A method and system for predicting the optimal depth of CO2 geological storage in marine saline water layers

Abstract

The present invention relates to 2 The technical field of sealing is particularly related to a marine saline layer CO 2 Method and system for predicting optimal depth of geological storage, wherein the marine saline layer C0 2 The optimal depth prediction method for geological storage includes the following steps: obtaining CO 2 The first function between the injection depth and the saline layer temperature; obtaining CO 2 The second function between the injection depth and the saline layer pressure; obtain the saline layer temperature, saline layer pressure and CO 2 The third function between the adsorption amount and the adsorption amount; using the first function and the second function, the CO 2 Injection depth and CO 2 The fourth function between the adsorption amount; Fitting CO according to the fourth function 2 Injection depth and CO 2 The change curve corresponding to the adsorption amount is used to predict the CO adsorption in the marine saline layer based on the change curve. 2 The optimal depth prediction method and system provided by the present invention can be used to formulate the optimal depth prediction for storing CO2 in the marine saline layer. 2 The strategy of optimal depth provides data support.

Description

Technical Field

[0001] The present invention relates to the technical field of CO2 storage, and in particular to a method and system for predicting the optimal depth of CO2 geological storage in marine saline water layers. Background Art

[0002] Due to the sharp increase in CO2 emissions, the trend of global warming has gradually deepened. The current CO2 concentration in the atmosphere has reached 420ppm. In order to cope with climate warming, a solution has been proposed to inject CO2 into deep saline water layers in the ocean for storage. In this solution, the amount of CO2 adsorbed and stored is an important indicator for evaluating a CO2 storage site.

[0003] The amount of CO2 adsorption and storage is closely related to the depth of the injection formation. Although parameters such as temperature and pressure can be controlled in the laboratory, the sample size in the laboratory is limited and cannot truly reflect the impact of the CO2 injection formation depth on the CO2 adsorption amount on a macro scale. In addition, the selection of the CO2 injection formation depth also seriously affects the economic efficiency of the CO2 injection project construction. Therefore, a method and system for predicting the optimal depth of CO2 geological storage in marine saline layers is urgently needed to analyze the CO2 adsorption and storage at different depths in the CO2 injection target area, and provide data support for the optimal depth strategy for storing CO2. Summary of the invention

[0004] In view of the deficiencies of the prior art and the needs of practical applications, the present invention provides a method and system for predicting the optimal depth of geological storage of CO2 in marine saline layers, aiming to provide data support for formulating a strategy for the optimal depth of CO2 storage in marine saline layers.

[0005] In a first aspect, the present invention provides a method for predicting the optimal depth of CO2 geological storage in marine saline water layers, comprising the following steps: obtaining a first function between the CO2 injection formation depth and the saline water layer temperature, the independent variable of the first function being the CO2 injection formation depth, and the dependent variable of the first function being the saline water layer temperature; obtaining a second function between the CO2 injection formation depth and the saline water layer pressure, the independent variable of the second function being the CO2 injection formation depth, and the dependent variable of the second function being the saline water layer pressure; obtaining a third function between the saline water layer temperature, the saline water layer pressure and the CO2 adsorption amount, the independent variables of the third function being the saline water layer temperature and the saline water layer pressure, and the dependent variable of the third function being the CO2 adsorption amount; using the first function and the second function, obtaining a fourth function between the CO2 injection formation depth and the CO2 adsorption amount based on the third function, the independent variable of the fourth function being the CO2 injection formation depth, and the dependent variable of the fourth function being the CO2 adsorption amount; fitting a variation curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount according to the fourth function, and predicting the optimal depth of CO2 storage in marine saline water layers based on the variation curve.

[0006] The method for predicting the optimal depth of geological storage of CO2 in marine saline layers provided by the present invention has the following benefits: the present invention uses the temperature and pressure of the saline layer as intermediate variables, and realizes the construction of a correlation model between the CO2 injection formation depth and the CO2 adsorption amount. The correlation model between the CO2 injection formation depth and the CO2 adsorption amount can be used to quantify the CO2 storage capacity of saline layers at different depths, thereby providing strong data support for formulating a strategy for the optimal depth of CO2 storage in marine saline layers.

