Hydrocarbon migration simulation method and medium

Abstract

The application discloses an oil and gas migration simulation method and medium, comprising the following steps: calculating hydrocarbon generation intensity and hydrocarbon discharge intensity through a three-dimensional data body of organic carbon of a hydrocarbon source rock; obtaining an initial oil and gas migration direction through a main separation groove of the hydrocarbon source rock and the hydrocarbon generation intensity and the hydrocarbon discharge intensity; establishing an oil and gas three-dimensional transportation system based on numerical modeling integration of a carrier; obtaining overpressure spatial distribution characteristics through prediction of a present formation pressure field to quantitatively represent oil and gas migration driving force; and performing four-dimensional dynamic simulation of oil and gas migration through the three-dimensional data body of organic carbon of the hydrocarbon source rock, the initial oil and gas migration direction, the oil and gas three-dimensional transportation system and the oil and gas migration driving force. The application improves the accuracy of oil and gas migration simulation by simulating oil and gas migration from four dimensions of the three-dimensional data body of organic carbon of the hydrocarbon source rock, the initial oil and gas migration direction, the oil and gas three-dimensional transportation system and the oil and gas migration driving force.

Description

Technical Field

[0001] This invention relates to the field of model simulation technology, and in particular to a method and medium for simulating oil and gas migration. Background Technology

[0002] Oil and gas migration is the core link between hydrocarbon generation from source rocks and hydrocarbon accumulation in traps, and accurate evaluation determines the spatial distribution and enrichment level of oil and gas reservoirs. Currently, oil and gas migration evaluation technologies at home and abroad have evolved from early qualitative descriptions to semi-quantitative simulations, mainly including three categories: pseudo-three-dimensional migration and accumulation simulations using basin simulation software, quantitative evaluation of single transport elements, and planar prediction technology of source rock organic carbon (TOC) based on seismic inversion. The pseudo-3D migration and accumulation simulation constructs a stratigraphic layer model to simulate the fluid potential distribution of that layer during a specific geological period, thereby predicting the direction and accumulation range of oil and gas migration. Its shortcomings are that it can only simulate the fluid migration of a single stratigraphic layer and cannot depict the three-dimensional migration path and process of oil and gas in space. Furthermore, it simplifies the transport conductor to a homogeneous stratum and does not consider the heterogeneity of the transport conductor. The quantitative evaluation of single transport elements evaluates the vertical transport capacity of faults through parameters such as fault growth index, fault displacement, and mudstone smearing coefficient. It only evaluates a single transport conductor and cannot predict the migration path of oil and gas coupled in different transport conductors. Moreover, it does not consider dynamic evolution and cannot reflect the changes in transport capacity in different geological periods. The seismic inversion source rock organic carbon planar prediction technology predicts the planar distribution of source rock organic carbon by combining well and seismic data. It can only predict the planar distribution and does not generate a three-dimensional organic carbon data volume.

[0003] The existing three types of migration technologies are only applicable to simplified geological models and cannot handle the multi-fault and thin-layer sand geological conditions of complex offshore rift basins. They are particularly limited in offshore areas with multiple depressions supplying hydrocarbons, long-distance migration, and complex tectonic lithology. The accuracy of oil and gas migration simulation is low and cannot meet the needs of high-risk offshore exploration. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address at least one defect of the related technologies mentioned in the background art: low accuracy of oil and gas migration simulation, and to provide an oil and gas migration simulation method and medium.

[0005] The technical solution adopted by this invention to solve its technical problem is: to construct an oil and gas migration simulation method, the method comprising the following steps: S1: Generate a three-dimensional data volume of organic carbon in source rocks based on the three-dimensional structural model, and calculate hydrocarbon generation intensity and hydrocarbon expulsion intensity through the three-dimensional data volume of organic carbon in source rocks; S2: Based on the occurrence and fault development characteristics of source rocks, the main septum of source rocks is divided, and the initial migration direction of oil and gas is obtained through the main septum of source rocks, as well as the hydrocarbon generation intensity and hydrocarbon expulsion intensity. S3: Establishing a three-dimensional oil and gas transport system based on reservoir numerical modeling and integrating transport conductors; S4: Obtain the spatial distribution characteristics of overpressure by predicting the current formation pressure field to quantitatively characterize the driving force of oil and gas migration; S5: Four-dimensional dynamic simulation of oil and gas migration is performed using three-dimensional organic carbon data volume of source rocks, initial migration direction of oil and gas, three-dimensional oil and gas transport system, and oil and gas migration force.

