Gas dissolved storage amount calculation method, system, storage medium and electronic equipment

Abstract

The embodiment of the present invention provides a method, system, storage medium and electronic device for calculating the amount of gas dissolved and stored. The method includes: performing molecular dynamics simulation on a rock simulation area containing organic molecules to obtain an organic matrix model; adding ion pairs and water molecules to the organic matrix model to obtain a water-containing organic rock pore model; simulating the adsorption and dissolution process of the target gas in the water-containing organic rock pore model, and when the adsorption amount of the target gas on the rock pore wall in the water-containing organic rock pore model and the dissolution amount in water are both saturated, determining the solubility of the target gas in the water-containing organic rock pore model; and calculating the amount of dissolved and stored gas in the organic rock based on the solubility in the water-containing organic rock pore model. The present invention takes into account the adsorption effect of the rock pore wall on the gas, and can improve the calculation accuracy of the amount of gas dissolved and stored.

Description

Technical Field

[0001] The present invention relates to the field of computer technology, and in particular to a method, system, storage medium and electronic equipment for calculating dissolved gas storage capacity. Background Art

[0002] There are a large number of nanopores between rock particles in the formation, which can provide sufficient storage space for the geological storage of gas. In addition to the existence of the gas in the pores in the form of free and adsorbed states, the geological storage form of gas in the formation also includes the dissolved state dissolved in the formation water because some pores contain water under the influence of formation water.

[0003] The dissolved gas storage capacity is the amount of gas that can be dissolved when the original formation water reaches gas saturation. Currently, the dissolved gas storage capacity in the formation is calculated based on the solubility of the gas in water under bulk conditions, which will cause the calculated dissolved gas storage capacity to have a large error. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a method, system, storage medium and electronic device for calculating the amount of dissolved gas storage, which takes into account the adsorption effect of the rock pore wall on the gas and can improve the calculation accuracy of the amount of dissolved gas storage. The specific technical solution is as follows:

[0005] The present invention provides a method for calculating the amount of dissolved gas storage, comprising:

[0006] Performing molecular dynamics simulation on a rock simulation area containing organic molecules to obtain an organic matrix model; wherein the number of the organic molecules is determined based on the density of the organic rock of the target formation, and the organic rock contains the organic molecules;

[0007] Adding ion pairs and water molecules to the organic matrix model to obtain a water-containing organic rock pore model; wherein the number of the water molecules and the number of the ion pairs are determined based on the unit volume pore water content of the organic rock in the target formation and the rock pore volume of the organic matrix model; the ion pairs include sodium ions and chloride ions;

[0008] Simulating the adsorption and dissolution process of the target gas in the water-containing organic rock pore model, when the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the water-containing organic rock pore model are both saturated, determining the solubility of the target gas in the water-containing organic rock pore model; the solubility of the target gas in the water-containing organic rock pore model is obtained based on the total number of the target gas molecules in the water-containing organic rock pore model;

[0009] The dissolved storage amount of the target gas in the organic rock is calculated based on the solubility in the water-containing organic rock pore model.

[0010] Optionally, it also includes:

[0011] Obtaining an inorganic matrix model based on inorganic molecules; wherein the inorganic rock of the target formation contains the inorganic molecules;

[0012] Adding the ion pairs and water molecules to the inorganic matrix model to obtain a water-containing inorganic rock pore model; wherein the number of the water molecules and the number of the ion pairs are determined based on the pore water content per unit volume of the inorganic rock in the target formation and the rock pore volume of the inorganic matrix model;

[0013] Simulating the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model, when the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the water-containing inorganic rock pore model are both saturated, determining the solubility of the target gas in the water-containing inorganic rock pore model; the solubility of the target gas in the water-containing inorganic rock pore model is obtained based on the total number of the target gas molecules in the water-containing inorganic rock pore model;

[0014] The dissolved storage amount of the target gas in the inorganic rock is calculated based on the solubility in the water-containing inorganic rock pore model.

[0015] Optionally, the molecular dynamics simulation of the rock simulation area containing organic molecules to obtain the organic matrix model specifically includes:

[0016] The first model was obtained by molecular dynamics simulation of the NVT ensemble in the rock simulation area containing organic molecules;

[0017] Performing molecular dynamics simulation of the NPT ensemble on the first model to obtain a second model;

[0018] Determining a rock parameter value of the second model, and judging whether the rock parameter value is within a preset rock parameter value range;

[0019] If yes, the second model is used as the organic matrix model;

[0020] If not, update the NPT ensemble, wherein the temperature of the updated NPT ensemble is less than the temperature of the NPT ensemble; perform molecular dynamics simulation of the updated NPT ensemble on the second model to obtain an updated second model, use the updated second model as the second model, use the updated NPT ensemble as the NPT ensemble, and then return to the step of "determining the rock parameter value of the second model, and judging whether the rock parameter value is within the preset rock parameter value range".

