Method and apparatus for determining migration range of carbon dioxide in saline aquifer by inversion, and computer device
By constructing a numerical prior calculation model and geological constraints, and combining formation pressure and gravity anomaly data, the carbon dioxide migration range of the saline aquifer is inverted, solving the problems of high cost and low accuracy in existing technologies, and realizing low-cost and efficient carbon dioxide migration range inversion.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CHINA NAT PETROLEUM CORP
- Filing Date
- 2025-10-22
- Publication Date
- 2026-05-07
AI Technical Summary
In existing technologies, carbon dioxide transport prediction based on geophysical monitoring methods is costly and it is difficult to accurately invert the range of carbon dioxide transport using gravity anomaly data, resulting in problems of high inversion difficulty and high cost.
By constructing a numerical prior calculation model, combining geological constraints and formation pressure data, and utilizing gravity anomaly data and carbon dioxide density distribution, the proportion of mass change of carbon dioxide within the migration range of the tectonic trap area is calculated. Combined with solubility and density distribution, the migration range of carbon dioxide in the potential overflow area is inverted.
It reduces the cost of carbon dioxide migration range inversion, improves inversion accuracy and efficiency, reduces reliance on geophysical monitoring methods, and enhances the operability and accuracy of the inversion process.
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Figure CN2025129227_07052026_PF_FP_ABST
Abstract
Description
Methods, apparatus and computer equipment for inverting the range of carbon dioxide transport in saline aquifers
[0001] Cross-reference to related applications
[0002] This application claims the benefit of Chinese Patent Application No. 202411513257.7, filed on October 28, 2024, the contents of which are incorporated herein by reference. Technical Field
[0003] This application belongs to the field of geological carbon dioxide sequestration and utilization, specifically relating to a method for inverting the range of carbon dioxide migration in saline aquifers, a device for inverting the range of carbon dioxide migration in saline aquifers, a computer device, and a machine-readable storage medium. Background Technology
[0004] Monitoring carbon dioxide (COD) storage sites is a crucial step in achieving large-scale, safe, and effective geological COD storage. Monitoring of COD geological storage involves continuous / intermittent monitoring during the COD injection phase, as well as long-term monitoring after injection cessation to ensure storage safety. Geophysical monitoring is the primary method, utilizing time-delayed geophysical methods, which involve dynamic monitoring of the COD storage process through repeated geophysical observations. Geophysical methods primarily employ seismic methods, including 3D seismic, inter-well seismic, downhole seismic, and microseismic methods. Other monitoring methods include satellite remote sensing, time-delayed geomagnetism, and time-delayed gravity. Most geophysical monitoring methods are costly and susceptible to limitations imposed by measurement conditions. Gravity methods measure abnormal changes in gravity based on the non-uniformity of mass distribution of rock and fluid media in the formation after COD injection. Gravity detection is conducted at different stages of COD geological storage projects, and the obtained time-delayed gravity data can be used to infer the migration of COD in the formation based on changes in gravity anomalies. Time-delayed gravity measurement is more economical than geophysical monitoring methods such as seismic surveys. It does not rely on sensors within monitoring or injection wells and can be performed on the surface using gravity measuring instruments, offering advantages in flexibility and mobility, depending on the monitoring network at different engineering stages. Currently, time-delayed gravity measurement has been applied in oil and gas reservoirs and saline water layer carbon dioxide geological sequestration projects, including the Sleipner project in Norway, the Gundih pilot project in Indonesia, the CarbonSAFE project in North Dakota, the SECARB Cranfield project in Mississippi, and the Kevin Dome project in Montana. Studies have been completed on the impact of gravity data background values and the adaptability of gravity detection methods in different reservoirs. Furthermore, by combining seismic data, the inversion of carbon dioxide sequestration volume and carbon dioxide migration paths has been achieved. However, the gravity anomalies caused by carbon dioxide injection operations are related to many factors such as carbon dioxide saturation, carbon dioxide density, brine density, rock density, storage unit volume and porosity. Existing studies cannot complete the inversion of the carbon dioxide migration range solely through gravity anomaly data. Therefore, it is urgent to study methods to predict the carbon dioxide migration range through gravity data in order to identify potential leakage risks and promote the development of carbon dioxide geological storage monitoring technology. Summary of the Invention
[0005] The purpose of this application is to provide a method for inverting the range of carbon dioxide migration in saline aquifers, a device for inverting the range of carbon dioxide migration in saline aquifers, a computer device, and a machine-readable storage medium, so as to overcome the shortcomings of the prior art, such as the high cost of carbon dioxide migration prediction based on geophysical monitoring methods, and the difficulty of inverting the prediction of carbon dioxide migration based solely on gravity anomaly data due to the many influencing factors in the interpretation of gravity anomaly data.
[0006] To achieve the above objectives, a first aspect of this application provides a method for inverting the migration range of carbon dioxide in a saline aquifer, comprising: constructing a numerical prior calculation model for simulating the carbon dioxide sequestration process in a saline aquifer, wherein the carbon dioxide sequestration area constructed by geological constraints in the numerical prior calculation model includes a structural trap area and a potential overflow area; using the numerical prior calculation model to characterize the possible distribution range of carbon dioxide, obtaining a first extension thickness and the migration range of carbon dioxide in the structural trap area, wherein the first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well; calculating the carbon dioxide density distribution of the sequestration area using formation pressure data of the sequestration area; determining the proportion of the mass change caused by pore confinement of carbon dioxide within the migration range of the structural trap area in the total mass change within the migration range of the structural trap area based on gravity anomaly data of the sequestration area, carbon dioxide density distribution, and the migration range of carbon dioxide in the structural trap area, and determining the proportion as a first coefficient; calculating the area of the actual carbon dioxide overflow area based on the first coefficient, the solubility of carbon dioxide in formation water, and the carbon dioxide density distribution, to obtain the migration range of carbon dioxide in the potential overflow area.
[0007] In a specific embodiment of this application, the method for inverting the carbon dioxide migration range of a saline aquifer includes: constructing a numerical simulation model for carbon dioxide sequestration in a saline aquifer, wherein the carbon dioxide sequestration area obtained through geological modeling in the numerical simulation model includes a structural trap area and a potential overflow area; simulating the carbon dioxide injection process using the numerical simulation model to obtain a first extension thickness and the migration range of carbon dioxide in the structural trap area, wherein the first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well; calculating the carbon dioxide density distribution of the sequestration area using formation pressure data of the sequestration area; determining the proportion of the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap area to the total mass change within the migration range of the structural trap area based on the gravity anomaly data of the sequestration area, the carbon dioxide density distribution, and the migration range of carbon dioxide in the structural trap area, and determining the proportion as a first coefficient; calculating the actual overflow area of carbon dioxide based on the first coefficient, the solubility of carbon dioxide in formation water, and the carbon dioxide density distribution, to obtain the migration range of carbon dioxide in the potential overflow area.
[0008] In a specific embodiment of this application, determining the proportion of the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap, based on gravity anomaly data of the sealed area, carbon dioxide density distribution, and the migration range of carbon dioxide within the structural trap, to the total mass change within the migration range of the structural trap, and defining this proportion as a first coefficient, includes: calculating the fluid density change at different locations in the sealed area based on gravity anomaly data of the sealed area; calculating the total mass change within the migration range of the structural trap based on the fluid density change; obtaining the porosity, bound gas saturation, and formation water density of the sealed area; calculating the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area; and calculating the ratio of the total mass change within the migration range of the structural trap to the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap, and using this ratio as the first coefficient.
[0009] In a specific embodiment of this application, calculating the total mass change within the migration range of the structural trap based on the fluid density change includes: calculating the average value of the fluid density change at different locations within the migration range of the structural trap in the sealed area, to obtain the average fluid density change within the migration range of the structural trap. The total volume V of the geological grid for calculating the migration range of the tectonic trap area. s ; Calculate the total mass change within the transport range of the constructed trap region.
[0010] In a specific embodiment of this application, the calculation of the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap area based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area includes:
[0011] Calculate the mass change caused by carbon dioxide being bound by pores within the transport range of a structurally confined region.
[0012] Wherein, φ represents the porosity of the sealed area; S gr N represents the saturation of the bound gas in the sealed area. s,x N represents the total number of geological grids in the x-direction representing the migration range of the tectonic trap region, where i represents the grid number in the x-direction; s,y N represents the total number of geological grids in the y-direction representing the migration range of the tectonic trap area, where j represents the grid number in the y-direction; s,z V(x) represents the total number of geological grids along the z-direction of the migration range of the tectonic trap area, where k represents the grid number along the z-direction; i ,y j ,zk ) represents coordinates (x i ,y j ,z k The geological grid volume; ρ w This indicates the density of formation water in the sealed area; The coordinates are (x i ,y j ,z k The carbon dioxide density at the geological grid.
[0013] In a specific embodiment of the application, the step of calculating the actual area of carbon dioxide overflow based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide includes: calculating the total amount of carbon dioxide within the migration range of the structural trap based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide; calculating the residual gaseous amount of carbon dioxide in the potential overflow zone based on the total amount of carbon dioxide injected, the total amount of carbon dioxide within the migration range of the structural trap, the density distribution of carbon dioxide, and the first coefficient; and calculating the actual area of carbon dioxide overflow based on the residual gaseous amount of carbon dioxide in the potential overflow zone, the first extension thickness, and the first coefficient.