[0006] In some embodiments, the method for obtaining the three-dimensional construction model in step S1 includes: S01: Establish the sequence stratigraphic framework of a three-dimensional geological work area within a preset range; S02: Based on sequence stratigraphy, well logging-seismic joint calibration is performed to establish a three-dimensional velocity model applicable to different lithologies; S03: Based on three-dimensional velocity models of different lithologies, time-depth conversion and seismic inversion are performed to obtain seismic interpretation horizons and faults, and a three-dimensional structural model is obtained through seismic interpretation horizons and faults.

[0007] In some embodiments, step S1, generating a three-dimensional data volume of source rock organic carbon based on a three-dimensional construction model, includes: S11: Establish a single-well organic carbon logging prediction model based on measured organic carbon data and logging data from a single well; S12: Obtain the organic carbon logging prediction curve of a single well through the organic carbon logging prediction model, and establish a quantitative model between the organic carbon logging prediction curve of a single well and seismic attributes. S13: The quantitative model between the single-well organic carbon logging prediction curve and seismic attributes is transformed into a quantitative relationship between organic carbon and seismic attributes in the work area through neural network mapping; S14: Based on the three-dimensional structural model, a three-dimensional data volume of source rock organic carbon is generated by quantitatively relating organic carbon in the work area to seismic properties.

[0008] In some embodiments, in step S3, the three-dimensional oil and gas transport conductor includes at least a sandstone transport conductor and / or a fault transport conductor.

[0009] In some embodiments, the method for obtaining the sandstone conductor includes: Sandstone transport standards are established based on reservoir physical parameters and actual oil and gas show statistics; the sandstone transport standards include shallow and medium-depth sandstone transport standards and lower limits of deep sandstone body charging physical properties. Based on the sandstone transport standard, frequency division inversion technology was used to establish multiple sets of lithological differentiation lines applicable to different strata. Based on multiple sets of applicable lithological demarcation lines, the three-dimensional distribution of the transport conductor from the source rock layer to the target sandstone layer is obtained.

[0010] In some embodiments, the method for obtaining the fault conductor includes: classifying the fault into active phases, analyzing the faults according to the fault attributes classified by active phase, establishing a fault conduction capacity grading standard, and obtaining the fault conductor through the fault conduction capacity grading standard. The activity period classification includes long-term active type, early extension type, and late tension-torsion type.

[0011] In some embodiments, step S4 includes: S41: Based on the seismic velocity spectrum model, establish a quantitative relationship between seismic layer velocity and formation pressure; S42: Predict the current formation pressure field by quantitatively relating seismic layer velocity and formation pressure, and obtain the spatial distribution characteristics of overpressure in the current formation pressure field; S43: By combining basin simulation to reconstruct the paleopressure evolution history, analyze the coupling relationship between hydrocarbon generation and overpressure development in the spatial distribution characteristics of overpressure, and obtain the driving force for oil and gas migration.

[0012] In some embodiments, step S5 includes: S51: Improve the three-dimensional construction model by using the three-dimensional organic carbon data volume of source rocks, the three-dimensional oil and gas transport system, and the current formation pressure field as constraints; S52: Based on the improved three-dimensional structural model, four-dimensional dynamic simulation of oil and gas migration is carried out through the three-dimensional data volume of organic carbon in source rocks, the initial migration direction of oil and gas, the three-dimensional oil and gas transport system, and the migration force of oil and gas.

[0013] In some embodiments, the method further includes: analyzing the evolution law of oil and gas migration based on the four-dimensional dynamic simulation results of oil and gas migration, and predicting favorable oil and gas-bearing zones.

[0014] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the oil and gas migration simulation method as described in any of the above embodiments.

