i x Let i be the hydraulic gradient in the x-direction. y The hydraulic gradient is in the y-direction.

[0061] Hydraulic gradient i in the x direction x As shown in formula (3):

[0062]

[0063] Where H represents the total head, as shown in formula (4):

[0064]

[0065] Where h represents the position head, in meters (m), and P... w ρ represents pressure, with units of MPa. w The density of the aqueous phase is expressed in kg / m³. 3 ;u w This indicates the water flow velocity, with units of m / s.

[0066] Hydraulic gradient i in the y direction y As shown in formula (5):

[0067]

[0068] The migration process of the detached solid skeleton particles is shown in equation (6):

[0069]

[0070] Where, m fs This indicates the mass of solid particles undergoing transport, expressed in kg / m³. 3 ;u fs ρ represents the flow velocity of solid particles undergoing transport, expressed in m / s. s This indicates the density of the detached solid particles. Represents the gradient.

[0071] Solid particles undergoing transport have the same apparent flow velocity as the aqueous phase, as shown in equation (7):

[0072]

[0073] Among them, V fs V represents the volume of a solid particle undergoing transport. w Indicates the volume of the aqueous phase.

[0074] Porosity The dynamic change is shown in formula (8):

[0075]

[0076] in, The change in porosity caused by the change in effective stress, m s The total mass of the solid skeleton of the strata after detachment and the solid particles in the process of migration is represented by formula (9):

[0077] m s =m ssi +m fs (9)

[0078] The mechanical strength of a formation is directly proportional to the volume of its solid skeleton. The mechanical strength of a formation includes bulk modulus, shear modulus, and cohesion. Therefore, the bulk modulus, shear modulus, and cohesion of a formation are all directly proportional to the volume of its solid skeleton, as shown in formulas (10)-(12).

[0079]

[0080]

[0081]

[0082] Where K represents the bulk modulus of the formation, in MPa; K′ represents the bulk modulus of the solid skeleton of the formation after detachment, in MPa; Vssi V represents the volume of the solid skeleton of the formation after detachment. ssi0 G represents the initial volume of the solid skeleton of the formation; G represents the shear modulus of the formation, in MPa; G′ represents the shear modulus of the solid skeleton of the formation after detachment, in MPa; c represents the cohesion of the formation, in MPa; c′ represents the cohesion of the solid skeleton of the formation after detachment, in MPa.

[0083] S2. Based on the geological conditions of the carbon dioxide storage area and the on-site conditions, an initial reservoir model of the carbon dioxide storage target area is constructed. The initial conditions and boundary conditions of the initial reservoir model are set, and the grid is generated to obtain the initial reservoir grid model.

[0084] The geological conditions of the carbon dioxide storage area include reservoir types and the thickness values ​​of each reservoir. The height of the reservoir model is set according to the reservoir type and the thickness values ​​of each reservoir, and an initial reservoir model is drawn and established. The reservoir types include caprock, caprock, saline aquifer and basement. The initial reservoir model also includes horizontal wells, which are set at the saline aquifer. Specifically, the initial reservoir model is arranged from top to bottom as caprock, caprock, saline aquifer and basement.

[0085] The initial conditions for setting the initial reservoir model include: setting the initial temperature distribution, initial pressure distribution, water saturation, gas saturation, and formation prestress distribution of the initial reservoir model; as a preferred embodiment, the initial temperature distribution is determined by the surface temperature and geothermal gradient of the carbon dioxide sequestration area, the initial pressure distribution is determined by the hydrostatic pressure gradient of the carbon dioxide sequestration area, the water saturation of the initial reservoir model is set to 1, the gas saturation of the initial reservoir model is set to 0, and the formation prestress distribution is determined by the combined weight of the rock and the hydrostatic pressure of the carbon dioxide sequestration area.

