A method, system and storage medium for characterizing remaining oil in a fractured-vug reservoir

Abstract

This invention discloses a method for characterizing residual oil in fractured-vuggy reservoirs, comprising: establishing a numerical model of the fractured-vuggy reservoir based on production data, physical property data, and a geological model; performing verification and historical fitting; extracting static attributes, calculating oil saturation attributes, and calculating the reservoir reserve distribution of the numerical model at each time step; extracting the distribution of karst facies, fracture-void facies, and fracture facies, selecting the residual oil saturation of the corresponding relative permeability curves according to the flow characteristics of each facies, and constraining the range of movable residual oil; calculating the movable residual oil reserves of each grid using a grid traversal method based on the reservoir reserve distribution, and extracting the results to a seismic characterization module; setting attribute volume display parameters in the seismic characterization module, setting movable constraint values ​​based on the residual oil saturation parameters, characterizing the residual oil results, and displaying the three-dimensional morphology and location of the residual oil. This method reduces the impact of the heterogeneity of fractured-vuggy reservoirs on the characterization of residual oil.

Description

Technical Field

[0001] This invention relates to the field of fractured-vuggy reservoir technology, specifically to a method, system, and storage medium for characterizing residual oil in fractured-vuggy reservoirs. Background Technology

[0002] Currently, the development of fractured-vuggy reservoirs is affected by the development of fractures and vuggies, resulting in strong heterogeneity of reservoir space and making it difficult to understand the distribution pattern of remaining oil. The distribution morphology of remaining oil in reservoirs after water-drive and gas-drive is complex under different karst backgrounds and development stages. The mainstream methods for characterizing remaining oil include oil saturation method and reserve abundance method, but these methods are not applicable to fractured-vuggy reservoirs and are difficult to accurately characterize the morphology and location of remaining oil. Therefore, a method that can characterize the remaining oil in fractured-vuggy reservoirs is expected. Summary of the Invention

[0003] To achieve the above objectives, this invention provides a method, system, and storage medium for characterizing residual oil in fractured-vuggy reservoirs. The specific technical solution is as follows:

[0004] A method for characterizing residual oil in fractured-vuggy reservoirs includes the following steps:

[0005] Step S1: Based on the production data, physical property data and geological model of fractured-vuggy reservoirs, establish a numerical model of fractured-vuggy reservoirs;

[0006] Step S2: Verify and perform historical fitting on the numerical model of the fractured-vuggy reservoir;

[0007] Step S3: Extract the static properties of the fractured-vuggy reservoir numerical model, calculate the oil saturation properties, and calculate the reservoir reserve distribution of the fractured-vuggy reservoir numerical model at each time step;

[0008] Step S4: Extract the distribution of karst facies, fracture pore facies, and fracture facies from the numerical model of the fractured-vuggy reservoir, select the residual oil saturation of the corresponding phase permeability curve based on the flow characteristics of each phase, and constrain the range of movable residual oil.

[0009] Step S5: Based on the oil reservoir reserve distribution, the remaining movable oil reserves of each grid are calculated using the grid traversal method, and the results are extracted to the seismic characterization module;

[0010] Step S6: Set the attribute volume display parameters in the seismic characterization module, set the dynamic constraint value based on the residual oil saturation parameter, characterize the residual oil results, and display the three-dimensional morphology and location of the residual oil.

[0011] Preferably, in step S1, the Petrel RE module of the Petrel RE software is used to establish a numerical model of the fractured-vuggy reservoir. The production data includes daily oil production, daily water production, daily gas production, daily gas injection, and daily water injection. The physical property data includes water and crude oil volume coefficients, rock compressibility coefficients, dissolved gas-oil ratio, relative permeability curve data, water and crude oil density and viscosity. The geological model includes a porosity model, a permeability model, well data, and reserve data.

[0012] Preferably, step S2 is performed using the Petrel RE module of the Petrel RE software. The parameters for historical fitting include daily oil production, daily water production, cumulative oil production, cumulative water production, water break time, and water break volume, ensuring that the fitting error is within the allowable range.

[0013] Preferably, in step S3, the static properties are extracted using the Results section of the Cases module of the Petrel RE software. The static properties include porosity properties, grid volume properties, and crude oil density properties, and the extracted properties are for each time step.

[0014] Preferably, in step S4, the geological module of Petrel RE software is used to extract the distribution of karst facies, fracture-void facies, and fracture facies from the numerical model of fractured-vuggy reservoirs.