[0015] By implementing this invention, the following beneficial effects are achieved: This invention improves the accuracy of oil and gas migration simulation by simulating oil and gas migration from four dimensions: the three-dimensional data volume of organic carbon in source rocks from which oil and gas are generated, the initial migration direction of oil and gas after discharge, the three-dimensional transport system of oil and gas movement, and the driving force of oil and gas focusing. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings: Figure 1 A flowchart of one embodiment of the oil and gas migration simulation method of the present invention is shown; Figure 2 A flowchart of a method for obtaining a three-dimensional structural model in an embodiment of the oil and gas migration simulation method of the present invention is shown; Figure 3 A flowchart of step S1 in an embodiment of the oil and gas migration simulation method of the present invention is shown; Figure 4 A flowchart illustrating a method for obtaining sandstone transport conductors in one embodiment of the oil and gas migration simulation method of the present invention is shown; Figure 5 A flowchart of step S4 in an embodiment of the oil and gas migration simulation method of the present invention is shown; Figure 6 A flowchart of step S5 in an embodiment of the oil and gas migration simulation method of the present invention is shown; Figure 7 This invention illustrates an embodiment of the hydrocarbon migration simulation method, showing the division of the T80 main segmentation trough on the top surface of the source rock and the main hydrocarbon migration and accumulation direction. Figure 8 This paper shows a cross-sectional view of a sandstone transport conductor sculpted using a post-stack frequency division inversion technique, one embodiment of the oil and gas migration simulation method of the present invention. Figure 9 This diagram illustrates a schematic of a three-dimensional oil and gas transport network in a certain region, based on an embodiment of the oil and gas migration simulation method of the present invention. Figure 10 A comparison diagram of fault modeling modes in one embodiment of the oil and gas migration simulation method of the present invention is shown; Figure 11 This diagram illustrates the current spatial distribution of the pressure field in an embodiment of the oil and gas migration simulation method of the present invention. Figure 12-a This paper shows the 2D oil and gas migration simulation results of a certain profile in an embodiment of the oil and gas migration simulation method of the present invention; Figure 12-b This paper shows the 3D oil and gas migration simulation results of a certain profile in an embodiment of the oil and gas migration simulation method of the present invention; Figure 13-a This diagram illustrates a dual-fault-coordinated hydrocarbon accumulation model in one embodiment of the hydrocarbon migration simulation method of the present invention. Figure 13-b This diagram illustrates a fault-ridge linkage-controlled hydrocarbon accumulation model in one embodiment of the hydrocarbon migration simulation method of the present invention. Figure 13-c A three-dimensional spiral accumulation model diagram of an embodiment of the oil and gas migration simulation method of the present invention is shown. Detailed Implementation

[0017] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0018] It should be noted that the flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily need to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0019] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0020] like Figure 1 As shown, this invention discloses a method for simulating oil and gas migration, specifically a quantitative evaluation method for three-dimensional oil and gas migration and conduction based on four-dimensional spatiotemporal coupling. This method includes the following steps: S1: Generate a three-dimensional data volume of organic carbon from source rocks based on the three-dimensional structural model, and calculate hydrocarbon generation intensity and hydrocarbon expulsion intensity using the three-dimensional data volume of organic carbon from source rocks.

[0021] Organic carbon (TOC) refers to the carbon content of all organic matter in rocks (mainly shale / source rocks), expressed as a weight percentage (wt%), and is an indicator for evaluating the quality of source rocks. Three-dimensional organic carbon data volumes of source rocks can accurately characterize the control heterogeneity of source rock hydrocarbon generation potential, improving the accuracy of hydrocarbon generation potential prediction compared to homogeneous strata.

[0022] Hydrocarbon generation intensity is the total amount of oil and gas generated per unit area (or volume) of source rock during thermal evolution; hydrocarbon expulsion intensity is the total amount of oil and gas expelled from source rock per unit area (or volume) and enters the reservoir; hydrocarbon generation intensity and hydrocarbon expulsion intensity can characterize oil and gas generation.

[0023] like Figure 2 As shown, in some embodiments, the method for obtaining a three-dimensional construction model includes: S01: Establish the sequence stratigraphic framework of a three-dimensional geological work area within a preset range.

[0024] Conduct tectonic, burial, and thermal history studies to establish a sequence stratigraphic framework for a pre-defined three-dimensional geological area. A sequence stratigraphic framework refers to dividing the strata in a sedimentary basin into a series of genetically related and isochronous sequences, with unconformities (or corresponding conformable surfaces) as boundaries, and establishing the spatial superposition and distribution framework of the sequences for subsequent acquisition of three-dimensional models based on this sequence stratigraphic framework.

