North Jiangsu basin deep structure feature analysis method based on three-dimensional modeling

Abstract

The invention relates to the technical field of basin deep structure feature analysis, in particular to a three-dimensional modeling-based North Suzhou basin deep structure feature analysis method, which comprises the following steps of: firstly, collecting multi-source data required by modeling, carrying out digital processing on the collected multi-source data, establishing a North Suzhou basin three-dimensional geologic model by utilizing a software geologic modeling module, and establishing a three-dimensional geologic model of the North Suzhou basin; a software attribute modeling module is used for establishing a three-dimensional model of gravity, aeromagnetic and speed of the Subei basin, measuring lines are selected in combination with small-seismic fine positioning and fracture, and deep structure characteristics of the Subei basin are comprehensively analyzed in combination with geology, gravity, aeromagnetic and speed profiles. According to the method, a multi-source constraint quantitative technology method is adopted, a high-resolution and high-precision three-dimensional model of the Subei basin is established, the geometric structure relation of the deep part and the shallow part of the fault in the three-dimensional space is revealed, and the deep structure characteristics of the Subei basin are analyzed.

Description

Technical Field

[0001] The present invention relates to the technical field of basin deep structural feature analysis, and in particular to a method for analyzing deep structural features of the Subei Basin based on three-dimensional modeling. Background Art

[0002] With the continuous maturity of 3D modeling technology and the rapid development of computer technology, widely used software includes SKUA, GOCAD, Petrel, Surpac, 3DMine, Vulcan, MicroLynx, and GSI3D. SKUA-GOCAD, a more powerful combination of SKUA and GOCAD, is currently one of the most widely used 3D geological structure modeling software in China and abroad. Its 3D capabilities are particularly powerful, including the ability to handle arbitrarily complex geological conditions; the ability to generate large-scale 3D geological grids within the constraints of complex geological structure models and use them as the basis for attribute models; and the ability to accurately match the geometric shape of the geological structure model.

[0003] Since the late 1950s, numerous studies have investigated the conditions for oil and gas accumulation, diagenetic evolution, geophysical exploration, and active fault detection within the Subei Basin, accumulating a wealth of geological and geophysical data reflecting the basin's internal sedimentary and basement structures. However, these data and research findings have yet to be effectively integrated, resulting in a lack of understanding of the complex three-dimensional morphology of the Subei Basin from the surface to the depths, as well as the three-dimensional spatial geometry of the faults at both shallow and deep depths. Therefore, a three-dimensional model of the Subei Basin is needed to analyze its deep structural characteristics. Summary of the Invention

[0004] In response to the above technical problems, the present invention overcomes the shortcomings of the existing technology and provides a method for analyzing the deep structural characteristics of the Subei Basin based on three-dimensional modeling. It adopts a quantitative technical method with multi-source constraints to establish a high-resolution and high-precision three-dimensional model of the Subei Basin, revealing the geometric structural relationship between the deep and shallow parts of the fault in three-dimensional space, and analyzing the deep structural characteristics of the Subei Basin.

[0005] The deep structural characteristics analysis method of the Subei Basin based on 3D modeling in this proposal includes the following steps: Step 1: Collect multi-source data required for modeling; Step 2: Digitally process the collected multi-source data and use the software geological modeling module to establish a three-dimensional geological model of the Subei Basin; Step 3: Use the software attribute modeling module to establish the gravity, aeromagnetic, and velocity three-dimensional model of the Subei Basin; Step 4: Combine small earthquake precision positioning with fault selection to select survey lines; Step 5: Comprehensively analyze the deep structural characteristics of the Subei Basin by combining geology, gravity, aeromagnetic, and velocity profiles.

[0006] The technical solution further defined in the present invention is: Furthermore, the multi-source data in step 1 include at least one of surface traces, length, properties, slip rate, geometric structure, digital elevation model, drilling stratification, seismic reflection profile, Quaternary thickness, bedrock isopach lines, gravity and magnetism, small earthquake precise positioning, focal mechanism solution, and velocity of surface faults.

[0007] Furthermore, the geometric structure specifically includes at least one of inclination, dip, and depth.

[0008] Furthermore, the step 2 specifically adopts a quantitative technical method constrained by multi-source data to establish a three-dimensional geological model of the Subei Basin, reveal the geometric structural relationship between the deep and shallow parts of the fault in three-dimensional space, and explore the relationship between the three-dimensional geometric structure of the fault and the earthquake rupture behavior.

[0009] Furthermore, in step 3, based on the collected gravity, aeromagnetic and velocity data and the attribute modeling module under the software platform, a DSI discrete smooth interpolation method is used to establish a three-dimensional gravity, aeromagnetic and velocity model of the Subei Basin.

