- Created by YAVUZ TORE, last modified by ISACAN TUGBERK KÜÇÜK on Sep 12, 2023
Stratigraphic Modeling | Model Definitions
Model Definition
This is the area where borehole groups, topography, the method to be used for modeling, and the parameters of the selected method are determined for stratigraphic modeling.
Option | Description |
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Model Criteria | |
Template Name | This is the section where the active template, defined with the Template Definitions feature, is displayed. |
Topography | It is the area where topographic surface selection is made so that the models produced by the stratigraphic model can be limited to topography. |
Borehole Group | This is the area where borehole groups to be included in stratigraphic modeling are selected. Multiple group selection is possible. |
Methods | |
Inverse Distance Method | The surface is produced using the weighting method with the inverse of the distance. The weights to be assigned to the data used in estimation are a function of the inverse of the distance. However, the distance between the data is not taken into account in the estimation. The following parameters are used for the inverse distance method; Inverse Distance Parameters X/Y Grid Size: It is the distance value between the grid points to be produced in the X and Y directions. Alpha: The alpha value can be taken between 1 and 2. It is a parameter used for inverse distance estimation. Elips/Elipsoid ?: It enables the use of ellipses or ellipsoids during estimation while producing the surface. When no selection is made, an ellipse is used. Max. Neighbor: It is the maximum number of samples to be used in estimating a block. Mean: It is the mid-axis length of the ellipsoid to be used in the estimation process. Max.: It is the longest axis length of the ellipsoid to be used in the estimation process. Distance: It refers to the distance of the samples to be selected in the estimation process to the ellipsoid. Rake (Degree): It is the tilt angle of the ellipsoid. Angle: If the minimum value of the triangle's angles is less than the given value, it deletes the triangle. Area: Deletes triangles with areas greater than the entered value. |
Finite Elements Method (FEM) | The surface is produced using the finite element method. The method is based on dividing the estimation region into small elements and performing the estimation using polynomials within each element. Areas are used instead of distances to determine weights. The following parameters are used for the finite element method; FEM Parameters X/Y Grid Size: It is the distance value between the grid points to be produced in the X and Y directions. Weight Application Distance: It is the radius of the sphere used to find the two closest borehole data in three dimensions for the grid point estimated by the FEM method. FEM estimation is made again at the grid points with the borehole data entering the sphere within this radius. Show Trend: It enables the creation of a trend surface. Trend Polynomial Degree: This is the area where the degree of the polynomial to be used when creating the trend is determined. 1st and 2nd-degree polynomials can be used. The 1st order polynomial is used for models with a specific bed slope, while the 2nd order polynomial is used for models with multiple bed slopes that vary locally. Use Surface Trend: This is the option that allows using the trend surface. Angle: If the minimum value of the triangle's angles is less than the given value, it deletes the triangle. Area: Deletes triangles with areas greater than the entered value. |
Radial Basis Function (RBF) | The surface is generated using radial basis functions. It is a method based on the calculation of radial basis functions. It produces continuous estimation values. It is equivalent to the dual kriging method. The following parameters are used for radial basis functions; RBF Parameters X/Y Grid Size: It is the distance value between the grid points to be produced in the X and Y directions. Epsilon: The epsilon value expresses the average distance value between grid points. It is a parameter that can only be changed when multiquadric is selected. For the multiquadric function, as the epsilon value increases, the produced surface becomes smoother. Function Type: These are functions used in surface creation operations. These are linear, thin plate, and multiquadric functions. Smooth: As this value increases, smoother surfaces are produced. Angle: If the minimum value of the triangle's angles is less than the given value, it deletes the triangle. Area: Deletes triangles with areas greater than the entered value. |
Rules
It is the area where geological rules, relationships, and continuities are defined for stratigraphic modeling. The data type to be used in the modeling process (Lithology/Interval), the surface coordinates to be produced (top, bottom, bottom, etc.), and the relationship between units, continuity, and geological age can be defined. In this area, the ore and faults of the lithology or interval to be modeled can also be selected. The age order of the stratigraphic units to be used can be done practically.
