Creating 3D Stratigraphic Models and Diagrams

RockWorks | Borehole Manager | Stratigraphy | Model

Use this program to:

• Interpolate grid models for the upper and lower surfaces of the project's stratigraphic units (all units or selected ones) - or - read grid models that you've already created.
• Create a 3-dimensional diagram that illustrates these stratigraphic layers, with side panels. 
• Plot the view in RockPlot3D.

The surfaces and panels will be color-coded based on the formation's background color in the Stratigraphy Types Table. The surface grid models will be stored in the project folder.  The completed diagram will be displayed in a RockPlot3D window, with volume and mass of each formation noted. 

The program offers optional creation of a 3D solid model (.RwMod file) representing the stratigraphy surfaces layered from the bottom up, for use with other analysis tools. 

Feature Level: RockWorks Standard and higher

Menu Options
Step-by-Step Instructions

Menu Options

• Stratigraphy Types to be Included: This setting defines which of your formations are to be included in the modeling and display. (More.)
  • All Stratigraphic Units: Choose this if all units are to be modeled (if Interpolate Surfaces is checked, below) and displayed in the 3D diagram.
  • Only Units Flagged As "Show In Legend": You can limit the interpolation (Interpolate Surfaces checked) and display to only those formations with a check in the Show in Legend check-box, in the Stratigraphy Types table.
    
    
• Interpolate Surfaces: When this option is checked, the program will interpolate grid models for the top and bottom of all/selected stratigraphic units (as specified above).
  Interpolate Surfaces: When this option is not checked the program will assume that the grids already exist, from a previous pass with a Stratigraphy menu option, from making custom edits to the grids, from importing them from another source, etc. In other words, you may not want to create new grid models every time that you generate a diagram.
  ! Important Note: The existing grid models must follow the automatic naming scheme:  Models for formation tops are named formation_top.RwGrd and those for formation bases are named formation_base.RwGrd, where formation is the exact name of the formation as defined in the Stratigraphy Types Table.  The program will assume these grids exist if Interpolate Surfaces is turned off.
  
  Options: If you have Interpolate Surfaces turned ON, click the Options button to the right to set up the modeling options:
   
  • Gridding Options: On this tab you can establish the gridding method, the grid dimensions, and other gridding options.
    • Algorithms: Select a gridding method from the list on the left, and establish the method-specific Options in the middle pane.
    • Grid Dimensions:  Specify how the grid dimensions are to be established, using the settings on the right side of the dialog box.  Unless there's a specific reason to do otherwise, you should probably leave the grid dimensions set to the current project dimensions.
    • Additional options: Establish the other general gridding options (declustering, logarithmic, high fidelity, etc.).
      
      
  • Modeling Sequence: Click on this tab to tell RockWorks whether the formations are to be modeled as entered, from the base upward, or from the top down.
    • None: Choose this option to model the formations based on the data as entered, with any applicable rules you have activated.
    • Base-to-Top (Onlap): Click in this option to "fix" stratigraphic models in which portions of an upper unit extend below the base of a lower unit. The program will give lower units "priority," building model from the bottom-up.  (More.)
    • Top-to-Base (Underlap): Choose this option to give priority to upper units instead. Any portions of lower units which extend above the base of an upper unit will be constrained to the base of that unit.  (More.)
      
      
  • Constraining Surface: Insert a check here if you want the stratigraphy model to be filtered with a surface, typically representing the ground surface.  
    ! This model must have the same dimensions and node spacing as is represented in the stratigraphy model surfaces.  If you need to resample the ground surface grid, refer to the Utilities Grid | Resample option.  Use the settings to the right to specify the name of the ground surface grid model (.RwGrd) and the filtering direction.  (More.)
    
    
  • Polygon Filter:  Activate this option to remove portions of the stratigraphic surfaces that lie either the inside or outside of a user-defined polygon.  (More.)
    
    
  • Baseplate: Insert a check in the Baseplate option if you want the base of the lowest formation to be extended down to a set elevation. This is helpful for data sets missing depth-to-base values in the lowest formation (boreholes never reach the bottom). (More.)
    1.   
  • Volumetrics: Check this item if you want the volume of each unit to be calculated and displayed in RockPlot3D. Disabling this option can make large models process more quickly.
    
    
• Save Numeric Model: Insert a check here if you want the program to store on disk a numeric 3-dimensional solid model, with voxel nodes representing stratigraphy type. Use a .RwMod file name extension.  
  ! The solid model file will only be created if Interpolate Surfaces, above, is activated.
  ! RockWorks will not use this .RwMod file when displaying the stratigraphic block in RockPlot3D at this time; it will instead display the grid surfaces. But, you may still want to store the model on disk for later filtering, volumetric computations, etc., and later 3D display with the RockWorks Utilities Solid menu tools. The example below illustrates the difference between the 3D display of stacked stratigraphic surfaces (upper) and color-coded solid model voxels (lower). 