[0021] Optionally, after obtaining the organic matrix model, the method further comprises:

[0022] Adjusting the shape and / or size of rock pores in the organic matrix model to obtain an adjusted organic matrix model;

[0023] And / or, after obtaining the inorganic matrix model, the method further comprises:

[0024] The shape and / or size of the rock pores in the inorganic matrix model are adjusted to obtain an adjusted inorganic matrix model.

[0025] Optionally, the simulation of the adsorption and dissolution process of the target gas in the water-containing organic rock pore model specifically includes:

[0026] Using a grand canonical Monte Carlo method to simulate the adsorption and dissolution process of the target gas in the water-containing organic rock pore model under the conditions of a preset reservoir temperature and a preset pressure of the target gas;

[0027] And / or, the simulation of the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model specifically includes:

[0028] The Grand Canonical Monte Carlo method is used to simulate the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model under the preset reservoir temperature and preset pressure conditions of the target gas.

[0029] Optionally, the method for calculating the dissolved storage amount specifically includes:

[0030] The dissolved storage amount is calculated according to the following formula:

[0031] S 气体 =A×H×φ×W×R 气体 ×M 气体

[0032] In the formula, S 气体 is the dissolved storage capacity of the target gas, A is the distribution area of ​​the rock, H is the thickness of the rock, φ is the porosity of the rock, W is the water content per unit volume of pores, and R 气体is the solubility of the target gas, M 气体 is the molar mass of the target gas.

[0033] Optionally, the method for determining the number of water molecules specifically includes:

[0034] The number of water molecules is determined according to the following formula:

[0035] N1=V p ×W×N A / M1

[0036] In the formula, N1 is the number of water molecules, V p is the rock pore volume, W is the pore water content per unit volume, M1 is the molar mass of water, N A is Avogadro's constant;

[0037] And / or, the method for determining the number of ion pairs specifically includes:

[0038] The number of ion pairs is determined according to the following formula:

[0039] N2=V p ×W×c×N A

[0040] Where N2 is the number of ion pairs and c is the salt concentration of formation water.

[0041] The present invention also provides a gas dissolved storage amount calculation system, comprising:

[0042] A molecular dynamics simulation module, used to perform molecular dynamics simulation on a rock simulation area containing organic molecules to obtain an organic matrix model; wherein the number of the organic molecules is determined based on the density of the organic rock of the target formation, and the organic rock contains the organic molecules;

[0043] A model generation module, used for adding ion pairs and water molecules to the organic matrix model to obtain a water-containing organic rock pore model; wherein the number of the water molecules and the number of the ion pairs are determined based on the unit volume pore water content of the organic rock in the target formation and the rock pore volume of the organic matrix model; the ion pairs include sodium ions and chloride ions;

[0044] A solubility determination module is used to simulate the adsorption and dissolution process of the target gas in the water-containing organic rock pore model. When the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the water-containing organic rock pore model are both saturated, the solubility of the target gas in the water-containing organic rock pore model is determined; the solubility of the target gas in the water-containing organic rock pore model is obtained based on the total number of the target gas molecules in the water-containing organic rock pore model;

[0045] The dissolution storage volume calculation module is used to calculate the dissolution storage volume of the target gas in the organic rock based on the solubility in the water-containing organic rock pore model.

[0046] The present invention also provides a computer-readable storage medium, on which a program is stored, and when the program is executed by a processor, the above-mentioned method for calculating the dissolved gas storage amount is implemented.

[0047] The present invention also provides an electronic device, comprising:

[0048] At least one processor, and at least one memory and bus connected to the processor;

[0049] The processor and the memory communicate with each other via the bus; the processor is used to call program instructions in the memory to execute the above-mentioned gas dissolved storage amount calculation method.

[0050] The embodiments of the present invention provide a method, system, storage medium and electronic device for calculating gas dissolution storage capacity, which performs molecular dynamics simulation on a rock simulation area containing organic molecules to obtain an organic matrix model; adds ion pairs and water molecules to the organic matrix model to obtain a water-containing organic rock pore model; simulates the adsorption and dissolution process of the target gas in the water-containing organic rock pore model, and when the adsorption amount of the target gas on the rock pore wall in the water-containing organic rock pore model and the dissolution amount in water are both saturated, the solubility of the target gas in the water-containing organic rock pore model is determined; and the dissolution storage capacity of the target gas in the organic rock is calculated based on the solubility in the water-containing organic rock pore model. The present invention takes into account the adsorption effect of the rock pore wall on the gas, and can improve the calculation accuracy of the gas dissolution storage capacity.