[0007] Optionally, the first function satisfies the following characterization formula: ,in, represents the temperature of the saline layer when CO2 is injected into the formation at a depth of h, Indicates the depth of CO2 injection into the formation, Indicates the temperature gradient of the saline layer in the target area of ​​CO2 injection, Indicates the seabed surface temperature corresponding to the CO2 injection depth of 0. The present invention introduces a temperature gradient and seabed surface temperature , which can more accurately reflect the relationship between the depth of CO2 injection into the formation and the temperature of the saline water layer.

[0008] Optionally, the second function satisfies the following characterization formula: ,in, represents the pressure of the saline layer when CO2 is injected into the formation at a depth of h, Indicates the depth of CO2 injection into the formation, Indicates the pressure gradient of the saline layer in the target area of ​​CO2 injection, Indicates the seabed surface pressure corresponding to the CO2 injection depth of 0. The present invention introduces a pressure change gradient and seabed surface pressure , which can more accurately reflect the relationship between the CO2 injection formation depth and the saline water layer pressure.

[0009] Optionally, the obtaining of the third function between the saltwater layer temperature, the saltwater layer pressure and the CO2 adsorption amount comprises the following steps: constructing the third function between the saltwater layer temperature, the saltwater layer pressure and the CO2 adsorption amount according to the Langmuir equation, wherein the third function satisfies the following model: ,in, It means that when the temperature of the saltwater layer is T and the pressure of the saltwater layer is P, the total amount of CO2 adsorbed by the saltwater layer is It means that when the temperature of the saltwater layer is T, the pressure of the saltwater layer is As it approaches infinity, the first CO2 adsorption capacity of the saline layer is represents the Langmuir pressure corresponding to the saline water layer temperature T, Indicates the pressure of the saline layer. Based on the Langmuir equation, the present invention constructs a third function that can accurately describe the CO2 adsorption and storage capacity of the saline layer under different conditions, providing a model support for further obtaining a fourth function that characterizes the relationship between the CO2 injection depth and the CO2 adsorption amount.

[0010] Further optionally, the first CO2 adsorption amount The following calculation model is satisfied: ,in, It means that when the temperature of the salt water layer is 0K, the pressure of the salt water layer is As it approaches infinity, the second CO2 adsorption capacity of the saline layer is represents the enthalpy difference of all adsorption surfaces in the saline layer, T represents the temperature of the saline layer, represents the gas constant; the Langmuir pressure The following calculation model is satisfied: ,in, The pre-exponential factor representing the dependence of the Langmuir pressure on the temperature of the saline layer, represents the dynamic equilibrium enthalpy difference of adsorption-desorption in the saline water layer, T represents the temperature of the saline water layer, represents the gas constant.

[0011] Further optionally, using the first function and the second function, a fourth function between the CO2 injection depth and the CO2 adsorption amount obtained based on the third function satisfies the following model: ,in, It represents the total amount of CO2 adsorbed by the saline layer when CO2 is injected into the formation at a depth of h. It means that when the temperature of the salt water layer is 0K, the pressure of the salt water layer is When it approaches infinity, the second CO2 adsorption capacity of the saline layer is The pre-exponential factor representing the dependence of the Langmuir pressure on the temperature of the saline layer, represents the kinetic equilibrium enthalpy difference of adsorption-desorption in the saline water layer, represents the enthalpy difference of all adsorption surfaces in the saline layer, is the gas constant, Indicates the depth of CO2 injection into the formation, Indicates the temperature gradient of the saline layer in the target area of ​​CO2 injection, Indicates the seabed surface temperature corresponding to the CO2 injection depth of 0. Indicates the pressure gradient of the saline layer in the target area of ​​CO2 injection, It represents the seabed surface pressure when the CO2 injection depth is 0. The fourth function provided by the present invention provides a fitting model basis for predicting the relationship between the CO2 adsorption amount and the CO2 injection depth, which helps to provide data support for formulating the strategy of the optimal depth of CO2 storage in the marine saline layer.