[0010] Furthermore, the step 4 specifically involves selecting a survey line and generating a profile diagram based on the collected small earthquake precise positioning data and fault data.

[0011] Furthermore, the step 5 specifically involves comprehensively analyzing the deep structural characteristics of the northern Jiangsu basin based on the established three-dimensional model of the northern Jiangsu basin and the generated two-dimensional cross-section.

[0012] Furthermore, the software is specifically a three-dimensional modeling software platform having a geological modeling module and a property modeling module. The geological modeling module is used to execute step 2, and the property modeling module is used to execute step 3. Specifically, it can be SKUA-GOCAD.

[0013] The beneficial effects of the present invention are: (1) The present invention provides a method for analyzing the deep structural characteristics of the Subei Basin based on three-dimensional modeling, which can establish a three-dimensional model of the geology, gravity, aeromagnetic and velocity of the Subei Basin, and then comprehensively analyze the deep structural characteristics of the Subei Basin based on its cross-sectional diagram; (2) The present invention utilizes the collected multi-source data and information, based on the SKUA-GOCAD platform, and adopts a multi-source constrained quantitative technical method to establish a high-resolution and high-precision three-dimensional model of the Subei Basin, revealing the geometric structural relationship between the deep and shallow parts of the fault in three-dimensional space, and analyzing the deep structural characteristics of the Subei Basin. It has important social and economic benefits in promoting the improvement of the comprehensive disaster prevention capacity of the Subei Basin and reducing earthquake disaster losses, and also provides an important basis for carrying out earthquake prediction and earthquake risk prevention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A three-dimensional graph of multi-source data in a specific embodiment of the present invention; Figure 2 A three-dimensional geological model diagram of the Subei Basin in a specific embodiment of the present invention; Figure 3 A three-dimensional model diagram of the gravity field of the Subei Basin in a specific embodiment of the present invention; Figure 4 A three-dimensional model diagram of the aeromagnetic field of the Subei Basin in a specific embodiment of the present invention; Figure 5 3D model diagrams of the velocity field in the Subei Basin in a specific embodiment of the present invention, wherein (a) is a VP 3D model diagram and (b) is a VS 3D model diagram; Figure 6 The survey line distribution diagram in a specific embodiment of the present invention, wherein (a) is a survey line diagram and (b) is a survey line profile diagram; Figure 7 A geological survey line profile diagram in a specific embodiment of the present invention; Figure 8 A gravity line profile diagram in a specific embodiment of the present invention; Figure 9 This is a cross-sectional view of an aeromagnetic survey line in a specific embodiment of the present invention; Figure 10 is a profile diagram of the velocity (VP) measurement line in a specific embodiment of the present invention; Figure 11 A velocity (VS) profile diagram in accordance with a specific embodiment of the present invention; Figure 12 This is a flowchart of the steps of the method for analyzing deep structural characteristics of the Subei Basin based on three-dimensional modeling in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0015] like Figure 12 As shown, this embodiment discloses a method for analyzing deep structural characteristics of the Subei Basin based on three-dimensional modeling, which specifically includes the following steps: Step 1: Data collection and organization; We collected data from seismic networks, shallow seismic exploration, deep seismic exploration, and geochemical surveys acquired in recent years in the northern Jiangsu Basin. This data included surface fault traces, length, properties, slip rate, geometry (dip, inclination, depth), digital elevation models, well stratigraphy, seismic reflection profiles, Quaternary thickness, bedrock isopachs, gravity and magnetic data, precise location of small earthquakes, focal mechanism solutions, and velocity data. We digitized the existing data and standardized it into a format compatible with SKUA-GOCAD. This step primarily prepared the data for 3D modeling.

[0016] Step 2: Use the geological modeling module of SKUA-GOCAD software to establish a three-dimensional geological model of the Subei Basin; Load the Subei Basin data through SKUA-GOCAD software, select File→Import Object→Horizon Interpretations→Column-based File to import the sorted stratigraphic data; select File→Import Object→Cultural Data→Column-based File to import the sorted boundary, fault, small earthquake precise positioning and other data, such as Figure 1 shown.

[0017] Further, enter the workspace, click Workflow, double-click Stucture & Stratigraphy, and start 3D geological modeling.

[0018] Further, click Select domain→Depth to select the depth; click Select horizon data→All to select all stratigraphic data; click Select fault data→All to select all fault data.

[0019] Next, define the range of the 3D model to be created. Select From 2D boundary and height and select the boundary data imported in step 1. Define the bottom and top ranges of the 3D model to be created and enter the values directly. Finally, click Compute to perform the calculation.

[0020] Furthermore, generate the fault grid, select all strata and faults, and click Build All horizons under Build All.

[0021] Further, create a geological grid, click Build the Geologic Grid, and build a 3D geological model of the Subei Basin. Figure 2 shown.