[0086] Setting the boundary conditions of the initial reservoir model includes: setting the temperatures of the upper, lower, left, and right boundaries of the initial reservoir model; setting the pressures of the upper, lower, left, and right boundaries of the initial reservoir model; setting the pressure gradients of the upper, lower, left, and right boundaries of the initial reservoir model; setting the gas saturation of the upper, lower, left, and right boundaries of the initial reservoir model; setting the liquid saturation of the upper, lower, left, and right boundaries of the initial reservoir model; and setting the injection rate at the horizontal well boundary in the initial reservoir model. Preferably, in this embodiment, the upper, lower, and right boundaries of the initial reservoir model are set to constant temperatures; the upper, lower, and right boundaries of the initial reservoir model are set to constant pressures; and the horizontal well boundary in the initial reservoir model is set to a constant injection rate. When performing mesh generation, the minimum mesh size is less than 1m and located near the horizontal well.

[0087] S3. Input the initial reservoir grid model obtained in step S2 into the shedding-migration model obtained in step S1 to obtain the amount and rate of solid particles shedding from the formation solid skeleton during carbon dioxide storage. The amount and rate of shedding are used to characterize the degree of shedding of solid particles from the formation solid skeleton and the migration process of the shed solid particles during carbon dioxide storage.

[0088] Example 2

[0089] This embodiment provides a method for characterizing the degree of solid particle detachment and migration process in carbon dioxide sequestration. This embodiment selects the In Salah carbon dioxide sequestration area as the numerical simulation object of the initial reservoir model to predict the detachment-migration behavior of formation skeleton particles during carbon dioxide sequestration. Specifically, it includes the following steps:

[0090] S1. A detachment-transport model is constructed based on the detachment of solid particles from the formation solid skeleton and the migration behavior of detached solid particles involved in the carbon dioxide sequestration process, as detailed below:

[0091] When the hydraulic gradient is greater than the critical value for solid particle detachment, solid particles begin to detach. The mass of solid particles detached per unit volume per unit time is shown in formula (13):

[0092]

[0093] Where ω1 represents the control parameter for the solid particle shedding rate, in units of seconds (s). -1 ), m ssi This indicates the mass of the solid skeleton of the formation after detachment, expressed in kg / m³; m ssi0 ε represents the mass of the initial formation solid skeleton, expressed in kg / m³. d ω represents the deviatoric strain; ω2 represents the model parameter indicating the increased potential for solid particle detachment due to shear deformation; and t represents time.

[0094] The hydraulic gradient is shown in equation (14):

[0095]

[0096] Where i represents the hydraulic gradient, i x Let i be the hydraulic gradient in the x-direction. y The hydraulic gradient is in the y-direction.

[0097] Hydraulic gradient i in the x direction x As shown in formula (15):

[0098]

[0099] Where H represents the total head, as shown in formula (16):

[0100]

[0101] Where h represents the position head, in meters (m), and P... w ρ represents pressure, with units of MPa. w The density of the aqueous phase is expressed in kg / m³. 3 ;u w This indicates the water flow velocity, with units of m / s.

[0102] Hydraulic gradient i in the y direction y As shown in formula (17):

[0103]

[0104] The migration process of the detached solid skeleton particles is shown in equation (18):

[0105]

[0106] Where, m fs This indicates the mass of solid particles undergoing transport, expressed in kg / m³. 3 ;u fs ρ represents the flow velocity of solid particles undergoing transport, expressed in m / s. s This indicates the density of the detached solid particles. Represents the gradient.

[0107] Solid particles undergoing transport have the same apparent flow velocity as the aqueous phase, as shown in equation (19):

[0108]

[0109] Among them, V fs V represents the volume of a solid particle undergoing transport. w Indicates the volume of the aqueous phase.

[0110] Porosity The dynamic change is shown in formula (20):

[0111]

[0112] in, The change in porosity caused by the change in effective stress, m s The total mass of the solid skeleton of the strata after detachment and the solid particles in the process of migration is represented by formula (21):

[0113] m s =mssi +m fs (twenty one)

[0114] The mechanical strength of a formation is directly proportional to the volume of its solid skeleton. The mechanical strength of a formation includes bulk modulus, shear modulus, and cohesion. Therefore, the bulk modulus, shear modulus, and cohesion of a formation are all directly proportional to the volume of its solid skeleton, as shown in formulas (22)-(24).

