'Fracture-joint' type carbonate reservoir body inner-screen modeling method

Abstract

The invention provides a'fracture-fracture 'type carbonate reservoir body inner-screen modeling method, which comprises the following steps of: establishing a structure model according to a fracture system and a top surface structure interpretation result; re-sampling well point logging interpretation results, assigning interpretation lithofacies, porosity and permeability results to the grids, and establishing a single well facies model; determining a single well reservoir body development position according to well logging interpretation, establishing a reservoir body lithofacies model by taking a'fracture-fracture 'type reservoir body depicted by seismic inversion as a boundary, and representing a reservoir body inner lithofacies distribution rule; taking the well point fracture characteristic parameters as constraints, establishing a reservoir body inner-layer fracture development density function, and establishing a reservoir body inner-layer fracture geometric model through random simulation; equivalently converting the reservoir body inner crack geometric model into a porosity and permeability model; and establishing a matrix attribute model. The inner curtain of the'fracture-seam 'type reservoir body is in-layer and inter-layer irregular space combination, and the reservoir space of the inner curtain of the reservoir body is depicted.

Description

Technical Field

[0001] The present invention relates to the technical field of three-dimensional geological modeling for oil development geology, and particularly relates to a method for inner reservoir modeling of a "fault-fracture" type carbonate rock reservoir. Background Art

[0002] At present, the Lower Paleozoic and Archean carbonate buried hill reservoirs discovered in the Shengli Oilfield are mainly distributed in 37 block units of 15 oilfields in areas such as Zhuanghai and Chenjiazhuang Uplift, with a total proven reserve of 216 million tons. 29 units have been put into development, and the recovery factor is only 13%.

[0003] The carbonate rock reservoirs as a whole are in the development status of "low recovery factor and low oil production rate". After a short period of high production after production, the production is low for a long time, which seriously affects the further improvement of the oil recovery rate of the oilfield. The main reasons are analyzed from three aspects: First, the carbonate rock reservoirs have experienced multiple tectonic movements, with a developed fault system, complex structure, and fractured strata; Second, the reservoir lithology is diverse, mainly limestone and dolomite; Third, the types of reservoir spaces are diverse, and the scale is small. The reservoirs are mainly developed with centimeter-level to millimeter-level fractures, and it is difficult to describe the reservoir spaces.

[0004] Three-dimensional geological modeling technology has become a key link in the fine reservoir description of oil reservoirs during oilfield development. Due to the complexity and particularity of carbonate reservoirs, which are essentially different from the geological modeling methods of sandstone reservoirs, carbonate reservoirs require the establishment of a dual-medium geological model for the matrix and fracture systems. The invention patent "A Geological Modeling Method for Fractured-Vuggy Carbonate Reservoirs" (Application No. CN201910138421.3) considers the karst genetic types of fractured-vuggy reservoirs, determines the reservoir body types and distribution laws respectively according to different karst genetic types, uses different modeling algorithms for simulation for different types of reservoir bodies, constructs classified reservoir body models under different karst genetic backgrounds, fuses the classified reservoir bodies under different genetic backgrounds using different fusion methods, and optimizes the geological model based on various production dynamic data. "Reservoir Division and Classification and Grading Geological Modeling of Renqiu Buried Hill Reservoir" proposes to subdivide the reservoir from the original two levels into three levels, and uses facies-controlled modeling technology, ant tracking technology, and fracture network modeling technology to establish the reservoir grading facies model, matrix property model, discrete fracture network model, and fracture property model step by step; on this basis, the reserves are reviewed and refined by reservoir level, realizing the classified and graded modeling of dual-medium reservoirs, providing a basic guarantee for later numerical simulation and remaining oil distribution research. However, none of these methods consider that the pores, fractures, and vugs in the reservoir bodies of carbonate buried hill reservoirs storing oil and gas are not distributed in layers but form an irregular spatial combination within and between layers. Therefore, aiming at improving the recovery rate of carbonate reservoirs and realizing the fine characterization of the internal features of carbonate reservoir bodies in carbonate buried hill reservoirs, we invented a method for modeling the internal features of "fault-fracture" type carbonate reservoir bodies by combining seismic, logging, and geological comprehensive research, which can effectively depict the spatial distribution law of the internal features of reservoir bodies and specifically solve the problem of unclear understanding of the distribution of reservoir spaces in the internal features of reservoir bodies. Summary of the Invention