[0025] S02: Based on sequence stratigraphy, perform well logging-seismic joint calibration to establish a three-dimensional velocity model applicable to different lithologies.

[0026] A three-dimensional velocity model divides the geological space into numerous three-dimensional grids, assigning each grid a seismic wave propagation velocity value. This velocity value is determined by the lithology of that grid (sandstone, mudstone, carbonate rock, etc.). The three-dimensional velocity model is used to convert time-domain seismic interpretation results into depth-domain data to obtain input data for three-dimensional structural models.

[0027] S03: Based on three-dimensional velocity models of different lithologies, time-depth conversion and seismic inversion are performed to obtain seismic interpretation horizons and faults, and a three-dimensional structural model is obtained through seismic interpretation horizons and faults.

[0028] The mesh size of the three-dimensional structural model is no larger than 50m×50m×10m, and its accuracy ensures the effective characterization of thin sand layers and small faults. Hydrocarbon generation itself is the result of four-dimensional dynamic simulation, while the three-dimensional structural model provides the spatial framework and boundary conditions for the four-dimensional dynamic simulation, constraining the calculations.

[0029] like Figure 3 As shown, in some embodiments, a three-dimensional data volume of organic carbon from source rocks is generated based on a three-dimensional construction model, including: S11: Establish a single-well organic carbon logging prediction model based on measured organic carbon data and logging data from a single well.

[0030] Using well logging data (such as resistivity, acoustic wave, density, natural gamma, etc.) as input independent variables and single-well measured organic carbon data as dependent variables, a single-well organic carbon logging prediction model is established. This model is a mathematical expression for quantitatively estimating the organic carbon content (TOC, wt%) at a certain depth point underground. This organic carbon logging prediction model is based on single-well measured organic carbon data and therefore has the characteristics of that single well, but it also has certain limitations.

[0031] S12: Obtain the organic carbon logging prediction curve of a single well through the organic carbon logging prediction model, and establish a quantitative model between the organic carbon logging prediction curve of a single well and seismic attributes.

[0032] Seismic attributes are the seismic attributes near the wellbore corresponding to the single-well organic carbon prediction model. The projection of the well onto the ground is just a point, while the seismic trace is a vertical column. The seismic data volume summarizes each trace corresponding to a point on the ground. Therefore, only the seismic signal located directly below the wellhead coordinates (i.e., the well-side trace) records the physical information of the formation at that single well. Thus, obtaining the seismic attributes near the wellbore corresponding to the light gold organic carbon prediction model makes the quantitative model between the single-well organic carbon logging prediction curve and seismic attributes more accurate. However, the quantitative model between the single-well organic carbon logging prediction curve and seismic attributes also has certain limitations due to the characteristics of that single well.

[0033] S13: The quantitative model between the single-well organic carbon logging prediction curve and seismic attributes is transformed into a quantitative relationship between organic carbon and seismic attributes in the work area through neural network mapping.

[0034] Both the organic carbon logging prediction model and the quantitative model between the single-well organic carbon logging prediction curve and seismic attributes have limitations. Therefore, it is necessary to use neural network mapping to transform the quantitative model of single-well organic carbon estimation with single-well characteristics into a quantitative relationship of organic carbon prediction for each grid in the entire work area, thereby improving the accuracy of organic carbon prediction for the entire work area.

[0035] S14: Based on the three-dimensional structural model, a three-dimensional data volume of source rock organic carbon is generated by quantitatively relating organic carbon in the work area to seismic properties.

[0036] By acquiring three-dimensional organic carbon data volumes of source rocks, hydrocarbon generation intensity can be calculated using these data volumes, and then hydrocarbon expulsion intensity can be calculated using the hydrocarbon generation intensity. This improves the accuracy of hydrocarbon generation dimensions in hydrocarbon migration simulation.

[0037] S2: Based on the occurrence and fault development characteristics of source rocks, the main septum of source rocks is divided, and the initial migration direction of oil and gas is obtained through the main septum of source rocks, as well as the hydrocarbon generation intensity and hydrocarbon expulsion intensity.