[0051] Of course, it is not necessary to achieve all of the advantages described above at the same time to implement any product or method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0053] Figure 1 A flow chart of a method for calculating dissolved gas storage capacity provided in an embodiment of the present invention;

[0054] Figure 2 A schematic diagram of solubility comparison provided by an embodiment of the present invention;

[0055] Figure 3 A structural diagram of a gas dissolved storage volume calculation system provided in an embodiment of the present invention;

[0056] Figure 4 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] There are a large number of nanopores between rock particles in the formation, which can provide sufficient storage space for geological storage of gas, such as CO2 geological storage. Accurate assessment of the storage capacity of CO2 in reservoirs is an important basis for predicting the potential of CO2 geological storage.

[0059] At present, the amount of CO2 dissolved and stored in the formation is calculated based on the solubility of CO2 in water under bulk conditions, which will cause the calculated amount of CO2 dissolved and stored to have a large error.

[0060] The inventor of this application found through research:

[0061] The adsorption of the target gas by the rock pore wall is the reason for the large calculation error of the dissolved storage amount of the target gas in the formation. Optionally, the target gas is CO2 gas.

[0062] Based on this, the present invention provides a method for calculating the amount of gas dissolved storage. When calculating the amount of gas dissolved storage, the adsorption effect of the rock pore wall on the target gas is taken into account. The method includes:

[0063] Step 101: Perform molecular dynamics simulation on a rock simulation area containing organic molecules to obtain an organic matrix model; wherein the number of organic molecules is determined based on the density of organic rocks in the target formation, and the organic rocks contain organic molecules.

[0064] In this embodiment, if an organic matrix model is to be established, it is necessary to put organic molecules into the rock simulation area, and the organic molecules are organic molecules in the actual target stratum that matches the organic matrix model, and the target stratum includes at least organic rocks. If the target stratum contains kerogen components, the organic molecules can be kerogen molecules. In practical applications, the cubic simulation box can be regarded as a rock simulation area. In the initial state, the cubic simulation box does not contain any substance. The size of the cubic simulation box can be set, and the size can be used as the size of the organic matrix model. Optionally, the size of the cubic simulation box in the x, y, and z directions can be the same, and the size range can be in the range of 1-50nm. In a specific experiment, the size of the cubic simulation box is selected to be 10nm in all three directions.

[0065] Before performing molecular dynamics simulation on the rock simulation area containing organic molecules, a plurality of kerogen molecules are first randomly placed in the cubic simulation box. The number of kerogen molecules placed needs to be determined according to the density of the rock containing kerogen components in the target formation and the size of the cubic simulation box. In the present invention, 8 kerogen molecules are placed in the cubic simulation box under the condition that the size of the cubic simulation box in the x, y, and z directions is 10 nm. Then, the cubic simulation box with kerogen molecules added is subjected to a dynamic simulation process under the NVT ensemble from high temperature to low temperature and a series of NPT ensembles, in order to obtain an organic matrix model. In the experiment conducted by the present invention, since the kerogen molecules are used to form an organic matrix model, the obtained organic matrix model is a kerogen matrix model.

[0066] As an optional embodiment, a method for performing a dynamic simulation process under the NVT ensemble and a series of NPT ensembles from high temperature to low temperature on a cubic simulation box with kerogen molecules added thereto, specifically comprising: performing molecular dynamics simulation of the rock simulation area containing kerogen molecules under the NVT ensemble to obtain a first model; performing molecular dynamics simulation of the first model under the NPT ensemble to obtain a second model; determining rock parameter values ​​of the second model, and judging whether the rock parameter values ​​are within a preset rock parameter value range; if so, using the second model as a kerogen matrix model; if not, updating the NPT ensemble, wherein the temperature of the updated NPT ensemble is lower than the temperature of the NPT ensemble; performing molecular dynamics simulation of the updated NPT ensemble on the second model to obtain an updated second model, using the updated second model as the second model, using the updated NPT ensemble as the NPT ensemble, and then returning to the step of "determining rock parameter values ​​of the second model, and judging whether the rock parameter values ​​are within a preset rock parameter value range".

