CN115618768A - A Calculation Method for Effective Gas Storage Space of Gas Storage - Google Patents

Abstract

The invention discloses a method for calculating the effective gas storage space of a gas storage, which is carried out according to the following steps: S1, establishing a three-dimensional geological model of the gas storage; S2, coarsening the grid system; S3, preparing basic parameters for numerical simulation; S4, obtaining Relative permeability curve; S5. Obtaining PVT parameters; S6. Establishing the numerical simulation model of the gas storage; S7. Fitting the whole process history of the numerical simulation model of the gas storage; S8. Zone division; S9, extracting the pore volume of the gas storage; S10, determining the production efficiency of each permeable zone of the gas storage; S11, determining the effective gas storage space of the gas storage. This method can accurately determine the size of the effective gas storage space of the reservoir when the depleted oil and gas reservoir is rebuilt into a gas storage, and provides a scientific basis for the design of the storage capacity parameters of the gas storage.

Description

A Calculation Method for Effective Gas Storage Space of Gas Storage

technical field

The invention belongs to the technical field of oil and gas exploitation, and in particular relates to a method for calculating the effective gas storage space of a gas storage.

Background technique

Natural gas underground gas storage (hereinafter referred to as "gas storage") is a large underground container that has a certain sealing capacity and can store natural gas, which is rebuilt from the original oil and gas reservoirs, salt caverns and other reservoirs. Among them, the oil and gas reservoir-type gas storage is rebuilt from depleted or operating oil and gas reservoirs, and its working gas volume accounts for more than 75% of the total working gas volume of the world's gas storage. The type of gas storage with the most complete supporting facilities is the main facility for seasonal peak shaving and storage of natural gas in my country. The gas storage is different from the one-way gas production of the gas reservoir. It has the characteristics of severe alternating gas injection and strong production conditions, high-speed seepage of fluid huff and puff in the injection-production gas well, and periodic disturbance of the in-situ stress field. Most of the underground gas storages are depleted gas reservoirs with weak edge and water, and most of the reservoirs have a large volume of edge and bottom water. The relationship between oil, gas and water is complicated when the reservoir is built, and the water intrusion is serious, which intensifies the construction and operation of the gas storage. Technical difficulty of design.

The storage capacity is an important monitoring and control content for the normal operation of the gas storage, and the design and evaluation of the storage capacity parameters are the key technologies for the construction and operation of the gas storage. Among them, the static storage capacity evaluation method has poor applicability in the multi-period dynamic injection-production process, and cannot accurately evaluate the degree of storage capacity utilization; the dynamic method generally establishes a material balance injection-production dynamic prediction model and a storage capacity analysis model to reflect changes in storage capacity during real operation. However, the required parameters are often only the pressure test of some well points, which cannot represent the real pressure distribution of the whole area, and the test cost is high. Moreover, since most of the depleted oil and gas reservoirs are facing severe water flooding, there will be deviations in single well pressure tests, making it difficult to accurately calculate the storage capacity using the dynamic method.

Therefore, it is urgent to propose a reasonable method for extracting the effective gas storage space of the gas storage.

Contents of the invention

In view of this, the present invention provides a method for calculating the effective gas storage space of a gas storage to solve the problem in the prior art that it is difficult to determine the effective gas storage space of a gas storage.

Its technical scheme is as follows:

A method for calculating the effective gas storage space of a gas storage facility is performed according to the following steps:

S1. Establish a three-dimensional geological model of the gas storage;

According to the geological static data of the oil and gas reservoir and the vertical distribution of oil, gas and water, a three-dimensional geological model of the gas storage is established;

S2, grid system coarsening;

On the basis of the 3D geological model of the gas storage, the grid and attribute data volumes are coarsened;

S3. Prepare basic parameters for numerical simulation;

Prepare the required basic parameters for numerical simulation, which include reservoir parameters and fluid parameters of the gas storage;

S4, obtain the relative permeability curve;