[0014] In a specific embodiment of the application, the calculation of the total carbon dioxide accumulation within the migration range of the structural trap based on the first coefficient, the solubility of carbon dioxide in formation water, and the carbon dioxide density distribution includes: calculating the sum of the structural accumulation and the residual gaseous accumulation of carbon dioxide within the migration range of the structural trap. Calculate the amount of formation water M within the migration range of the tectonic trap area. s,w =V s ·φ·(1-S gr ·R r )·ρ w ; Calculate the amount of dissolved state within the migration range of the constructed trap region. The sum of the tectonic occurrence, residual gaseous occurrence, and dissolved occurrence of carbon dioxide within the migration range of the tectonic trap is calculated, and this sum is taken as the total occurrence of carbon dioxide within the migration range of the tectonic trap; where V s The total volume of the geological grid represents the migration range of the tectonic trap area; φ represents the porosity of the sealed area; S gr R represents the saturation of the bound gas in the sealed area. r Indicates the first coefficient; This represents the average carbon dioxide density of the structural trap area, obtained by averaging the carbon dioxide density of each geological grid within the migration range of the structural trap area using the aforementioned carbon dioxide density distribution; ρ w This indicates the density of formation water in the sealed area; M represents the solubility of carbon dioxide in formation water. s,r M represents the amount of residual gaseous matter within the migration range of the structural trap region; s,e This indicates the amount of tectonic deposits within the migration range of a tectonic trap region.
[0015] In a specific embodiment of the application, the step of calculating the residual gaseous carbon dioxide in the potential overflow zone based on the total carbon dioxide injection amount, the total amount of carbon dioxide stored within the migration range of the structural trap, the carbon dioxide density distribution, and a first coefficient includes: taking the difference between the total carbon dioxide injection amount and the total amount of carbon dioxide stored within the migration range of the structural trap as the amount of carbon dioxide entering the potential overflow zone; and calculating the residual gaseous carbon dioxide in the potential overflow zone. Among them, M f This indicates the amount of carbon dioxide entering the potential overflow area; This represents the average carbon dioxide density of the potential overflow area, obtained by averaging the carbon dioxide density of each geological grid within the potential overflow area using the aforementioned carbon dioxide density distribution; S gr R represents the saturation of the bound gas in the sealed area. r Represents the first coefficient; ρ w This indicates the density of formation water in the sealed area; This indicates the solubility of carbon dioxide in formation water.
[0016] In a specific embodiment of the application, the following formula is used when calculating the area of the actual carbon dioxide overflow region based on the residual gaseous content of carbon dioxide in the potential overflow zone, the first extension thickness, and the first coefficient:
[0017] Among them, A' f h represents the area of the actual carbon dioxide overflow. f Indicates the first extended thickness; M f,r This indicates the amount of residual gaseous carbon dioxide in the potential overflow area; This represents the average carbon dioxide density of the potential overflow area, obtained by averaging the carbon dioxide density of each geological grid within the potential overflow area using the aforementioned carbon dioxide density distribution; φ represents the porosity of the containment area; S gr R represents the saturation of the bound gas in the sealed area. r This represents the first coefficient.
[0018] In a specific embodiment of the application, the numerical prior calculation model for simulating the process of carbon dioxide sequestration in saline aquifers is constructed. The carbon dioxide sequestration region in the numerical prior calculation model, constructed through geological constraints, includes a tectonic trap zone and a potential overflow zone, comprising:
[0019] Obtain the formation physical properties and fluid physical properties of the carbon dioxide storage area;
[0020] The geological parameter field of the carbon dioxide sequestration area is constructed by using the stratigraphic properties of the carbon dioxide sequestration area as the geological attributes of each volume element in the geological parameter field. The carbon dioxide sequestration area in the geological parameter field includes structural trap areas and potential overflow areas.
[0021] By inputting the fluid properties of the carbon dioxide sequestration area and the pre-constructed fluid transport control equations into the geological parameter field, a numerical prior calculation model for simulating the carbon dioxide sequestration process in a saline aquifer is obtained.
[0022] In a specific embodiment of the application, the step of using the numerical prior calculation model to characterize the possible distribution range of carbon dioxide and obtain a first extended thickness and the migration range of carbon dioxide in the structural trap area, wherein the first extended thickness is the extended thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well, includes: simulating the pressure-driven process during carbon dioxide injection and the gravity-driven process after injection stops using the numerical prior calculation model to obtain the first extended thickness, wherein the first extended thickness is the extended thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well; calculating the migration thickness of carbon dioxide in the structural trap area based on the structural undulation parameters of the geological parameter field of the carbon dioxide storage area constructed through geological constraints in the numerical prior calculation model and the first extended thickness, wherein the direction of this thickness is parallel to the well depth direction of the carbon dioxide injection well; calculating the migration area of carbon dioxide in the structural trap area based on the structural undulation parameters of the geological parameter field; and obtaining the migration range of carbon dioxide in the structural trap area based on the migration thickness and migration area of carbon dioxide in the structural trap area.
[0023] In a specific embodiment of the application, the method for inverting the carbon dioxide migration range of the saline aquifer further includes: combining the distribution of gravity monitoring points and the distribution of gravity anomaly points in the sealed area determined by gravity anomaly data, drawing the migration range of carbon dioxide in the structural trap area and the migration range of carbon dioxide in the potential overflow area to obtain a rectangular migration range; and using the geological characteristics of the sealed area to correct the rectangular migration range, wherein the geological characteristics include the source direction, sand body distribution characteristics, and fault distribution.
[0024] In a specific embodiment of the application, the construction of a numerical simulation model for carbon dioxide sequestration in a saline aquifer includes the following steps: obtaining the stratigraphic and fluid properties of the carbon dioxide sequestration area; using the stratigraphic properties of the carbon dioxide sequestration area as the geological attributes of each volume element in the geological model to construct a geological model of the carbon dioxide sequestration area, wherein the carbon dioxide sequestration area in the geological model includes the stratigraphic and fluid properties; and inputting the fluid properties of the carbon dioxide sequestration area and the pre-constructed fluid transport control equations into the geological model to obtain the numerical simulation model for carbon dioxide sequestration in a saline aquifer.
[0025] In a specific embodiment of the application, the step of using the numerical simulation model to simulate the carbon dioxide injection process to obtain a first expansion thickness and the migration range of carbon dioxide in the structural trap area, wherein the first expansion thickness is the expansion thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well, includes: using the numerical simulation model to simulate the pressure-driven process during carbon dioxide injection and the gravity-driven process after injection stops, to obtain the first expansion thickness, wherein the first expansion thickness is the expansion thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well; calculating the migration thickness of carbon dioxide in the structural trap area based on the structural undulation parameters of the geological model of the carbon dioxide storage area obtained through geological modeling in the numerical simulation model and the first expansion thickness, wherein the direction of this thickness is parallel to the well depth direction of the carbon dioxide injection well; calculating the migration area of carbon dioxide in the structural trap area based on the structural undulation parameters of the geological model; and obtaining the migration range of carbon dioxide in the structural trap area based on the migration thickness and migration area of carbon dioxide in the structural trap area.
[0026] A second aspect of this application provides a device for inverting the carbon dioxide transport range of a saline aquifer, the device comprising:
[0027] The geological constraint construction module is used to construct a numerical prior calculation model for simulating the carbon dioxide sequestration process in a saline aquifer. The carbon dioxide sequestration area obtained by geological constraint construction in the numerical prior calculation model includes a tectonic trap area and a potential overflow area.
[0028] The prior calculation module is used to characterize the possible distribution range of carbon dioxide using the numerical prior calculation model, and obtain the first extension thickness and the migration range of carbon dioxide in the structural trap area. The first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well.
[0029] The density distribution calculation module is used to calculate the carbon dioxide density distribution of the storage area using the formation pressure data of the storage area.
[0030] The first coefficient determination module is used to determine the proportion of the mass change caused by carbon dioxide being bound by pores within the transport range of the structural trap area to the total mass change within the transport range of the structural trap area based on the gravity anomaly data of the sealed area, the carbon dioxide density distribution, and the transport range of carbon dioxide within the structural trap area, and to determine the proportion as the first coefficient.
[0031] The migration range determination module is used to calculate the actual overflow area of carbon dioxide based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide, so as to obtain the migration range of carbon dioxide in the potential overflow area.
[0032] In a specific embodiment of this application, the saline aquifer carbon dioxide transport range inversion device includes:
[0033] The modeling module is used to construct a numerical simulation model for carbon dioxide sequestration in saline aquifers. The carbon dioxide sequestration area obtained through geological modeling in the numerical simulation model includes tectonic trap areas and potential overflow areas.
[0034] The simulation module is used to simulate the carbon dioxide injection process using the numerical simulation model to obtain the first extension thickness and the migration range of carbon dioxide in the structural trap area. The first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well.
[0035] The density distribution calculation module is used to calculate the carbon dioxide density distribution of the storage area using the formation pressure data of the storage area.
[0036] The first coefficient determination module is used to determine the proportion of the mass change caused by carbon dioxide being bound by pores within the transport range of the structural trap area to the total mass change within the transport range of the structural trap area based on the gravity anomaly data of the sealed area, the carbon dioxide density distribution, and the transport range of carbon dioxide within the structural trap area, and to determine the proportion as the first coefficient.