[0012] Optionally, the fitting of the variation curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount according to the fourth function, and the prediction of the optimal depth of CO2 storage in the marine saline layer based on the variation curve, include the following steps: determining the value of the constant term in the fourth function; setting the CO2 injection formation depth range, and fitting the variation curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount within the CO2 injection formation depth range based on the fourth function that determines the value of the constant term; setting the optimal depth setting range, and predicting the optimal depth of CO2 storage in the marine saline layer within the optimal depth setting range according to the variation curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount. The variation curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount fitted by the present invention provides quantitative data support for the CO2 storage capacity of saline layers of different depths, and provides data support for the strategy of the optimal depth of CO2 storage in the marine saline layer, thereby helping to improve the effectiveness and rationality of the strategy of setting the optimal depth of CO2 storage in the marine saline layer.

[0013] Optionally, the predicting of the optimal depth for CO2 storage in the marine saline layer within the optimal depth setting range comprises the following steps: within the optimal depth setting range, the variation curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount has a maximum point of CO2 adsorption, and the CO2 injection formation depth corresponding to the maximum point of CO2 adsorption is set as the optimal depth for CO2 storage in the marine saline layer. The present invention can intuitively and effectively determine the optimal depth through the maximum point of adsorption within the optimal depth setting range, which helps to improve the CO2 storage efficiency and reduce the cost of CO2 injection engineering construction.

[0014] Further optionally, the optimal depth setting range is (1000m, 5000m). The optimal depth setting range provided by the present invention takes into account the storage effect and economic cost, provides a feasible depth range in practical applications, and helps to achieve the best storage effect of CO2.

[0015] In a second aspect, the present invention also provides a system for predicting the optimal depth of geological storage of CO2 in marine saline water layers, the system comprising an input device, a processor, a memory and an output device, wherein the input device, the processor, the memory and the output device are interconnected, wherein the memory is used to store a computer program, the computer program comprises program instructions, and the processor is configured to call the program instructions to execute a method for predicting the optimal depth of geological storage of CO2 in marine saline water layers.

[0016] The benefit of the optimal depth prediction system for geological storage of C02 in marine saline layers provided by the present invention is that the optimal depth prediction system for geological storage of C02 in marine saline layers provided by the present invention can more conveniently and efficiently provide data support for the strategy of optimal depth for storing C02 in marine saline layers, thereby helping to improve the effectiveness and rationality of the optimal depth setting strategy for storing C02 in marine saline layers. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flow chart of the optimal depth prediction method for geological storage of CO2 in saline marine layers provided by the present invention;

[0018] Figure 2 The CO2 injection depth h and the total CO2 adsorption amount of the saline layer provided in the embodiment of the present invention The first change curve between

[0019] Figure 3 The CO2 injection depth h and the total CO2 adsorption amount of the saline layer provided in the embodiment of the present invention The second variation curve between

[0020] Figure 4 The optimal depth prediction system for geological storage of CO2 in marine saline water layers provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described herein are only for illustration and are not intended to limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that these specific details do not need to be adopted to implement the present invention. In other examples, in order to avoid confusing the present invention, known circuits, software or methods are not specifically described.

[0022] Throughout the specification, references to "one embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in conjunction with the embodiment or example is included in at least one embodiment of the present invention. Therefore, the phrases "in one embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily all refer to the same embodiment or example. In addition, particular features, structures, or characteristics may be combined in one or more embodiments or examples in any suitable combination and / or subcombination. In addition, it should be understood by those of ordinary skill in the art that the figures provided herein are for illustrative purposes and that the figures are not necessarily drawn to scale.

[0023] In one embodiment, see Figure 1 , Figure 1 This is a flow chart of the optimal depth prediction method for geological storage of CO2 in the marine saline layer provided by the present invention. Figure 1 As shown, the method for predicting the optimal depth of CO2 geological storage in marine saline water layers provided by the present invention includes the following steps: S01, obtaining a first function between the CO2 injection formation depth and the saline water layer temperature, wherein the independent variable of the first function is the CO2 injection formation depth, and the dependent variable of the first function is the saline water layer temperature.