[0115]

[0116]

[0117]

[0118] Where K represents the bulk modulus of the formation, in MPa; K′ represents the bulk modulus of the solid skeleton of the formation after detachment, in MPa; V ssi V represents the volume of the solid skeleton of the formation after detachment. ssi0 G represents the initial volume of the solid skeleton of the formation; G represents the shear modulus of the formation, in MPa; G′ represents the shear modulus of the solid skeleton of the formation after detachment, in MPa; c represents the cohesion of the formation, in MPa; c′ represents the cohesion of the solid skeleton of the formation after detachment, in MPa.

[0119] S2. Based on the geological conditions of the carbon dioxide storage area and the on-site conditions, an initial reservoir model of the target carbon dioxide storage area is constructed. Initial conditions and boundary conditions of the initial reservoir model are set, and a mesh is generated to obtain the initial reservoir mesh model.

[0120] In this embodiment, the In Salah carbon dioxide sequestration area is selected as the numerical simulation object of the initial reservoir model to predict the formation skeleton particle detachment-migration behavior during carbon dioxide sequestration. It is worth noting that the selection of the simulation object is not fixed.

[0121] The reservoir model selected in this embodiment is as follows: Figure 2 As shown, the initial reservoir model has a total thickness of 2000m, consisting of a 900m thick caprock, a 900m thick topsoil layer, a 20m thick saline water layer, and a 180m thick basement layer, with the saline water layer located 1800m to 1820m below the surface. Furthermore, the horizontal length of the initial reservoir model can be set to 2000m. The initial temperature distribution of the initial reservoir model is determined by the surface temperature and geothermal gradient, where the surface temperature is 25°C and the geothermal gradient is 0.033K / m. The initial pressure distribution of the initial reservoir model is determined by the hydrostatic pressure gradient, where atmospheric pressure is 1 atm and the density of water is 997 kg / m³. 3The formation prestress distribution of the initial reservoir model is jointly controlled by the rock's own weight and hydrostatic pressure. The upper, lower, and right boundaries of the initial reservoir model are set to constant pressure and temperature, and the horizontal well is located at the saline aquifer with a constant injection rate at its boundary. Subsequently, the initial reservoir model with the initial and boundary conditions set is meshed, ensuring that the minimum mesh size is less than 1m and the minimum mesh is located near the horizontal well. The entire initial reservoir model is divided into 35,500 meshes.

[0122] S3. Input the initial reservoir grid model obtained in step S2 into the shedding-migration model obtained in step S1 to obtain the amount and rate of shedding of the skeleton during carbon dioxide storage. The amount and rate of shedding are used to characterize the degree of shedding of formation skeleton particles and the migration process of the detached solids during carbon dioxide storage.

[0123] Model calculation and result output: Figure 3 This is a schematic diagram of the evolution of CO2 saturation. Figure 4 This is a schematic diagram illustrating the volume fraction evolution of the solid skeleton of the formation after detachment. Figure 5 This is a schematic diagram illustrating the evolution of the volume fraction of solid particles during transport. Numerical simulation results show that during CO2 injection, particle detachment occurs in the CO2 flow region of the saline aquifer, with detached particles flowing further out and accumulating. Furthermore, from... Figure 6 As shown, quantitative analysis of the particle shedding rate indicates that, per unit horizontal well length, the particle shedding rate remains between 1 and 1.5 m. 3 / d.

[0124] The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the invention to the forms disclosed. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to better illustrate the principles and practical application of the invention, and to enable those skilled in the art to understand the invention and to design various embodiments with various modifications suitable for a particular purpose.