According to the oil-gas relative permeability data and oil-water relative permeability data obtained from the test of experimental samples, through normalization processing, the oil-gas relative permeability curve and the oil-water relative permeability curve are obtained;

S5, obtaining PVT parameters;

Using the experimental data of the high-pressure physical properties of the well fluid of the production well, establish the formation fluid state equation, get the PVT parameters by fitting, and determine the critical temperature and critical pressure;

S6. Establishing a numerical simulation model of the gas storage;

Based on the three-dimensional geological model of the gas storage, the basic parameters of numerical simulation, the relative permeability curve and the PVT parameters, the numerical simulation model of the gas storage is established, and the numerical simulation model of the gas storage is initialized;

S7. Carry out whole-process history fitting to the numerical simulation model of the gas storage;

According to the dynamic characteristics of gas storage production history and fluid distribution characteristics, the whole process history fitting is carried out for the numerical simulation model of gas storage;

S8. Carry out zoning of the gas storage based on the critical saturation parameter;

According to the different fluid saturation parameters, each permeable zone of the gas storage is divided into pure gas zone, gas-oil transition zone, pure oil zone and water flooded zone;

S9, extracting the pore volume of the gas storage;

Import the zone division results into the numerical simulation model of the gas storage in the form of data flow, and extract the pore volume of each permeable zone of the gas storage, which includes gas-bearing pore volume, oil-bearing pore volume, water-bearing pore volume and water-bearing pore volume. Hydrocarbon pore volume;

S10. Determine the production efficiency of each permeable zone of the gas storage;

According to the results of multi-cycle injection-production simulation experiments, the production efficiency of each permeable zone of the gas storage is determined;

S11. Determine the effective gas storage space of the gas storage;

According to the pore volume and production efficiency of each permeable zone of the gas storage, the effective gas storage space of the gas storage is calculated.

Compared with prior art, the beneficial effect of the present invention is:

The method for calculating the effective gas storage space of the gas storage provided by the present invention can accurately determine the size of the effective gas storage space of the reservoir when the depleted oil and gas reservoir is rebuilt into the gas storage, and provides a scientific basis for the design of the storage capacity parameters of the gas storage.

Description of drawings

Fig. 1 is a flowchart of the present invention;

Fig. 2 is the schematic diagram of geological model grid parameter design;

Fig. 3 is the schematic diagram of fault model;

Fig. 4 is the schematic diagram of level model;

Fig. 5 is the schematic diagram of sedimentary microfacies model;

Fig. 6 is a schematic diagram of the isochronous sandbody envelope surface of each single well;

Fig. 7 is the schematic diagram of interlayer mud facies model;

Fig. 8 is the schematic diagram of porosity model;

Fig. 9 is the schematic diagram of permeability model;

Fig. 10 is the schematic diagram of saturation model;

Figure 11 is the probability distribution of porosity data;

Figure 12 is the probability distribution of permeability data;

Figure 13 is the probability distribution of saturation data;

Fig. 14 is a comparison accuracy map of porosity correlation of each well;

Fig. 15 is the contrast accuracy diagram of the permeability correlation of each well.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings.

Referring to a method for calculating the effective gas storage space of a gas storage shown in Figure 1, it is characterized in that it is performed according to the following steps:

S1. Establish a 3D geological model of the gas storage

Based on the geological static data of oil and gas reservoirs and the vertical distribution of oil, gas and water, a three-dimensional geological model of the gas storage is established.

Specifically, step S1 is carried out according to the following steps:

S1-1. Set the grid unit and scale of the model.

Please refer to Figure 2. In order to control the shape of the geological body and ensure the modeling accuracy, this embodiment uses a corner grid, and the plane is divided by 20m×20m; in order to make the model reflect the vertical heterogeneity of the reservoir, the vertical scale The control is at the level of sublayers, divided by 0.5-1m.

S1-2. Establish the structural model of the gas storage.