[0015] Preferably, in step S5, the grid traversal method includes:

[0016] Calculate the initial crude oil reserves for each grid: Ni = Soi × Vp × ρo, and determine the residual oil saturation Sor and the actual oil saturation So of the current grid by combining the relative permeability curve to judge the mobility of the remaining oil. If So > Sor, then calculate the mobile residual oil reserves Nm = (So - Sor) × Vp × ρo.

[0017] Where Soi is the initial oil saturation, Vp is the pore volume, and ρo is the crude oil density.

[0018] Preferably, in step S6, the seismic characterization module displays the spatial distribution of the remaining oil through three-dimensional visualization and analyzes the location of the remaining oil in conjunction with seismic attributes.

[0019] The present invention also provides a residual oil characterization system for fractured-vuggy reservoirs, comprising:

[0020] The Numerical Model Building Module for Fractured-Void Reservoirs is used to build numerical models of fractured-void reservoirs based on production data, physical property data, and geological models.

[0021] The verification and history fitting module is used to verify and perform history fitting on the numerical model of the fractured-vuggy reservoir.

[0022] The attribute extraction module is used to extract the static attributes of the fractured-vuggy reservoir numerical model, calculate the oil saturation attribute, and calculate the reservoir reserve distribution of the fractured-vuggy reservoir numerical model at each time step.

[0023] The phase analysis module is used to extract the distribution of karst phase, fracture pore phase and fracture phase from the numerical model of the fractured-vuggy reservoir, select the residual oil saturation of the corresponding phase permeability curve according to the flow characteristics of each phase, and constrain the range of movable residual oil.

[0024] The calculation module is used to calculate the remaining movable oil reserves of each grid based on the oil reservoir reserve distribution using the grid traversal method, and extract the results to the seismic characterization module;

[0025] The characterization module is used to set attribute display parameters in the seismic characterization module, set dynamic constraint values ​​based on the residual oil saturation parameter, characterize the residual oil results, and display the three-dimensional morphology and location of the residual oil.

[0026] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the residual oil characterization method for fractured-vuggy reservoirs as described above.

[0027] The provided method for characterizing residual oil in fractured-vuggy reservoirs has the following technical advantages:

[0028] Existing technologies for characterizing residual oil in fractured-vuggy reservoirs have several drawbacks. The oil saturation range above the oil-water interface is too large, and the residual oil is often distributed in patches due to algorithmic limitations, making accurate characterization of its morphology impossible. Therefore, this invention addresses this issue by constraining the movable residual oil range in step S3, thus resolving the problem of inter-well residual oil patches not conforming to actual field conditions. Steps 5 and 6 employ a grid traversal method to characterize the residual oil and its three-dimensional morphology, reducing the impact of the heterogeneity of fractured-vuggy reservoirs on residual oil characterization. This invention solves the core needs of carbonate fractured-vuggy reservoirs, including the diverse types of residual oil in water-drive and gas-drive failure units, the poor performance of existing methods, and the difficulty in accurately classifying, quantifying, and locating residual oil. It fills a technological gap both domestically and internationally in the field of three-dimensional residual oil characterization in carbonate fractured-vuggy reservoirs. Attached Figure Description

[0029] Figure 1 A flowchart according to an embodiment of this disclosure;

[0030] Figure 2 A production data diagram according to an embodiment of this disclosure;

[0031] Figure 3 A diagram showing physical property data according to embodiments of this disclosure;

[0032] Figure 4A geological model diagram according to an embodiment of this disclosure;

[0033] Figure 5 This is a graph showing the cumulative water and oil production according to embodiments of this disclosure;

[0034] Figure 6 A fitting graph of daily water and daily oil production according to an embodiment of this disclosure;

[0035] Figure 7 This is a result extraction diagram of the Cases module according to an embodiment of this disclosure;

[0036] Figure 8 This is an extraction time step attribute map according to an embodiment of the present disclosure;

[0037] Figure 9 Phase permeation curves of different phases according to embodiments of this disclosure;

[0038] Figure 10 A diagram showing the remaining movable oil reserves according to an embodiment of this disclosure;

[0039] Figure 11 This is a residual oil characterization diagram based on the grid traversal method according to an embodiment of the present disclosure. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a method, system, and storage medium for characterizing residual oil in fractured-vuggy reservoirs proposed by this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the purpose of the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0041] This invention provides a method for characterizing residual oil in fractured-vuggy reservoirs, combined with Figure 1 This includes the following steps:

[0042] Step S1: Based on the production data, physical property data and geological model of fractured-vuggy reservoirs, establish a numerical model of fractured-vuggy reservoirs;

[0043] Step S2: Verify and perform historical fitting on the numerical model of the fractured-vuggy reservoir;

[0044] Step S3: Extract the static properties of the fractured-vuggy reservoir numerical model, calculate the oil saturation properties, and calculate the reservoir reserve distribution of the fractured-vuggy reservoir numerical model at each time step;

[0045] Step S4: Extract the distribution of karst facies, fracture pore facies, and fracture facies from the numerical model of the fractured-vuggy reservoir, select the residual oil saturation of the corresponding phase permeability curve based on the flow characteristics of each phase, and constrain the range of movable residual oil.

[0046] Step S5: Based on the oil reservoir reserve distribution, the remaining movable oil reserves of each grid are calculated using the grid traversal method, and the results are extracted to the seismic characterization module;

[0047] Step S6: Set the attribute volume display parameters in the seismic characterization module, set the dynamic constraint value based on the residual oil saturation parameter, characterize the residual oil results, and display the three-dimensional morphology and location of the residual oil.

[0048] In step S1, based on the production data, physical property data, and geological model of the fractured-vuggy reservoir, a numerical model of the fractured-vuggy reservoir is established using Petrel RE, such as... Figure 2 , Figure 3 and Figure 4 As shown.

[0049] Specifically, production data, physical property data, and geological models of fractured-vuggy reservoirs are acquired. The production data includes daily oil production, daily water production, daily gas production, daily gas injection, and daily water injection. The physical property data includes water and crude oil volume coefficients, rock compressibility coefficients, dissolved gas-oil ratios, relative permeability curves, water and crude oil densities, and water and crude oil viscosity data. The geological model includes porosity models, permeability models, well data, and reserve data. The production data, physical property data, and geological model are then imported into the Petrel RE module of the Petrel RE software to establish a numerical model of the fractured-vuggy reservoir. (Petrel RE is a powerful reservoir numerical simulation software.)

[0050] Next, we move on to step S2 to validate and fit the numerical model of the fractured-vuggy reservoir to historical data.

[0051] Figure 5 This is a cumulative water production and oil production fitting graph according to embodiments of this disclosure. Figure 6 This is a fitting graph of daily water and daily oil production according to an embodiment of the present disclosure.

[0052] In step S2, the Petrel RE module of Petrel RE is used to calculate the numerical model results of the fractured-vuggy reservoir. Historical data fitting is performed to correct and verify the oil-water interface, fluid properties, pressure distribution field, porosity field, permeability field, relative permeability curve parameters, fracture and cavern connectivity, well-reservoir relationship, and initialization parameters of the fractured-vuggy reservoir. This ensures that the trends of cumulative oil production and cumulative water production in the historical fitting are consistent and the error is within the allowable range. The parameters for historical fitting include daily oil production, daily water production, cumulative oil production, cumulative water production, water breakthrough time, and water breakthrough volume. The results are as follows: Figure 5 and Figure 6 As shown.

[0053] Next, proceed to step S3 to extract the static properties of the fractured-vuggy reservoir numerical model and calculate the oil saturation properties, and calculate the reservoir reserve distribution of the fractured-vuggy reservoir numerical model at each time step.

[0054] Figure 7 This is a result extraction diagram from the Cases module according to an embodiment of this disclosure. Figure 8 This is an extraction time step attribute map according to an embodiment of the present disclosure.

[0055] In step S3, firstly, the static properties of the fractured-vuggy reservoir numerical model are extracted from the Results section of the Cases module in Petrel RE; then, the oil saturation properties are calculated; the static properties include porosity, mesh volume, and crude oil density, and the extracted properties are for each time step; finally, the reservoir reserve distribution of the fractured-vuggy reservoir numerical model at each time step is calculated, such as... Figure 7 and Figure 8 As shown.

[0056] Specifically, oil saturation refers to the volume fraction of oil in the reservoir pores. For fracture-vuggy reservoirs, calculating oil saturation requires considering the distribution of oil phases in the matrix pores and fractures / vuggy areas.

[0057] The calculation formula is: Oil saturation attribute = Oil phase volume / (Porosity volume). The oil phase volume can be indirectly calculated using other simulation results or known conditions combined with attributes such as porosity and mesh volume. The pore volume can be calculated based on the extracted porosity and mesh volume attributes (pore volume = porosity × mesh volume). Furthermore, this calculation needs to be performed for each mesh cell at each time step, because the distribution of the oil phase in the reservoir is dynamic during development.