Claims

1. A method for characterizing the degree of detachment and migration process of solid particles in carbon dioxide sequestration, characterized by, The method comprises the following steps: S1. Constructing a detachment-migration model based on the detachment of solid particles in the solid skeleton of the formation and the migration behavior of the detached solid particles in the carbon dioxide storage process; S2. Constructing an initial reservoir model of the carbon dioxide storage target area based on the geological conditions and the field conditions of the carbon dioxide storage area, setting initial conditions and boundary conditions of the initial reservoir model, and performing grid division to obtain an initial reservoir grid model; S3. Inputting the initial reservoir grid model obtained in step S2 into the detachment-migration model obtained in step S1 to obtain the detachment amount and the detachment rate of the solid particles in the solid skeleton of the formation in the carbon dioxide storage process, and characterizing the detachment degree of the solid particles in the solid skeleton of the formation and the migration process of the detached solid particles in the carbon dioxide storage process through the detachment amount and the detachment rate; In the step S1, When the hydraulic gradient is greater than the critical value at which the solid particles begin to detach, the solid particles begin to detach, and the mass of the solid particles detached per unit volume per unit time is shown in formula (1): （1） wherein, a control parameter indicative of the rate of solid particle detachment, a mass of the formation solid skeleton after detachment has occurred, a mass of the initial formation solid skeleton, a deviatoric strain, a model parameter indicative of an increase in the potential for solid particle detachment due to shear deformation, a time, The hydraulic gradient is shown in formula (2): （2） wherein represents the hydraulic gradient, is the hydraulic gradient in the direction of flow, is the hydraulic gradient in the direction of flow, Hydraulic gradient in the direction As shown in equation (3): （3） wherein represents the total water head, as shown in equation (4): （4） wherein, represents the position head, represents the pressure, represents the density of the water phase, represents the water flow velocity, Hydraulic gradient in the direction As shown in equation (5): （5） The migration process of the detached solid skeleton particles is shown in formula (6): （6） wherein, M represents the mass of the solid particles in the migration process, V represents the flow velocity of the solid particles in the migration process, in units of m / s, , ρ represents the density of the detached solid particles, G represents the gradient, The solid particles in the migration process have the same apparent flow velocity as the water phase, which is shown in formula (7): （7） wherein Vp represents the volume of the solid particles in the process, Vw represents the volume of the aqueous phase, Porosity The dynamic change of the porosity is shown in equation (8): （8） wherein, represents the change in porosity caused by the change in effective stress, represents the total mass of the formation solid skeleton and the solid particles in the process of migration after the shedding, as shown in equation (9): （9） The bulk modulus, shear modulus and cohesion of the formation are proportional to the volume of the solid skeleton of the formation, which is shown in formulas (10)-(12): （10） （11） （12） where K represents the bulk modulus of the formation, represents the bulk modulus of the solid skeleton of the formation after sloughing, represents the bulk of the solid skeleton of the formation after sloughing, represents the bulk of the initial solid skeleton of the formation, G represents the shear modulus of the formation, represents the shear modulus of the solid skeleton of the formation after sloughing, represents the cohesion of the formation, represents the cohesion of the solid skeleton of the formation after sloughing.

2. The method of claim 1, wherein the method is characterized by, In the step S2, the geological conditions of the carbon dioxide storage area include the reservoir type and the thickness value of each reservoir, and the height of the reservoir model is set according to the reservoir type and the thickness value of each reservoir to draw and establish the initial reservoir model.

3. The method of claim 2, wherein the method is characterized by, The reservoir type includes the overburden layer, the cap rock, the saltwater layer and the basement layer.

4. The method of claim 3, wherein the method is characterized in that, The initial reservoir model further includes a horizontal well, and the horizontal well is arranged at the saltwater layer.

5. The method of claim 4, wherein the method is characterized in that, In the step S2, setting the initial conditions of the initial reservoir model includes setting the initial temperature distribution, the initial pressure distribution, the water saturation, the gas saturation and the formation pre-stress distribution of the initial reservoir model; Setting the boundary conditions of the initial reservoir model includes setting the temperature of the upper boundary, the lower boundary, the left boundary and the right boundary of the initial reservoir model, setting the pressure of the upper boundary, the lower boundary, the left boundary and the right boundary of the initial reservoir model, setting the pressure gradient of the upper boundary, the lower boundary, the left boundary and the right boundary of the initial reservoir model, setting the gas saturation of the upper boundary, the lower boundary, the left boundary and the right boundary of the initial reservoir model, setting the liquid saturation of the upper boundary, the lower boundary, the left boundary and the right boundary of the initial reservoir model, and setting the injection rate of the horizontal well boundary in the initial reservoir model.

6. The method of claim 5, wherein the method is characterized in that, In the step S2, when the grid division is performed, the minimum grid is less than 1 m and located near the horizontal well.

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