[0037] The migration range determination module is used to calculate the actual overflow area of carbon dioxide based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide, so as to obtain the migration range of carbon dioxide in the potential overflow area.
[0038] A third aspect of this application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for inverting the carbon dioxide transport range in saline aquifers as described in the first aspect of this application.
[0039] The fourth aspect of this application provides a machine-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for inverting the carbon dioxide transport range in saline aquifers as described in the first aspect of this application.
[0040] In the above technical solution, after simulating the first extended thickness using a numerical prior calculation model, the carbon dioxide migration range is inverted by combining gravity anomaly data and formation pressure data. The analytical solution process for determining the carbon dioxide migration range in the potential overflow zone is defined by considering the proportion of the mass change caused by carbon dioxide being confined by pores within the structural trap migration range in the total mass change within the structural trap migration range. Compared to carbon dioxide migration monitoring that relies on geophysical monitoring methods, the inversion of the entire carbon dioxide migration range does not depend on geophysical monitoring methods; it is achieved through gravity monitoring and formation pressure monitoring, thus reducing costs. In existing technologies, inversion using only gravity monitoring data can only obtain a rough carbon dioxide migration range with low accuracy. The above technical solution, by combining gravity anomaly data and formation pressure data for inversion, improves the accuracy of the carbon dioxide migration range inversion. At the same time, the entire inversion process does not involve the simulation of complex displacement flow processes. Compared with the computational complexity of displacement flow process simulation, the computational complexity of the defined analytical solution process is greatly reduced, thereby improving the inversion efficiency of the transport range.
[0041] In summary, the above technical solutions comprehensively consider inversion cost, inversion accuracy, and inversion efficiency, and the methods are easy to apply and highly feasible.
[0042] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description
[0043] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:
[0044] Figure 1 schematically illustrates a first flowchart of a method for inverting the range of carbon dioxide transport in saline aquifers according to an embodiment of this application;
[0045] Figure 2 schematically illustrates a second flowchart of the method for inverting the carbon dioxide transport range in saline aquifers according to an embodiment of this application;
[0046] Figure 3 schematically illustrates a third flowchart of the method for inverting the carbon dioxide transport range in saline aquifers according to an embodiment of this application;
[0047] Figure 4 schematically illustrates the technical roadmap of the method for inverting the carbon dioxide transport range in saline aquifers according to an embodiment of this application;
[0048] Figure 5 schematically illustrates a geological parameter field diagram of a carbon dioxide storage area according to an embodiment of this application;
[0049] Figure 6 schematically illustrates a simplified vertical cross-sectional view of the constructed enclosed area and potential overflow area according to an embodiment of this application;
[0050] Figure 7 schematically shows the arrangement of gravity measurement points according to an embodiment of this application;
[0051] Figure 8 schematically illustrates a rectangular concept diagram of the carbon dioxide transport range according to an embodiment of this application;
[0052] Figure 9 schematically illustrates a planar distribution of carbon dioxide transport range according to an embodiment of this application;
[0053] Figure 10 schematically illustrates the composition block diagram of a saline aquifer carbon dioxide transport range inversion device according to an embodiment of this application;
[0054] Figure 11 schematically illustrates a structural block diagram of a computer device according to an embodiment of this application. Detailed Implementation
[0055] The specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the embodiments of this application.
[0056] If the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.
[0057] Referring to Figure 1, this application proposes a method for inverting the carbon dioxide migration range in a saline aquifer. This method achieves the inversion of the carbon dioxide migration range through the following technical approach: Step 100, using geological constraints and numerical prior calculations, the possible distribution range of carbon dioxide during carbon dioxide sequestration in the saline aquifer is obtained as the first physical background condition; Step 102, using formation pressure data to calculate the carbon dioxide density distribution as the second physical background condition; Step 104, using the first and second physical background conditions as constraints, the carbon dioxide migration range is inverted based on gravity anomaly data within the area where carbon dioxide is sequestered in the saline aquifer to obtain the carbon dioxide migration range.
[0058] Based on the above technical concept, Figure 2 schematically illustrates a second flowchart of the method for inverting the carbon dioxide transport range in a saline aquifer according to an embodiment of this application. As shown in Figure 2, this application embodiment provides a method for inverting the carbon dioxide transport range in a saline aquifer, which may include the following steps 200 to 210.
[0059] Step 200: Construct a numerical prior calculation model to simulate the process of carbon dioxide sequestration in a saline aquifer. The carbon dioxide sequestration area obtained by geological constraints in the numerical prior calculation model includes the tectonic trap area and the potential overflow area.
[0060] In this application, the potential overflow zone refers to the area where a potential overflow path is located within the structural enclosure of the carbon dioxide storage area. Preferably, in a specific embodiment, the potential overflow zone is a certain area extending beyond the potential overflow path. The degree of extension can be differentiated according to the specific storage area, thereby avoiding the impact of errors in determining the potential overflow path on the inversion of the entire carbon dioxide migration range.
[0061] Step 202: Use a numerical prior calculation model to characterize the possible distribution range of carbon dioxide, and obtain the first extension thickness and the migration range of carbon dioxide in the structural trap area. The first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well.
[0062] In this application, geological constraints and numerical prior calculations are used to obtain the possible distribution range of carbon dioxide, which serves as the first physical background condition. The numerical prior calculation model is a model simulating the process of carbon dioxide sequestration in a saline aquifer. The process of carbon dioxide sequestration in a saline aquifer includes a pressure-driven process during carbon dioxide injection and a gravity-driven process after injection stops. When the carbon dioxide injection well is a vertical well, the first extension thickness is also referred to as the vertical thickness of carbon dioxide overflowing into the potential overflow zone.
[0063] Step 204: Calculate the carbon dioxide density distribution in the storage area using the formation pressure data of the storage area.
[0064] In this application, formation pressure data is used to calculate carbon dioxide density distribution, which serves as a second physical background condition to assist in defining the inversion range of carbon dioxide migration. The combination of the first and second physical background conditions supports subsequent inversion of the carbon dioxide migration range based on gravity anomaly data.
[0065] Step 206: Based on the gravity anomaly data of the sealed area, the carbon dioxide density distribution, and the migration range of carbon dioxide in the structural trap area, determine the proportion of the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap area in the total mass change within the migration range of the structural trap area, and determine this proportion as the first coefficient.
[0066] In this application, gravity anomaly data includes gravity anomaly values at various points within the storage area where gravity anomalies occur, obtained from gravity monitoring data. It is known that, according to the law of universal gravitation, the change in fluid density can be calculated from gravity anomaly data. Given the known spatial volume defined by the migration range within the structural trap, the total mass change within the migration range of the structural trap can be calculated by combining the fluid density change. Knowing the saturation of bound carbon dioxide in the porous medium under saline aquifer conditions, the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap can be calculated based on the pore volume of residual carbon dioxide gas within the migration range of the structural trap, the carbon dioxide density distribution within the storage area, and the formation water density.
[0067] Step 208: Calculate the actual area of carbon dioxide overflow based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide.
[0068] In this application, the solubility of carbon dioxide in formation water can be obtained through calculation or measurement. It should be understood that after obtaining the vertical thickness of carbon dioxide overflowing into the potential overflow zone in step 202, to determine the actual overflow area of carbon dioxide, the technical concept of designing a first coefficient in step 206 allows for the inversion of the actual overflow area of carbon dioxide using the first coefficient and the residual gaseous quantity of carbon dioxide in the potential overflow zone (residual quantity). The residual gaseous quantity of carbon dioxide in the potential overflow zone can be calculated using the total amount of carbon dioxide injected after calculating the total quantity within the migration range of a known volume of structural trap. The total quantity within the migration range of a known volume of structural trap needs to be determined in conjunction with the solubility of carbon dioxide in formation water and the carbon dioxide density distribution.
[0069] In one specific embodiment, calculating the solubility of carbon dioxide in formation water includes the following steps: obtaining formation pressure data and formation temperature data of the storage area; calculating the average pressure of each geological grid within the migration range of the tectonic trap area; calculating the average temperature of each geological grid within the migration range of the tectonic trap area; and calculating the solubility of carbon dioxide in formation water based on the formation water properties of the storage area, the calculated average pressure of each geological grid, and the average temperature of each geological grid.
[0070] For example, by monitoring the surface pressure and surface temperature of the sealed area, surface pressure data and surface temperature data of the sealed area can be collected. Then, based on the geothermal gradient and geopressure gradient, the temperature and pressure of different geological grids in the geological parameter field can be calculated.
[0071] Step 210: Based on the calculated area of the actual carbon dioxide overflow and the first extended thickness, obtain the migration range of carbon dioxide in the potential overflow zone.
[0072] As in the above embodiment, a numerical prior calculation model is first used to characterize the possible distribution range of carbon dioxide to obtain the first extended thickness. Then, a first coefficient is defined, and an analytical solution method for inverting the migration range of carbon dioxide in the potential overflow zone is constructed using the first coefficient. The entire analytical solution process abandons the complex numerical simulation of the displacement flow process in the prior art. The analytical solution process combines gravity anomaly data and formation pressure data, thereby making the accuracy of the migration range obtained by inversion better than the migration inversion results obtained solely through gravity monitoring data. Moreover, the inversion cost is significantly lower than the cost of migration inversion schemes that rely on geophysical monitoring methods, resulting in higher inversion efficiency. Therefore, the above embodiment also demonstrates strong operability.