Option | Description |
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Interval/Lithology | |
Data Type | This is the area where lithology or interval selection is made for modeling. |
Interval Type | The data type is the field that is active when the Interval is selected. From this area, vein, oxidation, sulfur, alteration interval types, and intervals previously produced by interval merging and stack definition processes can be selected. |
Coordinate Filter | This is the area where the surface coordinates (top, bottom, bottom, etc.) of the lithology or intervals to be modeled are selected. |
Relation Between Units | It is the area where vertical relationships between units are defined. With this field, Compatible, Non-Conformable, Transgressive, and Contiguous definitions between units can be made. |
Continuity of the Units | It is the area where the horizontal continuity of the units is determined. With this field, Pinched, Zero Point, and Continuous definitions of the units can be made. |
Lithology/Interval Display | When the lithology or interval lines transferred to the Modeling Interval/Lithology section are clicked, the relevant lithology or interval is highlighted on the graphic screen. |
Lithology/Interval to be Modelled | |
Ore | It allows marking the definition representing the ore from the Interval/Lithology definitions that will be modeled with stratigraphic modeling. With this feature, for definitions where ore selection has been made, the "Interval Separation" feature calculates the waste volumes that are within the ore and outside of parameters. |
Faults | It allows faults added to the project data catalog to be included in the stratigraphic modeling process. In order to see the faults that will be used in the model definitions, the "Fault Sorting" process must be performed beforehand. |
Order | It is used to sort Interval/Lithology definitions stratigraphically, from young to old, using age relationships. |
Reset | This is the option used to remove the selections made and the lists produced in the Interval/Lithology area and Interval to be Modeled/Lithology sections. |
Advance Settings
This is the area where advanced settings regarding stratigraphic modeling are made. With this area, the thickness limits of the lithologies/intervals to be used in the modeling process and the detailed parameters of the pinch and zero rules are determined. Additionally, there are parameters for the output model type and the ability to extend the model up to a certain grid limit.
Option | Description |
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Default Settings | |
Min. Ore Thickness, (m) | If there are lithologies shorter than the specified value, they are not included in the model. Its unit is a meter. |
Min. Waste Thickness, (m) | If the thickness of a unit within a lithology is less than a specified minimum thickness, this unit is included in the lithology. |
Min. Ore/Waste Separation, (m) | For lithologies designated as ore in the model definitions, lithologies falling between the minimum waste thickness and the value defined here are considered waste. |
Pinch Search Distance, (m) | The determined distance value is added to the average distance value between boreholes. The pinch rule is applied for boreholes within this distance. |
Pinch Search Angle, (^{o}) | The closest borehole within the slice belonging to the specified angle value is taken into account. |
Zero Surface Simplification Distance, (m) | On surfaces where the zero rule is applied, if the maximum length between points is shorter than this value, simplification is made. |
Output Model Settings | |
Grid | This is the option that shows the limit of the boreholes that will enter the modeling process. When no limit is selected, the model to be produced is extended up to the grid limits. If the user wishes, users can expand the model outwards by setting an impact value for the grid boundary. |
Extend Lithology/Interval Surface | When the boundary and grid distance are not defined, extension is applied to the lithology and interval surfaces. |
Extra Distance (in X Direction), (m) | It is the distance value at which the model to be produced will be extended beyond the borehole boundaries. |
Extra Distance (in Y Direction), (m) | It is the distance value at which the model to be produced will be extended beyond the borehole boundaries. |
Simplification Distance, (m) | It enables the simplification process to be performed on the produced surfaces. With this feature, simplification is performed on surfaces with small grid distances. |
Output Model | This is the area where the type of output is to be selected after the stratigraphic Modeling/Produce Model process is done. After the model generation process, surfaces, solid models or both can be produced. |
Calculate of surface perpendicular | The result to be produced is the option used to calculate surface normals on surfaces. It is used to correct distortions that may occur on solid model edges. |
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