[0067] Optionally, the rock parameters may be rock density and rock porosity. After obtaining the second model, the rock density and rock porosity of the second model may be measured. If the rock density is within a preset rock density range and the rock porosity is also within a preset rock porosity range, it indicates that the rock parameter value is within the preset rock parameter value range.

[0068] In the specific experimental process, after multiple tests, the molecular dynamics simulation of the NVT ensemble can be performed once during the dynamics simulation, and the molecular dynamics simulation of the NPT ensemble can be performed four times. The temperature of the NPT ensemble at different times can be set according to geological changes. For details, please refer to the above dynamics simulation process implemented in Table 1.

[0069] Table 1 Ensemble table

[0070]

[0071] As can be seen from Table 1, first, the rock simulation area containing kerogen molecules is subjected to molecular dynamics simulation of the NVT ensemble. Under the NVT ensemble, the temperature is 900K and the relaxation time is 400ps. After the above molecular dynamics simulation is completed, the first model is obtained; then, four consecutive groups of NPT ensemble molecular dynamics simulations are performed on the rock simulation area containing kerogen molecules. After one group of NPT ensemble molecular dynamics simulations is completed, the second model is obtained. The next group of simulations is performed based on this model until the molecular dynamics simulations of the four NPT ensembles are completed, and finally the kerogen matrix model can be obtained. As can be seen from the above table, in the first NPT ensemble, the temperature is 900K, the relaxation time is 400ps, and the pressure is 20MPa; in the second NPT ensemble, the temperature is 700K, the relaxation time is 400ps, and the pressure is 20MPa; in the third NPT ensemble, the temperature is 500K, the relaxation time is 400ps, and the pressure is 20MPa; in the fourth NPT ensemble, the temperature is 338.15K, the relaxation time is 1000ps, and the pressure is 20MPa. As can be seen from Table 1, from the first NPT ensemble to the fourth NPT ensemble, the temperature gradually decreases, while the pressure remains unchanged. The relaxation time of the last ensemble is 2.5 times longer than that of the first three ensembles. Of course, in addition to the temperature, relaxation time and pressure of each ensemble shown in Table 1, the ensemble temperature, relaxation time and pressure used will be different according to different experimental requirements and the organic matrix model simulating different organic components. In addition, the number of NPT ensembles can be adjusted according to the characteristics of the target formation.

[0072] Optionally, after obtaining the organic matrix model, the method further comprises: adjusting the shape and / or size of the rock pores in the organic matrix model to obtain an adjusted organic matrix model. The shape and size of the rock pores determined during the experiment are adaptively adjusted based on the rock pore size of the organic rock of the actual target formation.

[0073] Optionally, after obtaining the organic matrix model, the rock pore volume, Vp (nm 3 ).

[0074] Step 102: adding ion pairs and water molecules to the organic matrix model to obtain a water-containing organic rock pore model; wherein the number of water molecules and the number of ion pairs are determined based on the unit volume pore water content of the organic rock in the target formation and the rock pore volume of the organic matrix model; the ion pairs include sodium ions and chloride ions.

[0075] Since the highest content of cations in formation water is sodium ion, and the highest content of anions in formation water is chloride ion, the present invention can simulate formation water with sodium chloride solution. Optionally, by adding ion pairs and water molecules to the organic matrix model, an organic rock pore model containing formation water can be obtained.

[0076] Before adding ion pairs and water molecules, the structural model of water molecules must be constructed and structured. In the specific simulation process, the 3D modeling image software Skech tool of the material performance simulation software Materials Studio can be used to draw the three-dimensional molecular structure model of water molecules, and the structure can be optimized through the open source software package LAMMPS to obtain the minimum energy conformation. After obtaining the three-dimensional molecular structure model of water molecules, ion pairs and water molecules are added to the organic matrix model to obtain a water-containing organic rock pore model.

[0077] As an optional implementation, the method for determining the number of water molecules specifically includes:

[0078] The number of water molecules is determined according to the following formula:

[0079] N1=V p ×W×N A / M1

[0080] In the formula, N1 is the number of water molecules, V p is the rock pore volume, W is the pore water content per unit volume, M1 is the molar mass of water, N A is Avogadro's constant.

[0081] As an optional implementation, the method for determining the number of ion pairs specifically includes:

[0082] The number of ion pairs is determined according to the following formula:

[0083] N2=V p ×W×c×N A

[0084] Where N2 is the number of ion pairs and c is the salt concentration of formation water.

[0085] In practical applications, ion pairs are not limited to sodium ions and chloride ions, and the types of ion pairs in the brine can be determined based on the actual formation water samples.