[0038] The main trough of the source rock is the core area with the greatest hydrocarbon generation potential and the most concentrated hydrocarbon discharge in the entire basin. Oil and gas migrate outward from the inside of the main trough in a centrifugal manner. That is, the location and geometry of the main trough of the source rock determine the direction of the initial migration of oil and gas, which can characterize the discharge of oil and gas.

[0039] S3: Establish a three-dimensional oil and gas transport system based on reservoir numerical modeling and integrated transport conductors.

[0040] Numerical modeling of oil reservoirs involves building a "digital oilfield" in a computer—discretizing the geological features, rock physical properties, and fluid distribution of underground oil reservoirs in a three-dimensional grid using mathematical equations, and then simulating the flow behavior of oil, gas, and water underground using a computer.

[0041] A three-dimensional transport system refers to a composite network system with transport capabilities formed by transport layers (sandstone, faults, unconformities, fractures, etc.) with different occurrences, scales, and transport properties cutting, overlapping, and connecting with each other in three-dimensional space. It is a three-dimensional channel assembly that oil and gas must pass through to migrate from the source rock (main separator of the source rock) to the trap (reservoir), and it can characterize the movement of oil and gas.

[0042] In some embodiments, the three-dimensional oil and gas transport conductors include at least sandstone transport conductors and / or fault transport conductors.

[0043] like Figure 4 As shown, in some embodiments, the method for obtaining sandstone conductors includes: Sandstone transport standards are established based on reservoir physical parameters and actual oil and gas show statistics; the sandstone transport standards include shallow and medium-depth sandstone transport standards and lower limits of deep sandstone body charging properties.

[0044] For example, reservoir physical properties can be porosity, permeability, sand content, etc. The standard for transport of shallow and medium-depth sandstone is a sand content >30%, and the lower limit of charging physical properties for deep sandstone bodies is 9% porosity and 1 millidarcy for crude oil, and 7% porosity and 0.1 millidarcy for natural gas.

[0045] Based on the sandstone transport standard, frequency division inversion technology is used to establish multiple sets of lithological boundaries applicable to different strata.

[0046] Frequency division inversion technology includes pre-stack frequency division inversion and post-stack frequency division inversion. It establishes multiple sets of lithological demarcation lines applicable to different stratigraphic systems based on sandstone transport standards through actual well lithology correction and virtual well constraints. Actual well lithology correction corrects and calibrates the lithology prediction results to ensure consistency with actual subsurface lithology, while virtual well constraints add constraints to improve prediction accuracy. Lithological demarcation lines bridge the qualitative sandstone transport standard to a quantitative stage, and the results obtained through actual well lithology correction and virtual well constraints are more precise.

[0047] Based on multiple sets of applicable lithological demarcation lines, the three-dimensional distribution of the transport conductor from the source rock layer to the target sandstone layer is obtained.

[0048] The three-dimensional distribution of sandstone transport conductors from source rock layers to target layers essentially clarifies the sandstone transport conductors, i.e., the movement path of oil and gas. Sandstone transport conductors consist of multiple transport layers (such as a sandstone layer, a fault, and an unconformity). The transport layers are divided into effective transport layers and ineffective transport layers. By statistically analyzing the sand content of each transport layer, it is determined whether the sand body is an effective transport layer or an ineffective transport layer, thus avoiding the inclusion of ineffective transport layers in the obtained sandstone transport conductors and improving the prediction accuracy of sandstone transport conductors.

[0049] In some embodiments, the method for obtaining fault conductors includes: classifying faults into active phases, analyzing faults based on the fault attributes of the active phase classification, establishing a fault conduction capacity grading standard, and obtaining fault conductors through the fault conduction capacity grading standard; the active phase classification includes long-term active type, early extensional type, and late tensional-torsional type.

[0050] Fault attributes include fault growth index, fault displacement during hydrocarbon accumulation, dip angle, mud content in the fault surface, and effective stress. In this embodiment, the vertical conductivity of the three-dimensional hydrocarbon transport conductor is evaluated by the fault conductor, which accounts for 70% to 90% of the vertical conductivity, thus improving the accuracy of the three-dimensional hydrocarbon transport conductor. In other embodiments, other attributes such as fracture conductivity and vertical connectivity of cross-layer sand bodies may also be used, which are not limited here.