[0005] In view of the above problems, the present invention is proposed to provide a method for modeling the internal features of "fault-fracture" type carbonate reservoir bodies that overcomes the above problems or at least partially solves the above problems.

[0006] According to one aspect of the present invention, there is provided a method for modeling the internal features of "fault-fracture" type carbonate reservoir bodies, the modeling method comprising:

[0007] Step S1: Establish a structural model according to the results of fault system interpretation and top surface structure interpretation;

[0008] Step S2: Resample the well point attributes according to the logging interpretation results, assign the interpreted lithofacies, porosity, and permeability results to the grid, and establish a single well facies model;

[0009] Step S3: Determine the development location of the single-well reservoir body, establish an internal reservoir facies model with the "fault-fracture" reservoir body inverted from seismic data as the boundary, and establish a reservoir facies model to characterize the distribution law of the internal reservoir facies;

[0010] Step S4: With the well point fracture characteristic parameters as constraints, establish a density function of internal reservoir fractures, and establish a geometric model of internal reservoir fractures;

[0011] Step S5: Equivalently convert the geometric model of the internal reservoir fractures into porosity and permeability models;

[0012] Step S6: Based on well point data, carry out a geostatistical model for the matrix rock blocks, establish a matrix property model, and fuse it with the fracture system to establish a "fault-fracture" reservoir property model to finely characterize the development characteristics of the internal reservoir of the "fault-fracture" reservoir body, and guide the research on the development countermeasures of the block.

[0013] Optionally, the establishment of the structural model specifically includes: applying the fault interpretation and top surface structure interpretation results of the study area to establish a fine three-dimensional structural model to control the boundaries and configuration relationships of each fault block in the area.

[0014] Optionally, the Step S2: Resampling specifically includes: based on core observation and logging data, classifying the well point lithofacies into six major lithologies of mudstone, limestone, dolomite, argillaceous dolomite, and argillaceous limestone, and resampling at 0.125 m intervals.

[0015] Optionally, the Step S3: Determine the development location of the single-well reservoir body and establish a reservoir facies model to characterize the distribution law of the internal reservoir facies specifically includes: determining the development location of the single-well reservoir body according to imaging logging and core observation; using seismic inversion to depict the "fault-fracture" reservoir body as the boundary to establish a reservoir facies model to characterize the distribution law of the internal reservoir facies.

[0016] Optionally, the Step S4: With the well point fracture characteristic parameters as constraints, establish a geometric model of internal reservoir fractures specifically includes:

[0017] With the well point fracture characteristic parameters as constraints, comprehensively analyze the influence of stress field simulation, fault distance, structural curvature, etc. on fracture density, carry out multiple regression, and establish a density function of internal reservoir fractures

[0018] where Y - fracture density constraint data volume X i - factors K reflecting fracture density i - regression coefficients of corresponding factors, and use the density function of internal reservoir fractures as constraints to randomly simulate and establish a geometric model of internal reservoir fractures.

[0019] Optionally, step S5: converting the internal crack geometric model of the reservoir body into porosity and permeability values specifically includes:

[0020] Converting the internal crack geometric model of the reservoir body into porosity and permeability values.

[0021] Optionally, before step S1: establishing the structural model, it further includes:

[0022] Based on the regional tectonic sedimentary evolution history, combining well and seismic data to identify the fault system;

[0023] Using data such as cores, conventional logging, and imaging logging in the study area to determine the exposed horizons, remaining formation thickness, and reservoir space types of the buried hill reservoir in the study area, and to determine whether the internal part of the reservoir body in the study area is mainly of the "fault - fracture" type; the process enters step S1; otherwise, the process ends.