[0024] The marine CO2 saltwater layer described in the present invention refers to a saltwater layer at a certain depth below the seabed for storing CO2. The mineralization of the saltwater layer is between 3g / L and 50g / L. The water in the saltwater layer has dissolved high concentrations of salts (salinity is higher than 10g / L), which is not suitable for agriculture and human production and life. The saltwater layer is widely distributed and covers a large area. It can store CO2 for up to millions of years and has huge storage potential.

[0025] It is easy to understand that the first function is used to characterize the corresponding relationship between the CO2 injection depth and the saltwater layer temperature. Generally, as the CO2 injection depth increases, the corresponding saltwater layer temperature also gradually increases.

[0026] In one or some specific embodiments, as the depth of CO2 injection into the formation increases, the temperature of the corresponding saline layer increases linearly. In this or these embodiments, the first function satisfies the following characterization formula: ,in, represents the temperature of the saline layer when CO2 is injected into the formation at a depth of h, Indicates the depth of CO2 injection into the formation, Indicates the temperature gradient of the saline layer in the target area of ​​CO2 injection, Indicates the seabed surface temperature corresponding to the CO2 injection depth of 0.

[0027] In one or more other specific embodiments, as the CO2 injection depth increases, the temperature of the saline layer in the CO2 injection target area increases to a value greater than or less than The gradient of change increases linearly.

[0028] Furthermore, if Figure 1 As shown, the method for predicting the optimal depth of CO2 geological storage in marine saline water layers provided by the present invention also includes the following steps: S02, obtaining a second function between the CO2 injection formation depth and the saline water layer pressure, the independent variable of the second function is the CO2 injection formation depth, and the dependent variable of the second function is the saline water layer pressure.

[0029] It is easy to understand that the second function is used to characterize the corresponding relationship between the CO2 injection depth and the saline water layer pressure. Generally, as the CO2 injection depth increases, the corresponding saline water layer pressure also gradually increases.

[0030] In one or some specific embodiments, as the depth of CO2 injection into the formation increases, the corresponding saltwater layer pressure increases linearly. In this or these embodiments, the second function satisfies the following characterization formula: ,in, represents the pressure of the saline layer when CO2 is injected into the formation at a depth of h, Indicates the depth of CO2 injection into the formation, Indicates the pressure gradient of the saline layer in the target area of ​​CO2 injection, It indicates the seabed surface pressure corresponding to the CO2 injection depth of 0.

[0031] In one or more other specific embodiments, as the depth of CO2 injection into the formation increases, the pressure of the saline layer in the corresponding CO2 injection target area increases to greater than or less than The gradient of change increases linearly.

[0032] Furthermore, if Figure 1 As shown, the method for predicting the optimal depth of CO2 geological storage in marine saline water layers provided by the present invention also includes the following steps: S03, obtaining a third function between the saline water layer temperature, the saline water layer pressure and the CO2 adsorption amount, the independent variables of the third function are the saline water layer temperature and the saline water layer pressure, and the dependent variable of the third function is the CO2 adsorption amount.

[0033] It is easy to understand that the third function is used to characterize the corresponding relationship between the two independent variables, namely, the temperature and pressure of the saline water layer and the amount of CO2 adsorption.

[0034] In this embodiment, the third function is constructed according to the Langmuir equation. It can be known that the Langmuir equation characterizes the coverage of molecules on the solid surface under certain temperature conditions.

[0035] Furthermore, the third function between the saline water layer temperature, saline water layer pressure and CO2 adsorption amount constructed according to the Langmuir equation satisfies the following model: ,in, It means that when the temperature of the saltwater layer is T and the pressure of the saltwater layer is P, the total amount of CO2 adsorbed by the saltwater layer is It means that when the temperature of the saltwater layer is T, the pressure of the saltwater layer is As it approaches infinity, the first CO2 adsorption capacity of the saline layer is represents the Langmuir pressure corresponding to the saline water layer temperature T, Indicates the pressure of the salt water layer.