[0058] The calculation of reservoir reserve distribution is based on the previously extracted attributes and the calculated oil saturation attribute.

[0059] The basic formula for calculating reserve distribution is: Reserve (for a specific grid cell) = Oil saturation × Pore volume × Crude oil density. For the entire reservoir, the reserves of all grid cells need to be summed to obtain the total reserve distribution. Since the oil saturation, pore volume (although the physical grid volume remains constant, it is considered in conjunction with other attributes for calculation), and crude oil density may change at different time steps during reservoir development, the above calculation must be performed for each time step to obtain the reservoir reserve distribution at each time step. This allows for observation of the dynamic changes in reservoir reserves over time, providing a basis for reservoir development decisions.

[0060] Next, proceed to step S4, extract the distribution of karst facies, fracture-void facies, and fracture facies from the petrel RE geological module, and then select the residual oil saturation of the corresponding phase permeability curve to constrain the range of movable residual oil based on the different flow characteristics of each phase.

[0061] Figure 9 This is a phase permeation curve diagram of different phases according to embodiments of the present disclosure.

[0062] In step S4, the geological module of Petrel RE is used to extract the distribution of karst facies, fracture-void facies, and fracture facies from the numerical model of fractured-vuggy reservoirs. Based on the flow characteristics of fractured-vuggy reservoirs with different facies, the residual oil saturation of different facies permeability curves is selected as the constraint condition for movable residual oil, such as... Figure 9 .

[0063] The geology module typically refers to a component of reservoir numerical simulation software (such as Petrel RE). This module is primarily used to construct the geological model of the reservoir, including stratigraphic structure, lithological distribution, pore structure, and descriptions of special geological structures such as caverns and fractures. Within the geology module, various geological data (such as seismic data, well logging data, and core data) can be integrated to generate a three-dimensional geological model of the reservoir. It can also provide detailed classification and visualization of different geological facies within the model (such as cavernous facies, fracture-void facies, and fracture facies). Through this module, the distribution information of different geological facies within the reservoir model can be queried and extracted, which forms the basis for subsequent reservoir fluid flow simulation and remaining oil analysis.

[0064] Relative permeability curves describe the relative permeability of different phases (oil, gas, and water) in an oil reservoir at different saturations. Residual oil saturation refers to the saturation of immovable oil remaining in the rock pores after a certain relative permeation process has ended.

[0065] Based on the flow characteristics of different phases, the residual oil saturation in the corresponding phase permeability curve is selected to constrain the movable remaining oil. For example, for the cavernous phase, due to its low flow resistance, oil may be effectively displaced at a relatively low residual oil saturation. Therefore, a suitable residual oil saturation in the cavernous phase permeability curve is selected as a lower limit constraint for movable remaining oil. For the fractured phase, its linear flow characteristics mean that the determination of residual oil saturation may be related to factors such as fracture connectivity. By analyzing the fractured phase permeability curve, this constraint condition is determined, thereby more accurately judging which oils can be displaced (i.e., movable remaining oil) during reservoir development, providing a basis for tapping the remaining oil potential of the reservoir.

[0066] Next, proceed to step S5.

[0067] In step S5, the reserve calculation module based on Petrel RE obtains the reserve calculation results of the fractured-vuggy reservoir at different time steps in the numerical model of the fractured-vuggy reservoir. Using the grid traversal method, the remaining movable oil reserves of each grid are calculated, and then the remaining movable oil reserves of each grid are extracted to the seismic characterization module, such as... Figure 10 As shown.

[0068] Figure 10 The remaining movable oil reserves according to embodiments of this disclosure.

[0069] By running the reserves calculation module in Petrel RE software, and based on the mass balance principle or other suitable calculation methods (e.g., for the black oil model, reserves calculation may involve parameters such as pore volume, oil saturation, and crude oil density), the reserves calculation results of fractured-vuggy oil reservoirs at different time steps in the numerical model were obtained. These results are typically stored on a per-grid basis and include information such as crude oil reserves, natural gas reserves, and water reserves of the reservoir.

