ArcGIS-based fault complex structure processing method in geological modeling

Abstract

The invention discloses an ArcGIS-based fault complex structure processing method in geological modeling, which comprises the following steps: collecting related geological data of a research area, laying section lines according to modeling precision and certain density when actual drilling data is lacked, laying virtual drilling points on the section lines, and carrying out modeling on the virtual drilling points; calculating modeling data, including thickness and burial depth, of the underlying stratum of the virtual drill hole through the geological profile map; in combination with geological data and field survey data, finding out basic features of a fault in a modeling area, including a fault angle (alpha) and a stratum thickness (h), and before modeling, arranging a section which has a certain density and passes through the fault according to the step S1; taking the fault plane as a boundary of modeling, and performing independent modeling on geologic bodies on two sides of the fault plane based on ArcGIS; and after the geologic models on the two sides of the fault are built according to the previous steps, the three-dimensional geologic models on the two sides are combined together, so that a complete three-dimensional geologic model capable of reflecting the fault characteristics can be formed.

Description

Technical Field

[0001] The patent of this invention belongs to the field of automatic sectioning technology of geological bodies, and specifically relates to a method for processing complex fault structures in geological modeling based on ArcGIS. Background Art

[0002] ArcScene's strengths in geological modeling lie in its powerful 3D visualization capabilities, efficient automated modeling methods, multi-source data integration and analysis capabilities, support for real-time rendering and optimization algorithms, rich interactive analysis tools, and a wide range of application scenarios. These features make it a very powerful and flexible tool in geological modeling.

[0003] Although ArcGIS is one of the most commonly used software for 3D geological modeling, the inventors discovered that accurately reflecting fault structures with a specific attitude during 3D geological modeling is a major challenge for modelers. Geological bodies on either side of a fault should be dislocated and disconnected. If the geological bodies on both sides of the fault are created simultaneously during modeling, the top and bottom plates of the same strata on both sides of the fault are connected, which neither reflects the effect of the strata being dislocated by the fault nor conforms to the actual geological conditions.

[0004] Therefore, this paper proposes a method based on ArcGIS to deal with complex fault structures in geological modeling. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides a method for processing complex fault structures in geological modeling based on ArcGIS. This method can basically solve the fault problems encountered when using ArcGIS for three-dimensional geological modeling.

[0006] In order to achieve the above technical effects, the present invention is implemented by the following technical solutions: a method for processing complex fault structures in geological modeling based on ArcGIS, specifically comprising the following steps: S1. Collect relevant geological data of the study area. In the absence of actual drilling data, lay out section lines at a certain density based on modeling accuracy, and lay out virtual drilling points on the section lines. Calculate the modeling data of the underlying strata of the virtual drilling holes, including thickness and burial depth, from the geological section map. S2. Combine geological data and field survey data to determine the basic characteristics of the fault in the modeling area, including the fault angle (α) and the formation thickness (h). Before modeling, first lay out a certain density of sections that pass through the fault as described in S1; S3, using the fault plane as a modeling boundary, the geological bodies on both sides of the fault plane are modeled separately based on ArcGIS; Furthermore, when separately modeling the geological bodies on both sides of the fault plane in S3, the same section needs to be shared for arranging virtual boreholes.

[0007] Furthermore, during the process of separately modeling the geological bodies on both sides of the fault plane in S3, virtual boreholes need to be set at the intersection positions of the ground surface and the fault plane, and at the intersections of the bottom plates of all strata and the fault; this step can enable the formed geological model to accurately combine the geological bodies in the hanging wall and footwall of the fault and truly reflect the characteristics of the offset segments on both sides of the fault.

[0008] Furthermore, the specific steps for setting virtual boreholes in S3 include: adding the first virtual borehole with the outcrop position of the unilateral fault plane as the base point, thereby determining the known base point coordinate point 1 (X1, Y1). The virtual borehole position coordinates at the inclined position of the fault are calculated successively to the right based on the base point coordinates, and the fault angle is indirectly expressed in the model through the virtual borehole position relationship. Then, the X coordinates of each virtual borehole are obtained by accumulating the X coordinate of the base point. l After that, the position coordinates of each point are imported into ArcGIS to establish a unilateral three-dimensional geological model.

[0009] Furthermore, the specific steps of the calculation process of the virtual borehole position coordinates of the unilateral fault in S3 include: point 1 is the known coordinate point. Since the fault angles are the same, l 1 =h 1 / tanα , X2 (the X coordinate of point 2) = X1 (the X coordinate of point 1) + l 1 , the Y coordinates of point 1 and point 2 are the same, that is, the coordinates of point 2 are (X1 + l 1 , Y1). The strata II and III are both calculated in the same way to obtain l 2 and l 3 , and the Y coordinates are all the same.

[0010] Furthermore, during the process of separately modeling the geological bodies on both sides of the fault plane in S3, when modeling each stratum, some geological bodies involving the vertical projection of the fault plane need to be modeled separately. Specifically, if there are n strata from the ground surface to the modeling base, 2n geological body modules need to be built; finally, these 2n geological modules are integrated together and the fault plane is seamlessly spliced, then the fault characteristics can be truly reflected.