[0024] Optionally, step S1: establishing the structural model specifically includes:

[0025] Applying the small - window dip - scanning stacking technique to identify small faults that are difficult to distinguish on conventional 3D seismic profiles;

[0026] Using the fault interpretation and top - surface structure interpretation results in the study area to establish a fine 3D structural model to control the boundaries and configuration relationships of each fault block in the area.

[0027] Optionally, after establishing the single - well facies model in step S2, it further includes:

[0028] According to the results of the secondary logging interpretation, assign the porosity and permeability results interpreted at the well points to the well - point grids.

[0029] Optionally, before step S3: determining the development position of the single - well reservoir body, using the "fault - fracture" type reservoir body characterized by seismic inversion as the boundary, and establishing the reservoir body lithofacies model to characterize the internal lithofacies distribution law of the reservoir body, it further includes:

[0030] Determine the development position of the "fault - fracture" type reservoir body at the well points according to the imaging logging and core observation results;

[0031] Fully consider the phase - change characteristics of the reservoir body space, apply waveform - indicating inversion to predict medium - and small - scale fractures, and use verification wells to determine the coincidence degree of the fracture sections interpreted by well - point logging, and predict the development status of small - scale fracture zones in the lateral direction;

[0032] By fusing two data volumes of coherence - clutter and waveform - indicating inversion, optimizing the fusion frequency spectrum range, taking the coherence - clutter information of 0 - 10 Hz and the waveform - indicating inversion data information of 10 - 40 Hz for fusion, determine the spatial development range of the "fault - fracture" type reservoir body.

[0033] Optionally, step S3: determining the development position of the single-well reservoir body and establishing a reservoir body lithofacies model to characterize the internal lithofacies distribution law of the reservoir body specifically includes:

[0034] Taking the seismic inversion to depict the "fault-fracture" reservoir body as the boundary, establishing a reservoir body lithofacies model to characterize the internal lithofacies distribution law of the reservoir body;

[0035] Assigning matrix lithofacies to the grids outside the inverted reservoir body, realizing the simulation of the internal spatial distribution law of the "fault-fracture" type reservoir body, and determining the connectivity between reservoir bodies and the development law of internal lithofacies.

[0036] Optionally, step S4: establishing a geometric model of internal reservoir fractures with the well point fracture characteristic parameters as constraints specifically includes:

[0037] Statistical parameters of the strike, dip angle, extension length, penetration depth, and development density of different sets of fractures at well points;

[0038] With the well point fracture characteristic parameters as constraints, comprehensively analyzing the influence of stress field simulation, fault distance, structural curvature, etc. on fracture density, conducting multiple regression, and establishing a function of the development density of internal reservoir fractures where Y - fracture density constraint data volume X i - factors K reflecting fracture density i - regression coefficients of corresponding factors, and establishing a geometric model of internal reservoir fractures by stochastic simulation with the function of the development density of internal reservoir fractures as a constraint.

[0039] Optionally, step S5: equivalently converting the geometric model of internal reservoir fractures into porosity and permeability models specifically includes:

[0040] Equivalently converting the geometric model of internal reservoir fractures into porosity and permeability values;

[0041] Using the co-located co-sequential Gaussian simulation method and using the seismic inversion data volume as a constraint condition, establishing an attribute model of the fault-fracture type reservoir body.

[0042] Optionally, step S6: carrying out a geostatistical mode for the matrix rock blocks based on well point data, establishing a matrix attribute model, and fusing with the fracture system to establish an attribute model of the "fault-fracture" reservoir body, and finely characterizing the development characteristics of the internal reservoir of the "fault-fracture" reservoir body to guide the research on block development countermeasures specifically includes:

[0043] Carrying out geostatistical simulation for the matrix rock blocks based on well point data, applying variogram constraints, and the main direction of the development of the fracture system is the dominant direction of matrix pore development, and establishing a matrix attribute model;

[0044] Integrate with the fracture system to establish an "fault - fracture" reservoir property model, accurately characterize the development characteristics of the internal reservoir of the "fault - fracture" reservoir, and guide the research on the development countermeasures of the block.