[0051] In step S3, a fault-sand body coupled three-dimensional oil and gas transport system is established by integrating sandstone transport conductors and fault transport conductors, clarifying the spatial configuration relationship of different transport conductors, and characterizing oil and gas movement.

[0052] S4: Obtain the spatial distribution characteristics of overpressure by predicting the current formation pressure field to quantitatively characterize the driving force of oil and gas migration.

[0053] like Figure 5 As shown, in some embodiments, step S4 includes: S41: Based on the seismic velocity spectrum model, establish a quantitative relationship between seismic layer velocity and formation pressure.

[0054] The seismic velocity spectrum model refers to a quantitative mathematical model in seismic data processing that uses velocity spectrum technology to extract the seismic wave propagation velocity from seismic reflection records as a function of time and space. Specifically, it refers to a three-dimensional data volume (X, Y, T, V), where a seismic wave propagation velocity value (V) corresponds to each spatial location (X, Y) and time depth (T) underground.

[0055] S42: Predict the current formation pressure field by quantitatively relating seismic layer velocity to formation pressure, and obtain the spatial distribution characteristics of overpressure in the current formation pressure field.

[0056] S43: By combining basin simulation to reconstruct the paleopressure evolution history, analyze the coupling relationship between hydrocarbon generation and overpressure development in the spatial distribution characteristics of overpressure, and obtain the driving force for oil and gas migration.

[0057] Basin simulation and reconstruction of paleopressure evolution history refers to the use of basin simulation technology to invert the continuous changes in formation pressure of a specific stratum from its deposition to the present day over geological time. Hydrocarbon generation refers to the entire process by which organic matter in sedimentary rocks gradually transforms into oil and natural gas during burial and warming. The essence of hydrocarbon migration is the difference in fluid potential energy. Paleopressure evolution history provides the evolutionary framework of the pressure field, while the coupling relationship between hydrocarbon generation and overpressure development provides the source and release mechanism of the driving force. Therefore, hydrocarbon accumulation traps can be obtained through hydrocarbon migration dynamics.

[0058] S5: Four-dimensional dynamic simulation of oil and gas migration is performed using three-dimensional organic carbon data volume of source rocks, initial migration direction of oil and gas, three-dimensional oil and gas transport system, and oil and gas migration force.

[0059] The hydrocarbon generation intensity and hydrocarbon expulsion intensity in the three-dimensional organic carbon data volume of source rocks characterize hydrocarbon generation, the initial migration direction of hydrocarbons characterizes hydrocarbon expulsion, the three-dimensional hydrocarbon transport system including sandstone transport conductors and fault transport conductors characterizes hydrocarbon movement, and on the basis of the first three, the hydrocarbon migration force is combined to characterize the hydrocarbon accumulation trap, and a four-dimensional dynamic simulation is carried out from the four dimensions of the entire process of hydrocarbon “generation-expulsion-transport-accumulation”.

[0060] like Figure 6 As shown, in some embodiments, step S5 includes: S51: perfecting the three-dimensional construction model with constraints such as the three-dimensional organic carbon data volume of source rock, the three-dimensional oil and gas transport system, and the current formation pressure field; S52: on the basis of the perfected three-dimensional structural model, performing four-dimensional dynamic simulation of oil and gas migration through the three-dimensional organic carbon data volume of source rock, the initial migration direction of oil and gas, the three-dimensional oil and gas transport system, and the migration force of oil and gas.

[0061] The migration of oil and gas underground is the result of the combined action of multiple forces. Based on the improved three-dimensional structural model, a four-dimensional dynamic simulation of the entire process of oil and gas “generation-discharge-transport-accumulation” is carried out by comprehensively considering multiple driving forces such as buoyancy, capillary force, and overpressure. This restores the complete dynamic process of oil and gas migration and improves the accuracy of oil and gas migration simulation.

[0062] In some embodiments, the method further includes: analyzing the evolution law of oil and gas migration based on the four-dimensional dynamic simulation results of oil and gas migration, and predicting favorable oil and gas-bearing zones.