[0011] S4. After the geological models on both sides of the fault are built according to S3, finally, the three-dimensional geological models on both sides are combined together to form a complete three-dimensional geological model that can reflect the fault characteristics.

[0012] The beneficial effects of the present invention are as follows: By proposing a set of "local modeling" methods, the present invention basically solves the problem of complex fault structures encountered in 3D geological modeling using ArcGIS. This modeling method can not only truly reflect the nature of the faults, but also realistically and reasonably display the geological conditions on both sides of the faults, improving the accuracy and precision of the modeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Those skilled in the art can also obtain other drawings based on these drawings without creative efforts.

[0014] Figure 1 is the flowchart of the method of the present invention; Figure 2 is the schematic diagram of the left geological model coordinates in the practical application of the present invention; Figure 3 is the schematic diagram of the left 3D geological model in the practical application of the present invention; Figure 4 is the schematic diagram of the right geological model coordinates in the practical application of the present invention; Figure 5 is the schematic diagram of the right 3D geological model in the practical application of the present invention; Figure 6 is the schematic diagram of the overall geological model coordinates in the practical application of the present invention; Figure 7 is the schematic diagram of the overall 3D geological model coordinates in the practical application of the present invention; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0015] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. All other embodiments obtained by those skilled in the art without creative efforts based on the embodiments of the present invention belong to the scope of protection of the present invention. Embodiment 1

[0016] As Figure 1 shown, the following problems exist in the prior art in this embodiment: The inventor found in daily applications that in the current geological modeling process, there are problems of non-universal data formats of geological body models between modeling platforms and low model cutting efficiency.

[0017] Therefore, the inventor provides a method for dealing with complex fault structures in geological modeling based on ArcGIS, which specifically includes the following steps: The method for processing complex fault structures in geological modeling based on ArcGIS specifically includes the following steps: S1. Collect relevant geological data of the study area. In the absence of actual drilling data, lay out section lines at a certain density based on modeling accuracy, and lay out virtual drilling points on the section lines. Calculate the modeling data of the underlying strata of the virtual drilling holes, including thickness and burial depth, from the geological section map. S2. Combine geological data and field survey data to determine the basic characteristics of the fault in the modeling area, including the fault angle (α) and the formation thickness (h). Before modeling, first lay out a certain density of sections that pass through the fault as described in S1; S3, using the fault plane as a modeling boundary, the geological bodies on both sides of the fault plane are modeled separately based on ArcGIS; Furthermore, when the geological bodies on both sides of the fault plane are modeled separately in the above-mentioned S3, the same section needs to be shared to lay out the virtual boreholes.

[0018] Furthermore, in the process of separately modeling the geological bodies on both sides of the fault plane in S3, virtual boreholes need to be set at the intersection of the ground surface and the fault plane, and at the intersection of all stratum floors and faults; this step enables the resulting geological model to accurately combine the geological bodies of the upper and lower plates of the fault and truly reflect the characteristics of the offset segments on both sides of the fault.

[0019] Furthermore, the specific steps of setting up virtual boreholes in S3 include: adding the first virtual borehole with the exposed position of the single-side fault plane as the base point, thereby determining the known base point coordinate point 1 (X1, Y1), and calculating the virtual borehole position coordinates of the fault tilt position to the right in sequence based on the base point coordinates, and indirectly expressing the fault angle in the model through the virtual borehole position relationship, and then accumulating the X coordinate of the base point. l The X coordinates of each virtual borehole were obtained, and then the coordinates of each position were imported into ArcGIS to establish a single-sided three-dimensional geological model.

[0020] Furthermore, the specific steps of the unilateral fault virtual drilling position coordinate calculation process in S3 include: the known point 1 is a known coordinate point, and since the fault angle is consistent, l 1 =h 1 / tanα , X2 (X coordinate of point 2) = X1 (X coordinate of point 1) + l 1 , the Y coordinates of point 1 and point 2 are the same, that is, the coordinates of point 2 are (X1+ l 1 , Y1), strata II and III are calculated using the same method l 2 andl 3 The Y coordinates are all the same.

[0021] Furthermore, in the process of separately modeling the geological bodies on both sides of the fault plane in S3, when modeling each stratum, some geological bodies involving the vertical projection of the fault plane need to be modeled separately. Specifically, if there are n strata from the surface to the modeling base, 2n geological body modules need to be built. Finally, the 2n geological modules are integrated together and the fault plane is seamlessly spliced, so as to truly reflect the fault characteristics.

[0022] S4. After the geological models on both sides of the fault are built according to S3, finally, the three-dimensional geological models on both sides are combined together to form a complete three-dimensional geological model that can reflect the fault characteristics. Embodiment 2

[0023] As Figure 4 shown, based on the above embodiment, the inventor made the following practical applications: It is necessary to separately establish local geological models on the left and right sides (the hanging wall and footwall) of the fault, and then the two models are fitted at the angle controlled by the fault. According to the borehole data and field measured data, combined with the geological map, the fault angle (α) and stratum thickness (h) are determined. Virtual boreholes are added at the outcrop position of the fault plane (i.e., the position base with known XY coordinates, point 1 (X1, Y1)). The virtual borehole position coordinates at the inclined position of the fault are calculated successively to the right based on the base point coordinates, and the fault angle is indirectly expressed in the model through the virtual borehole position relationship.