[0045] A method for modeling the internal part of a "fault - fracture" type carbonate reservoir provided by the present invention, the modeling method includes: Step S1: Establish a structural model according to the results of fracture system interpretation and top surface structure interpretation; Step S2: Resample the well point properties according to the logging interpretation results, assign the interpreted lithofacies, porosity, and permeability results to the grid, and establish a single - well facies model; Step S3: Determine the development position of the single - well reservoir body, establish an internal lithofacies model of the reservoir body with the "fault - fracture" reservoir body inverted from seismic data as the boundary, and establish a reservoir body lithofacies model to characterize the distribution law of the internal lithofacies of the reservoir body; Step S4: Establish a density function of internal fracture development of the reservoir body with the well - point fracture characteristic parameters as constraints, and establish a geometric model of the internal fractures of the reservoir body; Step S5: Equivalently convert the geometric model of the internal fractures of the reservoir body into a porosity and permeability model; Step S6: The matrix rock blocks carry out a geostatistical model based on well - point data to establish a matrix property model, integrate with the fracture system to establish an "fault - fracture" reservoir property model, accurately characterize the development characteristics of the internal reservoir of the "fault - fracture" reservoir, and guide the research on the development countermeasures of the block. This method fully considers that the internal part of the "fault - fracture" type reservoir body is an irregular spatial combination within and between layers, solves the problem that the distribution law of the reservoir space in the internal part of the carbonate reservoir is not clearly understood due to multiple - stage tectonic movements, and the prediction of the actual oil well cumulative oil and water cut change laws is inaccurate, provides a method for characterizing the internal part of the "fault - fracture" type carbonate reservoir body, and clarifies the development law of the reservoir space in different internal parts of the reservoir body.

[0046] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the description. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are specifically given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0048] Figure 1 It is a flowchart of a method for modeling the internal part of a "fault - fracture" type carbonate reservoir provided by an embodiment of the present invention.

[0049] Figure 2Single-well logging interpretation of porosity and permeability provided by the embodiments of the present invention;

[0050] Figure 3 Lithofacies model of "fault-fracture" type carbonate rock reservoir body provided by the embodiments of the present invention;

[0051] Figure 4 Development density function of internal fractures in the reservoir body provided by the embodiments of the present invention;

[0052] Figure 5 Attribute model of "fault-fracture" reservoir body provided by the embodiments of the present invention. Detailed implementation manners

[0053] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be fully conveyed to those skilled in the art.

[0054] The terms "including" and "having" and any variations thereof in the description embodiments, claims and drawings of the present invention are intended to cover non-exclusive inclusion. For example, including a series of steps or units.

[0055] Hereinafter, in combination with the accompanying drawings and embodiments, the technical solutions of the present invention will be further described in detail.

[0056] As Figure 1 shown, the present invention provides a modeling method for "fault-fracture" type carbonate rock reservoir bodies, which solves the problems that the distribution law of the internal reservoir space of carbonate rock reservoirs is not clearly understood due to multiple tectonic movements, and the variation laws of cumulative oil production and water cut of actual oil wells are not accurately predicted. A characterization method for determining the interior of "fault-fracture" type carbonate rock reservoir bodies is provided to clarify the development laws of the internal reservoir space of different reservoir bodies.