[0036] Specifically, in the third function constructed by the Langmuir equation, the first CO2 adsorption amount The following calculation model is satisfied: ,in, It means that when the temperature of the salt water layer is 0K, the pressure of the salt water layer is When it approaches infinity, the second CO2 adsorption capacity of the saline layer is represents the enthalpy difference of all adsorption surfaces in the saline layer, T represents the temperature of the saline layer, represents the gas constant.

[0037] Combining the first function and the second function, the first CO2 adsorption amount It can be further characterized as the following calculation model: ,in, Indicates the temperature gradient of the saline layer in the target area of ​​CO2 injection, Indicates the depth of CO2 injection into the formation, Indicates the seabed surface temperature corresponding to the CO2 injection depth of 0.

[0038] Specifically, in the third function constructed by the Langmuir equation, the Langmuir pressure The following calculation model is satisfied: ,in, The pre-exponential factor representing the dependence of the Langmuir pressure on the temperature of the saline layer, represents the dynamic equilibrium enthalpy difference of adsorption-desorption in the saline water layer, T represents the temperature of the saline water layer, represents the gas constant.

[0039] Combining the first function and the second function, the Langmuir pressure It can be further characterized as the following calculation model: ,in, Indicates the temperature gradient of the saline layer in the target area of ​​CO2 injection, Indicates the depth of CO2 injection into the formation, Indicates the seabed surface temperature corresponding to the CO2 injection depth of 0.

[0040] Furthermore, if Figure 1 As shown, the method for predicting the optimal depth of CO2 geological storage in marine saline layers provided by the present invention also includes the following steps: S04, using the first function and the second function, based on the third function, obtaining a fourth function between the CO2 injection formation depth and the CO2 adsorption amount, the independent variable of the fourth function is the CO2 injection formation depth, and the dependent variable of the fourth function is the CO2 adsorption amount.

[0041] In this embodiment, the calculation model based on the third function , the constructed fourth function satisfies the following model: ,in, It indicates the total amount of CO2 adsorbed by the saline layer when the CO2 is injected into the formation at a depth of h. It represents the first CO2 adsorption amount of the saline layer when the CO2 injection depth is h, represents the Langmuir pressure when CO2 is injected into the formation at a depth of h, It represents the pressure of the saline layer when the CO2 is injected into the formation at a depth of h.

[0042] The fourth function constructed in step S04 further satisfies the following model: ,in, It represents the total amount of CO2 adsorbed by the saline layer when the CO2 is injected into the formation at a depth of h. It means that when the temperature of the salt water layer is 0K, the pressure of the salt water layer is When it approaches infinity, the second CO2 adsorption capacity of the saline layer is The pre-exponential factor representing the dependence of the Langmuir pressure on the temperature of the saline layer, represents the kinetic equilibrium enthalpy difference of adsorption-desorption in the saline water layer, represents the enthalpy difference of all adsorption surfaces in the saline layer, is the gas constant, Indicates the depth of CO2 injection into the formation, Indicates the temperature gradient of the saline layer in the target area of ​​CO2 injection, Indicates the seabed surface temperature corresponding to the CO2 injection depth of 0. Indicates the pressure gradient of the saline layer in the target area of ​​CO2 injection, Indicates the seabed surface pressure when the CO2 injection depth is 0.

[0043] Furthermore, if Figure 1 As shown, the method for predicting the optimal depth of CO2 geological storage in marine saline water layers provided by the present invention also includes the following steps: S05, fitting the change curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount according to the fourth function, and predicting the optimal depth of CO2 storage in marine saline water layers based on the change curve.

[0044] In this embodiment, the step S05 of fitting the variation curve corresponding to the CO2 injection depth and the CO2 adsorption amount according to the fourth function, and predicting the optimal depth of CO2 storage in the marine saline water layer based on the variation curve, includes the following steps:

[0045] S051. Determine the value of the constant term in the fourth function.