The structural model reflects the spatial framework of the reservoir, including fault models and layer models. In order to improve the quality of the fault model, the following treatments are carried out: (1) Small fault processing: For small faults that do not break through the entire model in the longitudinal direction, when processing the fault column, the length of the fault column should be extended appropriately to make it penetrate the entire model, so that The top and bottom of each fault column are on the same level to prevent confusion in the skeleton mesh model. (2) Fault column direction processing: The direction of all fault columns in the block should be grasped as a whole, that is, the directions of all fault columns in the model area should be roughly similar, the spacing should be evenly distributed, and the number should be appropriate to correctly reflect the cross-sectional shape. Please refer to Figure 3. The fault model established on this basis can accurately reflect the true shape of the fault distribution in the three-dimensional space in the work area.

In this example, the structural model of the gas storage is established based on the single well basic data, seismic interpretation data, and regional geological data in the gas storage area. To reflect the three-dimensional distribution of the stratum interface, please refer to Figure 4. The layer model of each small layer is superimposed together to form the structural model of the gas storage.

S1-3. Establish the sedimentary microfacies model of the gas storage.

The sedimentary microfacies model is the three-dimensional spatial distribution of different microfacies types in the reservoir. Sedimentary facies control the distribution direction and distribution law of reservoir physical parameters and the characteristics of subsurface fluid flow to a certain extent. Therefore, accurately establishing a three-dimensional model of sedimentary microfacies is a key technology for facies-controlled simulation of reservoir physical properties and study of reservoir heterogeneity.

In this example, the sedimentary microfacies in the gas storage area are first divided according to the research results of regional background data, logging interpretation, and core analysis, and then the boundaries of the two-dimensional sedimentary microfacies distribution maps of each sublayer are digitized. The value assignment method establishes the sedimentary microfacies model of the gas storage, as shown in Fig. 5.

S1-4. Establish the lithofacies model of the gas storage.

The lithofacies model mainly reflects the three-dimensional distribution of different lithologies of the target interval in the study area, and is the basis for fault sealing calculation, geomechanical modeling, and reservoir physical property simulation. In this example, the enveloping surface method is used for lithofacies modeling. Specifically, on the basis of completing the fine identification of single sand bodies at each well point, on the basis of completing the fine identification of single sand bodies at each well point, etc. In the sub-layer at the same time, the isochronous sandbody envelope surface at the top and bottom of each single sandbody is determined based on the top-bottom data of the single sandbody identified by each single well (see Fig. 6). The envelope surface is The lithofacies model of a single sand body and the interlayer mud facies model between sand bodies (see Fig. 7) are established, so that the lithofacies model of the gas storage is composed of the lithofacies models of each single sand body and the mud facies models of each interlayer.

S1-5. Establish an attribute model of the gas storage, the attribute model of the gas storage includes a porosity model, a permeability model and a saturation model.

In this example, on the basis of the sedimentary microfacies model of the gas storage and the lithofacies model of the gas storage, with the sedimentary facies as constraints, the correlation of reservoir physical properties in each sedimentary facies is first analyzed, and then the stochastic simulation method is used to analyze the While performing interpolation calculations on well data, the co-kriging method is used to weight and conditionally constrain the simulation calculations, so that the interpolation of well logging values is close to the distribution between wells, and the combination of deterministic modeling and stochastic modeling can be realized , the porosity model (see Fig. 8), the permeability model (see Fig. 9) and the saturation model (see Fig. 10) were respectively established.

S1-6. Check whether the accuracy of the structural model of the gas storage, the sedimentary microfacies model of the gas storage, the lithofacies model of the gas storage and the property model of the gas storage are qualified: No, return to step S1-1, and adjust the parameters; Yes, Go to step S2.