[0057] The technical solution of the present invention is realized through the following technical steps:

[0058] Step S1: Establish a structural model. By applying the fault interpretation and top surface structure interpretation results of the study area, establish a fine three-dimensional structural model to control the boundaries and configuration relationships of each fault block in the area;

[0059] Step S2: Based on core observations and logging data, classify the well-point lithofacies into six major lithologies: mudstone, limestone, dolomite, muddy dolomite, and muddy limestone, re-sample at 0.125 m, and assign the interpreted lithofacies, porosity, and permeability results to the grid to establish a single-well facies model;

[0060] Step S3: Determine the development location of the single-well reservoir body based on imaging logging and core observation; taking the "fault-fracture" reservoir body characterized by seismic inversion as the boundary, establish a reservoir body lithofacies model to characterize the distribution law of the internal lithofacies of the reservoir body;

[0061] Step S4: Taking the well-point fracture characteristic parameters as constraints, comprehensively analyze the influence of stress field simulation, fault distance, structural curvature, etc. on fracture density, conduct multiple regression, and establish a fracture development density function for the internal part of the reservoir body (Y - fracture density constraint data volume X i - factors K reflecting fracture density i - regression coefficients of corresponding factors), taking this as a constraint, randomly simulate to establish a geometric model of the internal fractures of the reservoir body;

[0062] Step S5: According to equivalently convert the geometric model of the internal fractures of the reservoir body into porosity and permeability models;

[0063] Step S6: Based on well-point data, carry out a geostatistical model for the matrix rock blocks, establish a matrix property model, and fuse it with the fracture system to establish a "fault-fracture" reservoir body property model, finely characterize the development characteristics of the internal reservoir of the "fault-fracture" reservoir body, and guide the research on block development countermeasures.

[0064] The object of the present invention needs to be achieved by the following measures:

[0065] This method for modeling the internal part of the "fault-fracture" type carbonate rock oil reservoir also includes, before step 1, first determining the fault system by combining well and seismic data according to the regional tectonic sedimentary evolution history; secondly, applying data such as cores, conventional logging, and imaging logging in the study area to determine the exposed horizon, residual formation thickness, and reservoir space type of the buried hill oil reservoir in the study area, and determine whether the internal part of the reservoir body in the study area is mainly of the "fault-fracture" type; the process enters step 1; otherwise, the process ends.

[0066] In step 1, apply the small-time-window dip scanning and stacking technology to determine small faults that are difficult to distinguish on conventional 3D seismic profiles, and improve the accuracy of structural interpretation. Apply the fault interpretation and top surface structure interpretation results in the study area to establish a fine 3D structural model to control the boundaries and configuration relationships of each fault block in this area.

[0067] In step 2, based on core observation and logging data, subdivide the lithofacies of the completed wells into six lithology classifications: mudstone, limestone, dolomite, argillaceous dolomite, and argillaceous limestone, and resample the well-point data at 0.125 m, accurately assign the interpreted lithofacies results to the well-point grid to establish a single-well facies model; secondly, according to the results of the second logging interpretation, assign the porosity and permeability results interpreted at the well points to the well-point grid.

[0068] Before step 3, it is necessary to determine the development location of the "fault-fracture" type reservoir body at the well point according to the imaging logging and core observation results. Fully considering the phase change characteristics of the reservoir body space, waveform indication inversion is applied to predict medium and small fractures, and verification wells are used to determine the coincidence degree of the logging interpretation fracture sections at the well points, and the development status of small-scale fracture zones in the lateral direction is predicted. By fusing two data volumes of coherence-disorder and waveform indication inversion, optimizing the fusion frequency spectrum range, taking the coherence-disorder information of 0-10 Hz and the waveform indication inversion data information of 10-40 Hz for fusion, the spatial development range of the "fault-fracture" type reservoir body is determined.

[0069] In step 3, taking the seismic inversion to depict the "fault-fracture" reservoir body as the boundary, a reservoir body lithofacies model is established to characterize the distribution law of the internal lithofacies of the reservoir body; the grids outside the inverted reservoir body are assigned matrix lithofacies, realizing the simulation of the spatial distribution law of the "fault-fracture" type reservoir body, and implementing the connectivity between reservoir bodies and the development law of the internal lithofacies.