[0063] Based on the results of four-dimensional dynamic simulation of oil and gas migration, we extract the migration paths and accumulation ranges at different historical locations to analyze the evolutionary patterns of oil and gas migration. This approach provides a more precise analysis of the evolutionary patterns of oil and gas migration, building upon the high accuracy of the simulation.

[0064] Based on the results of four-dimensional dynamic simulation of hydrocarbon migration, this study analyzes the controlling effects of source rocks, faults, sandstone conduits, structural ridges, or paleo-uplifts on hydrocarbon migration, identifying convergent and divergent flow patterns. Then, it identifies fault-dominated migration paths to clarify the main controlling factors for hydrocarbon enrichment. Finally, it summarizes hydrocarbon accumulation models to predict favorable hydrocarbon-bearing zones and exploration targets. Convergent flow refers to fluid flowing from different directions towards the same low-potential area / structural high point, with streamlines gradually converging. Divergent flow refers to fluid flowing from the same high-potential area in different directions, with streamlines gradually dispersing. Building upon the high accuracy of hydrocarbon migration simulation, the identification of hydrocarbon-rich areas is more precise.

[0065] For example, this embodiment provides a method for simulating oil and gas migration, taking a basin as an example. This method is only an example and is not intended to limit this application. Other methods are also possible, as detailed below: A detailed three-dimensional structural model covering the entire work area was established, with a grid size of 50m×50m×10m, to depict the complete sequence stratigraphic framework from the Wenchang Formation to the Wanshan Formation; for example... Figure 7 As shown, the predicted three-dimensional organic carbon data volume of the Wenchang Formation source rocks clearly identifies the third member of the Wenchang Formation as a high-quality source rock, divides it into three main subdivisions, and determines that the main migration direction of oil and gas is the eastern uplift zone and the western depression zone; as shown Figures 8-10 As shown, post-stack frequency division inversion technology was used to sculpt sandstone transport conductors of six layers, identify effective transport layers, delineate 25 major faults, and identify 8 long-term active oil-source faults, establishing a fault-sandbody coupled three-dimensional oil and gas transport system; Figure 11 As shown in Figure 12, the predicted pressure coefficient of the Wenchang Formation pressure field reaches 1.3, confirming that hydrocarbon generation is the main contributing factor to overpressure development. As shown in Figure 12, the four-dimensional dynamic oil and gas migration simulation results show that oil and gas mainly migrate vertically along long-term active faults and then accumulate laterally through sandstone transport conductors. The four-dimensional dynamic oil and gas migration simulation results are in agreement with the actual drilling oil and gas data by 82%.

[0066] In addition, as shown in Figure 13, the results of hydrocarbon migration simulation summarize three hydrocarbon accumulation models: double fault combination, fault-ridge joint control, and three-dimensional spiral. It is also predicted that the Neogene structure near the depression zone and the Wenchang Formation composite trap within the depression are favorable exploration zones for the next step.

[0067] The present invention also discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the oil and gas migration simulation method as described in any of the above embodiments.

[0068] It is understood that the above embodiments only illustrate some implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can freely combine the above embodiments or technical features without departing from the concept of the present invention, and can also make several modifications and improvements, all of which fall within the protection scope of the present invention. That is, the embodiments described "in some embodiments" can be freely combined with any of the preceding and following embodiments. Therefore, all equivalent transformations and modifications made within the scope of the claims of the present invention should be covered by the claims of the present invention.

Claims

1. A method for simulating oil and gas migration, characterized in that, The method includes the following steps: S1: Generate a three-dimensional data volume of organic carbon in source rocks based on the three-dimensional structural model, and calculate hydrocarbon generation intensity and hydrocarbon expulsion intensity through the three-dimensional data volume of organic carbon in source rocks; S2: Based on the occurrence and fault development characteristics of source rocks, the main septum of source rocks is divided, and the initial migration direction of oil and gas is obtained through the main septum of source rocks, as well as the hydrocarbon generation intensity and hydrocarbon expulsion intensity. S3: Establishing a three-dimensional oil and gas transport system based on reservoir numerical modeling and integrating transport conductors; S4: Obtain the spatial distribution characteristics of overpressure by predicting the current formation pressure field to quantitatively characterize the driving force of oil and gas migration; S5: Four-dimensional dynamic simulation of oil and gas migration is performed using three-dimensional organic carbon data volume of source rocks, initial migration direction of oil and gas, three-dimensional oil and gas transport system, and oil and gas migration force.