[0046] It can be seen that the constant term includes the second CO2 adsorption amount , the kinetic equilibrium enthalpy difference of adsorption-desorption in saline water layer , the enthalpy difference of all adsorption surfaces in the saline layer , the gas constant , the temperature gradient of the saline layer in the target area of ​​CO2 injection , when CO2 is injected into the formation at a depth of 0, the seabed surface , the pressure gradient of the saline layer in the target area of ​​CO2 injection , and the seabed surface pressure when CO2 is injected into the formation at a depth of 0 .

[0047] S052. Set a CO2 injection formation depth range, and based on a fourth function for determining a constant term value, fit a variation curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount within the CO2 injection formation depth range.

[0048] The CO2 injection depth range of the present invention is used to fit the independent variable range in the variation curve corresponding to the CO2 injection depth and the CO2 adsorption amount. Usually, in order to ensure the economic benefits of CO2 injection, the CO2 injection depth range is ; In one or some other embodiments, the CO2 injection formation depth range can also be set according to actual conditions.

[0049] It is known that when CO2 is injected into the formation When the depth is less than 1000m, the CO2 storage effect is poor; when the CO2 is injected into the formation When the depth is greater than 5000m, the economic benefits of CO2 injection are low. The corresponding change curve can be fitted by mathematical statistics software such as MATLAB and Excel.

[0050] S053. Setting an optimal depth setting range, and predicting the optimal depth for CO2 storage in the marine saline water layer within the optimal depth setting range according to a variation curve corresponding to the CO2 injection formation depth and the CO2 adsorption amount.

[0051] In this embodiment, the optimal depth setting range is the selection range of the CO2 storage depth in the marine saline layer. Generally, in order to ensure the CO2 storage effect and the economic benefits of CO2 injection, the optimal depth setting range of CO2 storage in the marine saline layer is In one or some other embodiments, the optimal depth setting range for storing CO2 in the marine saline layer can also be set according to actual conditions.

[0052] In a specific embodiment, at a location in the Qiongdongnan Sea Basin, according to the relevant stratigraphic survey report, the constant term in the fourth function is taken as follows: The second CO2 adsorption amount is 1mmol / g, the gas constant The temperature gradient of the saline layer in the target area of ​​CO2 injection is 8.31451 J / (mol*K). The pressure gradient of the saline layer in the target area of ​​CO2 injection is 0.03K / m. 0.01MPa / m, the seabed surface temperature when CO2 is injected into the formation at a depth of 0 is 298.15K, and the seabed surface pressure when CO2 is injected into the formation at a depth of 0 is 1 MPa, the enthalpy difference of all adsorption surfaces in the saline layer =-5KJ / mol, the kinetic equilibrium enthalpy difference of adsorption-desorption in the saline water layer 5KJ / mol; the CO2 injection depth range is , the optimal depth setting range is .

[0053] Further, based on the fourth function , fitting the CO2 injection depth h and the total CO2 adsorption in the saline layer For the corresponding change curve, see Figure 2 , Figure 2 The CO2 injection depth h and the total CO2 adsorption amount of the saline layer provided in the embodiment of the present invention The first change curve between .

[0054] like Figure 2 As shown, the CO2 injection depth h ranges from The maximum value of CO2 adsorption appeared in the variation curve. Within the CO2 injection formation depth h before the maximum value of CO2 adsorption, the deeper the CO2 injection formation depth, the greater the total CO2 adsorption of the saline layer. The larger the CO2 injection depth h after the maximum CO2 adsorption point, the deeper the CO2 injection depth, the greater the total CO2 adsorption in the saline layer. Therefore, in this embodiment, the CO2 injection formation depth h corresponding to the maximum CO2 adsorption amount point is the optimal depth for CO2 storage in the marine saline layer.