[0070] In step 4, by statistically analyzing parameters such as the strike, dip angle, extension length, penetration depth, and development density of different sets of fractures at the well points; taking the fracture characteristic parameters at the well points as constraints, comprehensively analyzing the influence of stress field simulation, fault distance, structural curvature, etc. on fracture density, conducting multiple regression, and establishing a function for the development density of internal fractures in the reservoir body (Y - fracture density constraint data volume X i - factors K reflecting fracture density i - regression coefficients of corresponding factors), taking this as a constraint, randomly simulating to establish a geometric model of internal fractures in the reservoir body;

[0071] In step 5, according to the geometric model of internal fractures in the reservoir body is equivalently converted into porosity and permeability models; at the same time, using the co-located co-sequential Gaussian simulation method, using the seismic inversion data volume as a constraint condition, an attribute model of the "fault-fracture" type reservoir body is established.

[0072] In step 6, geostatistical simulation is carried out on the matrix rock blocks based on well point data, applying variogram constraints, and the main direction of the development of the fracture system is the dominant direction of matrix pore development, establishing a matrix attribute model; and fusing with the fracture system to establish an attribute model of the "fault-fracture" reservoir body, finely characterizing the development characteristics of the internal reservoir of the "fault-fracture" reservoir body, and guiding the research on block development countermeasures.

[0073] Figure 2 Based on core observation, conventional logging data, and imaging logging data, the interpreted lithofacies, porosity, and permeability results are assigned to the grids to establish a single-well facies model and determine the development location of the reservoir body in a single well;

[0074] Figure 3Taking the "fault - fracture" reservoir body delineated by seismic inversion as the boundary, a reservoir facies model is established to characterize the internal facies distribution law of the "fault - fracture" reservoir body;

[0075] Figure 4 Constrained by the well - point fracture characteristic parameters, comprehensively analyzing the influence of stress field simulation, fault distance, structural curvature, etc. on fracture density, multiple regression is carried out to establish the internal fracture development density function of the reservoir body;

[0076] Figure 5 Based on well - point data, a geostatistical model is carried out for the matrix rock blocks to establish a matrix property model, which is integrated with the fracture system to establish a "fault - fracture" reservoir body property model to finely characterize the internal reservoir development characteristics of the "fault - fracture" reservoir body and guide the research on block development countermeasures.

[0077] Beneficial effects: The present invention fully considers the characteristics of carbonate reservoirs, such as complex structures caused by multi - stage tectonic movements and small reservoir space scales. It breaks through the limitation that the internal reservoir space distribution law of the "fault - fracture" type reservoir body cannot be predicted due to seismic clutter, and re - considers that the oil and gas storage space of the carbonate reservoir body is an irregular combination of intra - layer and inter - layer. The technical achievements of this time have better operability compared with the past, and are innovative, practical and conducive to popularization. This method has guided the well - site deployment of Che 571 and Chegu 208 buried - hill wells, designed 14 new wells, and increased the recoverable reserves by 4.5 million tons.

[0078] The above - mentioned specific implementation manners further elaborate in detail the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above are only the specific implementation manners of the present invention, and are not used to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for modeling the internal structure of a carbonate reservoir with a "fault - fracture" type, characterized in that, the modeling method includes: Step S1: Establish a structural model based on the interpretation results of the fault system and the top - surface structure interpretation; Step S2: Resample the well - point attributes according to the logging interpretation results, assign the interpreted lithofacies, porosity, and permeability results to the grid, and establish a single - well facies model; Step S3: Determine the development position of the single - well reservoir body, and establish an internal - structure lithofacies model of the reservoir body with the "fault - fracture" reservoir body inverted from seismic data as the boundary to characterize the distribution law of the internal - structure lithofacies of the reservoir body; Step S4: Establish a density function of the internal - structure fracture development of the reservoir body with the well - point fracture characteristic parameters as constraints, and establish a geometric model of the internal - structure fractures of the reservoir body; Step S5: Equivalently convert the geometric model of the internal - structure fractures of the reservoir body into a porosity and permeability model; Step S6: Carry out a geostatistical model for the matrix rock blocks based on the well - point data, establish a matrix property model, and fuse it with the fracture system to establish a "fault - fracture" reservoir body property model to finely characterize the development characteristics of the internal - structure reservoir of the "fault - fracture" reservoir body and guide the research on the development countermeasures of the block.