[0024] First, take the left geological model as an example (as Figure 2 shown), point 1 is the known coordinate point. Since the fault angles are the same, then l 1 = h 1 / tanα , X2 (the X coordinate of point 2) = X1 (the X coordinate of point 1) + l 1 , the Y coordinates of point 1 and point 2 are the same, that is, the coordinates of point 2 are (Y1, X1 + l 1 ). Strata II and III are both calculated in the same way to obtain l 2 and l 3 . The Y coordinates are all the same. The X coordinates of each virtual borehole are obtained by accumulating the X coordinates of the position base points, and then the respective position coordinates are imported into ArcGIS to establish the left three-dimensional geological model (as Figure 3 shown).

[0025] For the right geological model (asFigure 4 As shown in the figure, with the position reference point (point 1) remaining unchanged, using a similar processing method, the l 1 、l 2 、l 3 X coordinates of the virtual boreholes in the right geological model are calculated respectively based on the thickness (h) of each stratum and the dip angle (α) of the fault, while the Y coordinates remain consistent. After obtaining the X coordinates of the virtual boreholes on the right, the positions of each virtual borehole are imported into ArcGIS to establish the three-dimensional geological model on the right (as Figure 5 shown).

[0026] As Figures 6 to 7 shown, after establishing the geological models on both the left and right sides, the three-dimensional geological entities are imported into the same ArcGIS project file. When the models on both sides are joined together, the overall three-dimensional geological model at the fault structure is obtained. Based on the practical application of the above embodiments, the inventor draws the following conclusions: By proposing a set of "local modeling" methods, the present invention basically solves the problem of complex fault structures encountered in three-dimensional geological modeling using ArcGIS. This modeling method can not only truly reflect the nature of the fault but also realistically and reasonably display the geological conditions on both sides of the fault, improving the accuracy and precision of the modeling.

[0027] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any perspective, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0028] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for dealing with complex fault structures in geological modeling based on ArcGIS, characterized in that The specific steps include: S1. Collect relevant geological data of the study area. In the absence of actual drilling data, lay out section lines at a certain density based on modeling accuracy, and lay out virtual drilling points on the section lines. Calculate the modeling data of the underlying strata of the virtual drilling holes, including thickness and burial depth, from the geological section map. S2. Combine geological data and field survey data to determine the basic characteristics of the fault in the modeling area, including the fault angle (α) and the formation thickness (h). Before modeling, first lay out a certain density of sections that pass through the fault as described in S1; S3, using the fault plane as a modeling boundary, the geological bodies on both sides of the fault plane are modeled separately based on ArcGIS; S4. After the geological models on both sides of the fault are constructed according to S3, the three-dimensional geological models on both sides are finally combined together to form a complete three-dimensional geological model that can reflect the characteristics of the fault.

2. The method for processing complex fault structures in geological modeling based on ArcGIS according to claim 1, wherein: When the geological bodies on both sides of the fault plane are modeled separately in the aforementioned S3, the same section needs to be shared to lay out the virtual boreholes.

3. The method for processing complex fault structures in geological modeling based on ArcGIS according to claim 1, characterized in that: In the process of separately modeling the geological bodies on both sides of the fault plane in S3, virtual boreholes need to be set at the intersection of the ground surface and the fault plane, and at the intersection of all stratum floors and faults.

4. The method for processing complex fault structures in geological modeling based on ArcGIS according to claim 3, characterized in that The specific steps for setting virtual boreholes in S3 are as follows: Add the first virtual borehole with the outcrop position of the unilateral fault plane as the base point, so as to determine the known base point coordinate point 1 (X1, Y1). The virtual borehole position coordinates at the fault inclination position are calculated sequentially to the right based on the base point coordinates, and the fault angle is indirectly expressed in the model through the virtual borehole position relationship. Then, accumulate the X coordinates of the base point l to obtain the X coordinates of each virtual borehole, and then import the position coordinates into ArcGIS to establish a unilateral three-dimensional geological model.

5. The method for processing complex fault structures in geological modeling based on ArcGIS according to claim 4, wherein: The specific steps of the calculation process of the unilateral fault virtual drilling position coordinates in S3 are as follows: The known point 1 is a known coordinate point. Since the fault angles are the same, then l 1 =h 1 / tanα , X2 (the X coordinate of point 2) = X1 (the X coordinate of point 1) + l 1 , the Y coordinates of point 1 and point 2 are the same, that is, the coordinates of point 2 are (X1 + l 1 , Y1). The strata II and III are both calculated in the same way to obtain l 2 and l 3 , and the Y coordinates are all the same.

6. The method for processing complex fault structures in geological modeling based on ArcGIS according to claim 1, wherein: In the process of separately modeling the geological bodies on both sides of the fault plane in S3, when modeling each stratum, the part of the geological body involving the vertical projection of the fault plane needs to be modeled separately, specifically: if there are n strata from the surface to the modeling base, 2n geological body modules need to be built.

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