When building a model, the size of the model grid size, the selection of the variogram and the difference in the modeling method will all affect the accuracy of the model. Therefore, the implementation uses the following two methods to test the accuracy of the gas storage structure model, gas storage sedimentary microfacies model, gas storage lithofacies model and gas storage attribute model:

(1) Probability distribution consistency test

When applying the geostatistical method for modeling, the 3D geological model of the gas storage established through conditional simulation, because the unknown space points are interpolated and extrapolated to a certain accuracy, the 3D data of the target interval gridded are obtained body, and its data volume increases tens of thousands of times. If the accuracy of the model is high, its data distribution law should be close to the same as that of the original data, that is, the two have the same distribution interval and peak shape; otherwise, there is a big difference between the two. Please refer to Figure 11-Figure 13, respectively compare the model data volume of porosity, permeability and saturation with the original data distribution histogram, where the blue represents the data volume of the attribute model, the red is the original data volume, and the green represents the From the data volume obtained after discretizing the original data, it can be seen that, except that there is a certain non-difference between the first and last maximum and minimum values due to the peak-suppression effect, they have similar distribution rules, indicating that the accuracy of the three models is relatively high.

(2) Inspection of the coincidence degree between the physical parameters of a single well and the original curve

When using stochastic simulation method for interwell prediction of reservoir parameters, the model must be faithful to the well data. Therefore, the accuracy of reservoir properties on a single well depends on the size of the vertical grid of the model and is not affected by the modeling method. If the vertical grid size is too small, the model accuracy is high, but the computational load is large; if the vertical grid size is too large, the model accuracy is low, and the well attribute is too different from the original curve. Therefore, when determining the size of the vertical grid, it is necessary to ensure that the physical properties of the single well reservoir can be accurately represented, and the feasibility of modeling should also be considered, and the smaller the grid size, the better. Please refer to Fig. 14 and Fig. 15. The envelope curve of discretized data from each well grid is in good agreement with the original porosity, permeability and saturation curves, reaching more than 95%, which guarantees the accuracy of the model to a certain extent.

S2, grid system coarsening

On the basis of the 3D geological model of the gas storage, the grid and attribute data volumes are coarsened. The accuracy of numerical simulation modeling of gas storage is higher than that of ordinary remaining oil and gas prediction models. Generally, the step size of the plane grid does not exceed 25×25m, and the vertical grid needs to consider the actual complex conditions such as edge and bottom water and oil ring.

S3. Prepare basic parameters for numerical simulation

The required basic parameters for numerical simulation are prepared, and the basic parameters for numerical simulation include reservoir parameters and fluid parameters of the gas storage. The gas storage reservoir parameters mainly include reservoir temperature and pressure, surface temperature and pressure, oil-gas-water interface, matrix rock compressibility coefficient, etc.; fluid parameters mainly include natural gas relative density, surface crude oil density, crude oil volume coefficient, formation water viscosity, original dissolution gasoline ratio etc.

S4. Obtain the relative permeability curve

According to the oil-gas relative permeability data and oil-water relative permeability data obtained from the experimental samples, the oil-gas relative permeability curve and the oil-water relative permeability curve are obtained through normalization processing.

Among them, the normalization process is carried out by the following formula:

Oil-water two-phase system:

表示束缚水饱和度下的油相相对渗透率，mD；S_w表示含水饱和度；S_orw表示油水两相中残余油饱和度，％；S_wc表示束缚水饱和度；K_rw表示水的相对渗透率；

表示残余油饱和度下水相相对渗透率；n_o表示油相相对渗透率曲线指数，无因次；n_w表示水相对渗透率曲线指数，无因次；In formula (1) and formula (2), K _ro represents the relative permeability of oil;

Indicates the relative permeability of the oil phase at irreducible water saturation, mD; S _w indicates the water saturation; S _orw indicates the residual oil saturation in the oil-water two-phase, %; S _wc indicates the irreducible water saturation; K _rw indicates the relative permeability of water permeability;

Indicates relative permeability of water phase at residual oil saturation; n _o indicates relative permeability curve index of oil phase, dimensionless; n _w indicates relative permeability curve index of water, dimensionless;

Oil-gas two-phase system:

表示残余气饱和度下的油相相对渗透率，mD；S_g表示含气饱和度；S_lc表示总临界液体饱和度，％，并且，S_lc＝S_wc+S_org；S_org表示油气两相中残余油饱和度，％；S_gc表示临界气饱和度，％；K_rg表示气的相对渗透率；

表示残余油饱和度下气相相对渗透率；S_gc表示残余气饱和度，％；n_g表示气相对渗透率曲线指数，无因次；n_go表示气油两相中油的相对渗透率曲线指数，无因次。In formula (3) and formula (4),

Indicates relative permeability of oil phase at residual gas saturation, mD; S _g indicates gas saturation; S _lc indicates total critical liquid saturation, %, and S _lc = S _wc + S _org ; S _org indicates oil-gas Residual oil saturation in phase, %; S _gc means critical gas saturation, %; K _rg means relative gas permeability;

Indicates the relative permeability of the gas phase under the residual oil saturation; S _gc indicates the residual gas saturation, %; n _g indicates the index of the gas relative permeability curve, dimensionless; n _go indicates the index of the oil relative permeability curve in the gas-oil two-phase, Dimensionless.

S5. Acquiring PVT parameters

Using the experimental data of the high-pressure physical properties of the well fluid of the production well, the state equation of the formation fluid is established, the PVT parameters are obtained by fitting, and the critical temperature and critical pressure are determined. Among them, the PVT parameters include the PVT phase diagram of the gas storage, natural gas volume coefficient, fluid density, dissolved gas-oil ratio and other parameters.

S6. Establish a numerical simulation model of the gas storage

Based on the three-dimensional geological model of the gas storage, the basic parameters of numerical simulation, the relative permeability curve and the PVT parameters, the numerical simulation model of the gas storage is established by using the reservoir numerical simulation software ECLIPSE, and the numerical simulation model of the gas storage is initialized, including Reference pressure, reference depth, oil-water contact and oil-gas contact, and use the vertical gravity balance method to obtain the initial gas saturation field, oil saturation field and pressure distribution field of the reservoir. Due to the slightly different oil-gas-water contact between different fault blocks and layers in the reservoir, it is necessary to use the sim-office numerical simulation software during initialization, based on the disconnected fault blocks and layers, to carry out the reservoir grid system construction. Balanced partition assignment, imported into the numerical simulation model. Because the reservoir pore volume changes slightly when the model grid system is coarsened, the original oil and gas geological reserves should be fitted in different regions.

S7. Carry out whole-process history fitting for the gas storage numerical simulation model

When the numerical simulation method is used to study the migration characteristics of reservoir fluids, due to the limitation of geological understanding of oil and gas reservoirs, the physical parameters of reservoirs in simulation calculations cannot fully reflect the real situation of oil and gas reservoirs. In order to reduce the calculation error caused by reservoir physical properties, the whole process history fitting of the gas storage numerical simulation model should be carried out according to the historical production dynamic characteristics and fluid distribution characteristics of the gas storage, including the gas storage and single well index fitting.

When fitting, the gas storage index fitting can be based on the historical dynamic data of the gas storage development, based on the type of the gas storage and the degree of reservoir fragmentation, and the history fitting can be carried out by means of layering and fault block; the single well index fitting can be According to the specific production of oil, gas and water in the production data, the method of constant gas production, constant water production, constant oil production and constant liquid production is used for history matching. Generally, the historical fitting error is controlled above 90%. It is considered that the numerical simulation model can accurately reflect the seepage conditions of reservoir fluid.

S8. Divide the gas storage zone based on the critical saturation parameters

According to the different fluid saturation parameters, the permeable zones of the gas storage are divided into pure gas zone, gas-oil transition zone, pure oil zone and water flooded zone. When dividing zones, the critical saturation parameters of different zones should be determined on the basis of initial gas saturation, residual oil saturation, residual gas saturation and irreducible water saturation. Based on the current oil-gas-water three-phase fluid saturation distribution characteristics obtained by the numerical simulation model of the whole process history fitting, combined with the critical saturation parameters of different zones, the pure gas zone, the gas-oil transition zone, the oil ring and the water flooding zone are finely described. district.