2. A method for modeling the internal structure of a carbonate reservoir with a "fault - fracture" type according to claim 1, characterized in that, the establishment of the structural model specifically includes: applying the interpretation results of the faults and the top - surface structure in the study area to establish a fine three - dimensional structural model to control the boundaries and configuration relationships of each fault block in the area.

3. A method for modeling the internal structure of a carbonate reservoir with a "fault - fracture" type according to claim 1, characterized in that, the resampling in Step S2 specifically includes: based on core observation and logging data, classifying the well - point lithofacies into six major lithologies: mudstone, limestone, dolomite, muddy dolomite, and muddy limestone, and resampling at intervals of 0.125 m.

4. A method for modeling the internal structure of a carbonate reservoir with a "fault - fracture" type according to claim 1, characterized in that, the determination of the development position of the single - well reservoir body and the establishment of the lithofacies model of the reservoir body to characterize the distribution law of the internal - structure lithofacies of the reservoir body in Step S3 specifically include: determining the development position of the single - well reservoir body according to imaging logging and core observation; using seismic inversion to depict the "fault - fracture" reservoir body as the boundary to establish the lithofacies model of the reservoir body to characterize the distribution law of the internal - structure lithofacies of the reservoir body.

5. A method for modeling the internal structure of a carbonate reservoir with a "fault - fracture" type according to claim 1, characterized in that, the establishment of the geometric model of the internal - structure fractures of the reservoir body with the well - point fracture characteristic parameters as constraints in Step S4 specifically includes: Constrained by the characteristic parameters of well-point fractures, comprehensively analyze the influence of stress field simulation, fault distance, structural curvature, etc. on fracture density, conduct multiple regression, and establish the density function of internal fractures in the reservoir Among them, the Y-fracture density constraint data volume X i - Factor K reflecting fracture density i - Regression coefficient of the corresponding factor. Constrained by the density function of internal fractures in the reservoir body, a geometric model of internal fractures in the reservoir body is established by stochastic simulation.

6. A method for modeling the internal structure of a carbonate reservoir with a "fault - fracture" type according to claim 1, characterized in that, the equivalent conversion of the geometric model of the internal - structure fractures of the reservoir body into a porosity and permeability model in Step S5 specifically includes: According to Convert the geometric model of internal microfractures in the reservoir body into a porosity and permeability model equivalently.

7. A method for modeling the internal structure of a carbonate reservoir with a "fault - fracture" type according to claim 1, characterized in that, before Step S1: establishing the structural model, it further includes: Based on the regional tectonic sedimentary evolution history, combine wells and seismic data to verify the fault system; Using data such as cores, conventional logging, and imaging logging in the applied research area, determine the exposed horizons of the buried hill oil reservoir in the research area, the remaining formation thickness, and the types of reservoir spaces in the reservoir, and determine whether the interior of the reservoir body in the research area is mainly of the "fault-fracture" type; the process proceeds to step S1; otherwise, the process ends.

8. A method for modeling the interior of a "fault-fracture" type carbonate reservoir body according to claim 1, characterized in that, the step S1: establishing a structural model specifically includes: Applying the small-window dip scanning and stacking technique to determine small faults that are difficult to distinguish on conventional 3D seismic profiles; Using the fault interpretation and top surface structure interpretation results in the research area, establish a fine 3D structural model to control the boundaries and configuration relationships of each fault block in the area.

9. A method for modeling the interior of a "fault-fracture" type carbonate reservoir body according to claim 1, characterized in that, after establishing the single-well facies model in the step S2, it further includes: According to the results of the second logging interpretation, assign the porosity and permeability results interpreted at the well points to the well point grids.