2. The oil and gas migration simulation method according to claim 1, characterized in that, The method for obtaining the three-dimensional construction model in step S1 includes: S01: Establish the sequence stratigraphic framework of a three-dimensional geological work area within a preset range; S02: Based on sequence stratigraphy, well logging-seismic joint calibration is performed to establish a three-dimensional velocity model applicable to different lithologies; S03: Based on three-dimensional velocity models of different lithologies, time-depth conversion and seismic inversion are performed to obtain seismic interpretation horizons and faults, and a three-dimensional structural model is obtained through seismic interpretation horizons and faults.

3. The oil and gas migration simulation method according to claim 2, characterized in that, In step S1, a three-dimensional data volume of organic carbon from source rocks is generated based on the three-dimensional construction model, including: S11: Establish a single-well organic carbon logging prediction model based on measured organic carbon data and logging data from a single well; S12: Obtain the organic carbon logging prediction curve of a single well through the organic carbon logging prediction model, and establish a quantitative model between the organic carbon logging prediction curve of a single well and seismic attributes. S13: The quantitative model between the single-well organic carbon logging prediction curve and seismic attributes is transformed into a quantitative relationship between organic carbon and seismic attributes in the work area through neural network mapping; S14: Based on the three-dimensional structural model, a three-dimensional data volume of source rock organic carbon is generated by quantitatively relating organic carbon in the work area to seismic properties.

4. The oil and gas migration simulation method according to claim 3, characterized in that, In step S3, the three-dimensional oil and gas transport conductor includes at least sandstone transport conductors and / or fault transport conductors.

5. The oil and gas migration simulation method according to claim 4, characterized in that, The method for obtaining the sandstone conductor includes: Sandstone transport standards are established based on reservoir physical parameters and actual oil and gas show statistics; the sandstone transport standards include shallow and medium-depth sandstone transport standards and lower limits of deep sandstone body charging physical properties. Based on the sandstone transport standard, frequency division inversion technology was used to establish multiple sets of lithological differentiation lines applicable to different strata. Based on multiple sets of applicable lithological demarcation lines, the three-dimensional distribution of the transport conductor from the source rock layer to the target sandstone layer is obtained.

6. The oil and gas migration simulation method according to claim 4, characterized in that, The method for obtaining fault conductors includes: classifying faults by their active phase, analyzing the faults based on the fault attributes classified by their active phase, establishing a fault conduction capacity grading standard, and obtaining fault conductors through the fault conduction capacity grading standard. The activity period classification includes long-term active type, early extension type, and late tension-torsion type.

7. The oil and gas migration simulation method according to claim 5 or 6, characterized in that, Step S4 includes: S41: Based on the seismic velocity spectrum model, establish a quantitative relationship between seismic layer velocity and formation pressure; S42: Predict the current formation pressure field by quantitatively relating seismic layer velocity and formation pressure, and obtain the spatial distribution characteristics of overpressure in the current formation pressure field; S43: By combining basin simulation to reconstruct the paleopressure evolution history, analyze the coupling relationship between hydrocarbon generation and overpressure development in the spatial distribution characteristics of overpressure, and obtain the driving force for oil and gas migration.

8. The oil and gas migration simulation method according to claim 7, characterized in that, Step S5 includes: S51: Improve the three-dimensional construction model by using the three-dimensional organic carbon data volume of source rocks, the three-dimensional oil and gas transport system, and the current formation pressure field as constraints; S52: Based on the improved three-dimensional structural model, four-dimensional dynamic simulation of oil and gas migration is carried out through the three-dimensional data volume of organic carbon in source rocks, the initial migration direction of oil and gas, the three-dimensional oil and gas transport system, and the migration force of oil and gas.

9. The oil and gas migration simulation method according to claim 1, characterized in that, The method also includes: based on the results of four-dimensional dynamic simulation of oil and gas migration, analyzing the evolution law of oil and gas migration, and predicting favorable oil and gas-bearing zones.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the oil and gas migration simulation method as described in any one of claims 1-9.

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