[0086] Step 103: Simulate the adsorption and dissolution process of the target gas in the hydrated organic rock pore model. When the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the hydrated organic rock pore model reach saturation, determine the solubility of the target gas in the hydrated organic rock pore model. The solubility of the target gas in the hydrated organic rock pore model is obtained based on the total number of target gas molecules in the hydrated organic rock pore model.

[0087] In this embodiment, the target gas may be carbon dioxide gas, and the purpose of calculating the dissolved storage amount of carbon dioxide is to predict the amount of carbon dioxide that can be stored in the formation in the atmosphere, thereby alleviating the greenhouse gas effect. Therefore, improving the calculation accuracy of the dissolved storage amount of carbon dioxide gas can reduce the content of carbon dioxide in the air to a greater extent, which is helpful to improve the greenhouse gas effect.

[0088] As an optional implementation, simulating the adsorption and dissolution process of carbon dioxide gas in a water-containing organic rock pore model specifically includes: using the Grand Canonical Monte Carlo method to simulate the adsorption and dissolution process of carbon dioxide gas in a water-containing organic rock pore model under the preset reservoir temperature and preset pressure conditions of carbon dioxide gas.

[0089] Step 104: Calculate the dissolved storage amount of the target gas in the organic rock based on the solubility in the water-containing organic rock pore model.

[0090] The calculation method of dissolved storage volume specifically includes:

[0091] The dissolved storage volume is calculated according to the following formula:

[0092] S 气体 =A×H×φ×W×R 气体 ×M 气体

[0093] In the formula, S 气体 is the dissolved storage capacity of carbon dioxide gas, A is the distribution area of ​​rock, H is the thickness of rock, φ is the porosity of rock, W is the water content per unit volume of pores, R 气体 is the solubility of carbon dioxide gas, M 气体 is the molar mass of carbon dioxide gas.

[0094] Figure 2 A schematic diagram comparing the solubility of carbon dioxide gas in organic rocks and the solubility of carbon dioxide gas under bulk conditions provided by the present invention, Figure 2 The squares in the figure represent the solubility of carbon dioxide gas calculated by the present invention taking into account the influence of pores. Figure 2 The circle in the figure represents the calculated carbon dioxide solubility under bulk conditions. Figure 2 It can be seen that based on Figure 2 After calculating the dissolved storage capacity based on the solubility shown, the dissolved storage capacity of carbon dioxide in the pores of organic rocks calculated by the present invention is 3-4 times the dissolved storage capacity under bulk conditions, indicating that the method provided by the present invention can improve the calculation accuracy of the dissolved storage capacity of gas.

[0095] As another optional embodiment, the present invention can also calculate the amount of target gas dissolved and stored in inorganic rocks. When calculating the amount of target gas dissolved and stored in inorganic rocks, the following steps are used:

[0096] An inorganic matrix model is obtained based on inorganic molecules; wherein, inorganic rocks in the target formation contain inorganic molecules; ion pairs and water molecules are added to the inorganic matrix model to obtain a water-containing inorganic rock pore model; wherein, the number of water molecules and the number of ion pairs are determined based on the unit volume pore water content of the inorganic rock in the target formation and the rock pore volume of the inorganic matrix model; the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model is simulated, and when the adsorption amount of the target gas on the rock pore wall in the water-containing inorganic rock pore model and the dissolution amount in water are both saturated, the solubility of the target gas in the water-containing inorganic rock pore model is determined; the solubility of the target gas in the water-containing inorganic rock pore model is obtained based on the total number of target gas molecules in the water-containing inorganic rock pore model; the dissolved storage amount of the target gas in the inorganic rock is calculated based on the solubility in the water-containing inorganic rock pore model.

[0097] In this embodiment, the inorganic molecules in the inorganic rock of the target formation may be silicon dioxide molecules, and the inorganic matrix model may be obtained by performing cell expansion processing on the silicon dioxide molecules.

[0098] Optionally, the method for obtaining a water-containing inorganic rock pore model may be the method in step 102.

[0099] Optionally, after the inorganic matrix model is obtained, the shape and / or size of the rock pores in the inorganic matrix model may be adjusted to obtain an adjusted inorganic matrix model.

[0100] Optionally, simulating the adsorption and dissolution process of the target gas in the pore model of the water-containing inorganic rock specifically includes: using the grand canonical Monte Carlo method to simulate the adsorption and dissolution process of the target gas in the pore model of the water-containing inorganic rock under the preset reservoir temperature and preset pressure conditions of the target gas.