10. A method for modeling the interior of a "fault-fracture" type carbonate reservoir body according to claim 1, characterized in that, the step S3: determining the development position of the single-well reservoir body, before establishing a reservoir body lithofacies model with the "fault-fracture" type reservoir body characterized by seismic inversion as the boundary to characterize the lithofacies distribution law of the interior of the reservoir body, it further includes: Determine the development position of the "fault-fracture" type reservoir body at the well points according to the imaging logging and core observation results; Fully consider the phase change characteristics of the reservoir body space, apply waveform indication inversion to predict medium and small fractures, and use verification wells to determine the coincidence degree of the fracture sections interpreted by well logging at the well points, and predict the development status of small-scale fracture zones in the lateral direction; By fusing two data volumes of coherence-disorder and waveform indication inversion, optimize the fusion frequency spectrum range, take the coherence-disorder information of 0-10Hz and the waveform indication inversion data information of 10-40Hz for fusion to determine the spatial development range of the "fault-fracture" type reservoir body.

11. A method for modeling the interior of a "fault-fracture" type carbonate reservoir body according to claim 1, characterized in that, the step S3: determining the development position of the single-well reservoir body and establishing a reservoir body lithofacies model to characterize the lithofacies distribution law of the interior of the reservoir body specifically includes: Taking the "fault-fracture" reservoir body characterized by seismic inversion as the boundary, establish a reservoir body lithofacies model to characterize the lithofacies distribution law of the interior of the reservoir body; Assign the matrix lithofacies to the grids outside the inverted reservoir body, realizing the simulation of the spatial distribution law of the interior of the "fault-fracture" type reservoir body, and implementing the connectivity between reservoir bodies and the development law of the interior lithofacies.

12. A method for modeling the interior of a "fault-fracture" type carbonate reservoir body according to claim 1, characterized in that, the step S4: establishing a geometric model of the interior fractures of the reservoir body with the fracture characteristic parameters at the well points as constraints specifically includes: Statistical parameters of the strike, dip angle, extension length, penetration depth, and development density of different sets of fractures at the well points; Constrained by the characteristic parameters of well-point fractures, comprehensive stress field simulation, fault distance, structural curvature and other factors affecting fracture density analysis are carried out, multiple regression is carried out, and a density function of internal fractures in the reservoir body is established. Among them, Y - fracture density constraint data volume X i - factor K reflecting fracture density i - regression coefficient of the corresponding factor. Constrained by the density function of internal fractures in the reservoir body, a geometric model of internal fractures in the reservoir body is established by stochastic simulation.

13. A method for modeling the interior of a "fault-fracture" type carbonate reservoir body according to claim 1, characterized in that, The step S5: Equivalently converting the internal fracture geometric model of the reservoir body into a porosity and permeability model specifically includes: According to equivalently convert the geometric model of internal microfractures in the reservoir body into a porosity and permeability model; Using the co-located co-sequential Gaussian simulation method and using the seismic inversion data volume as a constraint condition, an attribute model of the fault-fracture type reservoir body is established.

14. A method for building an internal model of a "fault-fracture" type carbonate reservoir body according to claim 1, characterized in that The step S6: Based on well point data, a geostatistical model is carried out for the matrix rock blocks to establish a matrix attribute model, and it is integrated with the fracture system to establish a "fault-fracture" reservoir body attribute model, and the internal reservoir development characteristics of the "fault-fracture" reservoir body are finely characterized to guide the research on the development countermeasures of the block, specifically including: Based on well point data, a geostatistical simulation is carried out for the matrix rock blocks, and the variogram is used for constraint. The main direction of the development of the fracture system is the dominant direction of the development of the matrix pores, and a matrix attribute model is established; And it is integrated with the fracture system to establish a "fault-fracture" reservoir body attribute model, and the internal reservoir development characteristics of the "fault-fracture" reservoir body are finely characterized to guide the research on the development countermeasures of the block.

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