[0055] In another specific embodiment, at another location in the Qiongdongnan Sea Basin, according to the relevant stratigraphic survey report, the constant term in the fourth function is taken as follows: The second CO2 adsorption amount is 1mmol / g, the gas constant The temperature gradient of the saline layer in the target area of ​​CO2 injection is 8.31451 J / (mol*K). The pressure gradient of the saline layer in the target area of ​​CO2 injection is 0.03K / m. 0.01MPa / m, the seabed surface temperature when CO2 is injected into the formation at a depth of 0 is 298.15K, and the seabed surface pressure when CO2 is injected into the formation at a depth of 0 is 1 MPa, the enthalpy difference of all adsorption surfaces in the saline layer =-5KJ / mol, the kinetic equilibrium enthalpy difference of adsorption-desorption in the saline water layer is 10KJ / mol; the CO2 injection depth range is , the optimal depth setting range is .

[0056] Further, based on the fourth function , fitting the CO2 injection depth h and the total CO2 adsorption in the saline layer For the corresponding change curve, see Figure 3 , Figure 3 The CO2 injection depth h and the total CO2 adsorption amount of the saline layer provided in the embodiment of the present invention The second variation curve between .

[0057] like Figure 3 As shown in the figure, within the optimal depth setting range of CO2 storage in the marine saline layer, the total amount of CO2 adsorbed by the saline layer There is no inflection point. Therefore, according to the quantitative data of the CO2 storage capacity of saline layers at different depths in the second change curve and the economic benefits of CO2 injection, the optimal depth setting range can be set. Select the optimal depth.

[0058] In yet another embodiment, see Figure 4 , Figure 4 The optimal depth prediction system for geological storage of CO2 in saline marine layers provided by the embodiment of the present invention is as follows. Figure 4 As shown, the optimal depth prediction system for geological storage of CO2 in marine saline water layers includes an input device, a processor, a memory and an output device.

[0059] In this embodiment, the input device, the processor, the memory and the output device are interconnected, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions to execute the optimal depth prediction method for geological storage of CO2 in marine saline layers.

[0060] The input device is an interface of the system, used for receiving external data or user input of external data, and the external data may be the constant value of the first function, the second function, the third function and the fourth function.

[0061] The processor is the core part of the system, performing the task of calculating and processing input data, and calling the program instructions in the memory to perform depth prediction calculations. Specifically, the processor can be a computer or an embedded system with sufficient computing power to execute complex depth prediction algorithms. It calls the program instructions stored in the memory to execute the depth prediction method based on the data provided by the input device.

[0062] The memory is used to store data and program instructions required by the system, including a computer program for executing an optimal depth prediction method for ocean CO2 saline layer storage. Specifically, the memory may include a RAM (random access memory) and a ROM (read-only memory), wherein the RAM is used to temporarily store data, and the ROM stores program instructions required when the system is started.