[0101] Optionally, the method in step 104 may be to calculate the dissolved storage amount of the target gas in the inorganic rock based on the solubility in the pore model of the water-containing inorganic rock.

[0102] As an optional implementation, if the target formation contains both organic rocks and inorganic rocks, the above method can be used to calculate the dissolved storage amount of the target gas in the organic rocks and the dissolved storage amount of the target gas in the inorganic rocks, and the two calculated dissolved storage amounts are added together to obtain the final dissolved storage amount.

[0103] The present invention takes into account the influence of the widespread pores in the formation on the calculation of the dissolution storage amount of the target gas in the rock, and also takes into account the influence of the formation water salt concentration, thereby improving the accuracy of the prediction of the dissolution storage potential of the target gas in the geology. The prediction of the dissolution storage amount of the target gas in the water-bearing formation of the present invention can be a deep saline layer, an oil field, a gas field, etc.

[0104] The present invention also provides a system for calculating the amount of dissolved gas storage. Figure 3 As shown, the system includes:

[0105] The molecular dynamics simulation module 301 is used to perform molecular dynamics simulation on the rock simulation area containing organic molecules to obtain an organic matrix model; wherein the number of organic molecules is determined based on the density of the organic rock in the target formation, and the organic rock contains organic molecules.

[0106] The molecular dynamics simulation module 301 is specifically used to: perform molecular dynamics simulation of the NVT ensemble on the rock simulation area containing organic molecules to obtain a first model; perform molecular dynamics simulation of the NPT ensemble on the first model to obtain a second model; determine the rock parameter values ​​of the second model, and judge whether the rock parameter values ​​are within the preset rock parameter value range; if so, use the second model as an organic matrix model; if not, update the NPT ensemble, wherein the temperature of the updated NPT ensemble is less than the temperature of the NPT ensemble; perform molecular dynamics simulation of the updated NPT ensemble on the second model to obtain an updated second model, use the updated second model as the second model, use the updated NPT ensemble as the NPT ensemble, and then execute the step of determining the rock parameter values ​​of the second model and judging whether the rock parameter values ​​are within the preset rock parameter value range.

[0107] The model generation module 302 is used to add ion pairs and water molecules to the organic matrix model to obtain a water-containing organic rock pore model; wherein the number of water molecules and the number of ion pairs are determined based on the unit volume pore water content of the organic rock in the target formation and the rock pore volume of the organic matrix model; the ion pairs include sodium ions and chloride ions.

[0108] The model generation module 302 specifically includes:

[0109] The water molecule number determination unit is used to determine the number of water molecules according to the following formula:

[0110] N1=V p ×W×N A / M1

[0111] In the formula, N1 is the number of water molecules, V p is the rock pore volume, W is the pore water content per unit volume, M1 is the molar mass of water, N A is Avogadro's constant.

[0112] The ion pair number determination unit is used to determine the number of ion pairs according to the following formula:

[0113] N2=V p ×W×c×N A

[0114] Where N2 is the number of ion pairs and c is the salt concentration of formation water.

[0115] The solubility determination module 303 is used to simulate the adsorption and dissolution process of the target gas in the water-containing organic rock pore model. When the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the water-containing organic rock pore model are saturated, the solubility of the target gas in the water-containing organic rock pore model is determined; the solubility of the target gas in the water-containing organic rock pore model is obtained based on the total number of target gas molecules in the water-containing organic rock pore model.

[0116] The solubility determination module 303 is specifically used to simulate the adsorption and dissolution process of the target gas in the water-containing organic rock pore model under the preset reservoir temperature and preset pressure conditions of the target gas by using the Grand Canonical Monte Carlo method.

[0117] The first dissolved storage volume calculation module 304 is used to calculate the dissolved storage volume of the target gas in the organic rock based on the solubility in the water-containing organic rock pore model.

[0118] The first dissolved storage volume calculation module 304 is specifically used to calculate the dissolved storage volume according to the following formula:

[0119] S 气体 =A×H×φ×W×R 气体 ×M 气体

[0120] In the formula, S 气体 is the dissolved storage capacity of the target gas, A is the distribution area of ​​the rock, H is the thickness of the rock, φ is the porosity of the rock, W is the water content per unit volume of pores, and R 气体 is the solubility of the target gas, M 气体 is the molar mass of the target gas.