[0022] Step 3: Use the attribute modeling module of SKUA-GOCAD software to establish the gravity, aeromagnetic, and velocity three-dimensional model of the Subei Basin; Use SKUA-GOCAD software to load the gravity, aeromagnetic, and velocity data of the Subei Basin. Select File → Import Object → Velocity Data → Column-based File to import the sorted data. Further, click Voxet→New→From Objects Box to create a voxel that is large enough to contain all the data.

[0023] Further, enter the workspace, click Workflow, double-click Reservoir, and start 3D modeling.

[0024] Further, click Property Modeling, select the element just created, and select the gravity data of the Subei Basin.

[0025] Next, click Conditioning, select the data to be interpolated, and select Arithmetic Average.

[0026] Further, click Everywhere, select Interpolation→DSI, and use the DSI smooth discrete interpolation method to interpolate. The three-dimensional model of the gravity field of the Subei Basin is obtained, as shown in the figure. Figure 3 shown.

[0027] Furthermore, the three-dimensional models of the aeromagnetic field and velocity field of the Subei Basin were modeled in the same way. Figure 4 、 5 shown.

[0028] Step 4: Combine small earthquake precision positioning with fault selection to select survey lines; Select survey lines based on the distribution, aggregation, and fault orientation of small earthquakes. This implementation plan selects four lines. Select Cross Section → New → From Digitized Polyline to generate a cross-section diagram, as shown in the following example: Figure 6 shown.

[0029] Step 5: Combine geology, gravity, aeromagnetic and velocity profiles to comprehensively analyze the deep structural characteristics of the Subei Basin. In step 4, four survey lines have been selected. According to the geology, gravity, aeromagnetic and velocity profiles under each survey line, Figure 7-11 As shown in the figure, the deep structural characteristics of the Subei Basin are obtained through comprehensive analysis.

[0030] This invention is based on the SKUA-GOCAD platform and adopts a quantitative technical method with multi-source constraints to construct a three-dimensional model of the Subei Basin to analyze the deep structural characteristics of the Subei Basin. It emphasizes the digitalization, three-dimensionalization, visualization, intelligence and popularization and practicality of the expression of geological results, making the maps of the study area vivid, more intuitive and easy to understand, providing an important foundation for researchers to carry out earthquake prediction and earthquake risk prevention.

[0031] In addition to the above embodiments, the present invention may also have other implementations. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection required by the present invention.

Claims

1. A method for analyzing deep structural characteristics of the Subei Basin based on three-dimensional modeling, characterized in that: The method comprises: Step 1: Collect multi-source data required for modeling; Step 2: Digitally process the collected multi-source data and use the software geological modeling module to establish a three-dimensional geological model of the Subei Basin; Step 3: Use the software attribute modeling module to establish the gravity, aeromagnetic, and velocity three-dimensional model of the Subei Basin; Step 4: Combine small earthquake precision positioning with fault selection to select survey lines; Step 5: Comprehensively analyze the deep structural characteristics of the Subei Basin by combining geology, gravity, aeromagnetic, and velocity profiles.

2. The method for analyzing deep structural characteristics of the Subei Basin according to claim 1, characterized in that: The multi-source data in step 1 include at least one of surface traces, length, properties, slip rate, geometric structure, digital elevation model, drilling layering, seismic reflection profile, Quaternary thickness, bedrock isopach lines, gravity and magnetism, small earthquake precise positioning, focal mechanism solution, and velocity.

3. The method for analyzing deep structural characteristics of the Subei Basin according to claim 2, characterized in that: The geometric structure specifically includes at least one of inclination, dip, and depth.

4. The method for analyzing deep structural characteristics of the Subei Basin according to claim 1, characterized in that: The step 2 specifically adopts a quantitative technical method constrained by multi-source data to establish a three-dimensional geological model of the Subei Basin.

5. The method for analyzing deep structural characteristics of the Subei Basin according to claim 1, characterized in that: Specifically, step 3 involves establishing a three-dimensional gravity, aeromagnetic, and velocity model of the Subei Basin based on the collected gravity, aeromagnetic, and velocity data and the attribute modeling module under the software platform using the DSI discrete smooth interpolation method.

6. The method for analyzing deep structural characteristics of the Subei Basin according to claim 1, characterized in that: The step 4 specifically involves selecting a survey line and generating a profile diagram based on the collected small earthquake precise positioning data and fault data.

7. The method for analyzing deep structural characteristics of the Subei Basin according to claim 1, characterized in that: The step 5 specifically involves comprehensively analyzing the deep structural features of the northern Jiangsu basin based on the established three-dimensional model of the northern Jiangsu basin and the generated two-dimensional cross-section.

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