In order to describe the zone more precisely, the numerical simulation model is written into the numerical simulation software sim-office, and in the flow partition module, each zone is described by means of grid assignment.

S9. Extract the pore volume of the gas storage

Import the zone division results into the numerical simulation model of the gas storage in the form of data flow, and extract the pore volume of each permeable zone of the gas storage, which includes gas-bearing pore volume, oil-bearing pore volume, water-bearing pore volume and water-bearing pore volume. Hydrocarbon pore volume.

S10. Determine the production efficiency of each permeable zone of the gas storage

According to the formation characteristics of the gas storage, the injection-production simulation experiment system is used to carry out the multi-cycle injection-production simulation experiment of the gas storage, and the production efficiency of each permeable zone of the gas storage is determined according to the results of the multi-cycle injection-production simulation experiment. Among them, the simulated formation water in the research area was selected as the experimental water, the experimental gas was nitrogen, and the natural core samples of the formation were selected as the reservoir model, and the experimental pressure range was the design value of the operating pressure of the gas storage.

S11. Determine the effective gas storage space of the gas storage

According to the pore volume and production efficiency of each permeable zone of the gas storage, the effective gas storage space of the gas storage is calculated, and then the effective storage capacity of the gas storage is calculated based on the natural gas volume coefficient of the target layer, which provides information for the subsequent rational design of storage capacity parameters. support.

Finally, it should be noted that the above description is only a preferred embodiment of the present invention, and those of ordinary skill in the art can make a variety of similar implementations under the inspiration of the present invention without violating the purpose and claims of the present invention. It means that such transformations all fall within the protection scope of the present invention.

Claims (7)