[0121] As an optional embodiment, the gas dissolved storage capacity calculation system provided by the present invention further includes:

[0122] The second dissolved storage volume calculation module is used to obtain an inorganic matrix model based on inorganic molecules; wherein the inorganic rock of the target formation contains inorganic molecules;

[0123] Ion pairs and water molecules are added to the inorganic matrix model to obtain a water-containing inorganic rock pore model; wherein the number of water molecules and the number of ion pairs are determined based on the pore water content per unit volume of the inorganic rock in the target formation and the rock pore volume of the inorganic matrix model; the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model is simulated, and when the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the water-containing inorganic rock pore model are saturated, the solubility of the target gas in the water-containing inorganic rock pore model is determined; the solubility of the target gas in the water-containing inorganic rock pore model is obtained based on the total number of target gas molecules in the water-containing inorganic rock pore model; the dissolved storage amount of the target gas in the inorganic rock is calculated based on the solubility in the water-containing inorganic rock pore model.

[0124] The second dissolved storage volume calculation module is specifically used to simulate the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model under the preset reservoir temperature and preset pressure conditions of the target gas by using the grand canonical Monte Carlo method.

[0125] Optionally, the system of the present invention also includes: a pore adjustment module, which is used to adjust the shape and / or size of the rock pores in the organic matrix model to obtain an adjusted organic matrix model; and / or adjust the shape and / or size of the rock pores in the inorganic matrix model to obtain an adjusted inorganic matrix model.

[0126] An embodiment of the present invention provides a computer-readable storage medium having a program stored thereon, which implements the above-mentioned method for calculating the dissolved gas storage amount when executed by a processor.

[0127] An embodiment of the present invention provides an electronic device, such as Figure 4 As shown, the electronic device 40 includes at least one processor 401, at least one memory 402 connected to the processor 401, and a bus 403; wherein the processor 401 and the memory 402 communicate with each other through the bus 403; the processor 401 is used to call the program instructions in the memory 402 to execute the above-mentioned gas dissolved storage amount calculation method. The electronic device in this article can be a server, a PC, a PAD, a mobile phone, etc.

[0128] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program that initializes the steps included in the above-mentioned gas dissolved storage capacity calculation method.

[0129] The present application is described with reference to the flowcharts and / or block diagrams of the methods, systems and computer program products according to the embodiments of the present application. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of the processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0130] In a typical configuration, the device includes one or more processors (CPU), memory and bus. The device may also include input / output interface, network interface and the like.

[0131] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip. The memory is an example of a computer-readable medium.

[0132] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0133] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0134] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. It should also be noted that the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0135] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0136] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for calculating the amount of dissolved gas storage, characterized in that: include: Performing molecular dynamics simulation on a rock simulation area containing organic molecules to obtain an organic matrix model; wherein the number of the organic molecules is determined based on the density of the organic rock of the target formation, and the organic rock contains the organic molecules; Adding ion pairs and water molecules to the organic matrix model to obtain a water-containing organic rock pore model; wherein the number of the water molecules and the number of the ion pairs are determined based on the unit volume pore water content of the organic rock in the target formation and the rock pore volume of the organic matrix model; the ion pairs include sodium ions and chloride ions; Simulating the adsorption and dissolution process of the target gas in the water-containing organic rock pore model, when the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the water-containing organic rock pore model are both saturated, determining the solubility of the target gas in the water-containing organic rock pore model; the solubility of the target gas in the water-containing organic rock pore model is obtained based on the total number of the target gas molecules in the water-containing organic rock pore model; The dissolved storage amount of the target gas in the organic rock is calculated based on the solubility in the water-containing organic rock pore model.

2. The method for calculating dissolved gas storage capacity according to claim 1, characterized in that: Also includes: Obtaining an inorganic matrix model based on inorganic molecules; wherein the inorganic rock of the target formation contains the inorganic molecules; Adding the ion pairs and water molecules to the inorganic matrix model to obtain a water-containing inorganic rock pore model; wherein the number of the water molecules and the number of the ion pairs are determined based on the pore water content per unit volume of the inorganic rock in the target formation and the rock pore volume of the inorganic matrix model; Simulating the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model, when the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the water-containing inorganic rock pore model are both saturated, determining the solubility of the target gas in the water-containing inorganic rock pore model; the solubility of the target gas in the water-containing inorganic rock pore model is obtained based on the total number of the target gas molecules in the water-containing inorganic rock pore model; The dissolved storage amount of the target gas in the inorganic rock is calculated based on the solubility in the water-containing inorganic rock pore model.