[0073] In one specific embodiment of this application, the gravity anomaly data is surface gravity anomaly data. Surface gravity detection devices are portable and have short measurement times, allowing for real-time adjustments to monitoring schemes based on project needs. Analyzing surface gravity detection data makes the acquisition of basic data for carbon dioxide migration range inversion more flexible and cost-effective. This enables the inversion of the aforementioned carbon dioxide migration range throughout the entire lifecycle of a saline aquifer carbon dioxide sequestration project, thereby improving inversion efficiency, reducing inversion costs, and enhancing the operability of the inversion process.
[0074] In one specific embodiment of this application, step 200 involves constructing a numerical priori calculation model for carbon dioxide sequestration in a saline aquifer. The carbon dioxide sequestration area in the numerical priori calculation model, constructed through geological constraints, includes tectonic trap areas and potential overflow areas. This may include the following steps:
[0075] The formation physical parameters and fluid physical parameters of the carbon dioxide sequestration area are obtained. The formation physical parameters of the carbon dioxide sequestration area are used as the geological attributes of each volume element in the geological parameter field to construct the geological parameter field of the carbon dioxide sequestration area. The carbon dioxide sequestration area in the geological parameter field includes the tectonic trap area and the potential overflow area. The fluid physical parameters of the carbon dioxide sequestration area and the pre-constructed fluid migration control equations are input into the geological parameter field to obtain the numerical prior calculation model for simulating the carbon dioxide sequestration process in the saline aquifer.
[0076] In one specific embodiment of this application, step 202, which uses a numerical prior calculation model to characterize the possible distribution range of carbon dioxide and obtain a first extension thickness and the migration range of carbon dioxide in the structural trap area, wherein the first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well, may include the following steps: using a numerical prior calculation model to simulate the pressure-driven process during carbon dioxide injection and the gravity-driven process after injection stops, to obtain the first extension thickness, wherein the first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well; calculating the migration thickness of carbon dioxide in the structural trap area based on the structural undulation parameters of the geological parameter field of the carbon dioxide storage area constructed through geological constraints in the numerical prior calculation model and the first extension thickness, wherein the direction of this thickness is parallel to the well depth direction of the carbon dioxide injection well; calculating the migration area of carbon dioxide in the structural trap area based on the structural undulation parameters of the geological parameter field; and obtaining the migration range of carbon dioxide in the structural trap area based on the migration thickness and migration area of carbon dioxide in the structural trap area.
[0077] In one specific embodiment of this application, step 206, determining the proportion of the mass change caused by carbon dioxide being bound by pores within the structural trap's migration range to the total mass change within the structural trap's migration range, based on gravity anomaly data of the sealed area, carbon dioxide density distribution, and the migration range of carbon dioxide within the structural trap, and defining this proportion as a first coefficient, includes the following steps: calculating the fluid density change at different locations within the sealed area based on gravity anomaly data of the sealed area; calculating the total mass change within the structural trap's migration range based on the fluid density change; obtaining the porosity, bound gas saturation, and formation water density of the sealed area; and calculating the mass change caused by carbon dioxide being bound by pores within the structural trap based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area.
[0078] The ratio of the total mass change within the migration range of the structural trap to the mass change caused by carbon dioxide being confined by pores within the structural trap is calculated, and this ratio is used as the first coefficient.
[0079] For example, laboratory experiments can be conducted on core samples from the sealed area in advance to measure the porosity and permeability of the core samples. After saturating the core samples with formation water, high-temperature and high-pressure core displacement experiments can be carried out to obtain the relative permeability curves of carbon dioxide and formation water. Based on the relative permeability curves, the bound gas saturation of carbon dioxide in saturated formation water can be determined. This bound gas saturation is considered to be the bound gas saturation of carbon dioxide in the porous medium under saline aquifer conditions, and it represents the minimum carbon dioxide saturation within the carbon dioxide migration range. To obtain the formation water density, formation water samples from the sealed area can be collected and analyzed to obtain the salinity, salt ion composition, and density of the water samples.
[0080] For example, calculating the total mass change within the migration range of the structural trap based on the fluid density change may include the following steps: calculating the average fluid density change at different locations within the migration range of the structural trap in the sealed area, thereby obtaining the average fluid density change within the migration range of the structural trap. The total volume V of the geological grid for calculating the migration range of the tectonic trap area. s ; Calculate the total mass change within the transport range of the constructed trap region.
[0081] For example, calculating the mass change of carbon dioxide caused by its binding within the pores of a structural trap based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area may include the following steps:
[0082] Calculate the mass change caused by carbon dioxide being bound by pores in a structurally confined region.
[0083] Where φ represents the porosity of the sealed area; S gr Indicates the saturation of bound gas in the storage area; N s,x N represents the total number of geological grids in the x-direction representing the migration range of the tectonic trap region, where i represents the grid number in the x-direction; s,y N represents the total number of geological grids in the y-direction representing the migration range of the tectonic trap area, where j represents the grid number in the y-direction; s,z V(x) represents the total number of geological grids along the z-direction of the migration range of the tectonic trap area, where k represents the grid number along the z-direction; i ,y j ,z k ) represents coordinates (x i ,y j ,z k The geological grid volume; ρ w This indicates the density of formation water in the sealed area; The coordinates are (x i ,yj ,z k The carbon dioxide density at the geological grid.
[0084] To simplify the calculation, the mass change caused by carbon dioxide being bound by pores in the structural trap is calculated based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area. This calculation also includes the following steps:
[0085] By utilizing carbon dioxide density distribution, the mean carbon dioxide density of each geological grid within the migration range of the tectonic trap is calculated to obtain the average carbon dioxide density within the migration range of the tectonic trap.
[0086] Will The value is taken as the average density of carbon dioxide within the transport range of the structural trap region.
[0087] Based on the above embodiments, the first coefficient can be expressed as:
[0088] In one specific embodiment of this application, step 208, calculating the actual overflow area of carbon dioxide based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide, may include the following steps: calculating the total amount of carbon dioxide within the migration range of the structural trap based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide; calculating the residual gaseous amount of carbon dioxide in the potential overflow area based on the total amount of carbon dioxide injected, the total amount of carbon dioxide within the migration range of the structural trap, the density distribution of carbon dioxide, and the first coefficient; and calculating the actual overflow area of carbon dioxide based on the residual gaseous amount of carbon dioxide in the potential overflow area, the first extension thickness, and the first coefficient.
[0089] For example, calculating the total amount of carbon dioxide within the migration range of a structural trap based on a first coefficient, the solubility of carbon dioxide in formation water, and the carbon dioxide density distribution may include the following steps:
[0090] Calculate the sum of the tectonic and residual gaseous carbon dioxide reserves within the migration range of the tectonic trap region.
[0091] Calculate the amount of formation water M within the migration range of the tectonic trap area. s,w =V s ·φ·(1-S gr ·R r )·ρ w (Formula 5);
[0092] Calculate the amount of dissolved matter within the migration range of the structural trap region (dissolved matter content).
[0093] Calculate the sum of the structural occurrence, residual gaseous occurrence, and dissolved occurrence obtained from the above steps, and take the sum as the total occurrence of carbon dioxide within the migration range of the structural trap region.
[0094] Among them, V s The total volume of the geological grid represents the migration range of the tectonic trap area; φ represents the porosity of the sealed area; S gr R represents the saturation of bound gas in the storage area. r Indicates the first coefficient; This represents the average carbon dioxide density of the structural trap area, obtained by averaging the carbon dioxide density of each geological grid within the migration range of the structural trap area using carbon dioxide density distribution; ρ w This indicates the density of formation water in the sealed area; M represents the solubility of carbon dioxide in formation water. s,r M represents the amount of residual gaseous matter within the migration range of the structural trap region; s,e This indicates the amount of tectonic deposits within the migration range of a tectonic trap region.
[0095] For example, calculating the residual gaseous carbon dioxide in the potential overflow zone based on the total carbon dioxide injection volume, the total carbon dioxide accumulation within the migration range of the structural trap area, the carbon dioxide density distribution, and a first coefficient may include the following steps:
[0096] The difference between the total amount of carbon dioxide injected and the total amount of carbon dioxide stored within the migration range of the structural trap area is taken as the amount of carbon dioxide entering the potential overflow area.
[0097] Calculate the residual gaseous quantity of carbon dioxide in the potential overflow zone.
[0098] Among them, M f This indicates the amount of carbon dioxide entering the potential overflow area; This represents the average carbon dioxide density of the potential overflow area, obtained by averaging the carbon dioxide density of each geological grid within the potential overflow area using the carbon dioxide density distribution; S gr R represents the saturation of bound gas in the storage area. r Represents the first coefficient; ρ w This indicates the density of formation water in the sealed area; This indicates the solubility of carbon dioxide in formation water.
[0099] For example, when calculating the area of the actual carbon dioxide overflow region based on the residual gaseous quantity of carbon dioxide in the potential overflow zone, the first extension thickness, and the first coefficient, the following formula is used:
[0100] Among them, A f h represents the area of the actual carbon dioxide overflow. f Indicates the first extended thickness; M f,r This indicates the amount of residual gaseous carbon dioxide in the potential overflow area; This represents the average carbon dioxide density of the potential overflow area, obtained by averaging the carbon dioxide density of each geological grid within the potential overflow area using the carbon dioxide density distribution; φ represents the porosity of the containment area; S gr R represents the saturation of bound gas in the storage area. r This represents the first coefficient.