  

  ! To get a high-resolution solid model, be sure your project dimensions are set with Z-nodes spaced closely enough to adequately represent surface details.

  
   

• Diagram Options
  • Explode: Insert a check here to expand the stratigraphy layers by a user-specified distance for display purposes in RockPlot3D.  Expand this heading to specify the distance in your project units.  Note that this applies to the stratigraphic surfaces and their side panels only - striplogs are not exploded, so you should not display logs along with an exploded stratigraphic model.

  

  • Hide Thin Zones: When activated, this option will not display portions of the stratigraphic units where the thickness is less than a user-defined cutoff. When de-activated, the program will show the full extent of the formation even where the unit has zero thickness (i.e. the "old" way).
    • Cutoff: Type here the thickness cutoff, in your depth units, below which a surface is to disappear.  The right value to enter will depend on the nature of your surfaces, and you may need to experiment a bit.  If you have a number of thin units that have resulted from zero-thickness entries in your boreholes, an entry of 0.5 may work well.  Be careful not to remove too much material.

    

  • Plot Logs:  Check this box to append striplogs to your 3D diagram. 
    
    • Clip Logs: Check this sub-item if you want to restrict the logs to a particular elevation range.  This should match the elevation range of the stratigraphy model you are creating at this time. (More.)
    • 3D Striplog Designer: Click on the 3D Striplog Designer tab to the right, to select the items to display in the individual logs to plot with the model.  

    
     

    1. • Visible Items:  Use the check-boxes in the Visible Items column to select which log items are to be displayed.  See Visible Item Summary for information.
       • Options: Click on any of the Visible Items names to see the item's settings in the Options pane to the right.  See Visible Item Summary  for links to the Options settings.
       • Layout Preview: For each item you've activated, you'll see a preview cartoon in the upper pane, showing an overhead view of the log columns.  Click and drag any item to rearrange the log columns; click and drag the circle handles to resize a column.  See Using the 3D Log Designer.
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• Reference Cage: Insert a check here to include vertical elevation axes and X and Y coordinate axes in the 3D diagram.
  • Expand this item to set up the cage items. (More.)  
     
• Include Stratigraphy Legend: Insert a check in this item to include a legend that lists all of the formation names and their colors and patterns, as listed in the project's Stratigraphy Types Table.
  • Expand this item to set the legend width, size, and offset. (More.) 
    
    
• Rules & Filters: Use the settings on the far right side of the window to apply stratigraphic rules to data being processed here, and date filters for data you may be displaying in the 3D logs. More.
  
  

Step-by-Step Summary

1. Access the RockWorks Borehole Manager program tab. 
2. Enter/import your data into the Borehole Manager database. This tool specifically reads location, orientation (if any), and stratigraphy data.
3. Enable boreholes:  Be sure that all boreholes whose data are to be included in the stratigraphic model are enabled.
4. Select the Stratigraphy | Model menu option. 
5. Enter the requested menu settings, described above.
6. Click the Process button when the gridding and diagram settings are established to your satisfaction.
7. If you have activated Confirm Dimensions, above, the program will display a window with the model coordinates and node spacing.  Adjust these items if necessary and click OK.  (More.) 

If Interpolate Surfaces is turned on, the program will use the selected gridding algorithm to create grid models of the surfaces and bases of the formations listed in the Stratigraphy tabs, storing the models in the current project folder. The grid file names are assigned automatically, based on the formation: "formation_top.RwGrd" and "formation_base.RwGrd". Two grid models will be created for each formation. 

If Save Numeric Model is turned on, the program will initialize the solid model using the current project dimensions.  It will then "insert" each gridded formation into the solid model, by assigning the voxels between the surfaces the integer "G" value listed in the Stratigraphy Types Table. The program will store this stratigraphic model file in the project folder using the file name you requested.

The formation grid models will be displayed in a RockPlot3D tab in the Options window, with each formation represented by a lower and upper surface and enclosing sides. If logs were requested, they will be added to the view.

8. You can adjust any of the options along the left and click the Process button to regenerate the grid models and the stratigraphy model display.
   
   ! Each time you click the Process button, the existing display will be replaced.  
    
9. View / save / manipulate / print / export the image in the RockPlot3D window. 

Tips: Once displayed in RockPlot3D, you can expand the stratigraphy model item in the data pane to see the formation names. Expand the individual formations to see grid models for the base and the surface, and computed formation volume and mass (if available). 

See also:  Manually Building 3D Stratigraphic Diagrams for information about building diagrams from existing grid models (filtered, imported, etc.)

 Back to Stratigraphy Menu Summary

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