[0063] The output device is an interface used by the system to provide results to users or other devices, and is usually used to display, record or transmit the results of depth prediction. Specifically, the output device may include a display screen, a printer, a data recorder, etc. They are used to display the calculated optimal depth of marine CO2 saline layer storage so that users can understand the prediction results.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A marine saltwater layer The optimal depth prediction method for geological storage is characterized by: The steps include: Get The first function between the injection formation depth and the saline layer temperature, the independent variable of the first function is injection formation depth, the dependent variable of the first function is the temperature of the saline water layer; Get The second function between the injection depth and the pressure of the saline layer, the independent variable of the second function is injection depth, the dependent variable of the second function is the pressure of the saline layer; Get the saltwater layer temperature, saltwater layer pressure and The third function between the adsorption amount, the independent variables of the third function are the saltwater layer temperature and the saltwater layer pressure, and the dependent variable of the third function is Adsorption capacity; Using the first function and the second function, based on the third function, obtain Injection depth and The fourth function between the adsorption amount and the independent variable of the fourth function is Injection depth, the dependent variable of the fourth function is Adsorption capacity; According to the fourth function fitting Injection depth and A change curve corresponding to the adsorption amount, and a prediction of the marine saline layer based on the change curve Optimal storage depth; The first function satisfies the following characterization formula: ， in, express The temperature of the saline layer corresponding to the injection depth h, express Injection depth, express The temperature gradient of the saline layer in the injection target area, express The seabed surface temperature corresponding to the injection depth of 0; The second function satisfies the following characterization formula: ， in, express The corresponding saline layer pressure when the injection depth is h, express Injection depth, express The pressure gradient of the saline layer in the injection target area, express The seabed surface pressure corresponding to the injection depth of 0; The method for obtaining the saltwater layer temperature, saltwater layer pressure and The third function between the adsorption amounts includes the following steps: The Langmuir equation is used to construct the relationship between the saltwater layer temperature, saltwater layer pressure and The third function between the adsorption amounts satisfies the following model: ， in, It means that when the temperature of the salt water layer is , the saltwater layer pressure is When the saline layer The total adsorption It means that when the temperature of the salt water layer is , saltwater layer pressure As it approaches infinity, the first Adsorption amount, The temperature of the saltwater layer is The corresponding Langmuir pressure is, Indicates the pressure of the saline layer; The first Adsorption The following calculation model is satisfied: , in, It means that when the temperature of the salt water layer is 0K, the pressure of the salt water layer is As it approaches infinity, the second Adsorption amount, represents the enthalpy difference of all adsorption surfaces in the saline layer, represents the temperature of the saline layer, represents the gas constant; The Langmuir pressure The following calculation model is satisfied: ， in, The pre-exponential factor representing the dependence of the Langmuir pressure on the temperature of the saline layer, represents the kinetic equilibrium enthalpy difference of adsorption-desorption in the saline water layer, represents the temperature of the saline layer, represents the gas constant; Using the first function and the second function, based on the third function obtained Injection depth and The fourth function between the adsorption amounts satisfies the following model: ， in, express The injection depth of the saline layer is h The total adsorption It means that when the temperature of the salt water layer is 0K, the pressure of the salt water layer is As it approaches infinity, the second Adsorption amount, The pre-exponential factor representing the dependence of the Langmuir pressure on the temperature of the saline layer, represents the kinetic equilibrium enthalpy difference of adsorption-desorption in the saline water layer, represents the enthalpy difference of all adsorption surfaces in the saline layer, is the gas constant, express Injection depth, express The temperature gradient of the saline layer in the injection target area, express The seabed surface temperature corresponding to the injection depth of 0, express The pressure gradient of the saline layer in the injection target area, express The seabed surface pressure when the injection depth is 0.

2. The marine saltwater layer according to claim 1 The optimal depth prediction method for geological storage is characterized by: The fitting according to the fourth function Injection depth and A change curve corresponding to the adsorption amount, and a prediction of the marine saline layer based on the change curve The optimal sealing depth includes the following steps: determining a value of a constant term in the fourth function; set up The injection depth range is based on the fourth function that determines the value of the constant term, in the Fitting within the injection formation depth range Injection depth and The change curve corresponding to the adsorption amount; Set the optimal depth setting range according to the Injection depth and The variation curve corresponding to the adsorption amount predicts the marine saline layer within the optimal depth setting range Optimal storage depth.

3. The marine saltwater layer according to claim 2 The optimal depth prediction method for geological storage is characterized by: The method predicts the ocean saline layer within the optimal depth setting range The optimal sealing depth includes the following steps: Within the optimal depth setting range, the Injection depth and The change curve corresponding to the adsorption amount exists The maximum adsorption amount point is The maximum adsorption point corresponds to The injection depth is set to the marine saline layer Optimal storage depth.

4. The marine saltwater layer according to claim 3 The optimal depth prediction method for geological storage is characterized by: The optimal depth setting range is (1000m, 5000m).

5. A saltwater layer in the ocean The geological storage optimal depth prediction system is characterized by: The invention comprises an input device, a processor, a memory and an output device, wherein the input device, the processor, the memory and the output device are connected to each other, wherein the memory is used to store a computer program, the computer program includes program instructions, and the processor is configured to call the program instructions to execute the marine saltwater layer according to any one of claims 1 to 4. Method for predicting optimal depth of geological storage.

Images