1. A method for calculating the effective gas storage space of a gas storage, characterized in that, it is performed according to the following steps: S1. Establish a three-dimensional geological model of the gas storage; According to the geological static data of the oil and gas reservoir and the vertical distribution of oil, gas and water, a three-dimensional geological model of the gas storage is established; S2, grid system coarsening; On the basis of the 3D geological model of the gas storage, the grid and attribute data volumes are coarsened; S3. Prepare basic parameters for numerical simulation; Prepare the required basic parameters for numerical simulation, which include reservoir parameters and fluid parameters of the gas storage; S4, obtain the relative permeability curve; According to the oil-gas relative permeability data and oil-water relative permeability data obtained from the test of experimental samples, through normalization processing, the oil-gas relative permeability curve and the oil-water relative permeability curve are obtained; S5, obtaining PVT parameters; Using the experimental data of the high-pressure physical properties of the well fluid of the production well, establish the formation fluid state equation, get the PVT parameters by fitting, and determine the critical temperature and critical pressure; S6. Establishing a numerical simulation model of the gas storage; Based on the three-dimensional geological model of the gas storage, the basic parameters of numerical simulation, the relative permeability curve and the PVT parameters, the numerical simulation model of the gas storage is established, and the numerical simulation model of the gas storage is initialized; S7. Carry out whole-process history fitting to the numerical simulation model of the gas storage; According to the dynamic characteristics of gas storage production history and fluid distribution characteristics, the whole process history fitting is carried out for the numerical simulation model of gas storage; S8. Carry out zoning of the gas storage based on the critical saturation parameter; According to the different fluid saturation parameters, each permeable zone of the gas storage is divided into pure gas zone, gas-oil transition zone, pure oil zone and water flooded zone; S9, extracting the pore volume of the gas storage; Import the zone division results into the numerical simulation model of the gas storage in the form of data flow, and extract the pore volume of each permeable zone of the gas storage, which includes gas-bearing pore volume, oil-bearing pore volume, water-bearing pore volume and water-bearing pore volume. Hydrocarbon pore volume; S10. Determine the production efficiency of each permeable zone of the gas storage; According to the results of multi-cycle injection-production simulation experiments, the production efficiency of each permeable zone of the gas storage is determined; S11. Determine the effective gas storage space of the gas storage; According to the pore volume and production efficiency of each permeable zone of the gas storage, the effective gas storage space of the gas storage is calculated. 2. A method for calculating the effective gas storage space of a gas storage according to claim 1, wherein the step S1 is performed according to the following steps: S1-1. Set the grid unit and scale of the model; S1-2. Establish the structural model of the gas storage; S1-3. Establish the sedimentary microfacies model of the gas storage; S1-4. Establish lithofacies model of gas storage; S1-5. Establish an attribute model of the gas storage, the attribute model of the gas storage includes a porosity model, a permeability model and a saturation model; S1-6. Check whether the accuracy of the structural model of the gas storage, the sedimentary microfacies model of the gas storage, the lithofacies model of the gas storage and the property model of the gas storage are qualified: No, return to step S1-1, and adjust the parameters; Yes, Go to step S2. 3. A method for calculating the effective gas storage space of a gas storage according to claim 2, characterized in that: in the step S1-2, based on the basic data of a single well in the gas storage area, seismic interpretation data and regional geology The structural model of the gas storage is established based on the data, in which the gas storage is composed of multiple superimposed small layers, and the layer model of each small layer is superimposed to form the structural model of the gas storage. 4. A method for calculating the effective gas storage space of a gas storage according to claim 3, characterized in that: in the step S1-3, the boundary digitization is performed on the two-dimensional sedimentary microfacies distribution map of each small layer, using The value assignment method is used to establish the sedimentary microfacies model of the gas storage. 5. A method for calculating the effective gas storage space of a gas storage according to claim 4, characterized in that: in the step S1-4, on the basis of completing the fine identification of single sand bodies at each well point, isochronous In the small layer of each single sand body, the isochronous sand body envelope surface at the top and bottom of each single sand body is determined with the constraints of the top and bottom data of the single sand body identified by each single well, and the single sand body rock The lithofacies model of the gas storage is composed of the lithofacies model of each single sand body and the mud facies model of each interlayer. 6. A method for calculating the effective gas storage space of a gas storage according to claim 5, characterized in that: in the step S1-5, on the basis of the sedimentary microfacies model of the gas storage and the lithofacies model of the gas storage Firstly, with the sedimentary facies as the constraint, the correlation of reservoir physical properties in each sedimentary facies is firstly analyzed, and then the stochastic simulation method is used to interpolate the logging data, and at the same time, the simulation calculation is weighted and conditioned by the co-kriging method. Constraints make the interpolation of logging values close to the interwell distribution, which can realize the combination of deterministic modeling and stochastic modeling, and respectively establish porosity model, permeability model and saturation model. 7. A method for calculating the effective gas storage space of a gas storage according to claim 1, characterized in that: in the step S4, the normalization process is performed using the following formula: Oil-water two-phase system:

In formula (1) and formula (2), K _ro represents the relative permeability of oil;

Indicates the relative permeability of the oil phase at irreducible water saturation, mD; S _w indicates the water saturation; S _orw indicates the residual oil saturation in the oil-water two-phase, %; S _wc indicates the irreducible water saturation; K _rw indicates the relative permeability of water permeability;

Indicates relative permeability of water phase at residual oil saturation; n _o indicates relative permeability curve index of oil phase, dimensionless; n _w indicates relative permeability curve index of water, dimensionless; Oil-gas two-phase system:

In formula (3) and formula (4),

Indicates relative permeability of oil phase at residual gas saturation, mD; S _g indicates gas saturation; S _lc indicates total critical liquid saturation, %, and S _lc = S _wc + S _org ; S _org indicates oil-gas Residual oil saturation in phase, %; S _gc means critical gas saturation, %; K _rg means relative gas permeability;

Indicates the relative permeability of the gas phase under the residual oil saturation; S _gc indicates the residual gas saturation, %; n _g indicates the index of the gas relative permeability curve, dimensionless; n _go indicates the index of the oil relative permeability curve in the gas-oil two-phase, Dimensionless.

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