[0070] Using a grid traversal method, the remaining movable oil reserves for each grid are calculated as follows:

[0071] Calculate the initial crude oil reserves for each grid: Ni = Soi × Vp × ρo, and determine the residual oil saturation Sor and the actual oil saturation So of the current grid by combining the relative permeability curve to judge the mobility of the remaining oil. If So > Sor, then calculate the mobile residual oil reserves Nm = (So - Sor) × Vp × ρo.

[0072] Where Soi is the initial oil saturation, Vp is the pore volume, and ρo is the crude oil density.

[0073] The seismic characterization module is primarily used to analyze the seismic properties of oil reservoirs. By extracting the results of movable remaining oil reserves into this module, a correlation can be established between the geological properties (movable remaining oil reserves) and seismic properties (such as amplitude, frequency, phase, and other seismic response characteristics) of fractured-vuggy reservoirs. For example, studies have found that areas with high movable remaining oil reserves may exhibit specific amplitude anomalies or frequency changes on seismic profiles, thereby helping to identify seismic response patterns in areas rich in remaining oil.

[0074] Seismic characterization modules typically possess powerful visualization capabilities, enabling the display of various attributes of fractured-vuggy reservoirs in a three-dimensional manner. By incorporating movable remaining oil reserves into this seismic characterization module, the spatial distribution of remaining oil in fractured-vuggy reservoirs can be observed more intuitively. Furthermore, by combining seismic data with changes over time (such as time-lapse seismic monitoring), the changes in remaining oil can be dynamically monitored.

[0075] Next, proceed to step S6.

[0076] Figure 11 This is a residual oil characterization diagram based on the grid traversal method according to an embodiment of the present disclosure.

[0077] In step S6, the seismic characterization module is accessed to set attribute volume display parameters. Based on the residual oil saturation parameter, dynamic constraint values ​​are set to characterize the remaining oil results, displaying the three-dimensional morphology and location of the remaining oil, such as... Figure 11 As shown.

[0078] Specifically, determine the source of the residual oil saturation data: obtain the residual oil saturation data from previously calculated or imported residual oil-related data. This data may be stored in the software's data tables, attribute fields, or specific result files.

[0079] Setting Movable Constraint Values: Based on the actual conditions of the reservoir and the research objectives, set a reasonable movable constraint value for residual oil saturation. For example, if research shows that oil can be effectively displaced when the residual oil saturation is below 30%, then 30% will be used as the movable constraint value. In the software, by entering this constraint value in the attribute settings or filtering function, areas below this value are considered movable residual oil areas, and areas above this value are considered immovable residual oil areas.

[0080] Characterization Methods: Various methods can be used to characterize the remaining oil results, such as using color changes to represent the level of remaining oil saturation, and using different symbols or patterns to distinguish between movable and immovable remaining oil areas. In the software, these characterizations are implemented using its attribute assignment and visualization functions. For example, warm colors (such as red) can be used to represent areas with high remaining oil saturation, and cool colors (such as blue) can be used to represent areas with low saturation; solid symbols can be used for movable remaining oil areas, and hollow symbols can be used for immovable remaining oil areas.

[0081] Incorporating other parameters (optional): To more comprehensively characterize the remaining oil results, other reservoir parameters, such as porosity and permeability, can be incorporated. For example, while displaying the remaining oil saturation, variations in line thickness or transparency can represent the porosity, thus providing a better understanding of the remaining oil's occurrence environment.

[0082] 3D Visualization Settings: Enable the 3D view function in the seismic characterization module. Adjust parameters such as view angle and zoom level to obtain the optimal observation perspective. For example, by rotating the view, you can observe the 3D distribution of remaining oil in the reservoir from different directions.

[0083] Spatial Location Display: Utilizing the software's coordinate system and spatial positioning capabilities, the location of remaining oil is accurately displayed. Geological structures such as stratigraphic boundaries and faults can be shown in the view, allowing for the correlation between the location of remaining oil and geological structure. For example, it can be observed whether the remaining oil is mainly distributed in a specific stratum or near a fault, thus providing a basis for analyzing the formation mechanism and extraction strategy of the remaining oil. Furthermore, by adding auxiliary tools such as depth axes or contour lines, the vertical distribution of the remaining oil can be more clearly displayed.