[0101] Figure 3 schematically illustrates a third flowchart of the method for inverting the carbon dioxide transport range in a saline aquifer according to an embodiment of this application. As shown in Figure 3, this application provides a method for inverting the carbon dioxide transport range in a saline aquifer, which, based on the above embodiments, further includes the following steps:
[0102] Step 212: Combining the distribution of gravity monitoring points and the distribution of gravity anomaly points in the storage area determined by gravity anomaly data, the migration range of carbon dioxide in the structural trap area and the migration range of carbon dioxide in the potential overflow area are drawn to obtain a rectangular migration range.
[0103] Step 214: Using the geological characteristics of the sealed area, the rectangular migration range obtained in step 212 is corrected. The geological characteristics include the source direction, sand body distribution characteristics, and fault distribution.
[0104] As in the above embodiment, by drawing the migration range, it is convenient for operators to observe the migration of carbon dioxide and identify leakage risks in a timely manner.
[0105] Figure 4 schematically illustrates the technical roadmap of the method for inverting the carbon dioxide transport range in a saline aquifer according to an embodiment of this application, and is a specific application example of the above embodiment. As shown in Figure 4, in this application example, the method for inverting the carbon dioxide transport range in a saline aquifer includes the following steps:
[0106] Step A1, sample acquisition, specifically refers to acquiring formation water samples and core samples from the carbon dioxide sequestration area.
[0107] Step A2, experimental analysis, specifically includes:
[0108] A2.1 The collected formation water samples were analyzed to obtain the salinity, salt ion composition, and density of the formation water samples.
[0109] ρ w Table 1 shows the measurement results of the physical properties of the formation water samples.
[0110] Table 1
[0111] A2.2. The solubility of carbon dioxide in the saline aquifer is obtained through calculation or measurement. In the application example, the temperature and pressure in the middle of the saline aquifer were 55℃ and 16MPa, respectively. Under these conditions, the solubility of carbon dioxide in the formation water was 0.31 mol / L, which translates to 13.64 kg / m³. 3 The mass of dissolved carbon dioxide in 1 kg of formation water is
[0112] A2.3. The porosity φ and permeability k' of the core sample were measured, and the porosity was found to be 0.15 and the permeability to be 9.2 mD.
[0113] A2.4. Saturate the core sample with formation water and conduct a high-temperature and high-pressure core displacement experiment to obtain the relative permeability curves of carbon dioxide and formation water.
[0114] A2.5. Based on the relative permeability curve, the bound gas saturation of carbon dioxide in a core saturated with formation water is obtained. This bound gas saturation is considered to be the bound gas saturation S of carbon dioxide in the porous medium under saline aquifer conditions. gr S gr This represents the minimum carbon dioxide saturation within the carbon dioxide transport range; in the application example, the measured value is 0.18.
[0115] Step A3, model building, specifically includes:
[0116] A3.1 Based on the porosity φ and permeability k' of the carbon dioxide storage area, combined with well logging interpretation data, maps and other data, a geological parameter field of the carbon dioxide storage area is constructed, as shown in Figure 5. The constructed geological parameter field of the carbon dioxide storage area includes the structural trap area of the anticline structure where the injection well is located and the potential overflow area obtained after the potential overflow path is extended outward by a certain area.
[0117] A3.2 Divide the established geological parameter field into a three-dimensional grid (x,y,z) to ensure that gravity measurement points are distributed within different grids.
[0118] A3.3. Based on the geological parameter field of the carbon dioxide sequestration area, input the fluid properties obtained in step A2, and establish the fluid transport control equations considering gravity to construct a numerical prior calculation model for simulating the carbon dioxide sequestration process in the saline aquifer. The establishment of the numerical prior calculation model can refer to the establishment process of the black oil model for oil and gas reservoirs; the specific establishment process will not be elaborated further.
[0119] Step A4, data analysis, specifically includes:
[0120] A4.1 Divide the carbon dioxide sequestration area of the saline aquifer into a structural trap zone and a potential overflow zone. Generally, during short-term injection, the time-consuming mineralization and sequestration mechanism is ignored. The occurrence state of carbon dioxide in the structural trap zone includes structural occurrence, residual gaseous occurrence, and dissolved occurrence. The occurrence state of carbon dioxide in the potential overflow zone includes residual gaseous occurrence and dissolved occurrence.
[0121] A4.2. Using a numerical prior calculation model, calculate the pressure-driven process during carbon dioxide injection and the gravity-driven process after injection stops, to obtain the vertical thickness h of the overflowing carbon dioxide in the potential overflow zone. f (First extended thickness), combined with geological parameters and tectonic undulations, to calculate the structural trap area A. s Vertical thickness h s (The thickness of carbon dioxide transport in the structural trap region).
[0122] Based on the saline aquifer structure shown in Figure 5, draw the structural trap A. s and potential overflow area A f A simplified vertical cross-section diagram is shown in Figure 6. In Figure 6, A1 and A3 are two structural low points on the anticline structure cross-section, and A2 is the highest point of the anticline structure. A point A1, the relatively shallower of the two structural low points, is selected. A straight line is drawn through A1, intersecting the anticline profile at point B. The migration range of the structural trap area is the A1A2BDC1 region, and the potential overflow area is the BDG and A1C1FE regions. With the injection of carbon dioxide, carbon dioxide first fills the A1A2B region, and then overflows from point A1 to point E. After the injection stops, the carbon dioxide migration range is the A2EFG region. In this application example, h f =4m, the area of the confined zone is equal to the area of the plane containing A1B, and the area of the potential overflow zone is the area of the plane containing GF minus the area of the plane containing A1B. The height of the potential overflow zone (first extension thickness) is h. f =A1C1, the height h of the migration range within the structural trap region. s =H=h f +A2O, according to the geological parameters shown in Figure 5, A2O = 20m, then h s =h f +A₂O=24m.
[0123] A4.3. Based on the established geological parameter field, the migration area of the tectonic trap zone is obtained according to the tectonic undulation morphology. In this application example, based on the geological structure in Figure 5 and the migration range A of the tectonic trap zone drawn in Figure 6... s The transport area A of the structural trap region was calculated. r 2.7×10 6 m 2 .
[0124] A4.4. Based on the mesh size of the numerical prior calculation model, the volume of a single mesh can be calculated as V(x,y,z). In this application example, a uniform mesh size of 50m × 50m × 4m is used, therefore the volume of a single mesh V(x,y,z) = 1.0 × 10⁻⁶. 4 m 3 .
[0125] A4.5 Calculate the temperature and pressure of different grids, T(x,y,z) and P(x,y,z), based on the geothermal gradient and geopressure gradient of the storage area. In this application example, the calculated minimum temperature for each grid is 54.2℃, the maximum temperature is 55.8℃, the minimum pressure is 15.3MPa, and the maximum pressure is 16.7MPa.
[0126] A4.6. Carbon dioxide injection leads to a decrease in fluid density within the migration range, and gravity data on the plane shows a negative anomaly. Combined with the geological parameter field shown in Figure 5, it is determined that the migration is located within the tectonic trap migration range A. s The negative gravity anomaly point number and its location in potential overflow zone A f The negative gravity anomaly points within the area are numbered. Based on the law of universal gravitation, the change in fluid density Δρ(x,y) at different locations on the plane is calculated from the gravity anomaly value ΔG(x,y). Specifically, the gravity measurement points are shown in Figure 7. According to the gravity measurement results, negative gravity anomalies appear at points numbered 3–11 and 16–22. Within the constructed trap region A… s The negative gravity anomaly points within the potential overflow zone are 4–10 and 17–21. f The negative gravity anomaly points within the area are 3, 11, 16, and 22. In this application example, the maximum fluid density change at different locations is 0.004 kg / L, and the minimum fluid density change is 0.002 kg / L.
[0127] A4.7 Under the assumption of short-term storage conditions, construct the confined area A. s Internal carbon dioxide occurrence states include tectonic occurrence, residual gas occurrence, and dissolved occurrence, with potential overflow zone A. f The internal carbon dioxide occurrence states include residual gas occurrence and dissolved occurrence.
[0128] Step A5, determining the transport range, specifically includes:
[0129] A5.1 Calculate the mesh volume V(x,y) at position (x,y):
[0130] Where, N s,z To construct the migration range A of the confined region s Total number of grid cells in the inward z-direction; V(x,y,z) kLet V(x,y,z) be the mesh volume of the k-th layer along the z-direction at position (x,y). Specifically, the volume of a single mesh is V(x,y,z) = 1.0 × 10⁻⁶. 4 m 3 According to the migration range A of the structural trap region s The minimum number of inward vertical grid cells is 1, and the maximum is 5, so V(x,y) is at least 1.0 × 10⁻⁶. 4 m 3 The maximum value is 5.0 × 10. 4 m 3 .