3. The method for calculating dissolved gas storage capacity according to claim 1, characterized in that: The molecular dynamics simulation of the rock simulation area containing organic molecules to obtain an organic matrix model specifically includes: The first model was obtained by molecular dynamics simulation of the NVT ensemble in the rock simulation area containing organic molecules; Performing molecular dynamics simulation of the NPT ensemble on the first model to obtain a second model; Determining a rock parameter value of the second model, and judging whether the rock parameter value is within a preset rock parameter value range; If yes, the second model is used as the organic matrix model; If not, the NPT ensemble is updated, wherein the temperature of the updated NPT ensemble is less than the temperature of the NPT ensemble; a molecular dynamics simulation of the updated NPT ensemble is performed on the second model to obtain an updated second model, the updated second model is used as the second model, the updated NPT ensemble is used as the NPT ensemble, and then the process returns to the step of "determining the rock parameter value of the second model, and judging whether the rock parameter value is within the preset rock parameter value range".

4. The method for calculating dissolved gas storage capacity according to claim 2, characterized in that: After obtaining the organic matrix model, the method further comprises: Adjusting the shape and / or size of rock pores in the organic matrix model to obtain an adjusted organic matrix model; And / or, after obtaining the inorganic matrix model, the method further comprises: The shape and / or size of the rock pores in the inorganic matrix model are adjusted to obtain an adjusted inorganic matrix model.

5. The method for calculating dissolved gas storage capacity according to claim 2, characterized in that: The simulated adsorption and dissolution process of the target gas in the water-containing organic rock pore model specifically includes: Using a grand canonical Monte Carlo method to simulate the adsorption and dissolution process of the target gas in the water-containing organic rock pore model under the conditions of a preset reservoir temperature and a preset pressure of the target gas; And / or, the simulation of the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model specifically includes: The Grand Canonical Monte Carlo method is used to simulate the adsorption and dissolution process of the target gas in the water-containing inorganic rock pore model under the preset reservoir temperature and preset pressure conditions of the target gas.

6. The method for calculating dissolved gas storage capacity according to claim 1 or 2, characterized in that: The calculation method of the dissolved storage amount specifically includes: The dissolved storage amount is calculated according to the following formula: S 气体 =A×H×φ×W×R 气体 ×M 气体 In the formula, S 气体 is the dissolved storage capacity of the target gas, A is the distribution area of ​​the rock, H is the thickness of the rock, φ is the porosity of the rock, W is the water content per unit volume of pores, and R 气体 is the solubility of the target gas, M 气体 is the molar mass of the target gas.

7. The method for calculating dissolved gas storage capacity according to claim 1 or 2, characterized in that: The method for determining the number of water molecules specifically includes: The number of water molecules is determined according to the following formula: N1=V p ×W×N A / M1 Where N1 is the number of water molecules, V p is the pore volume of the rock, W is the water content per unit volume of the pores, M1 is the molar mass of water, N A is Avogadro's constant; And / or, the method for determining the number of ion pairs specifically includes: The number of ion pairs is determined according to the following formula: N2=V p ×W×c×N A Where N2 is the number of ion pairs and c is the salt concentration of formation water.

8. A gas dissolved storage volume calculation system, characterized in that: include: A molecular dynamics simulation module, used to perform molecular dynamics simulation on a rock simulation area containing organic molecules to obtain an organic matrix model; wherein the number of the organic molecules is determined based on the density of the organic rock of the target formation, and the organic rock contains the organic molecules; A model generation module, used for adding ion pairs and water molecules to the organic matrix model to obtain a water-containing organic rock pore model; wherein the number of the water molecules and the number of the ion pairs are determined based on the unit volume pore water content of the organic rock in the target formation and the rock pore volume of the organic matrix model; the ion pairs include sodium ions and chloride ions; A solubility determination module is used to simulate the adsorption and dissolution process of the target gas in the water-containing organic rock pore model. When the adsorption amount of the target gas on the rock pore wall and the dissolution amount in water in the water-containing organic rock pore model are both saturated, the solubility of the target gas in the water-containing organic rock pore model is determined; the solubility of the target gas in the water-containing organic rock pore model is obtained based on the total number of the target gas molecules in the water-containing organic rock pore model; The dissolution storage volume calculation module is used to calculate the dissolution storage volume of the target gas in the organic rock based on the solubility in the water-containing organic rock pore model.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a program, and when the program is executed by the processor, the method for calculating the dissolved gas storage amount according to any one of claims 1 to 7 is implemented.

10. An electronic device, characterized in that: include: At least one processor, and at least one memory and bus connected to the processor; The processor and the memory communicate with each other via the bus; The processor is used to call the program instructions in the memory to execute the gas dissolved storage capacity calculation method described in any one of claims 1-7.

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