[0084] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for characterizing residual oil in fractured-vuggy reservoirs, characterized in that, Includes the following steps: Step S1: Based on the production data, physical property data and geological model of fractured-vuggy reservoirs, establish a numerical model of fractured-vuggy reservoirs; Step S2: Verify and perform historical fitting on the numerical model of the fractured-vuggy reservoir; Step S3: Extract the static properties of the fractured-vuggy reservoir numerical model, calculate the oil saturation properties, and calculate the reservoir reserve distribution of the fractured-vuggy reservoir numerical model at each time step; Step S4: Extract the distribution of karst facies, fracture pore facies, and fracture facies from the numerical model of the fractured-vuggy reservoir, select the residual oil saturation of the corresponding phase permeability curve based on the flow characteristics of each phase, and constrain the range of movable residual oil. Step S5: Based on the oil reservoir reserve distribution, the remaining movable oil reserves of each grid are calculated using the grid traversal method, and the results are extracted to the seismic characterization module; Step S6: Set the attribute volume display parameters in the seismic characterization module, set the dynamic constraint value based on the residual oil saturation parameter, characterize the residual oil results, and display the three-dimensional morphology and location of the residual oil.

2. The method for characterizing residual oil in fractured-vuggy reservoirs according to claim 1, characterized in that, In step S1, the PetrelRE module of the PetrelRE software is used to establish a numerical model of the fractured-vuggy reservoir. The production data includes daily oil production, daily water production, daily gas production, daily gas injection, and daily water injection. The physical property data includes water and crude oil volume coefficients, rock compressibility coefficients, dissolved gas-oil ratio, relative permeability curve data, water and crude oil density and viscosity. The geological model includes a porosity model, a permeability model, well data, and reserve data.

3. The method for characterizing residual oil in fractured-vuggy reservoirs according to claim 2, characterized in that, Step S2 is performed using the Petrel RE module of the Petrel RE software. The parameters for historical fitting include daily oil production, daily water production, cumulative oil production, cumulative water production, water breakthrough time, and water breakthrough amount, ensuring that the fitting error is within the allowable range.

4. The method for characterizing residual oil in fractured-vuggy reservoirs according to claim 3, characterized in that, In step S3, the static properties are extracted using the Results section of the Cases module in the Petrel RE software. The static properties include porosity, mesh volume, and crude oil density. The extracted properties are for each time step.

5. The method for characterizing residual oil in fractured-vuggy reservoirs according to claim 4, characterized in that, In step S4, the geological module of Petrel RE software is used to extract the distribution of karst facies, fracture-void facies, and fracture facies from the numerical model of fractured-vuggy reservoirs.

6. The method for characterizing residual oil in fractured-vuggy reservoirs according to claim 5, characterized in that, In step S5, the grid traversal method includes: Calculate the initial crude oil reserves for each grid: Ni = Soi × Vp × ρo, and determine the residual oil saturation Sor and the actual oil saturation So of the current grid by combining the relative permeability curve to judge the mobility of the remaining oil. If So > Sor, then calculate the mobile residual oil reserves Nm = (So - Sor) × Vp × ρo. Where Soi is the initial oil saturation, Vp is the pore volume, and ρo is the crude oil density.

7. The method for characterizing residual oil in fractured-vuggy reservoirs according to claim 6, characterized in that, In step S6, the seismic characterization module displays the spatial distribution of the remaining oil through three-dimensional visualization and analyzes the location of the remaining oil in conjunction with seismic attributes.

8. A residual oil characterization system for fractured-vuggy reservoirs, characterized in that, include: The Numerical Model Building Module for Fractured-Void Reservoirs is used to build numerical models of fractured-void reservoirs based on production data, physical property data, and geological models. The verification and history fitting module is used to verify and perform history fitting on the numerical model of the fractured-vuggy reservoir. The attribute extraction module is used to extract the static attributes of the fractured-vuggy reservoir numerical model, calculate the oil saturation attribute, and calculate the reservoir reserve distribution of the fractured-vuggy reservoir numerical model at each time step. The phase analysis module is used to extract the distribution of karst phase, fracture pore phase and fracture phase from the numerical model of the fractured-vuggy reservoir, select the residual oil saturation of the corresponding phase permeability curve according to the flow characteristics of each phase, and constrain the range of movable residual oil. The calculation module is used to calculate the remaining movable oil reserves of each grid based on the oil reservoir reserve distribution using the grid traversal method, and extract the results to the seismic characterization module; The characterization module is used to set attribute display parameters in the seismic characterization module, set dynamic constraint values ​​based on the residual oil saturation parameter, characterize the residual oil results, and display the three-dimensional morphology and location of the residual oil.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the method for characterizing residual oil in fractured-vuggy reservoirs as described in any one of claims 1 to 7.

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