[0131] A5.2 Calculate the migration range A of the constructed trap region using V(x,y) and Δρ(x,y). s Average change in internal fluid density
[0132] Where, N s,x and N s,y These are structural trap regions A. s Total number of grid cells in the x and y directions; V(x i ,y j ) and Δρ(x i ,y j ) are respectively on the plane (x i ,y j The total thickness corresponding to the grid is h. s The total grid volume and the change in average fluid density within the grid; V s To construct the migration range A of the confined region s Total volume of the inner grid. Specifically, the migration range A of the constructed trap region. s The total number of internal grids is 213, and the total volume is V. s =2.13×10 6 m 3 The migration range A of the structural trap region was calculated. s The average change in internal fluid density is Potential overflow area A f The average change in internal fluid density is
[0133] A5.3 Calculate carbon dioxide density based on grid pressure P(x,y,z) Structural Trap Region A s Internal average carbon dioxide density and overflow area A f Average carbon dioxide density within Specifically, the grid pressure P(x,y,z) calculation is shown in A4.5. The minimum pressure of the model is 15.3 MPa, and the maximum pressure is 16.7 MPa. The carbon dioxide density under the minimum and maximum pressures of this model is obtained from flash evaporation calculations. The maximum value is 0.687 kg / L, and the minimum value is 0.603 kg / L. The migration range A within the structural trap region. s The average density of carbon dioxide inside is Potential overflow area A f Internal average carbon dioxide density
[0134] A5.4 Calculate the first coefficient R r In the application example, each grid cell has a volume of 1.0 × 10⁻⁶. 4 m 3 and by adopting Replace carbon dioxide density in different grids Simplify the calculation:
[0135] A5.5, in the structural trap region A s The presence of residual gas and tectonic activity are both major causes of the significant decrease in fluid density. Therefore, in tectonic trap region A... s The internal structure does not distinguish between residual gaseous occurrences and tectonic occurrences. Calculate the tectonic trap region A. s Internal residual gaseous carbon dioxide content M s,r and the construction of the endowment M s,e The sum of M s,g :
[0136] Where φ represents the measured core porosity, and the measured core porosity is the average porosity in the geological parameter field, M s,g To construct the closed region A s Total amount of carbon dioxide in the internal gas phase.
[0137] A5.6. Calculate the average temperature based on the geological parameters, field grid temperature T(x,y,z) and pressure P(x,y,z). and average pressure
[0138] A5.7, Based on the average temperature of the model mesh and average pressure Calculate the solubility of carbon dioxide in salt water In the application example, using Setschenow's law, the solubility was calculated to be 0.31 mol / L, which translates to a mass of 13.64 kg / m³. 3 That is, 13.64 ρ can be dissolved per unit mass of formation water.w -1 kg of carbon dioxide.
[0139] A5.8 Calculate the migration range of the structural trap region A s Inland formation water volume M s,w M s,w =V s ·φ·(1-S gr ·R r )·ρ w =2.13×10 6 ×0.15×(1-0.18×3.7)×1.07×10 3 =1.14×10 8 kg.
[0140] A5.9, Based on the solubility of carbon dioxide in salt water and the migration range of the tectonic trap region A s Inland formation water volume M s,w Calculate the construction of the closed region A s Internal dissolved carbon dioxide content M s,s :
[0141] A5.10 Calculate the potential overflow area A f Internal carbon dioxide content M f M f =M t -M s,g -M s,s =1.5×10 8 -1.33×10 8 -1.46×10 6 =1.554×10 7 kg;
[0142] Among them, M t This represents the total amount of carbon dioxide injected. In this application example, M... t =1.5×10 8 kg.
[0143] A5.11. Assume the ratio of gaseous carbon dioxide to dissolved carbon dioxide is equal in the constructed trap zone and the potential overflow zone. Given that A in the potential overflow zone... f Calculate the amount of carbon dioxide M f and A f Internal gas phase carbon dioxide M s,g With solubility M s,s The ratio can be used to calculate the potential overflow zone A. f Internal residual gaseous carbon dioxide content M f,r :
[0144] A5.12 Calculation of potential overflow zone A from material balance f Internal dissolved carbon dioxide content M f,s M f,s =M f -M f,r =1.554×10 7 -1.537×10 7 =1.7×10 5 kg.
[0145] A5.13 Calculate the area A' of the actual carbon dioxide overflow. f :
[0146] A5.14 Calculate the carbon dioxide transport area A = A r +A' f =2.7×10 6 +5.62×10 4 =2.7562×10 6 m 2 .
[0147] A5.15 Calculate the carbon dioxide transport thickness H = h s =24m, where h s To construct the migration range A of the confined region s Maximum inner thickness.
[0148] A5.16. Based on the layout of monitoring points in the gravity detection area and the location of negative gravity anomaly data points, draw a rectangular carbon dioxide transport range, as shown in Figure 8.
[0149] A5.17. Based on the area A of the carbon dioxide migration zone, the carbon dioxide migration thickness H, the source direction, the distribution characteristics of the sand body, and the fault distribution, draw the lateral and vertical migration ranges of carbon dioxide. The planar distribution of the carbon dioxide migration range is shown in Figure 9, and the vertical carbon dioxide migration thickness H = 24 m.
[0150] Figure 10 schematically illustrates a block diagram of a saline aquifer carbon dioxide transport range inversion apparatus according to an embodiment of this application. As shown in Figure 10, the saline aquifer carbon dioxide transport range inversion apparatus 400 provided in this embodiment includes:
[0151] The geological constraint construction module 410 is used to construct a numerical prior calculation model for simulating the process of carbon dioxide sequestration in a saline aquifer. The carbon dioxide sequestration area obtained by geological constraint construction in the numerical prior calculation model includes a tectonic trap area and a potential overflow area.
[0152] The prior calculation module 420 is used to characterize the possible distribution range of carbon dioxide using the numerical prior calculation model, and to obtain the first extension thickness and the migration range of carbon dioxide in the structural trap area. The first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well.
[0153] Density distribution calculation module 430 is used to calculate the carbon dioxide density distribution of the storage area using the formation pressure data of the storage area;
[0154] The first coefficient determination module 440 is used to determine the proportion of the mass change caused by carbon dioxide being bound by pores within the transport range of the structural trap area to the total mass change within the transport range of the structural trap area based on the gravity anomaly data of the sealed area, the carbon dioxide density distribution, and the transport range of carbon dioxide within the structural trap area, and to determine the proportion as the first coefficient.
[0155] The migration range determination module 450 is used to calculate the actual overflow area of carbon dioxide based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide, so as to obtain the migration range of carbon dioxide in the potential overflow area.
[0156] In one specific embodiment, determining the proportion of the mass change caused by carbon dioxide being confined by pores within the structural trap's migration range within the structural trap, based on gravity anomaly data of the sealed area, carbon dioxide density distribution, and the migration range of carbon dioxide within the structural trap, in the total mass change within the structural trap's migration range, and defining this proportion as a first coefficient, includes:
[0157] Calculate the fluid density change at different locations in the sealed area based on the gravity anomaly data of the sealed area;
[0158] Calculate the total mass change within the transport range of the structural trap region based on the fluid density change;
[0159] The porosity, bound gas saturation, and formation water density of the sealed area were obtained.
[0160] The mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap area is calculated based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area.
[0161] The ratio of the total mass change within the migration range of the tectonic trap to the mass change caused by carbon dioxide being confined by pores within the migration range of the tectonic trap is calculated, and this ratio is used as the first coefficient.
[0162] In one specific embodiment, calculating the total mass change within the transport range of the constructed trap region based on the fluid density change includes:
[0163] Calculate the average fluid density change at different locations within the migration range of the structural trap within the sealed area to obtain the average fluid density change within the migration range of the structural trap.
[0164] The total volume V of the geological grid for calculating the migration range of the tectonic trap area. s ;
[0165] Calculate the total mass change within the transport range of the constructed trap region.
[0166] In one specific embodiment, the calculation of the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap area, based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area, includes:
[0167] Calculate the mass change caused by carbon dioxide being bound by pores within the transport range of a structurally confined region.
[0168] Wherein, φ represents the porosity of the sealed area; S gr N represents the saturation of the bound gas in the sealed area. s,x N represents the total number of geological grids in the x-direction representing the migration range of the tectonic trap region, where i represents the grid number in the x-direction; s,y N represents the total number of geological grids in the y-direction representing the migration range of the tectonic trap area, where j represents the grid number in the y-direction; s,z V(x) represents the total number of geological grids along the z-direction of the migration range of the tectonic trap area, where k represents the grid number along the z-direction; i ,y j ,z k ) represents coordinates (x i ,y j ,z k The geological grid volume; ρ w This indicates the density of formation water in the sealed area; The coordinates are (x i ,y j ,z k The carbon dioxide density at the geological grid.
[0169] In one specific embodiment, calculating the actual area of carbon dioxide overflow based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide includes:
[0170] The total amount of carbon dioxide stored within the migration range of the tectonic trap area is calculated based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide.
[0171] The residual gaseous carbon dioxide in the potential overflow zone is calculated based on the total carbon dioxide injection, the total amount of carbon dioxide stored within the migration range of the structural trap, the carbon dioxide density distribution, and the first coefficient.
[0172] The actual area of carbon dioxide overflow is calculated based on the residual gaseous content of carbon dioxide in the potential overflow zone, the first extension thickness, and the first coefficient.
[0173] In one specific embodiment, the calculation of the total carbon dioxide reserves within the migration range of the structural trap area based on the first coefficient, the solubility of carbon dioxide in formation water, and the carbon dioxide density distribution includes:
[0174] Calculate the sum of the tectonic and residual gaseous carbon dioxide reserves within the migration range of the tectonic trap region.
[0175] Calculate the amount of formation water M within the migration range of the tectonic trap area. s,w =V s ·φ·(1-S gr ·R r )·ρ w ;
[0176] Calculate the amount of dissolved state within the migration range of the constructed trap region.
[0177] The sum of the tectonic occurrence, residual gaseous occurrence, and dissolved occurrence of carbon dioxide within the migration range of the tectonic trap is calculated, and the sum is taken as the total occurrence of carbon dioxide within the migration range of the tectonic trap.
[0178] Among them, V s The total volume of the geological grid represents the migration range of the tectonic trap area; φ represents the porosity of the sealed area; S gr R represents the saturation of the bound gas in the sealed area. r Indicates the first coefficient; This represents the average carbon dioxide density of the structural trap area, obtained by averaging the carbon dioxide density of each geological grid within the migration range of the structural trap area using the aforementioned carbon dioxide density distribution; ρ w This indicates the density of formation water in the sealed area; M represents the solubility of carbon dioxide in formation water. s,r M represents the amount of residual gaseous matter within the migration range of the structural trap region; s,e This indicates the amount of tectonic deposits within the migration range of a tectonic trap region.
[0179] In one specific embodiment, the calculation of the residual gaseous carbon dioxide in the potential overflow zone based on the total carbon dioxide injection volume, the total amount of carbon dioxide stored within the migration range of the structural trap area, the carbon dioxide density distribution, and a first coefficient includes:
[0180] The difference between the total amount of carbon dioxide injected and the total amount of carbon dioxide stored within the migration range of the structural trap area is taken as the amount of carbon dioxide entering the potential overflow area.
[0181] Calculate the residual gaseous quantity of carbon dioxide in the potential overflow zone.
[0182] Among them, M f This indicates the amount of carbon dioxide entering the potential overflow area; This represents the average carbon dioxide density of the potential overflow area, obtained by averaging the carbon dioxide density of each geological grid within the potential overflow area using the aforementioned carbon dioxide density distribution; S gr R represents the saturation of the bound gas in the sealed area. r Represents the first coefficient; ρ w This indicates the density of formation water in the sealed area; This indicates the solubility of carbon dioxide in formation water.
[0183] In one specific embodiment, the calculation of the actual overflow area of carbon dioxide based on the residual gaseous quantity of carbon dioxide in the potential overflow zone, the first extension thickness, and the first coefficient utilizes the following formula:
[0184] Among them, A f h represents the area of the actual carbon dioxide overflow. f Indicates the first extended thickness; M f,r This indicates the amount of residual gaseous carbon dioxide in the potential overflow area; This represents the average carbon dioxide density of the potential overflow area, obtained by averaging the carbon dioxide density of each geological grid within the potential overflow area using the aforementioned carbon dioxide density distribution; φ represents the porosity of the containment area; S gr R represents the saturation of the bound gas in the sealed area. r This represents the first coefficient.
[0185] In one specific embodiment, the numerical prior calculation model for simulating the carbon dioxide sequestration process in a saline aquifer is constructed. The carbon dioxide sequestration region in the numerical prior calculation model, constructed through geological constraints, includes a tectonic trap zone and a potential overflow zone, comprising:
[0186] Obtain the formation physical properties and fluid physical properties of the carbon dioxide storage area;
[0187] The geological parameters of the stratigraphic properties of the carbon dioxide sequestration area are used as the geological attributes of each volume element in the geological parameter field to construct the geological parameter field of the carbon dioxide sequestration area. The carbon dioxide sequestration area in the geological parameter field includes the tectonic trap area and the potential overflow area.
[0188] By inputting the fluid properties of the carbon dioxide sequestration area and the pre-constructed fluid transport control equations into the geological parameter field, a numerical prior calculation model for simulating the carbon dioxide sequestration process in a saline aquifer is obtained.
[0189] In one specific embodiment, the numerical prior calculation model is used to characterize the possible distribution range of carbon dioxide, obtaining a first extension thickness and the migration range of carbon dioxide in the structural trap area. The first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well, including:
[0190] The pressure-driven process during carbon dioxide injection and the gravity-driven process after injection is stopped are simulated using the numerical prior calculation model to obtain the first expansion thickness, which is the expansion thickness of carbon dioxide reaching the potential overflow zone in the direction parallel to the depth of the carbon dioxide injection well.
[0191] The migration thickness of carbon dioxide in the structural trap is calculated based on the structural undulation parameters of the geological parameter field of the carbon dioxide storage area constructed through geological constraints in the numerical prior calculation model and the first extended thickness. The direction of this thickness is parallel to the well depth direction of the carbon dioxide injection well.
[0192] The migration area of carbon dioxide in the tectonic trap area is calculated based on the tectonic undulation parameters of the geological parameter field.
[0193] The migration range of carbon dioxide in the structural trap can be obtained by measuring the migration thickness and area of carbon dioxide in the structural trap.
[0194] In one specific embodiment, the device further includes:
[0195] The drawing module is used to combine the distribution of gravity monitoring points and the distribution of gravity anomaly points in the sealed area determined by gravity anomaly data to draw the migration range of carbon dioxide in the constructed trap area and the migration range of carbon dioxide in the potential overflow area, and obtain a rectangular migration range.
[0196] The correction module is used to correct the rectangular migration range by utilizing the geological features of the sealed area, including the source direction, sand body distribution characteristics, and fault distribution.
[0197] Each module in the aforementioned saline aquifer carbon dioxide transport range inversion device can be applied to a computing device including a memory and a processor.
[0198] Figure 11 schematically illustrates a structural block diagram of a computer device according to an embodiment of this application. In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram is as shown in Figure 11. The computer device includes a processor A01, a network interface A02, a display screen A04, an input device A05, and a memory (not shown) connected via a system bus. The processor A01 of the computer device provides computing and control capabilities. The memory of the computer device includes internal memory A03 and a non-volatile storage medium A06. The non-volatile storage medium A06 stores an operating system B01 and a computer program B02. The internal memory A03 provides an environment for the operation of the operating system B01 and the computer program B02 in the non-volatile storage medium A06. The network interface A02 of the computer device is used for communication with an external terminal via a network connection. When the computer program is executed by the processor A01, it implements a method for inverting the range of carbon dioxide transport in a saline aquifer. The display screen A04 of the computer device can be an LCD screen or an e-ink screen. The input device A05 of the computer device can be a touch layer covering the display screen, or a button, trackball, or touchpad set on the casing of the computer device, or an external keyboard, touchpad, or mouse, etc.
[0199] Those skilled in the art will understand that the structure shown in Figure 11 is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.
[0200] In one embodiment, the saline aquifer carbon dioxide migration range inversion apparatus 400 provided in this application can be implemented as a computer program, which can run on the computer device shown in FIG11. The memory of the computer device can store the various program modules that make up the saline aquifer carbon dioxide migration range inversion apparatus. The computer program composed of the various program modules causes the processor to execute the steps in the saline aquifer carbon dioxide migration range inversion method of the various embodiments of this application described in this specification.
[0201] In one embodiment, this application also provides a machine-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for inverting the carbon dioxide transport range in saline aquifers in the above embodiments.
[0202] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.
[0203] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.
[0204] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.
[0205] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A method for inverting the range of carbon dioxide transport in a saline aquifer, characterized in that, include: A numerical prior calculation model is constructed to simulate the process of carbon dioxide sequestration in a saline aquifer. The carbon dioxide sequestration area obtained by geological constraints in the numerical prior calculation model includes a tectonic trap area and a potential overflow area. The numerical prior calculation model is used to characterize the possible distribution range of carbon dioxide, and the first extension thickness and the migration range of carbon dioxide in the structural trap area are obtained. The first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well. The carbon dioxide density distribution in the sealed area was calculated using the formation pressure data of the sealed area. Based on the gravity anomaly data of the sealed area, the carbon dioxide density distribution, and the migration range of carbon dioxide in the structural trap area, the proportion of the mass change caused by carbon dioxide being bound by pores in the migration range of the structural trap area is determined to be the proportion of the total mass change in the migration range of the structural trap area, and the proportion is determined as the first coefficient. The actual area of carbon dioxide overflow is calculated based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide, so as to obtain the range of carbon dioxide migration in the potential overflow area.
2. The method according to claim 1, characterized in that, The method involves determining the proportion of the mass change caused by carbon dioxide being confined by pores within the structural trap's migration range, based on gravity anomaly data, carbon dioxide density distribution, and the migration range of carbon dioxide within the sealed area, within the total mass change within the structural trap's migration range. This proportion is then defined as a first coefficient, including: Calculate the fluid density change at different locations in the sealed area based on the gravity anomaly data of the sealed area; Calculate the total mass change within the transport range of the structural trap region based on the fluid density change; The porosity, bound gas saturation, and formation water density of the sealed area were obtained. The mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap area is calculated based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area. The ratio of the total mass change within the migration range of the tectonic trap to the mass change caused by carbon dioxide being confined by pores within the migration range of the tectonic trap is calculated, and this ratio is used as the first coefficient.
3. The method according to claim 2, characterized in that, The calculation of the total mass change within the transport range of the structural trap region based on the fluid density change includes: Calculate the average fluid density change at different locations within the migration range of the structural trap within the sealed area to obtain the average fluid density change within the migration range of the structural trap. The total volume V of the geological grid for calculating the migration range of the tectonic trap area. s ; Calculate the total mass change within the transport range of the constructed trap region.
4. The method according to claim 2, characterized in that, The calculation of the mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap area, based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area, includes: Calculate the mass change caused by carbon dioxide being bound by pores within the transport range of a structurally confined region. Wherein, φ represents the porosity of the sealed area; S gr N represents the saturation of the bound gas in the sealed area. s,x N represents the total number of geological grids in the x-direction representing the migration range of the tectonic trap region, where i represents the grid number in the x-direction; s,y N represents the total number of geological grids in the y-direction representing the migration range of the tectonic trap area, where j represents the grid number in the y-direction; s,z V(x) represents the total number of geological grids along the z-direction of the migration range of the tectonic trap area, where k represents the grid number along the z-direction; i ,y j ,z k ) represents coordinates (x i ,y j ,z k The geological grid volume; ρ w This indicates the density of formation water in the sealed area; The coordinates are (x i ,y j ,z k The carbon dioxide density at the geological grid.
5. The method according to any one of claims 1 to 4, characterized in that, The calculation of the actual area of carbon dioxide overflow based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide includes: The total amount of carbon dioxide stored within the migration range of the tectonic trap area is calculated based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide. The residual gaseous carbon dioxide in the potential overflow zone is calculated based on the total carbon dioxide injection, the total amount of carbon dioxide stored within the migration range of the structural trap, the carbon dioxide density distribution, and the first coefficient. The actual area of carbon dioxide overflow is calculated based on the residual gaseous content of carbon dioxide in the potential overflow zone, the first extension thickness, and the first coefficient.
6. The method according to claim 5, characterized in that, The calculation of the total carbon dioxide reserves within the migration range of the structural trap area, based on the first coefficient, the solubility of carbon dioxide in formation water, and the carbon dioxide density distribution, includes: Calculate the sum of the tectonic and residual gaseous carbon dioxide reserves within the migration range of the tectonic trap region. Calculate the amount of formation water M within the migration range of the tectonic trap area. s,w =V s ·φ·(1-S gr ·R r )·ρ w ; Calculate the amount of dissolved state within the migration range of the constructed trap region. The sum of the tectonic occurrence, residual gaseous occurrence, and dissolved occurrence of carbon dioxide within the migration range of the tectonic trap is calculated, and the sum is taken as the total occurrence of carbon dioxide within the migration range of the tectonic trap. Among them, V s The total volume of the geological grid represents the migration range of the tectonic trap area; φ represents the porosity of the sealed area; S gr R represents the saturation of the bound gas in the sealed area. r Indicates the first coefficient; This represents the average carbon dioxide density of the structural trap area, obtained by averaging the carbon dioxide density of each geological grid within the migration range of the structural trap area using the aforementioned carbon dioxide density distribution; ρ w This indicates the density of formation water in the sealed area; M represents the solubility of carbon dioxide in formation water. s,r M represents the amount of residual gaseous matter within the migration range of the structural trap region; s,e This indicates the amount of tectonic deposits within the migration range of a tectonic trap region.
7. The method according to claim 5, characterized in that, The calculation of the residual gaseous carbon dioxide in the potential overflow zone based on the total carbon dioxide injection volume, the total carbon dioxide accumulation within the structural trap's migration range, the carbon dioxide density distribution, and the first coefficient includes: The difference between the total amount of carbon dioxide injected and the total amount of carbon dioxide stored within the migration range of the structural trap area is taken as the amount of carbon dioxide entering the potential overflow area. Calculate the residual gaseous quantity of carbon dioxide in the potential overflow zone. Among them, M f This indicates the amount of carbon dioxide entering the potential overflow area; This represents the average carbon dioxide density of the potential overflow area, obtained by averaging the carbon dioxide density of each geological grid within the potential overflow area using the aforementioned carbon dioxide density distribution; S gr R represents the saturation of the bound gas in the sealed area. r Represents the first coefficient; ρ w This indicates the density of formation water in the sealed area; This indicates the solubility of carbon dioxide in formation water.
8. The method according to claim 5, characterized in that, When calculating the area of the actual carbon dioxide overflow region based on the residual gaseous carbon dioxide content in the potential overflow zone, the first expansion thickness, and the first coefficient, the following formula is used: Among them, A′ f h represents the area of the actual carbon dioxide overflow. f Indicates the first extended thickness; M f,r This indicates the amount of residual gaseous carbon dioxide in the potential overflow area; This represents the average carbon dioxide density of the potential overflow area, obtained by averaging the carbon dioxide density of each geological grid within the potential overflow area using the aforementioned carbon dioxide density distribution; φ represents the porosity of the containment area; S gr R represents the saturation of the bound gas in the sealed area. r This represents the first coefficient.
9. The method according to claim 1, characterized in that, The numerical prior calculation model for simulating the carbon dioxide sequestration process in saline aquifers is constructed. The carbon dioxide sequestration region, constructed through geological constraints, in the numerical prior calculation model includes structural trap zones and potential overflow zones, including: Obtain the formation physical properties and fluid physical properties of the carbon dioxide storage area; The geological parameter field of the carbon dioxide sequestration area is constructed by using the stratigraphic properties of the carbon dioxide sequestration area as the geological attributes of each volume element in the geological parameter field. The carbon dioxide sequestration area in the geological parameter field includes structural trap areas and potential overflow areas. By inputting the fluid properties of the carbon dioxide sequestration area and the pre-constructed fluid transport control equations into the geological parameter field, a numerical prior calculation model for simulating the carbon dioxide sequestration process in a saline aquifer is obtained.
10. The method according to claim 1, characterized in that, The numerical prior calculation model is used to characterize the possible distribution range of carbon dioxide, obtaining the first extension thickness and the migration range of carbon dioxide in the structural trap area. The first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well, including: The pressure-driven process during carbon dioxide injection and the gravity-driven process after injection is stopped are simulated using the numerical prior calculation model to obtain the first expansion thickness, which is the expansion thickness of carbon dioxide reaching the potential overflow zone in the direction parallel to the depth of the carbon dioxide injection well. The migration thickness of carbon dioxide in the structural trap is calculated based on the structural undulation parameters of the geological parameter field of the carbon dioxide storage area constructed through geological constraints in the numerical prior calculation model and the first extended thickness. The direction of this thickness is parallel to the well depth direction of the carbon dioxide injection well. The migration area of carbon dioxide in the tectonic trap area is calculated based on the tectonic undulation parameters of the geological parameter field. The migration range of carbon dioxide in the structural trap can be obtained by measuring the migration thickness and area of carbon dioxide in the structural trap.
11. The method according to claim 1, characterized in that, Also includes: Combining the distribution of gravity monitoring points and the distribution of gravity anomaly points within the sealed area determined by gravity anomaly data, the migration range of carbon dioxide in the constructed trap area and the migration range of carbon dioxide in the potential overflow area are plotted to obtain a rectangular migration range. The rectangular migration range is modified by utilizing the geological characteristics of the sealed area, including the source direction, sand body distribution characteristics, and fault distribution.
12. A device for inverting the range of carbon dioxide transport in a saline aquifer, characterized in that, include: The geological constraint construction module is used to construct a numerical prior calculation model for simulating the carbon dioxide sequestration process in a saline aquifer. The carbon dioxide sequestration area obtained by geological constraint construction in the numerical prior calculation model includes a tectonic trap area and a potential overflow area. The prior calculation module is used to characterize the possible distribution range of carbon dioxide using the numerical prior calculation model, and obtain the first extension thickness and the migration range of carbon dioxide in the structural trap area. The first extension thickness is the extension thickness of carbon dioxide reaching the potential overflow area in the direction parallel to the well depth of the carbon dioxide injection well. The density distribution calculation module is used to calculate the carbon dioxide density distribution of the storage area using the formation pressure data of the storage area. The first coefficient determination module is used to determine the proportion of the mass change caused by carbon dioxide being bound by pores within the transport range of the structural trap area to the total mass change within the transport range of the structural trap area based on the gravity anomaly data of the sealed area, the carbon dioxide density distribution, and the transport range of carbon dioxide within the structural trap area, and to determine the proportion as the first coefficient. The migration range determination module is used to calculate the actual overflow area of carbon dioxide based on the first coefficient, the solubility of carbon dioxide in formation water, and the density distribution of carbon dioxide, so as to obtain the migration range of carbon dioxide in the potential overflow area.
13. The apparatus according to claim 12, characterized in that, include: The method involves determining the proportion of the mass change caused by carbon dioxide being confined by pores within the structural trap's migration range, based on gravity anomaly data, carbon dioxide density distribution, and the migration range of carbon dioxide within the sealed area, within the total mass change within the structural trap's migration range. This proportion is then defined as a first coefficient, including: Calculate the fluid density change at different locations in the sealed area based on the gravity anomaly data of the sealed area; Calculate the total mass change within the transport range of the structural trap region based on the fluid density change; The porosity, bound gas saturation, and formation water density of the sealed area were obtained. The mass change caused by carbon dioxide being bound by pores within the migration range of the structural trap area is calculated based on the porosity, bound gas saturation, formation water density, and carbon dioxide density distribution of the sealed area. The ratio of the total mass change within the migration range of the tectonic trap to the mass change caused by carbon dioxide being confined by pores within the migration range of the tectonic trap is calculated, and this ratio is used as the first coefficient.
14. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the method for inverting the carbon dioxide transport range of the saline aquifer as described in any one of claims 1-11.
15. A machine-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method for inverting the carbon dioxide transport range of the saline aquifer as described in any one of claims 1-11.
Citation Information
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